J-PARC
ANNUALREPORT2 O 1 6Vol.2: Materials and Life Science
Experimental Facility

MLF
ANNUALREPORTMaterials and Life Science Division
J-PARC Center
http://j-parc.jp/MatLife/en/
J-PARC was jointly constructed and is now operated by the High Energy Accelerator
Research Organization (KEK) and the Japan Atomic Energy Agency (JAEA).

Comprehensive Research Organization for Science and Society
http://www.cross-tokai.jp/

J-PARC 17-07

MLF Annual Report 2016

Preface

PrefaceToshiji Kanaya

Division Head of Materials and Life Science Division, MLF
In 2016, the operation of the Material and Life Science Experimental Facility (MLF) was rather stable, thanks to
the dedicated work of all the scientists and engineers involved in the facility. The availability of the scheduled beamtime reached over 90 percent. The stable operation was very important for conducting the user programs. However,in 2016, the power of the delivered beam was not as high as in the previous years, because of the following problems.
In November 2015, the neutron target vessel (#7) had a water leak as reported in MLF Annual Report 2015. In January
2016, a target vessel (#2) was installed, which has an older design without helium bubbling system. As a resul, thebeam power was reduced to 200 kW, and later in the autumn period of 2016 - to 150 kW. In addition, before the summer of 2016, the neutron source had a problem with the helium refrigerator of the cryogenic hydrogen circulation
system. We were forced to shut it down for 6 days for helium purification after a 3-week operation of the beam. The
operation of the muon production target, replaced by a target with a rotating design in 2014, continued without amajor problem. The scientific results from the delivered beam of neutrons and muons, as well as the status report ofthe beamlines, spectrometers and the research environment will be found in this Annual Report. In the coming years,
we will make efforts to achieve the beam power of 1 MW, while keeping the operations stable.
Many scientific and collaborating meetings were held at MLF in 2016. An important one was the European
Spallation Source (ESS) - J-PARC collaboration meeting, held at the J-PARC Center on June 1 and 2, 2016. The meeting
was carried out under the agreement on cooperation in the field of spallation neutron related development between
ESS and J-PARC. Sixteen delegates from ESS visited the J-PARC Center and we exchanged information about the management of the organization, radiation and general safety issues, accelerator technology, neutron sources, and neutron instruments. A complete list of the meetings can be found in this Annual Report.
The education of a new generation and invitation of new users are crucial for the sustainable development andresearch activities of the facility in the future. The Neutron and Muon School was held from November 22 to 26. Ten
host organizations and societies took part in organizing the school. Twenty nine young researchers and graduate students from Japan, Korea, Australia, Indonesia, India, Hong Kong, Taiwan, and the United Kingdom, participated in theschool. They enjoyed nine neutron and four muon lectures, a site tour to J-PARC and JRR-3, hands-experiments witheight neutron beamlines and one muon instrument at MLF, and a science seminar.
I would like to introduce the reader to the research highlights and status reports of MLF in fiscal year 2016.
A new framework of collaboration may be found in the national projects, such as the Element Strategy Initiative and
the Photon and Quantum Basic Research Coordinated Development Program, in addition to the individual research
programs.

Materials and Life Science Division, Japan Proton Accelerator Research Complex
http://j-parc.jp/MatLife/en/Preface

MLF Annual Report 2016

Preface

Hideaki Yokomizo

Director, CROSSCROSS has served as a Registered Institution of specific neutron beam Facilities of J-PARC, appointed by theGovernment in 2011. We have been supporting the appropriate user program operations of the Public Beamlines
at Materials and Life Science Experimental Facility (MLF). We have also been engaged in facility promotion activities,
such as operating a fair and open proposal selection system for the MLF Public Beamlines, providing high-quality user
support and promoting facility utilization for both academic and industrial researchers. CROSS increased the numberof science coordinators in order to encourage the industrial use and to help the management of the Industrial Users
Society for Neutron Application, so, we have three science coordinators in 2016.
CROSS supported the user programs at seven fully-operational Public Beamlines: BL01 4SEASONS, BL02 DNA, BL11
PLANET, BL15 TAIKAN, BL17 SHARAKU, BL18 SENJU and BL22 RADEN. In 2016, we accomplished a stable and highly reliable machine operation, which reached over 90% of the original operation plan. However, the beam power had to be
reduced to 150-200 kW, because we used a spare target vessel, which had no protection from the pitting damage on
the beam window.
A special program for new user promotion (NUP) started in 2016 to invite scientists new to the neutron research.
NUP has a preferential beam time allocation and provides courteous support to first-time or novice users from boththe industrial and academic sectors. NUP is expected to create a new science by conducting the cooperative research
between industrial and academic scientists. The special program of Element Strategy Initiative has also proceeded successfully this year. Element Strategy Initiative is an integrated strategic research program of the Japanese Governmentthat promotes the development of innovative materials and alternative technologies in the research areas of permanent magnets, catalysis and batteries, and electronic and structural materials. Complementary Use is a program thatencourages and facilitates the complementary and collaborative use of pulsed neutrons (J-PARC MLF), synchrotron
radiation (SPring-8), and supercomputer (K computer).
I hope this Annual Report would serve as a useful information source for anyone wishing to know more about thecurrent status of MLF, its recent scientific achievements, the technical R&D projects that support the science program,and the operational details of our facility.
On behalf of the team at Neutron Science and Technology Center, CROSS, I extend a warm welcome to all researchers who wish to use the Public Beamlines at J-PARC MLF.

Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society

www.cross-tokai.jp/en

Contents
PrefaceOrganization Chart
J-PARC Map
Muon and Neutron Instruments

Research and Development Highlights
Reconsidering Partially Ordered States of Ice XV····································································································································

2Composite Behavior of Lath-Martensite Steels Induced by Plastic Deformation,a New Paradigm for the Elastic-Plastic Response of Martensitic Steels····················································································

5

Crystal Structure and Electrode Performance of Li1.2−xTi0.4Mn0.4O2·····································································································

9

Nanometer-Size Effect on Hydrogen Sites in Palladium Lattice········································································································ 11
Deficient 5 Coordination Li+ in Solvate Ionic Liquid toward Electrolytes for Next Generation Li Batteries························ 13
Contrast Variation by Dynamic Nuclear Polarization and Time-of-Flight Small-Angle Neutron Scattering······················ 16
A Contrast Variation Study of Nanogels by Small-Angle Neutron Scattering··············································································· 19
Neutron Brillouin Scattering of Liquid Methanol···································································································································· 21
Dynamics Changes of Human Hemoglobin Detected by Quasielastic Neutron Scattering···················································· 23
Magnetic Structure and Excitations in La5Mo4O16··································································································································· 25
Structure of the Magnetic Excitations in the Spin-1/2 Triangular-Lattice Heisenberg Antiferromagnet Ba3CoSb2O9···· 27
Rotational Modes and Phonons of CH3NH3PbI3······································································································································· 30
Development of the Spin-Wave-Like Dispersive Excitations below the Pseudogap Temperaturein the High-Temperature Superconductor La2−xSrxCuO4················································································································ 33
Spin-Orbital Correlated Dynamics in the Spinel-Type Vanadium Oxide MnV2O4········································································ 35
Crystal Field Excitations on NdFe3(BO3)4 Investigated by Inelastic Neutron Scattering···························································· 38
Damped Spin-Wave Excitations in the Itinerant Antiferromagnet γ−Fe0.7Mn0.3··········································································· 40
Large Magnetovolume Effect Induced by Embedding Ferromagnetic Clusters into Antiferromagnetic Matrixof Cobaltite Perovskite················································································································································································ 42
Neutron Tolerance Evaluation of Perpendicular-Anisotropy CoFeB-MgO Magnetic Tunnel Junctions
using NOBORU at J-PARC··········································································································································································· 44
Two-Dimensional Microstructure Visualization in Engineering Materials using Bragg-Edge Imaging······························· 46
Neutron Study on the Nanoscale Structures and Dynamics of Rubber Materials for Tires······················································ 49
Hydrogen/Deuterium Dynamics in Kagome Hydroxyl Salts Co2(OH)3Cl/Co2(OD)3Cl································································· 53
Behavior of Hydrogen as Simulated by µ+ in Conductive and Functional Cement C12A7······················································ 55
Chemical Environmental Effect on Negative Muon Capture by an Atom Targeted
to Gaseous Simple Carbon Oxides: CO, CO2········································································································································ 57
Metastable Hydrogen Configurations in the BaTiO3−xHx Oxyhydride Associated with Hydrogen Exchange
and Transport································································································································································································· 60
Application of Profile-Fitting Method to Neutron Time-of-Flight Protein Single Crystal Diffraction Data
Collected at the iBIX····················································································································································································· 62

Neutron Source
Progress of Neutron Source Section···························································································································································· 68
Approaches to Improve the Robustness of the Mercury Target Vessel··························································································· 70
The Status of the Cryogenic Hydrogen System······································································································································· 72
Present Status of the Spare Decoupled Moderator Fabrication········································································································· 74
Progress of the Proton Beam Transport (3NBT)······································································································································· 76

Neutron Science
Neutron Science Section·················································································································································································· 80
BL01: 4D-Space Access Neutron Spectrometer 4SEASONS················································································································· 82
BL02: Current Status of the Broadband micro-eV Quasielastic and Inelastic Neutron Spectrometer DNA······················· 84
BL03: IBARAKI Biological Crystal Diffractometer iBIX····························································································································· 86
Measurement of the 133Cs(n,γ) Cross-Section Using a New DAQ System at ANNRI····································································· 88
Status of Fundamental Physics Beamline BL05 (NOP) 2016················································································································ 90
BL06: Commissioning Status of VIllage of Neutron ResOnance Spin Echo Spectrometers (VIN ROSE)······························· 92
Status Report on Super High Resolution Powder Diffractometer, SuperHRPD············································································ 94
BL09: Current Status of the Special Environment Powder Diffractometer, SPICA······································································· 96
BL10: NOBORU····································································································································································································· 98
BL11: in-situ Diffraction above 20 GPa with Diamond Anvil Cell······································································································· 99
HRC and Neutron Brillouin Scattering························································································································································· 101
YUI and HANA: Control and Visualization Programs for HRC·············································································································· 103
BL14 AMATERAS·································································································································································································· 106
Upgrading TAIKAN······························································································································································································ 108
Detector Development for the SOFIA Reflectometer···························································································································· 109
BL17: Current Status of the Polarized Neutron Reflectometer, SHARAKU······················································································ 111
Status of SENJU 2016························································································································································································· 113
BL19: 2D Detectors Installed to the Back-Scattering Bank of TAKUMI····························································································· 115
The Current Status of the Versatile Neutron Diffractometer, iMATERIA·························································································· 117
Status of the High Intensity Total Diffractometer (BL21, NOVA)········································································································ 119
Energy-Resolved Neutron Imaging System, BL22: RADEN·················································································································· 120
Recent Progress on the Polarized Neutron Spectrometer POLANO································································································· 122
Development of an in-situ Polarized 3He Neutron Spin Filter for POLANO···················································································· 124
The Current Status of the Computing Environment on POLANO····································································································· 125
Development of Proton Filter for POLANO················································································································································ 127
Sample Environment at MLF··········································································································································································· 128
Present Status of IROHA2················································································································································································· 130
A Large Area, Position-Sensitive Scintillation Neutron Detector······································································································· 132
A Scintillator / Wavelength-Shifting Fiber Coil Detector······················································································································ 133

Muon Science
Status of J-PARC MUSE: Overview································································································································································· 136
Recent Developments of Monitoring Systems and Remote Handling Devices for Muon Production Target
at J-PARC MLF MUSE···················································································································································································· 137
Present Status of D-line····················································································································································································· 139
The Status of the U-line····················································································································································································· 141
Experimental Area S1: from Beam Commissioning to Sample Environment and Autorun of ARTEMIS Spectrometer······ 143
Present Status of the H-line············································································································································································· 146

MLF Safety
Research Safety···································································································································································································· 150

MLF Operations in 2016
Beam Operation Status at MLF······································································································································································· 154
Users at the MLF·································································································································································································· 155
MLF Proposals Summary – FY2016······························································································································································· 156
MLF Division Staff 2016····················································································································································································· 158
CROSS Staff 2016································································································································································································· 161
Proposals Review System, Committees and Meetings·························································································································· 163
Workshops, Conferences, Seminars and Schools in 2016···················································································································· 168
Award List·············································································································································································································· 171
MLF Publication 2016························································································································································································ 172
Editorial Board - MLF Annual Report 2016················································································································································· 176

Organization Chart

MLF Annual Report 2016

Organization Chart

Organiza on Chart of
J-PARC Center
Director, J-PARC Center
Deputy Director (JAEA, KEK, Safety)
Safety Division

Organiza on Chart of
CROSS
CROSS is “Registered Ins tu on for facility Use Promo on”
for the public-access neutron beam facili es at J-PARC.

President
CROSS Head Office

Accelerator Division

Research center for
Science and Society

Materials & Life Science Division

Director,
CROSS

Neutron Source Sec on

Science Coordinators

Neutron Science Sec on

Safety Division

Neutron Instrumenta on
Sec onAdministra on Division

Muon Science Sec on
Technology Development
Sec onU liza on Promo on
Division
Neutron R&D Division

Par cle & Nuclear Physics Division
Nuclear Transmuta on Division
Cryogenics Sec on
Informa on System Sec on
Administra on Division

Users Office

The Role of CROSS
Under the terms of the legislation that supports the
Public Neutron Beam Facility, CROSS is entrusted withspecific responsibilities. In practical terms, the corefunctions of CROSS can be summarized as follows:•	Proposal Selection and Beamtime Allocation on the
Public Beamlines•	User Support on the Public Beamlines•	Establishment of an Information Resource for Facility
Users•	Outreach and Facility Utilization Promotion•	Contract Beamline Assessment and Selection

MLF Annual Report 2016

J-PARC Map
CROSS(Ibaraki Quantum Beam Research Center)

J-PARC Center Users Office

R245

KEK Tokai Campus

Main Gate
R245
Linac

HENDEL R&D Building

3 GeV Synchrotron

MLF

50 GeV Synchrotron

J-PARC Research Building

J-PARC Map

400 ｍm

D LineU Line

S Line25 m

BL22 RADEN

As of March 2017

1m

Muon and Neutron Instruments
MLF Annual Report 2016

Research and Development
Highlights

Research and Development Highlights

MLF Annual Report 2016

Reconsidering Partially Ordered States of Ice XV
1. Introduction
Water freezes below 0°C. This is considered a common fact, but it is valid only in our world at a pressure of
1 atm. The melting temperature of ice drops when pressure increases, and reaches its minimum at 0.21 GPa(Fig. 1). This fact was discovered by G. Tammann in1900 [1], he also found two new high pressure polymorphs, ice II and III, after observing the melting pointand density of ice. Even over 100 years after the after
the discovery of the ice polymorphs, the exploration of
new polymorphs of ice still continues, leading to the recent discovery of ice XVII [2].
Why do the ice structures display such rich varieties? One of the reasons could be the order-disorderphenomena of the hydrogen bonds in ices. Even a single water molecule in an ice structure has four hydrogen bonds to the adjacent water molecules, yielding
4C2 = 6 different hydrogen positions and the numberof possible configurations will be exponentially increased with multiplying the number of molecules. The
degree of freedom for these hydrogen configurations
contributes to the rich variety of ice structures, and infact, most ice polymorphs have disorder-order “pairs” interms of hydrogen positions. Ice VI-XV, which is one of
the “pairs”, is the target of our study.
Ice XV, the ordered form of ice VI, was identified by
Salzmann et al. [3], from their observation of neutron
diffraction for sample prepared from ice VI by slow cooling from 250 to 80 K. Prior to the identification of ice XV

by Salzmann et al., the phenomena suggesting hydrogen ordering in ice VI had been reported in a number ofstudies (see references in [4]). However, as Salzmann etal., noted in their review paper [5], there was an inconsistency among the various experiments and calculations
for ice XV, i.e., neutron diffraction observations suggested antiferroelectrically ordered structures, which disagreed with the dielectric measurement and theoreticalstudies, implying ferroelectrically ordered structures.
Here we re-investigate the in-situ neutron diffraction
measurements and density’s functional theory calculations to revisit the structure and stability of ice XV.
2. Stability of ice XVIn a previous neutron study, detailed structure andstability investigations were carried out on a sample
recovered at ambient pressure; they showed that thephase boundary between ice VI and ice XV is about
130 K, regardless of the pressure, because the volume
change (ΔV) accompanying the transition was so smallthat the phase boundary could be flat in terms of pressure based on the Clausius-Clapeyron relation (dT/dP =ΔV/ΔS). We noted that the entropy change (ΔS) would
also be rather small; it should be less than the Paulingentropy (Rln (3/2) ≅ 3.37 J mol-1 K-1) as the hydrogenordering is incomplete and occurs only partially.
In our neutron study, the ordering process from ice
VI to ice XV was clearly observed as appearing additional peaks (e.g., 003) or a c/a axial ratio (Fig. 2), and the350

Liquid

300

200

III

V

Ih II

150

Disordering

100

Ordering

0
−50
−100

VIII

−150
−200

50
0

VI

50

t / °C

T/K

250

VII

Ordered (ref. 3) & Peakbroadening (this study)

0.0

0.5

1.0

XV
1.5

−250
2.0

2.5

p / GPa
Figure 1.	Phase boundary between ice VI and XV, proposedin [4]. The phase boundary of ice VI and XV has aslightly negative slope, which is constrained by the
results from our neutron diffraction experiments
denoted as blue (ordering) and red (disordering)
circles.

2

Figure 2.	Selected area of neutron diffraction patterns showing the growth of the 003 peak (yellow shaded area)
as a function of time, indicating hydrogen ordering
process from ice VI to XV for the sample recoveredfrom 1.0 to 0 GPa with increasing and then maintaining the temperature constant. The detailed p-T
path is shown in the inset as arrows.

MLF Annual Report 2016

additional peak intensities or c/a ratio were still being
grown after nearly 10 h at a constant temperature of
128 K. The corresponding run at approximately 0.4 GPashows the disappearing of the additional peaks and adecreasing c/a ratio, displaying a trend toward disordering. These observations clearly showed that thephase boundary between ice VI and XV has a slightly
negative slope, as shown in Fig. 1.

aResearch and Development Highlightsb

P42/nmc

Pmmn
D3

D3

D3

D3
D1
D2
D3 D3

b

D1 D2

D4
D4

D2’
D3’ D3’

D1
D2

D4
D4’

D1’

a

3. Partially ordered structure of ice XV
A neutron diffraction pattern, which was registered at 80 K and ambient pressure after recovering at
80 K from high pressure, and subsequently annealed
at 130 K, was analyzed by the Rietveld refinement. We
first analyzed it through 45 completely ordered structure models derived from ice VI by using graph andgroup theories, and found that none of the completely ordered configurations was particularly favored. In
other words, several configurations, for example four
configurations 39-42, shown in Fig. 3, have the lowest
R factors with quite similar consistency among the 45
symmetry distinct configurations. Our DFT calculations also support the phenomenon that a particularsingle completely ordered configuration is not favorably established, but several configurations may coexist at finite temperatures, as our investigations haveshown.
Next, we tried to refine the structure based onpartially ordered Pmmn model (Fig. 3b), which was derived from the reflection conditions and had been already proposed as the hydrogen ordered form of ice VI,
called ice VI’, by Kamb more than 40 years ago [6]. The
result shows good consistency in the observed data,
especially the better fit compared to all completely ordered models. Although we do not insist that the noted
consistency shows the Pmmn partial ordered model as
the true structure of ice XV, i.e., other possibilities like
Pm21n, P21mn or even lower symmetry could not be
excluded from our observations, but we can at least
conclude that a completely ordered structure could
not be established and the mixture of locally orderedmotifs apparently produces the reflection conditions.
Although the space group Pmmn itself suggests an antiferroelectrically ordered state because of the presenceof a center of symmetry, this does not mean that the
crystal physically possesses antiferroelectricity. Even
ferroelectricity may appear due to the locally orderedmotifs and its presence does not conflict with the previous dielectric measurement.

c

#39

#41

#40

#42

Figure 3.	Structure models of (a) ice VI, (b) ice XV, and (c) four
seamlessly adjacent ordered configurations 39-42
formed without breaking ice rules. Of the 45 symmetry distinct configurations, the four configurations shown here have the lowest R factors andthe highest phase fractions obtained from Rietveld
analysis of the neutron diffraction pattern.

4. The issue is still debatedFinally, we should note that the structure of ice XVis still under debate; a more recent neutron diffraction
study [7] stated that the ice XV structure should be derived from a completely ordered structure model. The
key issue to recognize, is how we treat the partially ordered structure model, which may also be related toa more fundamental problem in physics, that is how
neutrons located apart can interact coherently. Further
experimental and theoretical approaches describing
partially ordered structure will be required for a complete understanding.
References[1] G. Tammann, Annaleu der Physik, 2, 1 (1900).
[2] L. del Rosso, M. Celli and L. Ulivi, Nature
Communications, 7, 13394 (2016).
[3] C. G. Salzmann, P. G. Radaelli, E. Mayer and J. L.
3

Research and Development Highlights

MLF Annual Report 2016

Finney, Physical Review Letters, 103, 105701 (2009).
[4] K. Komatsu, F. Noritake, S. Machida, A. SanoFurukawa, T. Hattori, R. Yamane and H. Kagi,
Scientific Reports, 6, 28920 (2016).
[5] C. G. Salzmann, P. G. Radaelli, B. Slater and J. L.
Finney, Physical Chemistry Chemical Physics, 13,
18468-18480 (2011).

[6] B. Kamb, in Physics and chemistry of ice, edited by
E. Whalley, S. J. Jones and L. W. Gold (Royal Societyof Canada, Ottawa, 1973), pp. 28-41.
[7] C. G. Salzmann, B. Slater, P. G. Radaelli, J. L. Finney,
J. J. Shephard, M. Rosillo-Lopez and J. Hindley, The
Journal of Chemical Physics, 145, 204501 (2016).

K. Komatsu1, F. Noritake1,†, S. Machida2, A. Sano-Furukawa3, T. Hattori3, R. Yamane1, and H. Kagi1
Geochemical Research Center, Graduate School of Science, The University of Tokyo; 2CROSS, Research Center for Neutron Science andTechnology; 3J-PARC Center, Japan Atomic Energy Agency; †Present address: Faculty of Engineering, Graduate Faculty of Interdisciplinary
Research, University of Yamanashi

1

4MLF Annual Report 2016

Research and Development Highlights

Composite Behavior of Lath-Martensite Steels Induced
by Plastic Deformation, a New Paradigm for the ElasticPlastic Response of Martensitic Steels
1. Introduction
Lath martensite steels are widely used iron basealloys with outstanding mechanical properties. Their
strength is due to phase transformation of fcc structure
into lamellar bcc plates during fast cooling. Coherency
strains induce large dislocation densities which are thesource of the alloy’s strength. Though this alloy has
been used since the existence of steel, the way its microstructure functions is still unclarified. High resolution
neutron diffraction peak profiles revealed that there is aload redistribution between martensitic laths orienteddifferently relative to the applied stress direction. Basedon characteristically asymmetric neutron diffraction
profiles, we showed that the initially homogeneous
microstructure becomes heterogeneous during plastic
deformation [1-3]. We also showed that lath packets
soften when the active Burgers vectors are parallel tothe lath planes, but harden when they are not parallel.
We found that in lath packets that soften, the annihilation distance and the mean free path of active dislocations are two orders of magnitude larger than in thosewhich harden. Knowledge of load partitioning during
plastic deformation in martensitic steels will open new
options for developing iron base structural materials
with several improved mechanical properties. Typicalmartensite steels consists of blocks of lamellar plates,
where the blocks are forming packets [4]. The blocks
are subdivided into sub-blocks, where the smallest

constituents are lamellar plates called martensite-laths.
The hierarchy of packets, blocks, sub-blocks and laths
is shown schematically in Fig. 1. Within the packets the
crystallographic orientation is the same. The 110 oriented lath planes align coherently with one of the 111
type planes of prior austenite. Within the prior austenite grain boundary several packets of different crystallographic orientations can coexist, as shown in Fig. 1a.
2. Experimental
Neutron diffraction patterns were collected in-situ
during tensile deformation of a martensitic steel specimen with a small amount of retained austenite at the
TAKUMI beamline of the Materials and Life Science
Facility of the Japan Proton Accelerator ResearchComplex, J-PARC [1-3]. The beamline was operated withthe high resolution and medium intensity time-of-flight(TOF) method. The schematic outline of the TOF diffractometer and the specimen geometry is shown in Fig. 2.
The instrumental peak width was tuned to 0.3% and thestrain rate was 10-5 s-1. The loading direction and thediffraction vectors are parallel or perpendicular for the+90° or the -90° detector, i.e. for the 'axial' or the 'side'
directions, relative to the applied stress, s. In order toimprove the counting statistics the deformation was interrupted at 9 consecutive strain values as shown in the
stress-strain curve in Fig. 3.

Figure 1.	Schematic illustration of the hierarchical structure of lath martensite with the active Burgers vectors. (a) Lath packets
consisting of parallel blocks in three different packet. (b) Two packets oriented with the active Burgers vectors either in- or
out-of-lath-plane relative to the direction of the applied stress, σ.

5Research and Development Highlights

MLF Annual Report 2016

Figure 2.	Schematic drawing of the in-situ neutron diffraction experiment at the TAKUMI beamline using two
detector banks at scattering angles of ±90°.

Figure 4.	Typical diffraction pattern of observed (black-circles) and CMWP evaluated (red line) neutron diffraction patterns for ε = 0.042 tensiled state.

of residual internal stresses, Ds, corresponding to theforward and backward stresses acting in the hard-orientation (HO) or soft-orientation (SO) packets, respectively. The two shifted dislocation profile functions were
evaluated for the dislocation densities in the HO and SO
packet components and the results are shown in Fig. 6a
as a function of strain.
The average flow stress, sav or tav, and the local flow
stress values acting in the HO and SO packets, sHO or tHO
and sSO or tSO, were calculated by the Taylor equation:
Figure 3.	Stress-strain curve with step by step loading followed by unloading at several strain values to improve counting statistics.

3. Results and discussion
A typical axial diffraction pattern is shown in Fig. 4
for the e = 0.042 tensile deformed state. In the initialstate the diffraction peaks were perfectly symmetric,
whereas they have become asymmetric in the tensile
deformed states, as shown for the 200 axial and side
diffraction peak profiles in Fig. 5. The figure showsthat the asymmetries of the axial and side case peaks
are in opposite direction. The diffraction patterns were
evaluated by the Convolutional-Multiple-Whole-Profile(CMWP) fitting procedure based on physically modelled
profile functions for dislocations, crystallite size andplanar defects [5]. The CMWP fitting was performed forall diffraction peaks from 110 to 330 simultaneously, as
shown in Fig. 4. The asymmetric profiles were handled
by the sum of two dislocation profile functions shiftedto smaller or larger K values around the center of gravityof the measured peaks, where K is the reciprocal spacecoordinate. The shifts, Dd* = DK, are evaluated in terms
6si = s0 + aGMTb√ ρi , ti = t0 + aGb√ ρi ,

(1)where i stands for, HO or SO, a is a free parameter usually between zero and unity, G is the shear modulus, b
is the absolute value of the Burgers vector of dislocations and ri is the total average dislocation density or
the local average dislocation density in the hard or soft
packets, respectively. The flow stress values, si, calculated by equation (1) are shown in Fig. 6b. vs. the measured applied stress, sapplied. The schematic microscopic
model of stress redistribution is based on the composite model [6, 7] and is shown in Fig. 7. After unloading
forward and backward residual stresses will remain in
the HO and SO packets respectively. Stress and strain
compatibility between the SO and HO packets is guaranteed by the geometrically necessary dislocations(GNDs) lined up along the interfaces of the differently
oriented packets shown schematically in Fig. 7a. The
forward and backward local residual stresses are shown
schematically in Fig. 7b. During loading the weighted
spatial average of the local stresses are adding up forthe applied stress:

MLF Annual Report 2016

Research and Development Highlights

Figure 5.	(a) The CMWP calculated sub-profiles corresponding to the HO (dark green line) and the SO (blue line) packets in theaxial direction, along with the measured data (open circles) and the CMWP calculated total profile (red line). The centerof gravity of the measured profile and the positions of the sub-peaks are indicated as dotted, dashed and dash-dot lines,
respectively. (b) The measured (open circle), the CMWP calculated total profile (red line) and the CMWP calculated subprofiles corresponding to the HO (dark green line) and the SO (blue line) packets in the side direction.

Figure 6.	(a) Dislocation densities in the HO (red symbols) and the SO packets (blue symbols), and the volume fraction weighted
average dislocation densities (black symbols). (b) Local stresses in the HO (red symbols) and the SO packets (blue symbols)
calculated from the dislocation densities according to Taylor's equation.

Figure 7.	(a) Schematic illustration of the GNDs lined up along the interfaces of the differently oriented packets. (b) Spatial distribution of the local long-range-internal-stresses in the HO and SO packets under the action of the applied stress.

7

Research and Development Highlights

MLF Annual Report 2016tapplied = fHOtHO + (1 - fHO)tSO .

(2)

After unloading the residual internal stresses in the
HO and SO packets are:
DtHO = tHO - tapplied , DtSO = tSO - tapplied ,where fHODtHO + (1 - fHO)DtSO = 0.

develop new ferritic steel base structural materials forvarious applications. The beamline TAKUMI will be used
to reveal the mechanical elastic-plastic response alongwith the load partitioning microstructure in many different ferritic steels for developing new high performance structural materials.

(3)

During plastic deformation the backward stresses
in the SO and the forward stresses in the HO packets
hamper and assist dislocation motion in such a mannerthat the entire material flows simultaneously. The backward and forward stresses ensure that macroscopic
flow takes place irrespective of the packet being soft or
hard. The experiments in [1-3] proved the existence ofthe long range internal stresses between the softened
and hardened lath packets and indicate the evolutionof load redistribution between the differently oriented
packets in lath martensite.
4. Future plans
The recognition of load redistribution in low-alloy
high-strength ferritic steels opens new perspectives toReferences[1] T. Ungár, S. Harjo, T. Kawasaki, Y. Tomota, G. Ribárik,Z. Shi, Met. Mat. Transact., A48, 159-167 (2017).
[2] S. Harjo, T. Kawasaki, Y. Tomota, W. Gong, K. Aizawa,
G. Tichy, T. Ungár, Met. Mat. Transact., A48, 40804092 (2017).
[3] Y. Wang, T. Ohnuki, Y. Tomota, S. Harjo, T. Ohmura,
Scripta Mater., 140 45-49 (2017).
[4] H. Kitahara, R. Ueji, N. Tsuji, Y. Minamino, Acta Mater.
54, 1279-1288 (2006).
[5] G. Ribárik, T. Ungár, Mater. Sci. Eng. A528, 112-121(2010).
[6] T. Ungár, H. Mughrabi, D. Rönnpagel, M. Wilkens,
Acta Metall. 32, 333-342 (1984).
[7] H. Mughrabi, T. Ungár, W. Kienle, M. Wilkens, Philos.
Mag. A53, 793-813 (1986).

T. Ungár1, S. Harjo2, T. Kawasaki2, Y. Tomota3, G. Ribárik4, and Z. Shi5
Materials Performance Centre, School of Materials, The University of Manchester, Manchester, M13 9PL, UK; 2J-PARC Center, Japan
Atomic Energy Agency; 3National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan; 4Department of Materials
Physics, Eötvös University, Budapest, PO Box 32, H-1518, Hungary; 5College of Materials and Chemical Engineering, China Three Gorges
University, Yichang 443002, PR China

1

8

MLF Annual Report 2016

Research and Development Highlights

Crystal Structure and Electrode Performance of
Li1.2−xTi0.4Mn0.4O2
1. Introduction
During the past two decades, the technology ofrechargeable lithium-ion batteries (LIBs) has become
highly sophisticated and contributed to the development of today’s convenient modern society with versatile portable electronic devices. However, due tothe ever-increasing demand for energy density, there
is a need to develop positive electrode materials withhigher energy density. The energy density of commercial LIBs is currently limited by positive electrodematerials. Lithium-excess positive electrode materials
such as Li2MnO3 and their derivatives have been studied extensively in the past decade. In this system, theoxidation state of manganese ions is tetravalent, andtherefore further oxidation of manganese ions is difficult on charge. Instead, oxide ions as anions contributein the charge compensation process. However, oxidation of oxide ions for Li2MnO3-based electrode materials causes oxygen loss as an irreversible process [1].
To use effectively the charge compensation of oxideions, several lithium-excess positive electrode materials
have been reported. Recently, our group successfully
synthesized new niobium- and titanium-based highcapacity positive electrode materials, which use effectively the solid-state redox reaction of oxide ions [2,3]. In this study, a detailed crystal structure of a binary
system of Li2TiO3-LiMnO2 is examined by neutron diffraction, and possibility of reversible solid-state redoxof oxide ions for the high-capacity positive electrodematerials is discussed.

2. Crystal structure of Li1.2Ti0.4Mn0.4O2
A binary system of Li2TiO3-LiMnO2 has been systematically examined as electrode materials. Both endmembers, Li2TiO3 and LiMnO2, crystallize into different
cation-ordered rocksalt-type structures. Li2TiO3 is expected to be a high capacity electrode material with anion redox if all lithium ions are reversibly extracted fromthe host structure. However, Li2TiO3 has no d electrons
in a conduction band, leading to an insulating characteras electrode materials. Therefore, pure Li2TiO3 is electrochemically inactive. Substitution of 3d transition metal
ions for Ti/Li ions effectively induces conductive electrons, and color of samples is also changed from whitefor Li2TiO3 to black for substituted samples with Mn3+.
Such 3d transition metals can accept electrons from oxide ions. However, a change in the crystal structure isalso unavoidable, and formation of a cation-disorderedrocksalt-type structure is noted. A neutron diffraction
pattern of the sample with the one to one composition
between Li2TiO3 and LiMnO2, which is reformulated
as Li1.2Ti0.4Mn0.4O2, is shown in Fig. 1. The neutron diffraction pattern was collected at BL09 (SPICA) in MLF.
Rietveld analysis of the neutron diffraction pattern revealed that the sample contains 1% vacancy at 4a site(cation sites). Moreover, no evidence is found for theformation of oxygen vacancy.
3. Electrode performance of Li1.2Ti0.4Mn0.4O2
Historically, such cation-disordered rocksalt phase
had been regarded as electrochemically inactive aselectrode materials because of a lack of the Li migrations.g. Fm-3m, a = 4.1567 Å

Li, Mn,and Ti

O

2.0

4.0

6.0

8.0
q/Å

10.0

12.0

−1

Figure 1.	A neutron diffraction pattern of as-prepared Li1.2Ti0.4Mn0.4O2. Refined structural parameters are found in Table 1.

9Research and Development Highlights

MLF Annual Report 2016

Table 1. Results of Rietveld analysis on the neutron diffraction pattern of Li1.2Ti0.4Mn0.4O2. The fitting result is shown in Fig. 1.

the plateau region around 4.2 V. Moreover, this process
is highly reversible. Solid-state redox reaction of oxideions is effectively stabilized by the presence of relatively
less covalent character of Mn4+ with oxide ions without
the sacrifice of electronic conductivity [3]. This finding
opens a path to develop a new series of high-capacity
positive electrode materials on the basis of oxide ion redox for rechargeable high-energy battery applications.

6.0
rdVoltage / V

nd

3 2

5.0

st

1

4.0
3.0
2.0
rd

1.0
0.0

3

Li/Li1.2Ti0.4Mn0.4O2
0

50

100

150

200

st

1

at 50°C
250

−1

300

350

400

Capacity / mAh g

Figure 2.	Charge/discharge curves of Li1.2Ti0.4Mn0.4O2 in a Li
cell at a rate of 5 mA g−1 at 50°C.

path in a bulk structure. Nevertheless, formation of percolating network for the Li-excess system (Li1+xMe1−xO2)
opens the path for Li migration in the cation-disorderedrocksalt-type structure [4].
Li1.2Ti0.4Mn0.4O2 was mixed with 10 wt% acetylene
black and ball milled to enhance the electrode performance. Thus prepared sample shows a large reversible
capacity in a Li cell, as shown in Fig. 2, and the sample
delivers more than 300 mAh g−1 at 50°C. Available energy density of Li1.2−xTi0.4Mn0.4O2 exceeds 1,000 mWh g−1
as a positive electrode material. Moreover, capacity retention is much better than that of pure Li2MnO3.
To examine whether oxide ions are oxidized andstabilized in Li1.2−xTi0.4Mn0.4O2, reaction mechanisms
were examined by soft X-ray absorption spectroscopy.
A study by soft X-ray absorption spectroscopy revealed
that, on the initial charge, Mn3+ is oxidized to Mn4+ forthe slope region to 4 V, and oxide ions are oxidized at

4. Summary
The use of solid-state redox reaction of oxide ions is
an effective strategy to further increase energy densityof rechargeable lithium batteries. We have demonstrated that the stabilization of redox reaction for oxide ionsis possible using a combination of only 3d transition
metals as the metallic constituents. Now, we are not
restricted any more by the conventional and classicalconcept of transition metal redox, which totally limited
the materials design and theoretical capacity of positiveelectrode materials as used in the past three decades.
We expect that many new positive electrode materials
with high capacity will appear, such as Li1.2Ti0.4Mn0.4O2.
References[1] N. Yabuuchi, Chemistry Letters 46 (2017) 412.
[2] N. Yabuuchi, M. Takeuchi, M. Nakayama, H. Shiiba,
M. Ogawa, K. Nakayama, T. Ohta, D. Endo, T. Ozaki, T.
Inamasu, K. Sato and S. Komaba, PNAS 112 (2015) 7650.
[3] N. Yabuuchi, M. Nakayama, M. Takeuchi, S. Komaba, Y.
Hashimoto, T. Mukai, H. Shiiba, K. Sato, Y. Kobayashi,
A. Nakao, M. Yonemura, K. Yamanaka, K. Mitsuhara
and T. Ohta, Nature Communications 7 (2016) 13814.
[4] J. Lee, A. Urban, X. Li, D. Su, G. Hautier, G. Ceder,
Science 343 (2014) 519.

N. Yabuuchi1 and M. Yonemura2,3
1
Department of Applied Chemistry, Tokyo Denki University; 2Institute of Materials Structure Science (IMSS), High Energy Accelerator
Research Organization (KEK); 3Department of Materials Structure Science, Sokendai (The Graduate University for Advanced Studies)

10

MLF Annual Report 2016

Research and Development Highlights

Nanometer-Size Effect on Hydrogen Sites in Palladium
Lattice
1. Introduction
Palladium hydride (PdHx, 0 < x < 1) is the best knownclassical metal hydride, which has been investigated bymany physicists and chemists. It has been remarked
also from industrial points of view, e.g., hydrogen storage, filters, sensors, catalysts, etc. In the hydrogen adsorption process, a hydrogen molecule (H2) dissociates
into two hydrogen atoms (2H), and the H atoms occupy
the interstitial sites of the Pd lattice. In the H concentration region higher than x = 0.6, the hydride crystal
takes the b phase with an fcc (NaCl-type) structure asshown in Fig. 1(a). In the b phase, it is known that the Hatoms are located only at the octahedral (O) sites (1/2,
1/2, 1/2) at ambient temperature and H2 pressure [1]. In
other transition metals with the fcc lattice, H atoms alsopreferentially occupy the O sites. In high-temperatureor high-pressure conditions, however, the tetrahedral(T) sites (1/4, 1/4, 1/4) are partially occupied, for example in PdDx [2] and fcc-FeDx [3].

The physical and chemical properties of nanometer-sized materials are of interest, since they are often
different from the bulk properties. As for the nanoparticles of palladium hydrides, there are drastic changesof the H2 pressure-composition phase diagram [4] andheat capacity [5]. To understand the characteristic properties of PdH nanoparticles from microscopic point ofview, it is first necessary to investigate their structure,including the location of hydrogen atoms. In this work,
therefore, we have performed in situ neutron powder
diffraction (NPD) experiments [6] for high-quality Pd
nanoparticles, as shown in Fig. 1(b). The nanoparticles
have a well-defined shape of an edge-cut octahedron
with diameter of 8.0 ± 0.9 nm. The nanoparticles arecovered with a protective polymer polyvinylpyrrolidone (PVP) to avoid adhesion between the nanoparticles. The NPD measurements were performed using
a high-intensity total diffractometer (NOVA) installed
at J-PARC.

Figure 1.	(a) Structure of the β phase of Pd hydrides. The redand blue spheres show the possible octahedral andtetrahedral sites for hydrogen atoms, respectively.
The gray spheres show the Pd fcc lattice. (b) Photographs of the transmission electron microscope(TEM) for Pd nanoparticles [5]. The size distributionof the nanoparticles and the schematic drawing ofan edge-cut octahedron are also shown.

2. Results and discussion
Figure 2 shows the neutron diffraction patternof PdD0.363 nanoparticles measured at 300 K under
0.11 MPa of D2 gas. The amount of the D atoms absorbed into Pd nanoparticles was precisely determinedby the hydrogen gas control system installed on NOVA.
The data shown in Fig. 2 were obtained after subtracting the large contribution of the incoherent scatteringfrom PVP. This is the first neutron diffraction data fornanoparticles of metal hydrides.
The crystal structure of PdD0.363 has been refined by
the Rietveld analysis using the Z-Rietveld software [7].
We have examined the following structural models:(model 1) the O sites are occupied by the D atoms homogeneously; (model 2) the O sites in the shell part(a few layers near the surface) are occupied; (model 3)both the O and T sites are occupied homogeneously;(model 4) the O and T sites in the shell part and the Osites in the core part are occupied. In models 2 and 4,
the hypothetical phase separation between the shelland core part was assumed to incorporate the surface effect of the nanoparticles. The best fit result was
obtained with model 4. The obtained fitting parameters are as follows: lattice constants of the shell andcore parts a(shell) = 4.0177(4) Å, a(core) = 4.0027(2) Å,
Pd atomic fraction of the shell part fS = 0.24 (fixed),
11

Research and Development Highlights

model 1

MLF Annual Report 2016

S = 2.09
Rwp = 14.2%

(a)
D(O)

I(Q) / arb. unit

model 2model 3(b)

S = 1.59
Rwp = 10.8%(c)

S = 1.20
Rwp = 8.1%
D(T)model 44(d)

S = 1.15
Rwp = 7.8%

6

8

Q/Å

10

12

−1

Figure 2.	Observed (black crosses) and calculated (red curves)diffraction patterns of the nanoparticles of PdD0.363
at 300 K. The Rietveld analyses were performed assuming structural models 1-4 shown schematicallyin the insets. The gray circles represent the Pd atoms, and the red and blue circles show the D atoms
at the O and T sites, respectively.

isotropic atomic displacements BPd = 0.280(5) Å2, BD(O) =1.99(6) Å2, BD(T) = 14.1(5) Å2, occupancies of the O and T
sites gD(O)(shell) = gD(O)(core) = 0.251(2) and gD(T)(shell) =0.234(3) under the constraints gD(O)(shell) = gD(O)(core), x= (1 − fS) gD(O)(core) + fS[gD(O)(shell) + 2gD(T)(shell)] = 0.363.
Our Rietveld analysis revealed that 30% of the D atoms
are located at the T sites and 70% at the O sites in the
Pd nanoparticles. This contrasts with the result that
only the O sites are occupied in bulk PdDx. We guessthat the T site occupation can be due to the change in
potential energy caused by the surface and/or distortion effects of the nanoparticles. The T site occupation
is associated with the drastic changes in the diffusionaland vibrational motions of the H atoms in Pd nanoparticles revealed in our recent quasielastic [8] and inelastic [9] neutron scattering investigations. Furthermore,
the present work will become a foundation for future
research in the nanoparticles of other metal and alloy
hydrides.
3. Acknowledgments
The experiment in the MLF at J-PARC was performed
with the approval of J-PARC (Proposal No. 2012B0246,
2014A0228). This work is financially supported by
CREST, Japan Science and Technology Agency.
References[1] H. E. Worsham, M. K. Wilkinson and C. G. Shull, J.
Phys. Chem. Solids 3, 303-310 (1957).
[2] K. G. Mclennan, E. M. Gray and J. F. Dobson, Phys.
Rev. B 78, 014104 (2008).
[3] A. Machida, H. Saitoh, H. Sugimoto, T. Hattori, A.
Sano-Furukawa, N. Endo, Y. Katayama, R. Iizuka,
T. Sato, M. Matsuo, S. Orimo and K. Aoki, Nat.
Commun. 5, 5063 (2014).
[4] M. Yamauchi, R. Ikeda, H. Kitagawa and M. Takata, J.
Phys. Chem. C 112, 3294-3299 (2008).
[5] H. Akiba, H. Kobayashi, H. Kitagawa, M. Kofu and O.
Yamamuro, Phys. Rev. B 92, 064202 (2015).
[6] H. Akiba, M. Kofu, H. Kobayashi, H. Kitagawa, K.
Ikeda, T. Otomo and O. Yamamuro, J. Am. Chem.
Soc. 138, 10238-10243 (2016).
[7] R. Oishi, M. Yonemura, Y. Nishimaki, S. Torii, A.
Hoshikawa, T. Ishigaki, T. Morishima, K. Mori and T.
Kamiyama, Nucl. Instrum. Methods Phys. Res. Sect.
A 600, 94-96 (2009).
[8] M. Kofu, N. Hashimoto, H. Akiba, H. Kobayashi, H.
Kitagawa, M. Tyagi, A. Faraone, J. R. D. Copley, W
Lohstroh and O. Yamamuro, Phys. Rev. B 94, 064303(2016).
[9] M. Kofu, N. Hashimoto, H. Akiba, H. Kobayashi, H.
Kitagawa, K. Iida, M. Nakamura and O. Yamamuro,Phys. Rev. B 96, 054304 (2017).

H. Akiba1, M. Kofu1, H. Kobayashi2, H. Kitagawa2, K. Ikeda3,4, T. Otomo3,4, and O. Yamamuro1
1Institute for Solid State Physics, University of Tokyo; 2Department of Chemistry, Graduate School of Science, Kyoto University; 3Institute ofParticle and Nuclear Studies, KEK; 4Neutron Science Section, Materials and Life Science Division, J-PARC Center

12

MLF Annual Report 2016

Research and Development Highlights

Deficient 5 Coordination Li+ in Solvate Ionic Liquid
toward Electrolytes for Next Generation Li Batteries
1. Introduction
Solvate ionic liquids (SIL) are a new category ofroom-temperature ionic liquids [1] that have novel applications as electrolytes in the next generation lithium
secondary batteries. Watanabe and Dokko et al. demonstrated that SILs composed of an equimolar mixtureof LiTFSA salt (TFSA: bis-(trifluoromethanesulfonyl)
amide) and oligo-ether glymes such as triglyme (G3:
CH3O–(CH2CH2O)3–CH3) and tetraglyme (G4: CH 3O–(CH2CH2O)4–CH3), can be utilized as electrolytes for Li
secondary batteries [2], particularly Li-sulfur ones, due
to the rather small solubility of the electrode active
species lithium polysulfide Li 2Sn [3]. In addition, theelectrode reactions and the Li2Sn solubility should begoverned by the liquid structure and/or the Li+ local
structure, because it is crucial to maintain the glyme
solvate complex of Li+ [Li(glyme)]+ structure [4].
Recently, the molecular level properties of the SILs
have been probed using the NMR diffusion coefficients,
Raman spectra analysis, and theoretical calculations,such as ab initio molecular orbital calculations andmolecular dynamics simulations. These studies clarified that the Li+ was coordinated with almost all of theglyme to form [Li(glyme)]+ in the SIL.
Quite recently, the Atkin’s group performed neutron scattering experiments with empirical potential
and structure refinement (EPSR) analysis to elucidate
the bulk nanostructure of various solvate ionic liquids
like [Li(G4)][TFSA] and [Li(G4)][NO3] [5]. However, theLi+ local structure in the SILs is still needed from an experimental perspective as this structure is critical for
the Li+ ionic conduction mechanism in the bulk and the
reduction/oxidization mechanisms at the SIL electrolyte/electrode interface. For that purpose, neutron scattering experiments with the 6/7Li isotopic substitution
technique are one of the most powerful tools and havesuccessfully revealed Li+ solvation structures in aqueous and non-aqueous solvent solutions.
Here, the Li+ local structure in [Li(G4)][TFSA] SIL is
determined using neutron total scattering experimentswith the 6/7Li isotopic substitution technique. We foundthe unique deficient 5 coordination structure of Li+ in
the SIL.
2. Experimental
The sample solution was introduced into athin-walled cylindrical V-Ni null alloy cell (6.0 mm in inner diameter and 0.1 mm in wall thickness) and sealed byan indium seal. Neutron scattering measurements werecarried out at 25°C using the NOVA total scattering spectrometer installed at BL21 of the MLF pulsed neutron
source in J-PARC, Tokai, Japan. The incident beam powerof the proton accelerator was 300 kW. Scattered neutrons(neutron wave band of 0.1 ≤ λ ≤ 8.7 Å) were detectedby ca. 900 of 20 atm 3He position sensitive proportionalcounters (1/2 inch f, 800 mm in active length with 5 mm
in positional resolution) installed at 20°(13.1° – 27.9°),45°(33.6° – 54.9°), 90°(72.7° – 107.4°) and back scattering(136.5° – 169.0°) detector banks. The data accumulation
time was ca. 6 h for each sample. Measurements weremade in advance for a 6 mm in diameter vanadium rod,
empty cell and instrumental background. The observed
scattering intensities for the sample were corrected for
instrumental background, absorption of sample and cell,
multiple and incoherent scatterings. The wavelength dependence of the total cross sections for H nucleus wasestimated from the observed total cross sections for
H2O. Since the attenuation coefficients calculated for theabsorption correction exhibit significant neutron wavelength (l) dependence for the sample with large absorption cross section, the attenuation coefficients, As,sc(2q, l)
and Ac,sc(2q, l), were successfully approximated by fitting
them in the form of exponential of the 7th polynomial ofl by the following equation,A(2q, l) = exp(S aili-1).(1)The first-order difference function, Δ Li(Q), (Q =4πsinθ/λ is a scattering vector, where θ and λ are thescattering angle and neutron wave length, respectively) is derived from the numerical difference between
scattering cross sections observed for two solutions
that are identical compositions except for the scattering length of Li. The ΔLi(Q) normalized for stoichiometricunits, (LiTFSA)x(G4)1-x can be written as linear combination of partial structure factors, aLij(Q), involving correlations form the Li - j pair:
ΔLi(Q) = A[aLiO(Q) - 1] + B[aLiC(Q) - 1] + C[aLiH(Q) - 1]
+ D[aLiF(Q) - 1] + E[aLiS(Q) - 1] + F[aLiN(Q) - 1]
+ G[aLiLi(Q) - 1](2)13Research and Development Highlights

MLF Annual Report 2016

where, A = 2x(5 - x)(b6Li - bnatLi)bO, B = 4x(5 - 4x)(b6Li- bnatLi)bC, C = 44x(1 - x)(b6Li - bnatLi)bH, D = 12x2(b6Li bnatLi)bF, E = 4x2(b6Li - bnatLi)bS, F = 2x2(b6Li - bnatLi)bN, andG = x2(b26Li - b2natLi). Since the observed ΔLi(Q) from forward angle detector pixels located at 13.1 ≤ 2q ≤ 27.9°
agree well within the statistical uncertainties, they werecombined at the Q-interval of 0.1 Å-1 and used for subsequent analyses.
The distribution function around Li+, GLi(r), was deduced from the Fourier transform of ΔLi(Q):GLi(r) = 1 + (A + B + C + D + E + F + G)-1(2p2r0r)-1
		∫QΔLi(Q) sin(Qr) dQ[AgLiO(r) + BgLiC(r) + CgLiH(r) + DgLiF(r) + EgLiS(r)=		+ FgLiN(r) + GgLiLi(r)] × (A + B + C + D + E + F		+ G)-1(3)The upper limit of the integral was set to 20 Å-1 in
the present study.
3. Results and discussion
The interference functions i(Q) were successfully
obtained in the 0 < Q/Å-1 < 26 range for sample solutionsof [*Li(G4)][TFSA] (* stands for both 6Li enriched andnatural abundance) solvate ionic liquids. Consequently,
ΔLi(Q) was also adequately determined in the 0 < Q/Å-1 <20 range. The radial distribution function GLi(r) obtainedby Fourier transformation of the Δ Li(Q) is shown in
Fig. 1. The first and the second peaks of GLi(r) can be assigned to the positions of atoms close to the Li+ cations.

Figure 1.	The partial radial distribution functions GLi(r) for thesolvate ionic liquid [Li(G4)][TFSA]. Dots and solidlines represent experimental and calculated basedon the model structure shown in the figure, respectively.

14

Such close neighbors can be unambiguously found at
about 2 and 3 Å, respectively. It should be noted thatthe broad valley found in the GLi(r) at around 3.5 Å canbe ascribed to the solvated G4 hydrogen atoms of thenegative neutron scattering length. The presence of thevalley in the GLi(r) suggests that most of the Li+ in the SIL
is solvated by G4 molecules, which is consistent withthe previous NMR and Raman studies.
We performed a quantitative analysis of the neutron scattering data based on a local structure model. In
the case of the G4 molecule, 5 oxygen atoms can potentially coordinate to the Li+ ion (although in solution theLi+ prefers a 4-atom coordinated structure). Therefore,
the fitting parameters considered here were the Li+ –G4 coordination number, the Li+–O bond lengths, their
thermal factors, the Li+–O–C bond angles, also twelve
significant torsion angles along the backbone of the G4
molecule. The GLi(r), calculated based on the obtained
structural parameters of the model structure, is shownin Fig. 1 as a solid line. As shown in the figure, the model
agrees with the experimental results. An atomistic depiction of the model structure is shown in Fig. 1.
In the least squared model structure, the Li+ is coordinated by five oxygen atoms in G4 that have theirown characteristic distances, 2.06, 2.09, 2.13, 1.93 and2.24 Å, respectively. Clearly, 2.24 Å is significantly larger
than the others. The average distance of 2.05 Å, except
the longest one, is still significantly larger than the values of 1.95 – 1.97 Å usually found in aqueous solutions.
However, the distances are similar to the values for cyclic and acyclic carbonates (2.04 – 2.08 Å) and for thepolyethyleneoxide solutions (2.07 – 2.1 Å). According
to Shannon and Bondi, the ionic radius for the 4-coordinated Li+ and van der Waals radius for the oxygen atom
are 0.59 and 1.52 Å, respectively. The sum of these twovalues, 2.11 Å, is close to the Li+ – O average distance of
2.05 Å. On the other hand, the 2.24 Å distance is considerably larger than 2.11 Å.
To obtain further insights, classic MD simulations
were performed. Figure 2 compares the MD-derived
GLi(r) with that from the experiments. This figure reveals
good agreement between them. In the MD simulations, the Li+ is on average a 5-coordinated structure:
4 oxygen atoms from the G4 molecule and 1 from the
TFSA anion, respectively. Figure 3 shows pair correlation functions g(r) and their integral curves N(r) for the
Li+ – O (G4) in the simulated [Li(G4)][TFSA] SIL. As shownin the figure, the first peak in g(r) for the central oxygen
atom in G4 is the shortest and sharpest, which suggeststhat the central oxygen inertly coordinates to the Li+. As

MLF Annual Report 2016

Research and Development Highlights

Figure 2.	The partial radial distribution functions GLi(r) for thesolvate ionic liquid [Li(G4)][TFSA]. Dots and a solidline represent experimental and calculated basedon MD simulations, respectively.

Figure 3.	The pair correlation functions and its integral curves
for the Li+ - O (G4) in the solvate ionic liquid [Li(G4)][TFSA].

the oxygen atoms locate closer to the terminal, the firstpeaks in g(r) shift further with broadening. The smallest coordination number of about 1.4 for the terminal
oxygen atoms with the longest position and the broadest width is consistent with the present neutron experiments. This means that on average one of the terminal
oxygen atoms in the G4 is not fully coordinated to the
Li+, which supports the longer 2.24 Å distance predicted by the model. Our MD simulations suggested thatthe terminal oxygen atoms never fully coordinate to theLi+ but rather undergo successive coordination/uncoordination stages.

after another. It is expected that the neutron scattering
techniques will strongly support further developmentof science and technology in this field.

4. Future
Here, we demonstrated that the neutron scatteringwith the 6/7Li isotopic substitution technique evidently reveals the Li+ local structure in much complicatedsolution systems as the SIL for the next generation Li
secondary batteries. To build electrochemical devices,
including Li batteries with much higher performance,
innovative electrolytes, which have new ionic conduction mechanisms and/or redox reactions at the electrode/electrolyte interface, are being discovered one

References[1] C. A. Angell, Y. Ansaria, Z. Zhaoa, Faraday Discuss,154,
9-27, (2012).
[2] T. Tamura, T. Hachida, K. Yoshida, N. Tachikawa, K.
Dokko, M. Watanabe, J. Power Sources, 195, 60956100, (2010).
[3] K. Dokko, N. Tachikawa, K. Yamauchi, M. Tsuchiya, A.
Yamazaki, E. Takashima, J-W. Park, K. Ueno, S. Seki,
N. Serizawa, M. Watanabe, J. Electrochem. Soc. 160,
A1304-A1310, (2013).
[4] K. Ueno, R. Tatara, S. Tsuzuki, S. Saito, H. Doi, K.
Yoshida, T. Mandai, M. Matsugami, Y. Umebayashi,
K. Dokko, M. Watanabe, Phys. Chem. Chem. Phys.
17, 8248-8257, (2015).
[5] T. Murphy, S. K. Callear, N. Yepuri, K. Shimizu, M.
Watanabe, J. N. C. Lopes, T. Darwish, G. G. Warr, R.
Atkin, Phys. Chem. Chem. Phys. 18, 17224-17236,(2016).

Y. Umebayashi1, H. Watanabe1, S. Saito1, K. Dokko2, M. Watanabe2, and Y. Kameda3
Graduate School of Science and Technology, Niigata University; 2Department of Chemistry and Biotechnology, Yokohama National University;
3Department of Material and Biological Chemistry, Faculty of Science, Yamagata University

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MLF Annual Report 2016

Contrast Variation by Dynamic Nuclear Polarization andTime-of-Flight Small-Angle Neutron Scattering
1. Introduction
Contrast variation for small-angle neutron scattering (SANS) is a very useful technique in investigating
multi-component systems. For contrast variation studies, deuterium substitution has been conventionallyused, which takes advantage of the difference in theneutron scattering length between protons and deuterons. The deuterium substitution technique can beeasily applied to solutions or gels, due to reasonableavailability of deuterated solvent, whereas the synthesis of deuterated polymer is costlier and requires significant efforts. Hence, alternative methods are needed.
Besides deuterium substitution, contrast variation canalso be achieved by controlling both spin states ofneutrons and protons. The coherent scattering length(bcoh,H) of a proton against a fully polarized neutron are
given by the following equation [1]:(1)bcoh,H = (−0.374 + 1.456 PH) × 10−12 [cm]
where P H denotes the proton spin polarization.
Polarization means the difference in populations between up and down spins. Figure 1 shows the PH dependence of bcoh,H. Note that the variation of bcoh,H isabout 2.5 times larger than the one caused only by
deuterium substitution. As for PH = 0, the coherent scattering length of hydrogen is −0.374 × 10−12 cm, whereasthat for a deuteron is 0.667 × 10−12 cm.
At room temperature, up and down proton spinsare almost equally populated. With decreasing temperature and increasing magnetic field, the proton spinpolarization increases. However, even at 3.3 Tesla and
1.2 K, the proton spin is polarized up to only 0.3%. In
contrast, the electron spin is largely polarized up to 95%
under the same conditions (at 3.3 Tesla and 1.2 K). This isbecause of a large difference in the gyromagnetic ratio

Figure 1.	Coherent scattering length of a proton against afully polarized neutron beam as a function of proton spin polarization, PH.

16

between the electron spin and the proton spin (|γe|/γH =658). The large polarization of an electron spin can betransferred to the proton spins by microwave irradiation with energy equal to the simultaneous flipping ofelectron and proton spins. Consequently, high proton
spin polarization is achieved. This is called dynamic nuclear polarization (DNP) and requires electron spin doping, magnetic field, low temperature, and microwave
irradiation.
A stable organic free radical, TEMPO [(2,2,6,6tetramethylpiperidine-1-yl)oxy] can be used as an electron spin source. TEMPO is sublimable around room
temperature. Vaporized TEMPO permeates spontaneously the rubbery phase of solid polymer samples (Fig. 2).
Based on this vapor sorption technique, we preparedpolymer systems for SANS studies after the constructionof a DNP cryostat [2] and polarized neutron ultra-smallangle scattering spectrometer (SANS-J-II) [3] at research
reactor JRR-3, Tokai, Japan. We investigated the polyethylene film [4] and the di-block copolymer to evaluate precisely the inhomogeneity of proton polarization
around doped TEMPO molecules [5]. Subsequently, thevapor sorption technique was successfully applied to silica-filled rubber, which is used for fuel-efficient tires [6].
The vapor sorption technique can be applied to industrial rubber products after a manufacturing process.
A tire is a multi-component nanocomposite and an
attractive target for contrast variation SANS with DNP.
To improve tear and wear resistance, filler particles,
such as carbon black (CB) and silica particles (SP), aremixed into the rubbery matrix. The spatial distributionof filler particles in rubbery matrix determines not only
the tires’ reinforcement but also the energy loss performance. According to the empirical knowledge thatthe homogeneous dispersion of filler particles lowers
the energy loss, various attempts to achieve dispersion

Figure 2.	TEMPO vapor sorption technique for rubber sample.

MLF Annual Report 2016

control have been conducted. A reliable methodology
for evaluating the filler particle dispersion is critical for
optimizing the tire rubber performance.
The combination of CB and SP is frequently usedin tire manufacturing. In addition to the above-mentioned effects, CB is useful for specific UV resistance andelectric discharge. For precise structural analyses, weneed to decompose the observed SANS profiles into individual partial scattering functions of CB and SP.
2. DNP experiment setup
As a model system for industrial tires, we prepareda ternary mixture of SBR (styrene-butadiene random
copolymer) with SP and CB particles (SBR/SP/CP). The
sample consisted of solution-SBR, silica particles, CB, silane-coupling agent and other additives. In the mixture,
the volume fractions of CB and SP were 2% and 10%,respectively. After cure process (170°C for 20 min), therubbery mixture was placed with TEMPO inside a sealedcontainer at 40°C for 1 week. Consequently, the vaporized TEMPO spontaneously permeated the rubbery
matrix. By ESR measurement, the TEMPO concentration
was determined to be 35 mM. It was close enough tothe empirically-known optimum value (30 mM) for DNP.
Figure 3 shows the schematic picture of the DNPSANS experiment performed at TAIKAN (BL15) in J-PARC
MLF. TAIKAN is equipped with a magnetic super-mirror
polarizer, composed of Fe/Si multilayer (4Qc) to polarize
neutron beams [7].
The top roof of the shield room has a slide hatch
covering over the sample stage. Through this slide
hatch, the DNP cryostat was introduced onto the sample stage. The DNP cryostat was originally designed for
SANS-J-II at JRR-3 and cannot fully cover the detectorsof TAIKAN, which has detectors for neutrons with widerscattering-angles (2θ > 15°).

Figure 3.	Schematic view of the experimental setup for DNP
in BL15.

Research and Development Highlights

The TEMPO doped rubber specimen was placed
into a chamber filled with liquid 4He. By evaporating theliquid 4He, the specimen was cooled down to 1.2 K during continuous irradiation of microwave (94 GHz). The
superconducting magnet generated a magnetic field
up to 3.5 Tesla at the sample position. The inhomogeneity of the magnetic field (∆B/B0) was designed to be lessthan 10−4. The neutron beam passed along the central
axis of the magnet coils. The windows through which
the neutron beam passed were formed by thin aluminium plates, which caused less background scattering.
The top roof of the shield room had two trenches
under the slide hatch. Through these trenches, pipes
and cables were pulled out. The pipes were necessary to evaporate liquid 4He. The cables were used forenergizing the superconducting magnet, monitoring
the signals from the liquid helium level meter and thepressure and temperature sensors, measuring the NMR
signals, and supplying voltage to the microwave generator. The mechanical booster pump unit and the twoelectronic racks were placed on the roof of the shieldroom. Consequently, we controlled remotely the magnetic field, sample temperature, NMR measurements
and microwave irradiation.
3. Contrast variation SANS results
Figure 4a shows the SANS results obtained for the
ternary mixture system (SBR/SP/CP). We employed thelimited wavelength range of 4 < λ < 7.6 Å, where theneutron polarization was high (PN > 97%). The q-dependence of the SANS profile varied as changing PH; thescattering maxima due to silica particles were observedfor PH = 0% and PH = −34%, whereas the scattering maxima disappeared for PH = +38%. As shown in Fig. 4b, thescattering length densities of silica and SBR match at PH= +30%. Around the matching point, the CB contribution was observed more obviously.
SANS for the ternary mixture is given by a sum of
three partial scattering functions (SSP-SP(q), SCP-CP(q) and
SSP-CP (q)), as follows
I(q; PH) = [ρSP − ρSBR(PH)]2 SSP-SP(q)+ [ρCP − ρSBR(PH)]2 SCP-CP(q)+ 2[ρSP − ρSBR(PH)] [ρCP − ρSBR(PH)] SSP-CP(q),(2)where the partial scattering functions are weighted bycontrast factors. In the above equation, ρSP, ρCP, and ρSBR
correspond to the neutron scattering-length density of
SP, CP and SBR phases: ρSP = 3.08 × 1010 cm−2, ρCP = 6.50
× 1010 cm−2, and ρSBR = (0.62 + 8.39 PH) × 1010 cm−2. Only
ρSBR depends on PH, because SBR contains hydrogen(Fig. 4b).
17

Research and Development Highlights

MLF Annual Report 2016

Figure 5 shows the separated partial scatteringfunctions calculated by applying singular value decomposition to the observed SANS profiles with various PH. The partial scattering function of silica, SSP-SP,
agreed well with the spherical form factor with the radius of 610 ± 40 Å. The same profile was observed forthe silica-filled SBR rubber sample (not shown here).
The partial scattering function of CB, SCP-CP, indicated a
power-law function of q−3.6, deviating from the Porodlaw (q−4). This originated from the surface structureof CB. The result agreed with the reports for CB-filledrubber specimens [8]. The decomposition into partial
scattering functions was successfully achieved. The
cross-correlation term between silica and CB, SSP-CP, wasalso determined. SSP-CP is negligibly small as compared
to SSP-SP and SCP-CP.

Figure 4.	(a) SANS profile for the SBR/SP/CP mixture at various PH. (b) Neutron scattering length density ofeach domains of the sample as a function of proton
spin polarization. The grey scale of the microscopic
view corresponds to the neutron scattering lengthdensity.

Figure 5.	Separated partial scattering functions for the
ternary mixture (SBR/SP/CP).

4. Conclusion
In this article, we report the first attempt of DNP
and contrast variation SANS experiments on the model
mixtures for industrial tire conducted at the MLF of the
J-PARC [9]. We performed TOF-SANS experiments using
neutrons with a wide λ-range, which caused imperfectneutron polarization and variations of coherent and incoherent scattering lengths. By carefully circumventing
the effect from the imperfect neutron polarization, thepartial scattering function separation was successfully
demonstrated for the ternary system (SBR/SP/CP).
Finally, the neutron scattering experiment at theMLF of the J-PARC was performed under the user program (Proposal No. 2016A0160). We appreciate the helpof the MLF instrument safety team and the sample environment team. This study was financially supported by aGrant-in-Aid for Young Scientist (A) (Grant No. 25706033)
of the Japan Society for the Promotion of Science.
References[1] V. F. Sears, Neutron News, 3(3), 26-37 (1992).
[2] T. Kumada, Y. Noda, T. Hashimoto and S. koizumi,
Phys. B, 404, 2637-2639 (2009).
[3] S. Koizumi, H. Iwase, J. Suzuki, T. Oku, R. Motokawa,
H. Sasao, H. Tanaka, D. Yamaguchi, H. M. Shimizu
and T. Hashimoto, J. Appl. Cryst. 40, s474-s479(2007).
[4] Y. Noda, T. Kumada, T. Hashimoto and S. Koizumi,
Phys. B, 404, 2572-2574 (2009).
[5] Y. Noda, T. Kumada, T. Hashimoto and S. Koizumi, J.
Appl. Cryst. 44, 503-513 (2011).
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S. Koizumi, T. Yuasa, T. Tominaga and T. Sone, Phys.
Procedia, 42, 52-57 (2013).
[7] T. Shinohara, J. Suzuki, T. Oku, S. Takata, H. Kira,
K. Suzuya, K. Aizawa, M. Arai, T. Otomo, and M.
Sugiyama, Phys. B. 404, 2640-2642 (2009).
[8] T. Koga, T. Hashimoto, M. Takenaka, K. Aizawa, N.
Amino, M. Nakamura, D. Yamaguchi, and S. Koizumi,
Macromolecules, 41, 453-464 (2008).
[9] Y. Noda, S. Koizumi, T. Masui, R. Mashita, H.
Kishimoto, D. Yamaguchi, T. Kumada, S. Takata, K.
Ohishi and J. Suzuki: J. Appl. Cryst., 49 2036-2045(2016).

Y. Noda1, S. Koizumi1, T. Masui2, R. Mashita2, H. Kishimoto2, D. Yamaguchi3, T. Kumada3, S. Takata4, K. Ohishi5, and J. Suzuki5
Institute of Quantum Beam Science, Ibaraki University; 2Sumitomo Rubber Industries Ltd; 3Material Science Research Center, Japan
Atomic Energy Agency; 4J-PARC Center, Japan Atomic Energy Agency; 5Neutron Science and Technology Center, Comprehensive Research
Organization for Science and Society (CROSS)

1

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MLF Annual Report 2016

Research and Development Highlights

A Contrast Variation Study of Nanogels by Small-Angle
Neutron Scattering

Incorporated
proteins or
drugs

Crosslinking
points[α] Pullulan
CH2

CH2OR

CH2OR
O

O
OR

O

OR
OR

R = H, D,

OR

O

OR

O
OR

2

0
0.2

0.4 0.00.6 0.20.8 0.41.0 0.6

ϕ (D2O)ϕ (D2O)

0.8

1.0

1.0

0.9

0.9

0.8
0.7
0

0.1

Scattering Intensity [a.u.]

4

Pullulan
Cholesterol
Water

0.8
0.7
0

0.1

Q [nm-1]

1

1

Q [nm-1]

Figure 2.	(a) Scattering length density of pullulan, cholesterol, and water as a function of the D2O volume
fraction in the water. The experimental conditions
are marked by black filled circles on the dotted line.
(b) Scattering intensities of CHP nanogels dispersedin solvents with a deuterium oxide (D2O) fraction,
ϕD2O = 1.0, 0.9, 0.8, 0.7, and 0.

ratio in the water. We determined the polymer network
structures and cross-linking points in the nanogels
individually.

I (Q) = Dρp2Spp(Q) + 2ΔρpΔρcScp(Q) + Δρc2Scc(Q)(1)Formationof nanogel
Proteins orhydrophobic drugs−2−2ρ [cm ]

6
Pullulan
Cholesterol
Water(b) ϕ (D2O) =1.0

2. Partial Scattering Functions and Contrast Variation
The CHP nanogel consists of pullulan, cholesterol,
and water. Therefore, the scattering intensities of the
CHP nanogel can be described using partial scatteringfunctions Sij(Q), as follows:

Hydrophilic
Polysaccharide [α]Hydrophobic
Group [β](b) ϕ (D2O) =Scattering Intensity [a.u.](a)ρ [cm ]

1. Introduction(a)Partially hydrophobic groups-bearing polysaccha6
rides spontaneously form stable nanogel of 20–30 nm
diameter in aqueous solution due to hydrophobic in4
teractions (Fig. 1) [1, 2]. Because the nanogel possesses
2
a high loading capacity for proteins and drugs mainly
through the hydrophobic interactions, they have been0
applied in drug delivery systems [3]. Although the nano0.0
scopic structure of the nanogels would be strongly related to their properties, no clear structural information
has been obtained so far due to their complex multicomponent structure. We investigated the structure of
the cholesterol (as a hydrophobic group) -bearing pullulan (as a polysaccharide) (CHP) nanogels by using asmeans of contrast variation small-angle neutron scattering (CV-SANS), which enables us to determine quantitative complex structure at nanometer scale.
CV-SANS is a powerful tool to investigate multicomponent structures with nanometer resolution [4].
Because the components (pullulan, cholesterol, andwater) in the CHP nanogel possess different scattering
length densities, as shown in Fig. 2(a), the scattering intensities are affected by the deuterium and hydrogenor X (Cholesterol)

O
OR

n

[β] Cholesterol (X)X = CONH (CH2)6NHCOO

Figure 1.	Schematic of a nanogel that is formed by self-associating partially hydrophobic modified polysaccharides.

Here, Dρi (with i = p and c for pullulan and cholesterol, respectively) is the difference in scattering lengthdensities between component i and Q is the momentum transfer defined as Q = 4p sin(q/2)/λ with scattering angle q and neutron wavelength λ. Spp(Q) and Scc(Q)are the self-terms, which represent the self-correlationsof pullulan and cholesterol, respectively. Scp(Q) is the
cross-term, which represents the cross-correlation between pullulan and cholesterol. The partial scatteringfunction possesses a volume dimension. In order to extract these three partial scattering functions, we tuned
the scattering length density of the solvents by mixing
deuterated and protonated water. The detailed procedure is described elsewhere [1, 4].
19

Research and Development Highlights

MLF Annual Report 2016

14.	Structures of the Polysaccharide Chains and the
Cross-Linking Points in the CHP Nanogel
Figure 3 shows the partial scattering functions ofpullulan, Spp(Q), choleterol, Scc(Q), and the pullulancholesterol cross-term, Scp(Q), which reflect the spatial
correlations of each component. At first, the partial
scattering function of pullulan, Spp(Q) was evaluated by
the sphere model with the Percus-Yevick (PY) structure
factor. This model can reproduce Spp(Q) shown by theblue solid curve in Fig. 3 with two tuning parameters,that is, the radius of the pullulan chain aggregate, Rp,
found to be 8.1 ± 0.3 nm and the standard distributionof Rp, sR, which is 1.1 ± 0.1 nm. The result indicates thatthe pullulan chains forms a CHP nanogel skeleton andthe nanogel particles can exist stably in water solution.
Next, we analyzed the partially scattering function ofcholesterol, Scc(Q), which reflects the distribution andthe individual volume of the cross-linking points in the
CHP nanogel. The spatial configuration of the crosslinking points was evaluated by the fractal dimension,
df and the upper-cutoff length, ξ. The red solid curve inSpullulan(Q)
Scholesterol(Q)Spullulan-cholesterol(Q)

0

10

4

3

Sii [*10 nm ]3. Scattering Intensity of the CHP Nanogel
The SANS experiments were performed using
TAIKAN [5] at J-PARC. For CV-SANS, we measured a series of CHP nanogel samples dispersed in water with adeuterium oxide (D2O) volume fraction, ϕD2O = 1.0, 0.9,
0.8, 0.7, and 0. Fig. 2(a) shows the variation of the scattering length density of pullulan, cholesterol, and water
as a function of ϕD2O, which was calculated on the basisof their chemical structures and mass densities. Fig. 2(b)shows the scattering intensities of the nanogels. The
scattering intensities vary with the D2O volume fraction in the water. This is characteristic of multicomponent systems because the contrast matching points for
pullulan and cholesterol against water are different asshown in Fig. 2 (a). The partial scattering function foreach component was extracted individually by the singular value decomposition [4], then the pullulan network structure and the cholesterol distribution in the
nanogels were evaluated.

10

−1

10

−2

10

−3

10

0.1

2

3

4

5 6

Q [nm−1]

2

Figure 3.	Partial scattering functions of pullulan, Spp(Q), cholesterol, Scc(Q), and pullulan-cholesterol cross-term,
Scp(Q).

Fig. 3 shows the fitting result for Scc(Q). From the analysis, a mean radius of the cross-linkers, Rc and fractal dimension, df of the cholesterol molecules were obtainedas Rc = 0.5 ± 0.1 nm and df = 2.6 ± 0.1 with x = 3.7 ±0.1 nm. Because the volume of the single cross-linking
point could also be evaluated by Rc, the aggregation
number of cholesterol molecules in a cross-linking
point was calculated to be 3.4. In conclusion, we foundthat the cross-linking points consisting of 3.4 cholesterol molecules dispersed inhomogeneously within the interior space of the nanogel, which may be represented
by a mass fractal distribution with a dimension of 2.6.
The unique internal space of the nanometer-scaled CHP
nanogel may contribute to the specific functions of the
nanogel, such as chaperone-like activity. The details aredescribed in paper [1].
References[1] Y. Sekine, et. al., J. Chem. Phys. B, 120, 11996-12002(2016).
[2] T. Nishikawa, K. Akiyoshi, J. Sunamoto, J. Am. Chem.
Soc., 118, 6110-6115 (1996).
[3] Y. Sasaki, K. Akiyoshi, Chem. Rec. 10. 366-376 (2010).
[4] H. Endo, Physica B, 385-386, 682-684 (2006).
[5] S. Takara, et. al., JPS Conf. Proc., 8. 036020 (2015).

Y. Sekine1 and H. Endo2
1
Materials Sciences Research Center, JAEA; 2Neutron Science Section, Materials and Life Science Division, J-PARC Center

20

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MLF Annual Report 2016

Research and Development Highlights

Neutron Brillouin Scattering of Liquid Methanol
1. Introduction
The structure and dynamics of liquids at molecularlevel reflect their macroscopic properties. In fact, sometransport properties of liquids were calculated fromtime-space correlation functions by the mode coupling
theory [1]. Molecular dynamics (MD) simulation is acommon tool to explain the physicochemical properties of liquids at molecular level. However, the outcomeof the simulation is very sensitive to the intermolecularpotentials used in the simulations, and the potential parameters are somewhat ambiguous. Therefore, the experimental investigation of liquid’s dynamics is highly
needed to verify the potential parameters. Particularity,
collective dynamics is important, since it contains structural information. Its comparison with the liquid’s static
structure would provide more detailed knowledge ofthe liquid.
We focus on the “fast sound” of liquids [2]. It has
been found that the dispersion relation obtained
through inelastic scattering experiments deviates positively from the line predicted by the adiabatic soundvelocity. The fast sound for liquid water was found by
MD, inelastic neutron (INS), and inelastic X-ray scattering (IXS) [2-4]. The velocity of the fast sound of liquidwater is about twice higher than the adiabatic sound’svelocity (positive dispersion ~100%) and similar to thatof ice. On the other hand, those for noble gas and other molecular liquids, such as carbon tetrachloride, aremuch lower (~30%) than that for water. Although theorigin of the high positive dispersion of water has been
discussed ever since it was ﬁrst discovered [2], its nature
is still not clear.
Methanol has been used as an appropriate reference to water in discussing the liquid structure. A
methanol molecule can be thought of as replacing one
hydrogen-bonding site of water with a methyl group.
Hence, methanol molecules possess a hydrogen-bonding chain-like structure, whereas water has a hydrogen-bonding three-dimensional network structure. A
comparison of collective dynamics of methanol withthat of water would clarify a relation between the static
structure formed via hydrogen bonding interactions
and the dynamics, which reﬂects these interactions.
So far, for collective dynamics measurements,
IXS has an advantage over INS because of the availability of high-ﬂux X-ray beams. However, a pulsed
neutron source, such as J-PARC, is desirable to observe the dynamics because observations over a wide

energy-momentum space are possible using a timeof-ﬂight spectrometer. Moreover, high-ﬂux neutron
beams are now available there. We measured the collective dynamics of D2O down to Q values of 0.2 Å−1 at
300 K with the High-Resolution Chopper Spectrometer(HRC) at J-PARC MLF [5, 6]. Data with higher incident
neutron energy, higher energy resolution, and lower
momentum transfer are obtained, compared withthose in Ref. [3].
In the present study [7], collective dynamics ofliquid deuterated methanol at room temperature wasmeasured with the HRC spectrometer at J-PARC/MLF.
The dispersion relation of liquid methanol was compared with that obtained using the IXS result to investigate collective dynamics of liquid methanol in moredetail.
2. Experimental
Deuterated methanol-d 4 (CD 3 OD) was purchased from Sigma Aldrich and used without further
puriﬁcation. An aluminum ﬂat container with inner dimensions of 40 × 40 × 10 mm3 was manufactured.
The sample container was installed into the vacuum chamber of the HRC spectrometer. Measurements
were performed at room temperature. The energy of
the incident neutron beam was Ei = 102 meV and theresolution was ΔE = 2.0 meV. The proton beam power of
the accelerator was 200 kW. The data were accumulated
for 2 days.
3. Results
Figure 1 shows the scattering intensity of methanol
at 298 K. The spectra showed shoulders due to symmetrical excitation peaks and a resolution-limited elastic
peak. The excitation peaks were fitted with a damped
harmonic oscillator scattering function convoluted
with resolution width multiplied by a temperature factor (Bose-Einstein factor). The peak positions E(Q) were
determined as a function of Q. The present analysis is
identical to that for D2O measured at HRC previously [5].
Figure 2 shows that the Q dependence of the excited peak positions E(Q) down to Q = 0.7 Å−1 was wellﬁtted to a straight line, equivalent to 1770 ± 30 m s−1.
The dispersion relation obtained from IXS is also depicted. This value is almost identical to that (1700 m s−1)
from IXS [8]. The adiabatic sound velocity of liquidmethanol is 1094 m s−1 [9]. Hence, the positive dispersion is ~60%. It is an intermediate value between those21

Research and Development Highlights

MLF Annual Report 2016

60

200
−1

Q = 0.6 Å

50500
Q = 1.8 Å−1−1

Q = 1.2 Å

400

30

S(Q, E)

S(Q, E)

S(Q, E)

40
100

20

200
100

10
0

300

−10

0
E / meV

10

0
−20

−10

0
10
E / meV200−30 −20 −10 0 10 20 30
E / meVFigure 1.	Dynamics structure factor of liquid methanol at room temperature. The solid lines indicate the fitting results by the DHO
model [7].

30methanol. This is because the scattering factor of thedeuterons is dominant in INS.
1770 ms−1

E / meV

20

10

0

0

1

Q / Å−1

2

Figure 2.	Dispersion relation of liquid deuterated methanol
at room temperature. Open symbols are the resultsby INS and closed ones are those by IXS. The dashedline corresponds to the adiabatic sound velocity ofliquid methanol [7].

of water and carbon tetrachloride [10]. It could be associated with the extent of hydrogen bonding. Moreover,in the Q range, above the ﬁrst peak in S(Q), at 1.7 Å−1,
the excitation energy of neutron increased more significantly than that of IXS. This was caused by anotherexcitation in the collective dynamics. Although it is
not yet to define the mode of the dynamics, it seems
to be internal vibration involving the methyl groups of

4. Future Plans
The present results indicate the importance ofcomplementary use of X-ray scattering to investigate
the collective dynamics of liquids. That collective dynamics could be measured through coherent scattering
performed with high-flux neutron beams, which would
provide more information about both the structure andthe dynamics.
References[1]	T. Yamaguchi, et al., J. Chem. Phys. 2016, 144,
124514.
[2]	A. Rahman, et al., Phys. Rev. A 1 (1974) 368.
[3]	J. Teixeira, et al., Phys. Rev. Lett. 54 (1985) 2681.
[4]	F. Sette, et al., Phys. Rev. Lett. 75 (1995) 850.
[5]	S. Itoh, et al., J. Phys. Conf. Ser. 502 (2014) 012043.
[6]	S. Itoh, et al., J. Phys. Soc. Jpn. 82 (2013) 043001.
[7]	K. Yoshida, et al., J. Mol. Liquids 222 (2016) 395–397.
[8]	K. Yoshida, et al., Chem. Phys. Lett. 440 (2006) 210.
[9]	A. Kumar, Acoust. Lett. 20 (1997) 203–212.
[10]	T. Kamiyama, et al., J. Phys. Soc. Jpn. 73 (2004)
1615–1618.

K. Yoshida1, T. Yamaguchi1, T. Yokoo2,3, and S. Itoh2,3Facluty of Science, Fukuoka University; 2Neutron Science Section, Materials and Life Science Division, J-PARC center; 3Institute of Materials
Structure Science, KEK
1

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Research and Development Highlights

Dynamics Changes of Human Hemoglobin Detected by
Quasielastic Neutron Scattering
1. Introduction
Hemoglobin (Hb) is a tetrameric hemoprotein thattransports O2 from lungs to tissues. Hb consists of two
a and two b subunits, each containing one heme groupto which O2 can bind reversibly. Binding of an O2 molecule to the heme of one subunit increases the O2 affinityof other subunits and thereby that of the whole molecule. This cooperative behavior (allosteric regulation)
makes efficient O2 transport by Hb possible. Allosteric
regulation is found in many proteins as a regulatory
mechanism of their functions, and thus elucidation of
the mechanism of allosteric regulation is important. Hb
has long served as a prototypical system for the studyof allosteric regulation, and its structures and function
have been extensively studied. The standard description, based on the structures of the fully-unliganded
tense (T) and fully-liganded relaxed (R) states, was thatHb switches between a low-affinity T conformation anda high-affinity R conformation upon ligand binding.
The recent identification of various intermediate
structures [1] and the finding that Hb in solution is in
a rapid equilibrium between the distinct structuralstates [2], however, cast doubts on this rather simple
picture of allosteric regulation. Furthermore, as it is evident from the structure of Hb, in which the heme groups
are buried deep inside the protein, conformational flexibility is required for the proper function of Hb. The information on the dynamics of Hb is thus important toelucidate the mechanism of allosteric regulation of Hb.
Compared to the wealth of structural data, muchless is known about their dynamics. While proteins
have a hierarchy of dynamics ranging from picosecond
thermal fluctuations of atoms within a protein, throughsubmillisecond diffusive motions of polypeptide chainsand domains, to conformational changes that occur
at millisecond or slower time scales [3], the dynamics at the picosecond time scale is known to work as
a lubricant for the slower motions, without which thestructural changes of the proteins do not occur [4].
Characterization of the dynamics at the picosecond
time scale is thus important as an elementary processof the hierarchy of protein dynamics.
Quasielastic neutron scattering (QENS) provides aunique tool to measure directly the dynamics at the picosecond time scale of proteins. We thus carried out the QENS
measurements on the T and R states of human hemoglobin

to extract the dynamics changes upon ligation [5].
2. Materials and methods
The solution samples of human adult Hb were prepared in D2O for the unliganded deoxy form (deoxyHb)
and the fully CO-liganded form (COHb), which correspond to the T and R states respectively, at concentrations of 100 mg/ml. The QENS experiments were carriedout using the near-backscattering spectrometer, BL02
(DNA), at MLF/J-PARC. The measurements were done atseveral temperatures between 280 K and 300 K, at energy resolution of 12 meV.
3. Results
Figure 1 shows examples of the QENS spectra ofdeoxyHb and COHb. The spectra, S(Q,w), can be fit withthe equation,
S(Q,w) = {A0(Q)δ(w) + (1 - A0(Q)) Llocal(Q,w)}⊗ Lglobal(Q,w) ⊗ RF(Q)+BG.(1)Here, Q is the momentum transfer, ℏw is the energy
transfer, A0(Q) is the elastic incoherent structure factor(EISF) that characterizes geometry of atomic motions,
Llocal(Q,w) and Lglobal(Q,w) are the Lorentzian functions
that characterize the local motions within the protein
and the global motions of the entire protein, respectively, and ⊗ denotes the convolution operation. By fitting the spectra with this phenomenological equation,
the global and local motions can be separated.
The Q-dependence of the width of Lglobal(Q,w) provides information on diffusive motions of the entire
molecules. Figure 2 shows the apparent diffusion coefficients (Dapp) of deoxyHB and COHb obtained from theanalysis of these widths. Significant differences are observed between deoxyHb and COHb. To investigate theorigin of these differences, Dapp was simulated from thetranslational and rotational diffusion coefficients calculated from the crystal structures. As shown in Fig. 2,
the simulated Dapp values of deoxyHb agree with theexperimental values, while those of COHb do not. This
indicates that while deoxyHb behaves like a rigid body,
COHb has additional internal motions. The test simulation of Dapp based on the translational diffusion coefficient of the entire COHb and the rotational diffusion of
the ab dimer in COHb shows agreement with the experimental values, suggesting that the additional motions
are the rotation of the ab dimers within the protein.
23

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MLF Annual Report 2016

Figure 1. Examples of quasielastic neutron scattering spectra, S(Q,ω). The spectra of (a) deoxyHb and (b) COHb at Q = 1.05 Å−1 andat 280 K, are shown along with the results of the fits using Eq. 1. In the upper panels, open squares denote the data, thicksolid lines in blue denote the total fits, solid lines in green and red denote Lglobal(Q,ω) and Llocal(Q,ω), respectively, thin solidlines in blue show the background, and dashed lines in black show the resolution functions. The lower panels show theresiduals of the fits.

Figure 2.	Summary of Dapp of deoxyHb (■) and COHb (■)
obtained from the QENS spectra and the simulated
values of deoxyHb (dashed line) and COHb (solidline in red) based on the crystal structures. The simulated values for COHb assuming the dimer rotations are also shown (solid line in blue). Errors bars
for the experimental data are within the symbols.

The Q-dependence of the width of Llocal(Q,w) provides information on the rates of the local atomic motions
within the protein. Figure 3 shows the Arrhenius plot of
the residence times of deoxyHb and COHb. Differencesin the residence time suggest that the frequency of thelocal motions is a little lower in deoxyHb than in COHb.
On the other hand, analysis of the EISF curves showedthat the amplitudes of the local motions are similar between deoxyHB and COHb (data not shown).
The QENS measurements on deoxyHb and COHb
thus show that the dynamics changes occur according

Figure 3.	The Arrhenius plot of the residence times of deoxyHb (■) and COHb (■), estimated according to thejump diffusion model.

to the changes in the ligation states. In particular, thesignificant motions at the quaternary structure level occur at the ligation, suggesting the important role of the
dynamics in allosteric regulation of the function of Hb.
References[1] N. Shibayama et al., J. Am. Chem. Soc. 136 (2014)
5097.
[2] J. A. Lukin et al., Proc. Natl. Acad. Sci. U. S .A. 100(2003) 517.
[3] K. Henzler-Wildman and D. Kern, Nature 450 (2007)
964.
[4] G. Zaccai, Science 288 (2000) 1604.
[5] S. Fujiwara et. al., J. Phys. Chem. B 121 (2017) 8069.

S. Fujiwara1, T. Chatake2, T. Matsuo1, F. Kono1, T. Tominaga3, K. Shibata4, A. Sato-Tomita5, and N. Shibayama5
Quantum Beam Science Research Directorate, QST; 2RRI, Kyoto Univ.; 3Neutron Science and Technology Center, CROSS; 4Neutron Science
Section, Materials and Life Science Division, J-PARC Center; 5Div. Biophysics., Dept. Physiology, Jichi Medical Univ.

1

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MLF Annual Report 2016

Research and Development Highlights

Magnetic Structure and Excitations in La5Mo4O16
1. Introduction
Magnetic insulators with 4d electrons have attracted research interest in condensed matter physics, since
they exhibit various magnetic phenomenaocausedby the intermediate scale of the spin-orbit interaction(SOI). La5Mo4O16 is a layered perovskite compound withlocalized 4d electrons, which shows fascinating bulk
magnetic properties, as described below.
La5Mo4O16 consists of corner-sharing Mo(1)O6 andMo(2)O6 octahedra forming a quasi-square checkerboard lattice. Mo(1) and Mo(2) sites have spins S = 1/2(4d1) and S = 1 (4d2). Mo(2)O6 is connected by nonmagnetic Mo2(3)O10 pillar, whichocreates a very weakinterlayer exchange coupling. La5Mo4O16 undergoes
antifferomagnetic phase below TN = 190 K. Recently,
La5Mo4O16 shows intriguing magnetic phenomena:
high-temperature magnetoresistance [1] and longtime magnetization decay [2]. To uncover their microscopic origin and the effect of the spin-orbit couplingin La5Mo4O16, we performed time-of-flight (TOF) elastic
and inelastic neutron scattering measurements using
iMATERIA, HRC, and 4SEASONS [3].
2. Experimental
Neutron powder diffraction (NPD) was performed
at T = 4, 40, and 220 K using iMATERIA. Inelastic neutron scattering (INS) measurements at HRC were performed using Ei = 102.4 meV with a Fermi chopper
rotating at a frequency of 400 Hz. INS measurements
were also performed using Ei = 15.3 meV with 250 Hz
at 4SEASONS. Both INS experiments were conducted
at 4 and 224 K.
3. Results and discussion
Figure 1(a) shows a NPD pattern at T = 4 K (< TN).
Below TN, magnetic Bragg peaks evolve at momentum transfers (Qs) of 1.138(2), 1.174(2), 1.400(6), and1.486(8) Å-1. The peak positions correspond to (-1, 1,
1/2), (1, 1, 1/2), (-1, 1, 3/2), and (1, 1, 3/2) in C2/m notation, and the magnetic propagation vector can be indexed by k = (0, 0, 1/2). The magnetic structure, whereMo(1) and Mo(2) show collinear antiferromagnetic coupling within the layers, the latter being also antifferomagnetically coupled along the c axis, as described inFig. 1(b), was indicated by the magnetic propagation
vector and single-crystal bulk measurements. As shownin Fig. 1(a), the observed NPD pattern was well fitted by
the magnetic structure with magnetic moments of μ1

Figure 1.	(a) NPD pattern in La5Mo4O16 at T = 4 K measured
by iMATERIA and the Rietveld refinement result [3].
The inset shows a magnified view. (b) Magnetic
structure of La5Mo4O16 with the magnetic propagation vector k = (0, 0, 1/2) [3]. Dashed lines represent
exchange interactions.

= 0.54(2)μB and μ2 = 1.07(3)μB where μ1 and μ2 were themagnetic moments of Mo(1) and Mo(2) sites. The ordered magnetic moments were about half of the spinonly values.
The INS intensity (I) map in La5Mo4O16 at T = 4 K as
a function of Q and energy transfer (ℏω) is shown in
Fig. 2(a). Broad-energy bands were observed around ℏω= 10 and 20 meV. The Q and T dependences of both excitations revealed that the excitations originate in spinwave excitations. To quantitatively understand the spinwave excitations, we calculated the linear spin wave
excitation assuming the magnetic structure shown in
Fig. 1(b) and found out that the spin Hamiltonian consisted of in-plane anisotropic exchange interactions,interlayer exchange interaction, and easy-axis singleion anisotropy. The calculated LSW intensity was fitted to the experimental spin wave excitations, and thespin Hamiltonian was determined. The calculated LSW
intensity, using the optimum parameters, is shown in
Fig. 2(b), which can explain the experiment well. The
estimated interlayer exchange interaction (J’) was very
weak compared to the nearest-neighbor exchange interaction (J’/J1 < 0.01).
25

Research and Development Highlights

MLF Annual Report 2016

dimensionality and J2 bond frustration [J’/J1 << 1 and J2> 0 in Fig. 1(b)] are the origin of the reduced magnetic
moments. The quantum fluctuation effect due to thespin S = 1/2 (and 1) may alsoecause reduced moments.
The small magnetic moments at Mo(1) and Mo(2) andthe large spin gap suggest that the SOI in La5Mo4O16 induces a strong easy-axis magnetic anisotropy insteadof the total momentum number J (= S + L). Therefore,
our results indicate that the SOI in La5Mo4O16 is similar
to that in 3d electron systems, rather than that in 5d and4f electron systems.

Figure 2.	(a) I(Q, ℏω) map in La5Mo4O16 at T = 4 K measured
by HRC with Ei = 102.4 meV [3]. (b) I(Q, ℏω) map at
4 K calculated by LSW theory [3]. (c) and (d) I(Q, ℏω)maps measured by 4SEASONS with Ei = 15.3 meV at
4 and 224 K [3].

To gain insight on the spin-orbit coupling in
La5Mo4O16, the INS maps using lower Ei (15.3 meV)are shown in Figs. 2(c) and 2(d) (below and above
TN). Above TN, a gapless quasielastic excitation centered around the magnetic zone centers (Q ~ 1.2 Å-1)
was observed [Fig. 2(d)]. On the other hand, althoughGoldstome modes of the spin wave excitations are expected to evolve in the vicinity of the magnetic zone
centers below TN, the I(Q, ℏω) map with better energy
resolution clearly shows the absence of the Goldstone
mode [Fig. 2(c)]. The observed spin gap at the magnetic
zone center is direct evidence of the strong magnetic
anisotropy due to the strong SOI in La5Mo4O16.
As reported above, the ordered magnetic moments at Mo(1) and Mo(2) are reduced to about half ofthe spin-only values. Since the valences of the Mo(1)and Mo(2) sites are about +5 and +4, respectively, at
all temperatures measured by our bond valence sum
method, anomalous charge disproportionation of the
Mo 4d electrons between Mo(1) and Mo(2) sites in thelong-range magnetic ordered state is ruled out. Instead,
our INS study suggests that fluctuations induced by low

4. Summary
The magnetic structure and spin dynamics in thelocalized 4d electron layered perovskite antiferromagnet La5Mo4O16 have been studied by TOF powder neutron measurements [3]. Our NPD refinement revealeda magnetic structure, where Mo(1) and Mo(2) are coupled antiferromagnetically within the layers and thelayers are also coupled antiferromagnetically along thec axis with reduced magnetic moments. The INS results
were analyzed using a model Hamiltonian, including
the easy-axis anisotropy and weak interlayer exchangeinteraction using the semiclassical LSW theory. The spin
gap at the magnetic zone center was explained by Ising
anisotropy due to the intermediate scale of the SOI.
The microscopic spin structure, strong easy-axis anisotropy, and very weak interlayer exchange interaction,compared with the intralayer exchange interactions
determined by our TOF elastic and inelastic neutron
scattering measurements, support the microscopic
models proposed for the high-temperature magnetoresistance and long-time magnetization decay in
La5Mo4O16.
References[1] K. Kobayashi and T. Katsufuji, Phys. Rev. B 83,
100411(R) (2011).
[2] T. Konishi, K. Kobayashi, and T. Katsufuji, Phys. Rev. B
92, 020419(R) (2015).
[3] K. Iida, R. Kajimoto, Y. Mizuno, K. Kamazawa, Y.
Inamura, A. Hoshikawa, Y. Yoshida, T. Matsukawa, T.
Ishigaki, Y. Kawamura, S. Ibuka, T. Yokoo, S. Itoh, and
T. Katsufuji, J. Phys. Soc. Jpn. 86, 064803 (2017).

K. Iida1, R. Kajimoto2, S. Itoh2,3, and T. Ishigaki4
1
Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS); 2Neutron Science Section,
Materials and Life Science Division, J-PARC center; 3Institute of Materials Structure Science, KEK; 4Frontier Research Center for Applied
Atomic Sciences, Ibaraki University

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Research and Development Highlights

Structure of the Magnetic Excitations in the Spin1/2 Triangular-Lattice Heisenberg Antiferromagnet
Ba3CoSb2O9
1. Introduction
A spin-1/2 triangular-lattice Heisenberg antiferromagnet (TLHAF) with a spatially isotropic lattice isa prototypical frustrated quantum magnet, which exhibits remarkable quantum effects that arise from thesynergy between spin frustration and quantum fluctuation. In 1973, Anderson proposed a resonating-valence-bond (RVB) state without a long-range magnetic
ordering as the ground state of the spin-1/2 TLHAFs [1].
A prolonged theoretical debate, which started fromthe RVB theory, reached a consensus that the groundstate is an ordered state of the 120° spin structurewith an extremely small sublattice magnetization [2].
Nevertheless, a remarkable quantum effect emerges
in magnetic fields. An up-up-down spin state is stabilized in a finite magnetic field range by the quantum
fluctuation, which gives the magnetization curve a plateau at one-third of the saturation magnetization [3].
The 1/3-magnetization-plateau was quantitatively
verified by high-field magnetization measurements
on Ba3CoSb2O9 [4], which demonstrates that this compound closely approximates the spin-1/2 TLHAF.
Although the ground state properties of a spin1/2 TLHAF with a uniform triangular lattice are wellunderstood both theoretically and experimentally,
the magnetic excitations are less well understood. The
theoretical consensus is limited only to single-magnon
excitations [5, 6]. There is no theoretical consensus forthe excitation continuum. According to the theory, thedispersion relation of low-energy excitations near the
K point is described by linear spin wave theory (LSWT).
However, in a large area of the Brillouin zone, the excitation energy is substantially renormalized downward,
which leads to the flat dispersion curve. Recently, themagnetic excitations in Ba3CoSb2O9 were investigatedby inelastic neutron scattering [7]. However, the energy
range was limited below 3 meV and the excitation spectrum appeared to be indistinct, although flat dispersion
was observed.
In this study [8], we investigated magnetic excitations of Ba3CoSb2O9 by inelastic neutron scattering. We
observed well-defined excitation spectra, which provide the whole picture of magnetic excitations in a spin1/2 TLHAF. From the previous high-field magnetizationand ESR measurements on Ba3CoSb2O9, the predominant intralayer exchange interaction and its anisotropy
were obtained as J = 1.67 meV and ΔJ/J = 0.046 [4].
2. Experiment
Ba3CoSb2O9 single crystal of 10 × 8 × 4 mm3 size
was grown from the melt, using a Pt crucible. The mosaicity of the crystal was found to be 0.5°. The magnetic excitations in a wide momentum-energy range
were measured using the cold-neutron disk chopper
spectrometer AMATERAS [9] installed in the MLF at
J-PARC. The sample was mounted in a cryostat withits (1,1,0) and (0,0,1) directions in the horizontal plane.
The sample was cooled to 1.0 K using a 3He refrigerator.
Scattering data were collected by rotating the sample
around the (-1,1,0) direction. All the data were analyzed
using the software suite Utsusemi [10].
3. Results and discussion
Figures 1(a)-(d) show energy-momentum maps ofthe scattering intensity along two high-symmetry directions parallel to Q = (H, H) and (-K, K) measured at
1.0 K (< TN = 3.8 K) with incident neutron energies of Ei= 3.14 and 7.74 meV. At 10 K, excitation spectra shownin Fig. 1 are considerably smeared and the intensities
decrease. This result verified their magnetic origin. The
scattering intensities in Fig. 1 were integrated over L to
obtain the statistics, assuming good two-dimensionality (2D), which was confirmed from the dispersion relation along the c* direction. The low-energy excitations
for Q = (1/3, 1/3, L) are dispersive, while those for Q =(1/2, 1/2, L) are almost dispersionless. This indicates thatthe interlayer exchange interaction is small and does
not affect the excitations above 1 meV. The low-energy
excitations near the K point can be described by LSWT,
as shown in Fig. 1a. Thus, by applying LSWT to the dispersion curves of the single-magnon excitations for Q =(1/3, 1/3, L), we evaluated the interlayer exchange interaction as J’ = 0.080 meV, which is less than 5% of J. Thus,
we can deduce that all the excitations, except the lowenergy excitations near the K point, can be attributed to
the 2D spin-1/2 TLHAF.
The most noteworthy feature of the excitation
spectrum is its three-stage energy structure. The lowest
27

Research and Development Highlights

MLF Annual Report 2016stage is composed of two distinct branches of singlemagnon excitations, which rise from the K point. The
middle and highest stages are dispersive continua.
This structure of magnetic excitations is significantly
different from the theoretical results. The solid lines in
Figs. 1(a) and (c) are dispersion curves calculated by
LSWT with J = 1.67 meV and ΔJ/J = 0.046 based on the
2D model. Near the K point, the lower bound of thespectrum, which closely approximates the spectrum atthe 2D limit, coincides with the LSWT result. However,3

the further the wave vector moves away from the K
point, the more rapidly the excitation energy deviates
downwards from the LSWT dispersion. This result isqualitatively consistent with the theory [5, 6]. Both single-magnon branches show distinct rotonlike minima
at the M point, although the theory predicts that only
the lowest branch shows a minimum [6]. The rotonlike
minimum is interpreted in terms of pairs of spin-1/2
fractionalized excitations, spinons, characteristic of the
RVB state [6].

7Ei = 3.14 meV

(a)
(meV)

(meV)

4

6

3

6

4

2

4

1

2

2

0
-0.2

(b)

5

2

1

Ei = 7.74 meV

6

0

0.0

0.2

0.4

0.6

0.8

0

0

1.0

0.0

(H, H)
36

7

Ei = 3.14 meV

6

(c)

2

(meV)

(meV)

1.0

1.5

(H, H)

4

2

0.5

0

6

Ei = 7.74 meV

4

(d)

5

2

4

0

3
1

2
1

0
-0.3

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

(0.5−K, 0.5+K)(− K, K)

-0.4

-0.2

0.0

0.2

0.4

0.6

(0.5−K, 0.5+K)

(e)
K

Γ
(0, 0)
K

28

0(0, 1)
M
K
K
M
M(1, 0)(1, 1)(H, H)

Figure 1. (a)-(d) Energy-momentum maps of the scattering
intensity along two high-symmetry directions parallel to Q = (H, H) and (-K, K) measured at 1.0 K withincident neutron energies of Ei = 3.14 and 7.74 meV,where the scattering intensities were integrated
over L. The solid lines in (a) and (c) are dispersion
curves calculated by LSWT with J = 1.67 meV and
ΔJ/J = 0.046 based on the 2D model. (e) 2D reciprocal lattice in Ba3CoSb2O9.

MLF Annual Report 2016

1st

2nd

3rd stage

4
3
2
1
0

1

2

3

0.8
0.6

4
3
2

Ei = 3.14 meV
Q = (0.5, 0.5)

1
0
0.0

0.5

0.4

1.0
1.5
(meV)

2.0

Ei = 15.16 meV
Q = (0.5, 0.5)

0.2
Background

Background0

Intensity (arb. units)

Intensity (arb. units)

5(b) 1.0

Ei = 7.74 meV
Q = (0.5, 0.5)

Intensity (arb. units)(a) 6

Research and Development Highlights

4
(meV)

5

6

7

0.0

4

6

8
(meV)

10

12

Figure 2.	Scattering intensity at M point for Q = (1/2, 1/2) as a function of energy measured at 1.0 K (a) with Ei = 7.74 and (b)15.16 meV. The horizontal blue lines in (a) and (b) are background level, which was estimated from the scattering intensity
between 0.12 and 0.5 meV measured with Ei = 3.14 meV as shown in the inset of (b).

A significant feature of the magnetic excitations is
the two strong dispersive continua that form the middle
and third stages of the excitation spectrum. The highest
third stage is accompanied by a columnar continuum
extending to at least 6 meV. Figures 2(a) and (b) show
the energy dependence of the excitation spectrum at
the M point for Q = (1/2, 1/2) measured with Ei = 7.74
and 15.16 meV, respectively, where the scattering intensity was integrated over L. The horizontal bars in Fig. 2(a)are the energy resolution. The inset of Fig. 2(b) showsthe energy dependence of the excitation spectrum for
Q = (1/2, 1/2) measured with Ei = 3.14 meV. The horizontal blue lines in Figs. 2(a) and (b) are background level,
which was estimated from the scattering intensity between 0.12 and 0.5 meV measured with Ei = 3.14 meV.
A three-stage energy structure composed of two single-magnon excitations and two excitation continua isclearly observed. The third stage has a long energy tailof excitation continuum. The energy tail continues toover 10 meV, which is six times larger than the exchangeinteraction J. Because the highest energy of single-magnon excitation is approximately equal to J =1.67 meV,as shown in Figs. 1(a) and (c), the observed excitation
continuum cannot be explained in terms of conventional two-magnon excitations [5]. Recently, magnetic
excitations in a spin-1/2 TLHAF were discussed fromthe standpoint of spinon, using mean field Schwinger

boson approach [6]. However, it is difficult to describe
the observed high-energy excitation continuum interms of a two-spinon continuum, because the highest
upper bound of the continuum is approximately 2J at
most. At present, no theory describes the structure of
the excitation continua observed in this experiment,
and thus, a new theoretical framework is required.
References[1] P. W. Anderson, Mater. Res. Bull. 8, 153 (1973).
[2] B. Bernu et al., Phys. Rev. B 50, 10048 (1994), S. R.
White and A. L. Chernyshev, Phys. Rev. Lett. 99,
127004 (2007), and references therein.
[3] D. J. J. Farnell et al., J. Phys.: Condens. Matter 21,
406002 (2009), T. Sakai and H. Nakano, Phys. Rev. B
83, 100405 (2011), and references therein.
[4] Y. Shirata et al., Phys. Rev. Lett. 108, 057205 (2012),
T. Susuki et al., Phys. Rev. Lett. 110, 267201 (2013).
[5] M. Mourigal et al., Phys. Rev. B 88, 094407 (2013),
and references therein.
[6] E. A. Ghioldi et al., Phys. Rev. B 91, 134423 (2015),
and references therein.
[7] H. D. Zhou et al., Phys. Rev. Lett. 109, 267206 (2012),
J. Ma et al., Phys. Rev. Lett. 116, 087201 (2016).
[8] S. Ito et al., Nat. Commun. 8, 235 (2017).
[9] K. Nakajima et al., J. Phys. Soc. Jpn. 80, SB028 (2013).
[10] Y. Inamura et al., J. Phys. Soc. Jpn. 82, SA031 (2013).

S. Ito1, N. Kurita1, H. Tanaka1, S. Ohira-Kawamura2, K. Nakajima2, S. Itoh3, K. Kuwahara4, and K. Kakurai5
Department of Physics, Tokyo Institute of Technology; 2Materials and Life Science division, J-PARC Center; 3Neutron Science Division,
Institute of Materials Structure Science, KEK; 4Institute of Quantum Beam Science, Ibaragi University; 5Science Coordination Section,
CROSS-Tokai

129

Research and Development Highlights

MLF Annual Report 2016

Rotational Modes and Phonons of CH3NH3PbI3
1. Introduction
Over the last few years, the inorganic-organic hybrid perovskite solar cells have taken the worldwide
research community by storm [1]. These hybrid compounds exhibit physical properties distinct from thosein conventional semiconductors. Their hot-phonon bottleneck effect of energetic carriers is obviously stronger than that of GaAs and other inorganic perovskites,
which has been attributed to the acoustic-opticalphonon up-conversion [2, 3]. The mobility of charge
carriers is relatively smaller compared with classicalsemiconductors and the scattering mechanism is still
under debate [4, 5]. Resembling the charge transport,
the thermal transport is unusual as well. The thermal
conductivity is surprisingly low, about 0.5 Wm-1K-1 forsingle crystals at room temperature [6], which is tenfold
lower than that of GaAs [7]. It is evident that atomic
dynamics underlies these peculiarities. However, theatomic-level description of CH3NH3PbI3 is complicatedby its hybrid nature, where both molecular jumping rotations and phonon excitations have to be taken into
account. Moreover, these two components also interact
via hydrogen bonds between H and I [8]. Here, we present the complete atomic pictures established using thehigh-resolution quasi-elastic neutron scattering (QENS)
and inelastic neutron scattering (INS) on a large single
crystal [9].
2. Experiments
The high-resolution QENS and INS measurements
were performed at the inverse-geometry time-of-flightchopper spectrometer BL02 DNA with Ei = 2.084 meV
and at the direct-geometry time-of-flight chopper spectrometer BL14 AMATERAS with Ei of 54, 16, 7 and 4 meVof J-PARC in Japan. The crystal was aligned at room

temperature at DNA. It took 12 hours to cool down to
140 K from room temperature at which it crystallizes inthe tetragonal structure. The four-dimension S(q,E) data
were reduced and visualized by using Utsusemi suite,–along [hh0], [00l] and [kk 0] based on a tetragonal unit
cell (a = 8.80625 Å, c = 12.712 Å).
3. Results and discussion• Jumping rotational modes of [CH3NH3]+
CH3NH3PbI3 crystallizes in the common perovskite
structure, where the organic cation [CH3NH3]+ occupies the center of the PbI6 octahedral cage, as shown in
Fig. 1a. It undergoes successive phase transitions, from–cubic (Pm3m) to tetragonal (I4/mcm) at 330 K, and thento orthorhombic (Pnma) at 165 K. While it is believedthat this transition is coupled with the orientation of[CH3NH3]+, the current reports on rotational dynamics
are contradictory [10, 11], probably owing to the lack ofresults on single crystals. Here, the accurate jumping rotational dynamics of molecules is obtained by performing ultrahigh energy resolution QENS measurementson the large single crystal at the backscattering neutron spectrometer, DNA, as summarized in Fig. 1b. At
about 80 K, the C3 rotational mode is activated, where
the protons of CH3 and NH3 groups are subjected to a
120° jumping rotation with respect to the C-N axis. As
temperature increases up to about 165 K, the whole
molecule undergoes a C4 rotation with respect to thefourfold axis of the tetragonal unit cell. At 180 K, theirrelaxation times are 0.71(3) and 64(2) ps, respectively.
• Optical phonons
The longitudinal optical phonons are shown in the
dynamic structure factor S(q,E) at 5 K in the direction of[00l] (Fig. 2a-c). With Ei of 54 meV, the full view of S(q,E)
is provided, indicating six prominent modes located at

Figure 1. a. Crystal structure of CH3NH3PbI3. b. The molecular rotational modes (taken from Ref [9]).

30MLF Annual Report 2016

11.3, 15.3, 18.3, 22.6, 26.0, and 37.6 meV, respectively.
With smaller Ei, more details are revealed. We found thepeak at 11.3 meV to be actually a superposition of threepeaks at 10.6, 11.5, and 12.6 meV (Figs. 2b). It seems
that a gap appears between 6 and 10 meV, but several
weaker modes can be roughly identified. The data with
Ei of 7 meV (Figs. 2c) suggest four low-energy modes at
2.28, 3.11, 3.79 and 4.35 meV. Thanks to the high-resolution, we were able to identify several modes that wereoverlooked in the previous Raman scattering [12] andINS measurements [13].
• Acoustic phonons
The detailed acoustic phonons of the Brillouinzone (220) were examined with Ei of 4 meV. Shown in
Fig. 3a-d are the longitudinal and transverse phonons at
5 and 180 K, respectively. Even though the backgroundResearch and Development Highlights

level is high, the dispersions can be seen in both directions. At 5 K, the dispersion curve of longitudinal acoustic (LA) phonon emanates from zone center of (220),
undergoes a steep increase and finally approaches the
top in the middle of zone centers and zone boundary (h~ 0.2), where it overlaps with longitudinal optical (LO)phonons. The dispersion of transverse acoustic (TA)phonon exhibits a moderate slope. Intense transverse
optical (TO) phonons are also present. At 180 K, theintensity of phonons is fairly enhanced, and we determined the accurate dispersions of LA and TA phonons
by fitting the momentum-transfer (filled circle) or energy-transfer (filled square) averaged spectra. The solidlines represent the slopes of dispersion curves near thezone centers, which determine the group velocities: νLA= 2841 m s-1 and νTA = 1155 m s-1.

Figure 2. Longitudinal optical phonons at 5 K measured with different Ei, 54 meV (a), 16 meV (b) and 7 meV (c) (taken from Ref [9]).

Figure 3. Phonon broadening at the orthorhombic-to-tetragonal phase transition (taken from Ref [9]).

31Research and Development Highlights

MLF Annual Report 2016

• Polar rotor scattering
The most striking features of the temperature dependence of the atomic dynamics is that the LO andTO phonons completely vanish, whereas the acoustic
phonons are robust, as the orthorhombic-tetragonalphase transition takes place. At 150 K, the lifetimesof TO phonons at 10.7 and 12.6 meV are 0.91(15) and0.62(7) ps while those of LO phonons are 0.82(5) and0.57(2) ps, respectively. At 180 K, just above the phasetransition, both TO and LO phonons are too broadened
to be distinguished. This means the actual lifetimes at
180 K are much shorter than those at 150 K. Such an
intriguing behavior might originate from the selective
scattering of the polar rotor [CH3NH3]+ activated in thetetragonal phase. Just for this reason, the thermal transport is dominated by acoustic phonons rather than optical phonons due to their extremely short lifetimes.
Similarly, the polar rotor scattering also plays an important role in the charge transport.
4. Conclusion and perspective
We determined precisely the jumping rotational dynamics of molecules and phonons in hybrid
perovskite CH3NH3PbI3 by conducting high-resolution
QENS and INS measurements. The characteristic timescales of various dynamics were completely revealed.
The dipole order of organic cations plays a decisive rolein determining the physical properties, such as carrier
mobility and thermal conduction, distinguishing it fromthe inorganic perovskites. Such observations could
probably apply generally to all hybrid compounds withpolar molecules. These fundamental insights are beneficial for the further study of the perovskite solar cells.
Especially, the short-lived optical phonons may be important for the large polaron formation in this system.
References[1] T. M. Brenner et al., Nat. Rev. Mater. 1, 15007 (2016).
[2] M. Price et al., Nat. Commun. 6, 8420 (2015).
[3] Y. Yang et al., Nat. Photon. 10, 53 (2016).
[4] A. D. Wright et al., Nat. Commun. 7, 11755 (2016).
[5] A. Filippetti et al., Phys. Chem. Chem. Phys. 18, 15352(2016).
[6] A. Pisoni et al., J. Phys. Chem. Lett. 5, 248 (2014).
[7] J. Blakemore, J. Appl. Phys. 53, R123 (1982).
[8] Y. Ren et al., Cryst. Growth Des. 16, 2945 (2016).
[9] B. Li et al., Nat. Commun. 8, 16086 (2017).
[10] A. M. A. Leguy et al., Nat. Commun. 6, 7124 (2015).
[11] T. Chen et al., Phys. Chem. Chem. Phys. 17, 31278(2015).
[12] A. M. A. Leguy et al., Phys. Chem. Chem. Phys. 18,27051 (2016).
[13] K. Drużbicki et al., J. Phys. Chem. Lett. 7, 4701 (2016).

Bing Li1, Yukinobu Kawakita1, Yucheng Liu2, Masato Matsuura3, Kaoru Shibata1, Seiko Ohira-Kawamura1, Takeshi Yamada3,
Kenji Nakajima1, and Shengzhong (Frank) Liu2,41
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2School of Materials Science and Engineering, Shaanxi
Normal University, China; 3Neutron R&D Division CROSS-Tokai; 4Dalian Institute of Chemical Physics, Chinese Academy of Sciences, China

32

MLF Annual Report 2016

Research and Development Highlights

Development of the Spin-Wave-Like Dispersive
Excitations below the Pseudogap Temperature in theHigh-Temperature Superconductor La2−xSrxCuO4
1. Introduction
The origin of the pseudogap, a partial gap opening in the spin or charge channel, has been the focus ofdebate in the recent study of high-Tc superconducting
cuprates [1]. Although inelastic neutron scattering (INS)studies have clarified the intimate correlations between
the pseudogap and low-energy spin fluctuations, thenature of the magnetic spectrum in the pseudogap
state remains to be understood, which requires themeasurement of magnetic excitations in a wide energy
range. For the magnetic excitations at base temperature (~5 K), systematic INS studies have clarified thatcarrier doping changes spin-wave excitations into thewell-known hourglass-shaped dispersion in the superconducting state [2]. On the other hand, there has beenno INS report using Fermi-chopper type spectrometerat high temperatures above room temperature forhigh-Tc cuprates. In order to elucidate the effect of thepseudogap on magnetic excitations, we performed systematic high-energy inelastic neutron scattering measurements using the chopper spectrometer 4SEASONS
from the superconducting state (T = 5 K) to high temperatures (T = 500 K) well above the pseudogap temperature (~360 K) on underdoped high-Tc cuprate
La2-xSrxCuO4 (LSCO) with x = 0.075 (Tc = 24 K) [3]. In addition, we measured the magnetic excitations in theparent compound La2CuO4 in the similar temperature
range as a reference to understand the thermal effects
on magnetic excitations at such high temperatures.
2. Experimental details
Single crystals were grown using the traveling solvent floating zone method. Tc for x = 0.075, defined as
the midpoint of the transition, was determined to be
24 K from the shielding signal. We estimated the pseudogap temperature T * for x = 0.075 to be 360 ± 20 K
from the universal doping dependence of the pseudogap energy [4] and the scaling factor between thepseudogap energy and T * [5]. Eight (with total mass of75 g) and four (33 g) single-crystal rods were co-aligned
for the underdoped LSCO (x = 0.075) and the parent
compound, respectively. The INS data using the Fermi
chopper spectrometer 4SEASONS were measured at T
= 5, 300, 400, and 500 K for the underdoped LSCO (x =Figure 1.	A schematic phase diagram of high-Tc cuprate
LSCO. Measured temperatures and compositions
are plotted as open circles in the diagram. AF and
SC denote antiferromagnetic ordered phase andsuperconducting phase, respectively. Tc (TN) aretransition temperatures of the SC (AF) phase. The
broken line shows the onset temperature of thepseudogap state (T *). (from Ref. [3])0.075) and T = 5 and 400 K for the parent compound, as
shown in the schematic phase diagram of LSCO (Fig. 1).
3. Results and discussion
Figures 2 (a) and (b) show contour maps of χ”(q,ω)
for the parent compound La2CuO4 measured at T = 5 K(< TN) and 400 K (> TN). At T = 5 K, we confirmed the wellknown spin-wave signal. At T = 400 K, we still observed
spin-wave signal due to the robust two-dimensional
antiferromagnetic spin correlations. The thermal effect on spin-wave excitation is a slight softening: theestimated exchange constant J decreases from 136 ±1 meV (T = 5 K) to 126 ± 1 meV (T = 400 K). In contrast,
the overall spectrum is strongly affected by heating for
the underdoped LSCO. First, the downward branch of
the hourglass-shaped dispersion below 35 meV merges at 300 K. Then, the upward branch of the hourglass
above 35 meV merges into a broad response above T= 400 K. Above the pseudogap temperature, magnetic
signal is accumulated at the magnetic zone center ina whole measured energy range (< 200 meV). A similar broad ridge feature at the magnetic zone center has
33Research and Development Highlights

MLF Annual Report 2016

Figure 2.	Contour maps of χ"(q,ω) for (a), (b) La2CuO4 and (c)–(f ) underdoped LSCO (x = 0.075), plotted in the energy momentum
space. The inset in (c) shows the enlarged plot around the neck of the hourglass on a double intensity scale. (from Ref. [3])been observed for itinerant antiferromagnets, such as
Cr [6] and Vanadium Oxide [7], suggesting itinerant nature of spin excitations for T > T *. In other words, theeffect of pseudogap on the magnetic excitation is therecovery of the localized spin nature at the high-energy
region. Thus, the current results support that the pseudogap is associated with the antiferromagnetic Mott
insulator rather than a precursor of the Cooper pairs [8].
4. Summary
We have shown that the hourglass-shaped magnetic dispersion for the underdoped LSCO (x = 0.075) issignificantly modulated into a broad ridge at temperatures well above T *. This thermal variation of the upward

branch in the hourglass-shaped dispersion contrasts
with the almost unchanged spin-wave dispersion in theparent compound in the same temperature range.
References[1] B. Keimer et al., Nature 518, 179 (2015).
[2] M. Fujita et al., J. Phys. Soc. Jpn. 81, 011007 (2012).
[3] M. Matsuura et al., Phys. Rev. B 95, 024504 (2017).
[4] S. Hüfner et al., Rep. Prog. Phys. 71 062501 (2008).
[5] T. Yoshida et al., Phys. Rev. Lett. 103, 037004 (2009).
[6] T. Fukuda et al., J. Phys. Soc. Jpn. 65, 1418 (1996).
[7] W. Bao et al., Phys. Rev. Lett. 78, 507 (1997).
[8] S. Badoux et al., Nature 531, 210 (2016).

M. Matsuura1, S. Kawamura2, M. Fujita2, R. Kajimoto3, and K. Yamada4
Neutron Science and Technology Center, CROSS; 2Institute for Materials Research, Tohoku University; 3Neutron Science Section, Materials
and Life Science Division, J-PARC Center; 4Institute of Materials Structure Science, KEK
134

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Research and Development Highlights

Spin-Orbital Correlated Dynamics in the Spinel-Type
Vanadium Oxide MnV2O4
1. Introduction
In the condensed matter physics, the physical phenomena can be described by the creation, annihilation,and motion of quasi-particles such as phonons andmagnons. Recently, the dynamical coupling of two or
more degrees of freedom, such as an electromagnon [1,2], has been extensively studied. In the present study,
we focus on the dynamical coupling between spin andorbital degrees of freedom as an example of such a coupled quasi-particle. A magnon is a particle that quantizes the fluctuation from the magnetic ordered state,
and transports the change in spin-angular momentum
ΔS via magnetic exchange interaction. The orbiton is a
dynamic modulation of the shape of electronic clouds
in the analogy of a magnon [3]. The change in orbital
angular momentum ΔL propagates via transfer integral
term between neighboring transition metal ions. So
far, the strong coupling between the orbital and lattice
degrees of freedom hinders the observation of spinorbital coupled waves. In addition, the momentum

dependence of the orbital excitations has not been wellinvestigated, since visible-light inelastic scattering wasused in most of the previous reports.
We chose spinel-type vanadium oxide MnV2O4 forobserving such spin-orbital coupled waves [Fig. 1(a)].
Mn2+ with a high-spin configuration (S = 5/2) on a tetrahedral site has no orbital degeneracy. The d orbitalsof the V-site ion, coordinated by an oxygen octahedron,are split into lower-lying t2g orbitals and higher-lying eg
orbitals. During cooling, a phase transition takes place
into a collinear ferromagnetic order at TC = 58 K. Below
TOO = 53 K, the magnetic structure changes into a noncoplanar ferrimagnetic order [Fig. 1(b)]. Simultaneously,a structural phase transition takes place from cubic totetragonal, accompanied by the V3+-site orbital order,in which |yz> and |zx> orbitals are alternately arranged
along the c-axis [Fig. 1(c)]. In this study, we investigatedthe magnetic dynamics in MnV2O4 by inelastic neutron scattering (INS) for observing spin-orbital coupledwaves.

(a) Spinel-type Structure(b) Mangetic Structure T < TOO (= 53 K)(C) Orbital Structure at V-site T < TOO (= 53 K)

Figure 1.	(a) Crystal structure of spinel-type oxide MnV2O4. Each A-site ion is surrounded by an oxygen tetrahedron. Each B-site ion
is coordinated by an oxygen octahedron. The V3+ ion has orbital degeneracy in the t2g orbital. (b) Magnetic structure in thetetragonal phase (c<a) below TOO = 53 K. The spin moment of the Mn2+ ion is parallel to the c-axis and that of V3+ ion is in
the opposite direction with a canted angle of 60° from the –c axis. (c) Proposed A-type antiferroic (AF) orbital structure at
V-sites below TOO = 53 K. (Taken from Ref. [4])35Research and Development Highlights

MLF Annual Report 2016

2. Experimental details
Single crystals were grown by the floating-zone
method. They were characterized by powder x-ray diffraction and magnetization measurements. Four crystal
bars, with a total mass of 10 g, were co-aligned usingbackscattering Laue photographs. The INS was carriedout using the 4SEASONS spectrometer at MLF, J-PARC.
The incident energies of neutrons were selected as 73,
34, 19, and 12 meV by a Fermi chopper. The temperature was maintained at 5.6 K.
3. INS results and spin-wave analysis
Figures 2 (a)-(c) show the experimental results of
the INS at Ei = 34 meV and T = 5.6 K along three highsymmetry axes (a) [hhh]c, (b) [hh0]c, and (c) [h00]c. The
corresponding calculations are shown in Figs. 2 (d)-(f ).
Our experimental results are summarized as follows.
First, we observed dispersive inelastic scattering intensity from 10 meV to 17 meV along [hh0]c, which was notobserved in the previous study [5]. Second, in Figs. 2(b)and (c), we can see a dispersive mode with large scattering intensity around 22 meV at both (2,2,0) and (4,0,0).
The dispersive character of this scattering was clarified
in the present study.
In order to identify spin-wave modes, we have

performed spin-wave calculations based on the
Heisenberg-type spin Hamiltonian with magnetic anisotropy. The magnetic scattering below 17 meV was
sufficiently well reproduced by our spin-wave calculation. 22 meV-scattering, however, cannot be explained
within our model. Therefore, 22 meV-scattering is not
explained by simple spin-wave picture.
4. Possible origin of the 22 meV- scattering
This 22 meV-scattering was observed in Raman
scattering [6], but it should not be attributed to twomagnon scattering. Here, we propose that the relativistic spin-orbit interaction ξ l · s (SOI) at the V-sites
affects the energy levels of the magnetic excited stateat Γ point within the first-order perturbation. For example, let us consider the SOI effect on the calculated spin-wave mode with the largest spin-fluctuation
along c-axis ΔSz. Then, this spin-wave mode shouldhave a better chance to couple with the orbital excitation through the spin-orbit term ξ lz sz. In terms of orbital, lz term leads to the transition between |yz> and|zx> orbitals. Interestingly, this spin-orbital correlated
excitation might propagate as collective modes. Let
us consider the excitation along the [-101]c direction[Fig. 2(l)-(n)]. In the ground state, the projection of spin

Figure 2.	Experimental inelastic intensity contour and the corresponding calculated intensity contour along (a)(d) [hhh]c, (b)(e) [hh0]cand (c)(f ) [h00]c directions at T = 5.6 K. The purple filled and black open circles are the calculated spin wave dispersions
along [h0h] and [hh0] directions in (b) and along [00l] and [h00] directions in (c), respectively. (g)-(k): Inelastic intensity
contour in the [h00]-[0k0] plane around [400]. (l) Schematic figures of superexchange paths via oxygen 2p orbital between
neighboring V3+ ions for [−101]c direction. These figures are based on A-type antiferroic orbital ordering (See also Fig. 1(c)).
The V3+ ions are at sites 1 and 2. The surrounding O2- ions are at sites 3 and 4. (m) Electronic structure in the ground statefor [−101]c direction. The spin moments are projected along the z direction. The dotted line indicates the overlapping
between orbitals. (n) Excited state along [−101]c direction. (Taken from Ref. [4] and modified for the present report.)

36

MLF Annual Report 2016

moments at the V-sites in the z direction is ferromagnetic, as shown in Fig. 2 (m). A neutron flips the |yz, ↑>electron at site 1 to |yz, ↓> electron [Fig. 2 (n), gray arrow at site 1]. In this excited state, the SOI ξ lz sz would
excite the |yz, ↓> electron at site 1 to |zx, ↓> electron.
This on-site excitation would recover the non-zero orbital angular momentum and gain energy of the SOI. In
addition, the |zx, ↓> electron at site 1 can be exchanged
with a |zx, ↑> electron at site 2 via direct exchange interaction [Fig. 2 (n)], propagating as the spin-orbital
correlated collective mode.
5. Future Plans
In the present study, we clarified the magnetic dynamics in a spin-orbital coupled system MnV2O4 overwide momentum space with the use of INS. We foundthat magnetic scattering existed from 10 to 17 meV.
Furthermore, we pointed out that the magnetic scattering around 22 meV was not simple spin-wave. In the future, we plan to perform INS on a single-domain sample
for more exact analysis. The polarized inelastic neutron
scattering should also provide us important information about the origin of the 22 meV-scattering.

Research and Development Highlights

Acknowledgement
The neutron experiments were performed at
the Materials and Life Science Experimental Facilityof the J-PARC under user program, Nos. 2012A0058,
2013A0141, 2014A0113, 2014B0152. We acknowledge
T. Masuda, M. Soda, and S. Hayashida for their assistance in taking high-energy Laue photographs at theInstitute for Solid State Physics, the University of Tokyo.
The crystal structures were visualized using VESTA 3 [7].
References[1] A. Pimenov et al., Nat. Phys. 2, 97 (2006).
[2] N. Kida et al., J. Opt. Soc. Am. B 26, A35 (2009).
[3] E. Saitoh et al., Nature 410, 180 (2001).
[4] K. Matsuura et al., Phys. Rev. Lett. 119, 017201(2017) (and see also K. Matsuura et al., Physica B:
Physics of Condensed Matter, in press).
[5] J. -H. Chung et al., Phys. Rev. B 77, 054412 (2008)
and Phys. Rev. B 87, 139907 (E) (2013).
[6] K. Takubo et al., Phys. Rev. B 84, 094406 (2011) and
S. L. Gleason et al., Phys. Rev. B 89, 134402 (2014).
[7] K. Momma and F. Izumi, J. Appl. Crystallogr. 44,
1272 (2011).

K. Matsuura1, H. Sagayama2, A. Uehara3, Y. Nii4, R. Kajimoto5, K. Kamazawa6, K. Ikeuchi6, S. Ji6, N. Abe1, and T. Arima1
Department of Advanced Materials Science, the University of Tokyo; 2Institute of Materials Structure Science, High Energy Accelerator
Research Organization; 3Department of Applied Physics, the University of Tokyo; 4Department of Basic Science, the University of Tokyo;
5
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 6Neutron Science and Technology Center, Comprehensive
Research Organization for Science and Society (CROSS)
1

37

Research and Development Highlights

MLF Annual Report 2016

Crystal Field Excitations on NdFe3(BO3)4 Investigated by
Inelastic Neutron Scattering
1. Introduction
Multiferroic materials, which exhibit both magnetic
and dielectric orders, have been an intriguing topic
since the discovery of a huge magnetoelectric (ME)effect in TbMnO3 [1]. In the multiferroic materials, therare-earth ferroborates RFe3(BO3)4 (R = Y and rare-earth
metal) are a series of new multiferroic compounds containing R3+ (4fn) and Fe3+ (3d5 S = 5/2) as magnetic ions.
They show diverse ME effects as a function of the species of the R3+ ions (R = Y, Pr, Nd, Sm, Gd, and Tb), since
there is a variety of the magnetic anisotropy of the R3+
moments coupled with the Fe3+ moments through the
Fe3+ and R3+ moments (f-d coupling) [2]. Recent studies
revealed that the mechanism of magnetoelectricity inthese compounds is explained by the spin-dependent
metal-ligand hybridization model [3, 4].
We focus on NdFe3(BO3)4, in which the Nd3+ ions
(4f3) carry magnetic moment with J = 9/2. The crystal
structure is trigonal with space group R32. The point
symmetry of the NdO6 octrahedra is D3; a threefold rotational symmetry along the crystallographic c-axis andthree twofold rotational axes in the ab-plane, as shownin Fig. 1. Studies on the specific heat, magnetic susceptibility [5], and ME effect [2] revealed that an easy-plane
type antiferromagnetic (AF) order and a spontaneouselectric polarization simultaneously occur at TN = 30 K.
The huge electric polarization is strongly enhanced bymagnetic field. An optical spectroscopy study exhibited
five Kramers doublets by the Nd3+ crystal field [6], and a
recent inelastic neutron scattering (INS) study revealed
that the magnetic anisotropy of the Nd3+ crystal fielddrove the multiferroicity in NdFe3(BO3)4 [7].

Figure 1.	The ab-plane projection of the NdO6 octahedrawith D3 symmetry [12].

38

In the present study, we explored the crystal field
excitations of the Nd3+ ion in NdFe3(11BO3)4 using the INS
technique. The investigation of the Nd3+ crystal field isimportant for further understanding of the ME effect in
the rare-earth ferroborates.
2. Experimental details
Single crystals of NdFe3(11BO3)4 were grown by
a flux method. 22 pieces of the single crystals werecoaligned so that the a*-c* plane was horizontal. We
performed the INS experiment at the High-Resolution
Chopper Spectrometer (HRC) installed in J-PARC/MLF.
We used a GM-type closed-cycle cryostat to achieve
40 K and 15 K. The energy of the incident neutron beam
was Ei = 51.04 meV yielding an energy resolution of ΔE =2.5 meV at the elastic position. We set the incident neutron beam with ki//a*.
3. Experimental results and discussions
An INS spectrum at 15 K is shown in Fig. 2(a). A
well-defined flat excitation is observed at 17 meV and aweak flat one is observed at about 8 meV. The strong intensities at ħω < 6 meV in the wide Q range come fromdispersive Fe-centered spin waves [7]. A weak flat intensity at about 20 meV comes from an instrumental artifact [7]. The dispersive spectra in the range of Q > 2 Å-1
come from the aluminum that is used for the sample
can and sample holder.
One-dimensional energy cuts obtained by integrating the intensities in the range of 1.5 Å-1 ≤ Q ≤ 1.9 Å-1 areshown in Fig. 2(b). The red triangles and blue circles indicate the data measured at 40 K and 15 K, respectively.
The data at 15 K are fitted by the sum of five Gaussianfunctions; the solid black curve is for an incoherent elastic scattering, the dashed curve is for the Fe-centeredspin-wave excitation, the solid green curve is for a couple
of intrinsic excitations, and the dotted curve is for the
instrumental artifact. The peak energies of the green
curve are estimated to be 8.5 meV and 17.4 meV, andthey agree with the energy of the first and second excited states of the Nd3+ crystal field reported in the optical
spectroscopy [6]. This suggests that these excitations aretransitions from the ground state to the first and second
excited states. A quite small temperature dependence isobserved between the data at 40 K and that at 15 K.
We simulated the neutron intensities of the Nd3+

MLF Annual Report 2016

Research and Development Highlights

Figure 2.	(a) An INS spectrum at 15 K. (b) ħω-dependence of the neutron intensities that are obtained by integration in the range of
1.5 Å−1 ≤ Q ≤ 1.9 Å−1. The triangles and circles are data at 40 K and 15 K, respectively. Solid, dashed and dotted curves are
Gaussian fits to the data at 15 K [12].

crystal field. At the Nd3+ site with the D3 symmetry, thecrystal filed Hamiltonian is defined as follows:
2

2

4

4

4

4

4

6

6

HCF(D3) = B0 C0 + B0 C0 + iB3 (C3 + C −3) + B0 C0
6

6

6

6

6

6

+ iB3 (C3 + C −3) + B6 (C6 + C −6)
The Bqps are the crystal field parameters and Cqps are
the spherical tensor operators. We used the values ofthe parameters Bqps reported in Ref. [6].
We calculated the excitation energies and theneutron intensities of the transferred states from theground state to the first and second excited stats using
McPhase software suite [8]. The ratio of the calculated
intensities (I1st/I2nd)cal is 0.71, and that of the experimental intensities (I1st/I2nd)exp is 0.49. The experimental results
are semi-quantitatively consistent with the calculations.
Furthermore, we obtained the temperature dependence of the intensity as (I40K/I15K)cal = 0.93 by assumingthat the initial state was the ground state. The small
temperature dependence is consistent with the data in
Fig. 2(b). The observed excitations are, thus, interpreted
as the first and second states of the Nd3+ crystal field.
It is noted that the peak at 8.5 meV is broader
than the peak at 17.4 meV in Fig. 2(b). This broadening
was also reported in the optical spectroscopy [6]. It is
known that a spectrum of the crystal field excitation isbroadened by coupling to a phonon [9] and dynamic
Jahn-Teller effect [10, 11]. This broadening of the peakis ascribed to an interaction between the Nd3+ momentand lattice vibration since the magnetoelastic coupling
was observed in Nd3(BO3)4 [3].

4. Conclusion
The INS measurements were performed on the
single crystals NdFe3(11BO3)4 to explore the Nd3+ crystal field excitations. In addition to the Fe-centered spinwave previously reported, dipersionless excitations
were observed at 8.5 meV and 17.4 meV. Our analysis
reveals that they are the transitions from the groundstate to the first and second excited states of the Nd3+
ion in the crystal field.
References[1] T. Kimura et al., Nature (London) 426, 55 (2003).
[2] A. M. Kadomtseva et al., Low Temp. Phys. 36, 511(2010).
[3] A. I. Popov et al., Phys. Rev. B 87, 024413 (2013).
[4] T. Kurumaji et al., Phys Rev. B 89, 195126 (2014).
[5] N. Tristan et al., J. Magn. Magn. Mater. 316, 621(2007).
[6] M. N. Popova et al., Phys. Rev. B 75, 224435 (2007).
[7] S. Hayashida et al., Phys. Rev. B 92, 054402 (2015);
MLF Annual report 2014, p22-23 (2015).
[8] M. Rotter, J. Magn. Magn. Mater. 272-276, e481
(2004).
[9] E. T. Heyen et al., Phys. Rev. Lett. 67, 144 (1991).
[10] S. Kern et al., Solid State Commun. 49, 295 (1984).
[11] A. T. Boothroyd et al., Phys. Rev. Lett. 86, 2082
(2001).
[12] S. Hayashida et al., J. Phys: Conf. Ser. 746, 012059(2016).

S. Hayashida1, M. Soda1, S. Itoh2,3, T. Yokoo2,3, K. Ohgushi4, D. Kawana1, and T. Mausuda1
The Institute for Solid State Physics, The University of Tokyo; 2Neutron Science Section, Material and Life Science Division, J-PARC center;
3Institute of Materials Structure Science, KEK; 4Department of Physics, Tohoku University

139Research and Development Highlights

MLF Annual Report 2016

Damped Spin-Wave Excitations in the Itinerant
Antiferromagnet γ−Fe0.7Mn0.3

2. Experimental Details
A Fe0.7Mn0.3 crystal was synthesized by a Bridgmantype induction furnace. The mass of the grown single
crystal was about 40 g. Inelastic neutron-scattering experiments were performed on HRC [6]. The sample wasmounted with a horizontal hkk scattering plane, sealed
in an aluminum can under a 4He gas atmosphere, andthen set in a closed-cycle 4He cryostat. Measurements
were performed at T = 14 K.
40

3. Results
Figure 1 shows the obtained dispersion relationof the magnetic excitations. At the excitation energiesħω = 48 and 78 meV, there is no difference in the peak
positions between all the three directions within theexperimental error, which indicates that the dispersion
is isotropic even at 78 meV. Then, we tried to fit the dispersion relation with a function. The energy gap was
fixed to Δ = 10.2 meV in the following fitting procedure,
which was obtained with the ħω dependence of the local spin susceptibility Imχ(ħω), as described later. The
black dashed curve in Fig. 1 shows the fit with the following equation(ħω)2 = c2q2 + Δ2,(1)which indicates that the function is unsuited. The dispersion could be fitted with Eq. (1) only below 40 meV. The
black solid curve in Fig. 1 shows the fit below 40 meV.
The spin-wave velocity is c = 226(5) meVÅ. Below thisenergy, the dispersion is reasonably consistent withthat in the previous reports for Fe0.7Mn0.3 at T = 0 K [c =195(30) meVÅ] [4] and Fe0.47Mn0.53 at room temperature(RT) (245–265 meVÅ) [5], shown by the green and blue
dashed curves in Fig. 1. Above 40 meV, the gradient of
the dispersion relation is considerably larger than that
expected from Eq. (1). The linear fit with the function,ħω = c'q + Δ', above 40 meV yields the group velocity c'= 470(40) meVÅ, shown by the black solid straight line.
The damping parameter γ was obtained under theassumption of a damped simple harmonic oscillator,120ħω = c’q + ∆’100ħω (meV)

1. Introduction
There has been renewed interest in magnetic excitations in itinerant antiferromagnets after the discovery
of superconductivity in copper oxides and iron pnictides/chalcogenides. Metallic chromium, γ-FeMn, γ-Mn,
and γ-Fe are prototypes of itinerant antiferromagnets.
In the itinerant antiferromagnets, the maximum energyof the collective spin-wave excitations is relatively highcompared to that of the Heisenberg magnets, and thus,
the overall picture of the excitations has not yet beenclarified. Unlike the case of the itinerant ferromagnets,
there is still little experimental understanding of thespin-wave damping due to the continuum of the particle-hole excitations in itinerant antiferromagnets [1]. In
the case of chromium, commensurate excitations, localized at the antiferromagnetic wave vector, extend up to
more than 550 meV [2]. A recent theoretical study [3]predicted that the commensurate excitations merge
with the continuum of the individual particle-hole excitations above 600 meV. However, spin excitations above
600 meV have yet to be elucidated experimentally.
To reveal the overall picture of the excitations initinerant antiferromagnets, we focused on γ-FeMn,
whose spin-wave velocity is much smaller than that ofmetallic chromium. The FexMn1−x alloy (0.3 < x < 0.85) is
crystallized in a face-centered-cubic structure, the socalled γ phase. The Fe and Mn ions are located randomly at the origin and face-center positions. γ-FeMn shows
the antiferromagnetic transition. Both Fe and Mn ionshave magnetic moments. The transition temperature is
TAF = 435 K, and the average moment size is 1.97 μB forFe0.7Mn0.3. We performed inelastic neutron-scattering
measurements on Fe0.7Mn0.3 to elucidate magnetic excitations in an energy-momentum space wider than thatin previously reported studies [4, 5].

8060ħω2 = c2q2 + ∆2
Fe0.47Mn0.53, T = RT,
Y. Endoh et al. (1973)

40
20
0

Fe0.7Mn0.3, T = 0 K,
K. Tajima et al. (1976)

0

0.1

0.2

0.3

q || [100]
[110]
[111]

0.4

0.5

q (Å−1)Figure 1.	Dispersion relation of the magnetic excitations. The
vertical error bars represent the energy resolution.
The horizontal bars represent the fitting error.

MLF Annual Report 2016

350

300

300

γ (meV)(a)γ (meV)

250

200

0

200

Mn90Cu10100
00.1 −10.2
q (Å )

0.3

CaFe2As2
La2−2xSr1+2xMn2O7

150

Fe0.7Mn0.3,
T = RT

100
50
0

(b)
Imχ (arb. unit)

8
6
4
2
0

0

20

40

60

80

100

120

ħω (meV)Figure 2.	(a) ħω dependence of the damping parameter γ.
The black solid lines are guides to the eyes. The qdependence of γ is shown in the inset. (b) ħω dependence of the local spin susceptibility Imχ(ħω).
The black solid line is a guide to the eyes. The arrow
represents the gap energy.

which is shown in Fig. 2(a). γ below 30 meV is in agreement with the previous report at RT [4]. γ shows a steadyincrease above approximately 40 meV and reaches
110(16) meV at ħω = 78 meV. γ above 40 meV is muchlarger than the metallic compounds, La2−2xSr1+2xMn2O7 [7]and CaFe2As2 [8]. The inset in Fig. 2(a) shows the q dependence of γ. γ increases steadily above q = 0.16 Å−1. γ
above 0.22 Å−1 is larger than that of Mn90Cu10, which isa dilute alloy of the itinerant antiferromagnet γ-Mn [9].
Figure 2(b) shows Imχ(ħω). The energy gap was estimated to be Δ(14 K) = 10.2(7) meV by linear extrapolation of Imχ below 15 meV. The result is consistent withthe value previously reported [4], Δ(0 K) = 9.4 meV. Imχreaches the maximum value around 40 meV and clearlydecreases above 60 meV.

Research and Development Highlights

4. Discussion
The deviation of the spin-wave dispersion from
Eq. (1) above 40 meV indicates the existence of otherexcitations that interact with the spin-wave because thegroup velocity decreases with energy, if the spin wave
does not interact. This result suggests that the spin wave
merges with the continuum of the individual particlehole excitations at 40 meV. When a spin-wave enters thecontinuum, an increase in the group velocity is expected
for a ferromagnetic electron gas [10]. On the other hand,a magnon-electron interaction will not cause a suddenchange. γ steadily increases above 40 meV, and Imχ
gradually decreases above 60 meV, which indicates thatthe spin wave gradually damps with increasing ħω in thecontinuum. Of course, other scenarios for explaining theexcitations cannot be ruled out. At least, it is unique thatthe spin-wave excitations show the linear q-dependent
dispersion and broad energy width above 40 meV. A
future theoretical study would be very interesting. This
work has been published in [11].
References[1] Y. Ishikawa, J. Appl. Phys. 49, 2125 (1978); Y. Endohand P. Böni, J. Phys. Soc. Jpn. 75, 111002 (2006).
[2] For example, J. R. Lowden, P. W. Mitchell et al., J.
Magn. Magn. Mater. 140–144, 1971 (1995).
[3] K. Sugimoto, Z. Li, E. Kaneshita, K. Tsutsui, and T.
Tohyama, Phys. Rev. B 87, 134418 (2013).
[4] K. Tajima, Y. Ishikawa, Y. Endoh, and Y. Noda, J. Phys.
Soc. Jpn. 41, 1195 (1976).
[5] Y. Endoh, G. Shirane, Y. Ishikawa, and K. Tajima,
Solid State Commun. 13, 1179 (1973).
[6] S. Itoh, T. Yokoo, S. Satoh et al., Nucl. Instrum.
Methods Phys. Res., Sect. A 631, 90 (2011).
[7] T. G. Perring, D. T. Adroja, G. Chaboussant, G. Aeppli
et al., Phys. Rev. Lett. 87, 217201 (2001).
[8] J. Zhao, D. T. Adroja, D.-X. Yao, R. Bewley, S. Li, X. F.
Wang et al., Nat. Phys. 5, 555 (2009).
[9] J. A. Fernandez-Baca, M. E. Hagen et al., J. Magn.
Magn. Mater. 104–107, 699 (1992).
[10] Y. Ishikawa, J. Appl. Phys. 49, 2125 (1978).
[11] S. Ibuka, S. Itoh, T. Yokoo, and Y. Endoh, Phys. Rev. B
95, 224406 (2017).

S. Ibuka1,2, S. Itoh1,2,3, T. Yokoo1,2,3, and Y. Endoh1,4,5
Institute of Materials Structure Science, KEK; 2Neutron Science Section, Materials and Life Science Division, J-PARC Center; 3Department ofMaterials Structure Science, School of High Energy Science, Graduate University for Advanced Science; 4RIKEN Center for Emergent Matter
Science; 5Department of Physics, Tohoku University
141Research and Development Highlights

MLF Annual Report 2016

Large Magnetovolume Effect Induced by Embedding
Ferromagnetic Clusters into Antiferromagnetic Matrix of
Cobaltite Perovskite
1. Introduction
Most of the solids expand on heating due to the anharmonic vibration of atoms. However, thermal expansion may cause problems in various fields, ranging fromlarge structural components to precision instruments.
On the other hand, some materials exhibit the opposite
tendency, known as negative thermal expansion (NTE).
The NTE materials have significant industrial merit because they can be used to compensate the unwanted
thermal expansion and fabricate zero thermal expansion materials [1]. In some materials, NTE is coupledwith spontaneous magnetization, which is called magnetovolume effect (MVE).

x corresponds to the hole doping level [2, 3]. The value of volume expansion coefficient β [β = dV/(V × dT )]for x = 0.24, as depicted in the inset in Fig. 1b, is -3.6 ×
10-5 K-1, making it one of the strongest NTE materials.
The results (see Fig. 1c) of high-resolution neutron powder diffraction from SuperHRPD (BL08) under proposal
No. 2014S05 demonstrate a striking MVE, i.e.,the squareof magnetic moment M is linearly correlated with thevolumetric order parameter ΔV for x = 0.24, where ΔV
is extracted by subtracting the phonon contribution
calculated on the basis of Debye-Grüneisen model (seeFig. 1b). After deriving the magnetic phase diagram (seeFig. 1d) from the neutron powder diffraction study, we
found out that the MVE reaches its maximum near theboundary between the ferromagnetic (F) and antiferromagnetic (AF) phases in the phase diagram, indicating
the essential role of the F-AF competition.

ab 471.5464.2

b 471.5

464.2

469.5

V (Å3)

b

467.5

Pr

Pr

Ba

Ba

Co

Co

O

O

O3
O4

O4

O3

465.5
463.5

c

x1.2
= 0.24|M|2 (µB2)

250

x = 0.24

0.8
0.4

0.0
0.0

0.0
0.2
0.0

V (Å3)

0.4
0.2

0.6
0.4
V (Å3)

200

465.5
463.5

V

461.5
459.5
50
100
0

0

d

300

TN1
TN2

150
50

200
100

T (K)

250 PI
200

150
250

PI

PM

300

TN2

15

TC

AFI
AFI(G-type)
100 (SSO)

AFI(G-type)FI

50

50

V/V

0

0

TC
10

V/V

20 × 10−3

PM
15

TN

AFI
100 (SSO)

250

20 × 10−3TN1

150 TN

150

200
300

T (K)

10

V/V

0.4

300

x=
0
0.12
0.24
0.35
0.41

V/V

|M|2 (µB2)

1.2
0.8

d

1.6

Temperature (K)

1.6

V

461.5
459.5

c

x=
0
0.12
469.5
x = 0.24
x =0.24
0.24
0.35
463.5
463.5
467.5
0.41
0 40 80 120
0 40 80 120
T (K)
T (K)

Temperature (K)

a

b

c

V (Å3)ac

V (Å3)aV (Å3)

2. Results
Here we report a new class of NTE material; namely,
a layered perovskite PrBaCo2O5.5+x (see Fig. 1a), where

FI
5

5

0

0

0.000.18
0.060.24
0.120.30
0.180.36
0.240.42
0.30 0.36 0.42
0.6 0.00 0.06 0.12
Hole doping level
Holexdoping level x

Figure 1.	a, Schematic drawing for the general crystal structure of PrBaCo2O5.5+x. b, Volume of unit cell as a function of the temperature for various hole-doping fractions x determined through high resolution-neutron-powder diffraction (NPD). c, Squareof magnetic moment |M|2 as a function of the volumetric order parameter ΔV for x = 0.24. d, Phase diagram, characterizing
the magnetic transition temperature and ΔV/V at 10 K as a function of x [3].

42MLF Annual Report 2016a

Research and Development Highlights

b

0.15

Corrected Asymmetryx = 0.24

Fcluster

0.1

0.05

0
0

AFMatrix

LF 0.4 T
LF 0.2 T
LF 0.1 T
LF 0.01 T
ZF

c
T=4K

5
Time (µs)

a10Figure 2.	a, Muon spin relaxation (μSR) time spectra at 4 K under various longitudinal magnetic fields for PrBaCo2O5.5+x (x = 0.24).
b, Schematic drawing for the ferromagnetic clusters embedded in the antiferromagnetic matrix [3].

A further muon-spin-relaxation (μSR) experiment (see Fig. 2a) performed at MUSE under proposal
No. 2017A0014, clearly exhibits the magnteoelectronic
phase separation for x = 0.24 at ground state. Specifically,
the damping of spectra under longitudinal field (LF) up
to 0.4 T reveals the dynamic phase; an increase in theinitial asymmetry by applying field indicates the static
phase with internal field; the lift-up of spectrum under
LF of 0.01 T suggests a static phase without internal
field. These phases are the result of interaction between
the F-clusters and the antiferromagnetic AF-matrix (seeFig. 2b). Such an inhomogeneous phase scenario isalso evidenced by the neutron pair distribution function (PDF) analysis from NOVA (BL21) under proposal
No. 2016A0023.

Through a comprehensive study with multiple
probes (neutron, muon, electron and X-ray), we foundthe MVE originates from the competition between the
F-clusters and the AF matrix.
References[1] J. Chen, L. Hu, J. Deng, X. Xing, Chem. Soc. Rev. 44,3522 (2015).
[2] P. Miao, X. Lin, S. Lee, Y. Ishikawa, S. Torii, T. Ueno, N.
Inami, K. Ono, Y. Wang, T. Kamiyama, Phys. Rev. B 95,
125123 (2017).
[3] P. Miao, X. Lin, A. Koda, S. Lee, Y. Ishikawa, S. Torii1,
M. Yonemura, T. Mochiku, H. Sagayama, S. Itoh, Y.
Wang, R. Kadono and T. Kamiyama, Adv. Mater. 29,
1605991 (2017).

Ping Miao1,2, X. Lin3, A. Koda1,2,4, S. Lee1, Y. Ishikawa1, S. Torii1,4, M. Yonemura1,2,4, T. Mochiku5, H. Sagayama1,2, S. Itoh1,2,4, Y. Wang3,
R. Kadono1,2,4, and T. Kamiyama1,2,4
1
Institute of Materials Structure Science, KEK; 2Department of Materials Structure Science, Sokendai; 3College of Chemistry and MolecularEngineering, Peking University; 4Neutron Science Section, Material and Life Science Division, J-PARC center; 5National Institute for Materials
Science43Research and Development Highlights

MLF Annual Report 2016

Neutron Tolerance Evaluation of PerpendicularAnisotropy CoFeB-MgO Magnetic Tunnel Junctions
using NOBORU at J-PARC
1. Introduction
Magnetic random access memory (MRAM) that employs magnetic tunnel junctions (MTJs) is a new nonvolatile memory that is very promising due to its highoperation speed. MRAM devices have already reachedperformance levels comparable to those of fast standalone memory such as static RAM (SRAM). Among
MRAM technologies, MTJs that use spin-transfer-torque(STT) switching are attracting much attention for theirpotential to reduce both power consumption and interconnection delays [1]. MTJs with a perpendicular magnetic easy axis (p-MTJ) are expected to simultaneously
realize a low STT switching current and high thermal
stability factor, Δ. The highest Δ was recently obtainedwith an MgO/CoFeB/Ta/CoFeB/ MgO double-interface
recording structure [2].
The physical dimensions of SRAM devices continue
to be reduced along with the operation voltage andpower consumption, so that SRAM has become moresensitive to fast neutron irradiation at ground level [3].
It has been claimed that MRAM is error-immune, basedon the internal characteristics of the MTJ that stores thedata. However, the neutron tolerance of p-MTJs witha CoFeB-MgO structure under fast neutron irradiation
at ground level has not yet been specifically reported. For this reason, we have begun fast neutron irradiation experiments (Proposal Numbers: 2014A0102,
2014B0120, and 2015A0134) using the J-PARC BL10,NOBORU, beamline to evaluate the fast neutron tolerance of p-MTJ devices with a junction diameter (D) ofapproximately 50 nm and a double-interface recording
structure.
2. Experimental methods
MTJ devices with the CoFeB-MgO structure were
fabricated on a 40 × 40 mm2 area (3-inch) SiO2/Si wafer. 461 p-MTJ devices equipped with a CoFeB-MgO
recording structure were used. Each p-MTJ has astacked profile structure from the SiO 2/Si substrateside: Ta (5)/Ru (10)/Ta (5)/Pt (5)/[Co (0.34)/Pt (0.4)]6/Co(0.34)/Ru (0.44)/[Co (0.34)/Pt (0.4)]2/Co (0.34)/Ta (0.3)/
CoFeB/MgO/ CoFeB/Ta (1)/Ru (7), where the numbers
in parentheses are the nominal thicknesses in nanometers, and the subscripts indicate the number of Co/Pt
44

multilayers. The stack is processed into circular p-MTJs
using electron beam lithography and Ar ion milling,followed by annealing at 300°C under vacuum with aperpendicular magnetic field of 0.4 T for 1 h. The junction diameter (D) of each p-MTJ was within the rangeof 46 to 64 nm. p-MTJ devices with tunnel magnetoresistance (TMR) ratios above 90% at room temperature
were used.
The neutron irradiation experiment was conducted using the BL10, NOBORU, beamline at J-PARC. The
neutron beam irradiation area was approximately 80
× 80 mm2. Low-energy neutrons were separated fromthe neutron beam using 5 mm thick B4C slits, while
gamma radiation was blocked using a 25 mm thickPb block. The total 1 MeV equivalent fluence of fastneutrons irradiated to the 461 p-MTJ devices was 3.79
× 1012 neutrons cm−2, which corresponded to 1.90 ×
1011 h (approximately 22 million years) irradiation in afast neutron environment at ground level (20 cm−2 h−1).
The effect of fast neutron irradiation was evaluated bycomparing the resistance-magnetic field (R-H) curves ofthe p-MTJs before and after neutron irradiation.
3. Results
Figure 1 shows R-H curves for a p-MTJ with D =48 nm and a TMR ratio of 108% following neutron irradiation up to 3.79 × 1012 cm-2. The dashed lines indicate
the resistance values in the parallel and anti-parallelstates prior to irradiation, RPbefore and RAPbefore, respectively. The resistance values and switching fields wereobserved to be unchanged from those prior to irradiation. Figure 2 shows a comparison of the TMR ratios of
the 461 p-MTJs before and after irradiation of 3.79 ×
1012 cm-2. After irradiation, the variation induced in the
TMR ratios and the standard deviation σ were approximately ±1% and 0.62%, respectively, and these values
remained within the experimental error. Therefore, theproperties of the CoFeB-MgO p-MTJ devices were notsignificantly affected by exposure to a fast neutron fluence of up to 3.79 × 1012 cm-2. This study represents thefirst result of the effects of fast neutron irradiation on
p-MTJs with a CoFeB-MgO structure and practical junction diameters [4].

MLF Annual Report 2016

Research and Development Highlights

Figure 1.	R-H curves for a p-MTJ with D = 48 nm and a TMR
ratio of 108% following fast neutron irradiation up
to 3.79 × 1012 cm−2. RPbefore and RAPbefore indicate theresistance values in the parallel and anti-parallelstates prior to irradiation, respectively.

Figure 2.	Comparison of TMR ratio before and after fast neutron irradiation of 3.79 × 1012 cm−2.

4. Future Plans
SRAM has become more sensitive to fast neutron
irradiation due to a reduction in the device size; therefore, it is important to ensure the fast neutron toleranceof p-MTJs with D below 50 nm. At present, we are evaluating the fast neutron tolerance of CoFeB-MgO p-MTJs
with D < 20 nm.
We plan to attempt the measurement of in situ current-voltage (I-V) curves during fast neutron irradiation
at NOBORU.

for technical support during the neutron irradiation
work at J-PARC.

Acknowledgments
This work was supported by the Research andDevelopment Project for ICT Key Technology of the
Ministry of Education, Culture, Sports, Science andTechnology. The authors wish to thank Dr. Motoki Ooi

References[1] S. Ikeda, J. Hayakawa, Y. M. Lee, F. Matsukura, Y.
Ohno, T. Hanyu, and H. Ohno, IEEE Trans. Elec. Dev.,
54 991 (2007).
[2] H. Sato, E. C. I. Enobio, M. Yamanouchi, S. Ikeda, S.
Fukami, S. Kanai, F. Matsukura, and H. Ohno, Appl.
Phys. Lett., 101 022414 (2012).
[3] E. Ibe, H. Taniguchi, Y. Yahagi, K. Shimbo, and T. Taba,
IEEE Trans. Elec. Dev., 57 1527 (2010).
[4] Y. Narita, Y. Takahashi, M. Harda, K. Oikawa, D.
Kobayashi, K. Hirose, H. Sato, S. Ikeda, T. Endoh, and
H. Ohno, Jpn. J. Appl. Phys., 56 0802B3 (2017).

Y. Narita1, Y. Takahashi1, M. Harada2, K. Oikawa2, D. Kobayashi3, K. Hirose3, H. Sato4,5,6,7, S. Ikeda4,5,6, T. Endoh4,5,6,8, and H. Ohno4,5,6,7,9
Graduate School of Science and Engineering, Yamagata University; 2Neutron Science Section, Materials and Life Science Division, J-PARC
Center; 3Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA); 4Center for Spintronics Research
Network, Tohoku University; 5Center for Innovative Integrated Electronic Systems, Tohoku University; 6Center for Spintronics Integrated
Systems, Tohoku University; 7Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku
University; 8Graduate School of Engineering, Tohoku University; 9WPI Advanced Institute for Materials Research, Tohoku University

145

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MLF Annual Report 2016

Two-Dimensional Microstructure Visualization in
Engineering Materials using Bragg-Edge Imaging
1. Introduction
The neutron transmission of steel materials has
characteristic energy dependency due to Bragg reflection (referred to as Bragg-edge spectrum). By obtaining
and analyzing the Bragg-edge spectrum two-dimensionally, it is possible to visualize the microstructuralproperties of the sample, such as texture, crystalline
phase, crystallite size, and lattice strain [1]. However,
the results must be verified by comparing them withthose obtained by conventional methods because theBragg-edge transmission (BET) imaging is a new developing technique.
Bending is one of the most frequently used operations in sheet forming to produce functional parts.
Bending deformation can introduce tension and compression stress states into materials simultaneously.
In order to examine the application of the BET
imaging to nondestructive inspection of engineering
products, we performed time-of-flight (TOF) 2D BET
imaging experiments for plastically bent plates using
high-intensity pulsed neutrons at J-PARC [2, 3]. The microstructure and residual elastic strain distributions of
the samples were evaluated, and the analyzed Braggedge imaging results were validated using the welldeveloped neutron diffraction method and electronbackscatter diffraction (EBSD) observations.
2. Experimental procedures
Two commercially available steels were used in thepresent investigation: a ferrite single-phase steel (FS)and a hot-rolled duplex stainless steel (DSS) consisting

Figure 1.	Photograph of a bent sample.

46

of face-centered cubic austenite and body-centeredcubic ferrite. An example of a bent sample used in thisstudy is shown in Fig. 1.
Pulsed neutron imaging experiments were performed at BL10 NOBURU of the MLF/J-PARC. A 100 ×
100 mm area 2D detector with a 0.8 × 0.8 mm pixel resolution was used to measure the position-dependenttransmission spectra. The RITS code [1] was used for
Bragg-edge spectral analysis to obtain 2D maps of texture, crystallite size, and phase volume fraction. Neutron
diffraction experiments were performed at BL19 TAKUMIof the MLF/J-PARC. Neutron diffraction data were collected with the gauge volume of 2 × 2 × 2 mm. The bent
samples were scanned at 14 positions from the outer tothe inner regions shown by a red box in Fig. 1 in intervals of 1 mm. The Z-Rietveld software [4] was used for
diffraction pattern analysis to obtain texture, residual
lattice strain, and phase volume fractions. EBSD measurements were conducted at a Hitachi 4300 SEM fittedwith an EBSD system. The local crystallographic orientation, grain size, and phase discrimination of the samples
were determined by means of EBSD analysis.
3. Results and discussion
Figure 2 shows an example of the measured and fitted transmission spectra of the FS sample, obtained atpoints A, B, and C as indicated in Fig. 1, the shape of the
BET spectra changes due to the bending plastic deformation. Enlarged views of the ferrite 110 edges in both
insets represent the single-edge profile fitting, which
provide the lattice plane spacing, d110.

Figure 2.	BET spectra of FS sample measured at the points
indicated in Fig. 1.

MLF Annual Report 2016

Research and Development Highlights

Figure 3.	2D maps determined by BET imaging: (a) texture variations, R, for the FS sample, (b) phase volume fraction, VFerrite, for the
DSS sample and (c) crystallite size, S, for the FS sample.

Texture variations, crystallite size, and phase volume fraction in both samples were analyzed by the
RITS code and are mapped in Fig. 3. A coefficient of the
March–Dollase (MD) function, R, provides the degreeof the preferred orientation, namely R = 1 for a random texture sample and R < 1 ([hkl] // incident beam)
or R > 1 ([hkl] ⊥ incident beam) for a textured sample,
where [hkl] represents the preferred orientation vector.
Figure 3(a) shows the map of the refined parameter R
for the FS sample. The coefficient R decreases graduallyfrom the outer to the inner zone in the bent sample.
This map indicates that the [750] orientation is perpendicular to the beam direction in the outer zone, whereas it is parallel to the beam direction in the inner zone.
Figure 3(b) shows the map of ferrite phase volume fraction, VFerrite, of the DSS sample, which was calculatedwith the obtained projection data of the atomic number density of ferrite and austenite of the sample. It indicates a mostly homogeneous distribution within thebulk of the sample with some slight variation along theouter edge. A value for VFerrite of 0.6 is estimated as theaverage over the entire measured region of the sample.
It confirmed that phase transformation does not occur
by plastic deformation in the DSS sample. Figure 3(c)shows the map of the crystallite size of the FS sample,
which was evaluated by the Sabine’s primary extinction
parameter, S. The crystallite size of the center zone is
obviously larger than that of the inner and outer zones,
which tells us that the average crystallite size is reduced

due to the tensile or compressive deformation.
Then, quantitative microstructure characteristics
for both samples obtained by the BET imaging method were compared with those gained by neutron diffraction and EBSD microscopic observations. Figure 4
shows the representative results. Firstly, Figure 4(a)shows texture variations for FS sample by comparisons
R results obtained by BET imaging and those of neutron diffraction methods. The coefficient R of the ferrite[750] orientation for the ferrite steel sample obtainedusing both methods shows a similar texture evolution
from the outer to inner zone, although the absolute values differ from each other. The coefficient R obtained
from the BET imaging method is a little higher than thatfrom the diffraction method, which might be causedby differences in the effective thickness of the samples.
Secondly, ferrite phase volume fraction, VFerrite, of DSS
sample (Fig. 4(b)) obtained by BET imaging, neutron
diffraction and EBSD is compared together. Thirdly, theresidual elastic strain distribution results (Fig. 4(c)) of
ferrite 110, ε, in DSS sample are compared, which are
obtained from the BET single-edge and diffraction single-peak fitting results. Furthermore, the crystallite size
distribution results of BET imaging for both samples arealso discussed by comparison with the EBSD sub-grain
analysis results [2, 3]. All the above-mentioned BETimaging results are in good agreement with those fromthe neutron diffraction and EBSD.

47

Research and Development Highlights

MLF Annual Report 2016

4. Conclusions
All of these results confirm that quantitative 2D TOF
neutron BET imaging is a very effective and powerfultool for revealing the microstructure and elastic strain
in engineering materials. These obtained 2D maps ofthe crystallographic texture, crystallite size, and volume
fraction distribution of constituent phases are applicable for nondestructive inspection of complicated engineering products.
Acknowledgments
This work was supported by the Photon and
Quantum Basic Research Coordinated Development
Program from the Ministry of Education, Culture, Sports,
Science and Technology, Japan. Neutron experiments
were performed under proposal Nos. 2014B0026 and2015P0700 at MLF/J-PARC.

Figure 4.	Comparisons of BET imaging results with thoseobtained by diffraction, and EBSD methods: (a) texture, R, for the FS sample, (b) phase volume fraction,
VFerrite, for the DSS sample and (c) residual latticestrain, ε, for the DSS sample.

References[1] H. Sato, et. al., Phys. Procedia., 43 186-195 (2013).
[2] Y. H. Su, et. al., Mater. Sci. Eng. Mater. Sci. Eng. A 675
19-31 (2016).
[3] K. Oikawa, et. al., Phys. Procedia., 88 34-41 (2017).
[4] R. Oishi-Tomiyasu, et. al., J. Appl. Cryst. 45 299-308(2012).

Y. H. Su1, K. Oikawa1, S. Harjo1, T. Shinohara1, T. Kai1, M. Harada1, K. Hiroi1, S.Y. Zhang2, J. D. Parker2, H. Sato3, Y. Shiota4, Y. Kiyanagi4,
and Y. Tomota5
1
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Neutron Science and Technology Center, CROSS; 3Faculty ofEngineering, Hokkaido University; 4Graduate School of Engineering, Nagoya University; 5Research Center for Strategic Materials, National
Institute for Materials Science48

MLF Annual Report 2016

Research and Development Highlights

Neutron Study on the Nanoscale Structures andDynamics of Rubber Materials for Tires
1. Introduction
Tires play an essential role of the automobile operation: supporting a vehicle’s weight in addition to driving, turning and stopping. At the same time, now there
is a growing market demand for tires that feature not
only excellent grip performance to ensure safety, butalso superior fuel-efficiency performance to meet theneeds of consumers with an increasing environmental
awareness, as well as wear-resistance performance in
response to the desire for longer lasting tires. To fulfill those diverse tire performance requirements, theneed for the development of high-performance rubber materials for tires is growing.
As shown in Fig. 1, tire rubber is composed of apolymer framework to which solid nanoparticles suchas silica and carbon black (i.e. filler) have been added
to reinforce the rubber. It also includes other additives,
such as oils or resins, as well as crosslinking agentsthat link the polymer chains together. Those materials
are dispersed throughout the rubber in an extremelycomplex disposition.
The different ingredients form hierarchicalstructures within the rubber that extend from thenanoscale to the macroscale. Figure 2 depicts the

Figure 1. Internal structure of tire rubber.

Figure 2.	
Relationship between tire performance and thetemporal-spatial hierarchical structure of tire rubber.

temporal-spatial hierarchical structure of tire rubber.
These temporal-spatial hierarchical structures within
the rubber are intimately related to the overall tire
performance. Therefore, to develop high-performancerubber materials, it is necessary to elucidate further
the nature of these temporal-spatial hierarchicalstructures.
Quantum beams, such as neutron beams and xrays, are effective tools for analyzing the nanoscale
structures and dynamics of rubber shown in Fig. 2.
At Sumitomo Rubber Industries, we have successfully developed a new materials development
technology that utilizes the world-class, cutting-edge
research and experimental facilities known as “J-PARC”
and “SPring-8” to shed light on the nanoscale structures and dynamics within rubber, combined with thepowerful supercomputer known as the “K computer”,
to perform advanced molecular dynamics simulations.
This new technology, called “ADVANCED 4D NANO
DESIGN,” is used currently to develop new rubber materials with superior wear-resistance performance.
In this report, we introduce the results of our recent research, conducted using ADVANCED 4D NANO
DESIGN, through which we elucidated successfully the
structures and dynamics of the polymer adsorbed to
the filler surface, which is an internal rubber structure,
believed to have a powerful effect on the overall tire
performance.
2. Overview of Experiments
The neutron reflectivity is used to analyze the adsorbed polymer of the silica surface. It is difficult to
examine the adsorbed polymer of the filler surface
within bulk rubber. Thus, we used a silicon substrate
as a model sample to simulate the silica within rubber. In this experiment, we took advantage of the factthat neutron scattering produces a pronounced contrast between hydrogen (protium) and deuterium by
preparing samples of partially deuterated styrene-butadiene copolymer rubber, in which only the styrene
component was replaced with deuterated styrene andthen placing these samples on a silicon substrate using spin coating. The samples were then measured
using SOFIA (BL16) and Motofit software [1] was used
to perform model analysis of the resulting reflectivity
data.
49

Research and Development Highlights

MLF Annual Report 2016

Quasi-elastic neutron scattering (QENS) was used
to examine the polymer dynamics. These experiments
were conducted using DNA (BL02) and AMATERAS(BL14). As DNA and AMATERAS have different capabilities in terms of measurable temporal and spatial ranges (for example, DNA can measure slower motion than
AMATERAS), these two spectrometers were utilized
in a mutually complementary manner. Samples withvarying filler contents or filler interface modifications
were prepared to study the effects of filler content andinterface state on the polymer mobility in polymers
and polymer composite materials.
Utilizing the neutron reflectivity method, we wereable to examine the adsorption structure of the polymer adsorbed to the surface of silica depth-wise withhigh precision by substituting a silicon substrate forthe silica surface. However, within actual tire rubber
the silica forms particles. Thus, we utilized small-angle
neutron scattering (SANS) to examine the structureof the polymer adsorbed to the silica interface withinbulk rubber. Previous research has shown that, when
toluene (a good polymer solvent) is added to crosslinked rubber, the polymer in the vicinity of the filler
interface shows greater resistance to solvent swelling [2]. Thus, we added toluene to crosslinked rubber
and then utilized SANS to measure the contents ofthe solvent in both silica-interface polymer and matrix rubber. These experiments were conducted using
J-PARC TAIKAN (BL15). Because neutron scattering
produces a pronounced contrast between hydrogen(protium) and deuterium, we used deuterated toluene
for the experiments.
3. Results and Analysis
Figure 3 shows the reflectivity curve obtained
through the neutron reflectivity experiments. The

Figure 3.	Neutron reflectivity curve of styrene-butadiene rubber on a silicon wafer. The solid curve indicates reflectivity, as derived from the model scattering lengthdensity distribution profiles shown on the right.

50

solid line on the left, which matches closely the experimental results, is the reflectivity curve, as derived
from the scattering length density distribution profiles
shown on the right. We found out that the scattering
length density of the styrene-butadiene rubber increases in the vicinity of the SiO2 surface (i.e. the oxide
layer of the silicon substrate). The styrene-butadiene
samples used in these experiments were composedof deuterated styrene and nondeuterated butadiene.
We discovered that the styrene component of the rubber had a higher scattering length density when compared with the butadiene component. Thus, we cansurmise that the increase in scattering length density
around SiO2 indicates that the styrene component of
this styrene-butadiene copolymer has a distribution
bias toward the silica interface. These results indicated that the styrene component of styrene-butadiene
copolymers has strong interactions with the silica
interface.
Next, we examined the effects of various silica
filler contents and silica surface modifications on themobility of the polymer in the vicinity of the silica interface. For these experiments, we prepared rubbersamples with varying silica filler contents, as well as
samples with a fixed silica filler content and various
silica surface modifications, before using QENS to examine the mobility of the polymer in the samples.
Figure 4 shows an example of the results of our
QENS measurements of silica-compounded rubber
using AMATERAS. Since hydrogen atoms possess alarge incoherent scattering cross section, we can view
these results as measuring motion derived from thehydrogen contained in the polymer component of therubber samples. We then performed data fitting basedon the sum of a single delta function (solid black line)
and two Lorentzian functions (blue and pink solid

Figure 4.	Quasi-elastic neutron spectra of silica-filled rubber.

MLF Annual Report 2016lines). The result of this data-fitting calculation is thesolid red line, which closely reflects our experimental results. Using this model, we were able to derive
the relaxation rate. We also utilized the same type ofmodel to analyze QENS measurement results fromsamples with varying silica filler contents or surface
modifications.
Figure 5 shows the variation in relaxation times
with varying silica filler rates within rubber, as measured in our QENS experiments. These results indicatethat the polymer motion does not simply decelerate
in proportion to filler content, but it rather accelerates upon reaching a certain filler content. In addition,
when we examined the effects of various silica surface
modifications on relaxation time, we found that thepolymer mobility could be controlled by altering thesilica surface modification. Further, when we analyzed
the elastic scattering component of our QENS measurements to examine the amount of polymer boundto the silica surface, we found out that altering themodification also resulted in changes in the amountof the bound polymer. In other words, we have discovered that both interactions between styrene andsilica and the mobility of proximate polymer can becontrolled through silica surface modifications.
We then utilized SANS to investigate the thickness of the polymer adsorbed to the filler surface as
one of the physical properties related to the amountof bound polymer. The results of these SANS experiments revealed that the thickness of the polymer
adsorbed to the filler surface was extremely thin, at

Figure 5.	Dependence of the silica volume fraction on residence time in the silica-filled rubber.

Research and Development Highlights

Figure 6. Relaxation times measured in the silica-filled rubber.

just a few nanometers, in polymer that is resistant tosolvent swelling, indicating that it is important to analyze not only the structures, but also the mobility ofthe polymer.
Currently, research analyzing the structures andmobility of the polymer adsorbed to the filler surface
using NSE [3] is beginning to shed light on the relationship between the structure of the polymer adsorbed to the silica interface (as understood throughanalysis of solvent swelling using SANS) and polymer
mobility (as understood using QENS).
Then we utilized the K computer to perform largescale molecular simulations based on the structure
and mobility data obtained from the described experiments. Thanks to these simulations, we were able toelucidate the causes behind the various forms of stressand heat generation that occur within rubber during
deformation. Further, from simulation studies of various new material designs developed to reduce rubberinternal stress, we used SPring-8 BL20B2 to perform
4D-CT scanning with high spatial resolution to analyze the breaking resistance of rubber samples. Theseexperiments allowed us to prove that the rubber samples with the best ability to reduce internal stress were
the same as the ones that were able to suppress theformation of voids, which is one of the causes of tirewear.
We have already found practical applications forthe results of the described research, incorporating
our findings into the development of our ENASAVENEXT II fuel-efficient tires, which have achieved a
51% improvement in wear-resistance performance,compared with the previous generation of tires,
while maintaining the same high level of fuel-efficiency (environmental) performance and grip (safety)
performance.
51

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MLF Annual Report 2016

Acknowledgements
The authors would like to thank the following
people and organizations for their immense and invaluable assistance in carrying out this research: Dr. K.
Nakajima, Dr. K. Shibata, Dr. S. Kawamura, Dr. T. Kumada
and Dr. D. Yamaguchi of the Japan Atomic Energy
Agency’s J-PARC Center; Dr. N. L. Yamada of the HighEnergy Accelerator Research Organization’s Instituteof Material Structures Science; Dr. T. Tominaga, Dr. T.
Yamada, Dr. S. Takata, Dr. K. Ohishi and Dr. J. Suzukiof the Comprehensive Research Organization for
Science and Society; Professor S. Koizumi and Dr. Y.
Noda of Ibaraki University, Associate Professor T. Kogaof the State University of New York; and Photon and
Quantum Basic Research Coordinated Development
Program “Fundamental Understanding of ‘Wear’ and‘Lubrication’ through Coordination of Neutrons andMuons” Project.
References[1] A. Nelson. Journal of Applied Crystallography(2006), 39, 273-276.
[2] M. Takenaka et al., Macromolecules (2009) 42
308-311.
[3] N. Jiang et al., Macro Letters (2015) 4 838-842.

T. Masui and H. Kishimoto
Chemical Analysis Center, Research ＆ Development HQ. SUMITOMO RUBBER INDUSTRIES, LTD.

52

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MLF Annual Report 2016

Hydrogen/Deuterium Dynamics in Kagome Hydroxyl
Salts Co2(OH)3Cl/Co2(OD)3Cl
The hydroxyl salts M2(OH)3X, where M represents
a d-electron magnetic ion and X represents a halogen
ion have been known for a long time. These hydroxyl
salts, specifically the ones that crystallize in deformed
pyrochlore structures, have recently attracted attention
because they were found to be geometrically frustrated magnets exhibiting intriguing magnetic properties
due to the competing interactions on the geometricconfigurations. Furthermore, simultaneous changes intheir unit cell lengths and dielectric constants occurredat their respective magnetic transition temperatures
TN, demonstrating universal magneic-lattice-dielectric
couplings in these hydroxyl salts [1]. Of particular interest is the finding of apparent ferroelectric responses inthe deuterated hydroxyl salts of high crystal symmetries, i.e., rhombohedral Co2(OD)3Cl and Co2(OD)3Br, attemperatures (220-230 K) much higher than their TN [1].
However, the mechanism for the ferroelectricity is still
unclear, and there are very few experimental resourcesthat are capable of detecting the hydrogen dynamics.
On this background, we performed a comparative
muon-spin-relaxation (µSR) study on Co2(OH)3Cl andCo2(OD)3Cl to explore the idea that µSR could “see” thedynamics of deuterium or hydrogen atoms throughprobing the fluctuation of their nuclear fields. This is enabled by the fact that the majority of the positive muonshould form a steady water-like combination with thehydroxyl OD-.
Polycrystalline Co2(OD)3Cl and Co2(OH)3Cl, as synthesized from hydrothermal reaction of NaOD/NaOH(a) 215 K

0.16

Co2(OD)3Cl
Asymmetry

0.14

0.18

ZF
LF 5G
LF 10G
LF 20G
LF 100G

ZF
LF 5G
LF 10G
LF 20G
LF 100G(b) 271 K

0.16

Co2(OD)3Cl

0.14

Asymmetry

0.18

and CoCl2, was used for the µSR experiments at the
J-PARC as well as RIKEN-RAL Muon Facility of theRutherford Appleton Laboratory, Didcot, UK. The powder samples of Co2(OD)3Cl and Co2(OH)3Cl, respectively,
were pressed into a pellet 3 cm in diameter and 1 mm
thick, and then tightly covered with a 25-µm thick highpurity silver foil and mounted to a sample-holder. A
double-pulsed positive surface muon beam was usedwith the temperature controlled by a standard He-4 gas
flow cryostat.
Examples of µSR spectra at two typical temperatures for Co2(OD)3Cl under zero-field (ZF) and longitudinal-field (LF), are given in Fig. 1. Although Co2(OD)3Cl
showed magnetic transition at TC = 10.5 K, the µSR experiments revealed magnetic couplings at much higher
temperatures. The ZF-µSR spectrum consists of KuboToyabe relaxation or dynamic Kubo-Toyabe relaxation
due to the nuclear fields of D and Cl nuclei, and exponential relaxations due to the magnetic spins of Co2+.
For example, for Co2(OD)3Cl at 215 K, a longitudinal fieldof 100 G eliminated the Kubo-Toyabe relaxation due
to the nuclear fields, thus only the exponential relaxations remained (Fig. 1a). Meanwhile, the dynamics ofthe nuclear field at 271 K are apparently different fromthose at 215 K (Fig. 1b). Therefore, by analyzing the ZFµSR and LF-µSR spectra, the distribution of the nuclear
fields and their dynamic change with temperature,i.e., the dynamics of the deuteriums on the lattice ofCo2(OD)3Cl at various temperatures, can be estimated.

0.12
0.1

0.12
0.1
0.08

0.08

J-PARC

0.06
02

J-PARC

0.06
4Time (µs)

6

8

10

0

2

4

6

8

10

Time (µs)

Figure 1.	An example of the µSR spectra under zero-field and longitudinal fields for Co2(OD)3Cl at 215 K and 271 K, respectively,
showing the change in the dynamics of nuclei. The solid lines are fitted according to Eq. (1).

53

MLF Annual Report 2016

A(t) = A1exp(−λ1t)GzDKT(t, Δ1, ν) + A2exp(−λ2t)GzKT(t, Δ2)(1)
Here, the first term is for the [OH/OD]-site muons
given by a combination of an exponential relaxation
due to the magnetic field of Co2+, and a Dynamic KuboToyabe function due to dynamically fluctuating dipolar
moments, where Δ1 represents the line width determined by the nuclear dipolar fields, and ν its fluctuation
rate. The second term is for the Cl-site muons given by
a combination of the exponential magnetic relaxation
and a static Kubo-Toyabe function due to the quasistatic Cl nuclei.
The most interesting result was reflected in thetemperature dependence of the fluctuation rate ν, as isseen in Fig. 2. In the paraelectric phase near room temperatre, the nuclei of D/H fluctuated quickly with a rateof several MHz. For Co2(OD)3Cl, ν rapidly decreased andshowed a critical slowing down following with Tc = Tε =230 K. Therefore, the deuterium atoms were violently
fluctuating at the paraelectric state, then they drastically slowed down toward the ferroelectric transition.
On the other hand, the hydrogen atoms in Co2(OH)3Cl
showed a similar critical slowing toward Tc = 210 K. One
evidence adding credit for the fitting was that being
revealed in the inset plot of Fig. 2, wherein the ratio of
the fluctuation rates for the hydrogen and deuterium
atoms in Co2(OH)3Cl and Co2(OD)3Cl is plotted versus
the temperature. At temperatures above 280 K, the ratio was almost equivalent to a square root of their mass
ratio,
i.e.,		mDνH≈
= √2 .
νD
mH

2.5

3
2.5

2

1.5

2

νH / νD

We found that the ZF-µSR spectra can be precisely
fitted by a physical model assuming two muon stopping sites near the (OD)/(OH) and Cl, as illustrated inFig. 1. In detail, the amplitude of muon spin polarization, A(t), can be expressed by

ν (MHz)Research and Development Highlights

1.51νH / νD

0.5

1

0
240

260

280

T (K)

300

320

ν [Co2(OD)3Cl]
0.5

ν [Co2(OH)3Cl]

0
100

150

200

250

Temperature (K)300

Figure 2.	Temperature dependence of the fluctuation rates νof the nuclear fields for Co2(OD)3Cl/Co2(OH)3Cl. The
thin solid lines are fitted curves according to theformula ν = ν0 ( TTc - 1)1.8 with Tc = 230 K and 210 K,
respectively, for Co2(OD)3Cl and Co2(OH)3Cl.

This strongly suggests the validity of the present
analysis. Therefore, although some imperfectness remained with the fitting function in Eq. (1), it fairly welldescribed the dynamics and the critical slowing of thehydrogen and deuterium atoms in the present system.
The critical slowing of the quantum atoms, however,may involve more complicated processes, like those occurred in the proton-ferroelectric KH2PO4 (KDP) [2].
In summary, the present study has revealed thatthe newly-identified ferroelectric response in the geometrically frustrated magnet Co2(OD)3Cl occurs with adrastic change in the dynamics of the deuterium atoms.
The present research supplemented by experiments of
NMR and Raman spectroscopic investigations has been
published in a recent paper [3].
References[1] X. G. Zheng et al., Phys. Rev. B 87 (2013) 174102 (1-8).
[2] S. Koval et al. Phys. Rev. Lett. 89 (2002) 187602; Phys.
Rev. B 71 (2001) 184102.
[3] X. L. Xu et al., Phys. Rev. B 95 (2017) 024111 (1-10).

X. G. Zheng1, X. L. Xu1, I. Yamauchi1, and I. Watanabe2
Department of Physics, Saga University; 2Advanced Meson Science Laboratory, RIKEN Nishina Center for Accelerator-Based Science

154

MLF Annual Report 2016

Research and Development Highlights

Behavior of Hydrogen as Simulated by µ+ in Conductive
and Functional Cement C12A7
Electric conductivity and optical transparency areoften contradicting features in electric materials, as one
can see that metals are shiny and optically nontransparent. Further, the low-work function (minimum energy
for a photon to excite a photo-electron) and stability ofthe material in the air are often incompatible features,as it has been observed, most low work function materials, such as, alkaline metals or alkaline earth elements,
are unstable due to high reactivity to air moisture.
Mayenite Ca12Al14O33, which has the same composition as 12 CaO (quick lime) and 7 Al2O3 (alumina), and ishence abbreviated as C12A7, is one of the rare examples
of such incompatible features: it has low-work function(~2.4 eV being comparable to alkaline metals) as well as
high stability in the air. These magical properties stemfrom the material’s peculiar structure: C12A7 consists of apositively charged lattice framework (Fig. 1), which looks
like a series of cages, and loosely bound oxide ions O2−
within the cage in the pristine insulator phase. The oxide ions are easily reduced by Titanium reducer to leave
an electron in the cage. This material is, hence, a class ofelectride, in which single electron serves as an anion, anegatively charged species to balance the charge neutrality of the material, a role usually taken by negatively
charged ions. Because of the light mass and quantum
mechanical overlap of the extended wave function ofelectrons in the cage, this material becomes conductive
after reduction. The low-work function occurs because of
the loose binding energy of the electride electrons, andthe stability is due to the strong cage structure of the lattice framework. The electrically contradicting features ofthis material are thus realized by the sharing of roles of

Figure 1.	3D representation of the crystal structure of C12A7
Mayenite in stereogram. Cages of Al-Ca-O are interconnected with each other. Ca, Al and O are represented as large dark gray, medium light gray, andsmall red spheres, respectively.

the lattice structure and electride electrons [1].
In 2012, Ruthenium loaded C12A7 was identified
to have a catalytic activity for ammonia synthesis under much lower pressure and temperature than in theindustrialized Haber-Bosch method [2]. Although thecatalytic function occurs at the surface of Ruthenium,
the C12A7 electride serves as an electron donor for thereaction mechanism and the cage structure for the temporal storage of hydride ions (H−), which otherwise covers the Ruthenium surface to lose its catalytic function(hydrogen poisoning). In this context, to understandthe functionality of C12A7, it is necessary to conduct a
microscopic probe to clarify the behavior of the hydrogen, which may take positively charged H+, neutral H0or negatively charged H− states.
Beams of positive muons (µ+) are employed to tackle
this question; the muon is an elementary particle with
sufficiently high intensity and spin polarization available at large accelerator facilities, such as, Materials andLife Science Experimental Facility (MLF) at J-PARC (Japan
Proton Accelerator Research Complex), which makes it
possible to use muon beams as a probe to investigate
the materials’ properties. Depending on the surrounding
environment, a positive muon in a matter captures zero,one or two electrons to form the positively charged µ+,
neutral muonium Mu0, or negatively charged Mu− state,
simulating the behavior of impurity hydrogen in the
low-concentration limit. By spectroscopy, called muon
spin relaxation (µSR), the three charged states are readily
distinguished by observing the effective gyromagnetic
ratio (the frequency vs. applied magnetic field ratio) todistinguish between Mu0 and other charged states, andby high-field chemical shifts, between µ+ and Mu−.
Figure 2 shows the time evolution of the muon
spin in C12A7, with nominally pure insulating composition [3]. The observed effective gyromagnetic ratio between the precession frequency and applied magnetic
field is that for diamagnetic muons in charged states(µ+ or Mu−), rather than in the neutral state Mu0. The
sign of the chemical shift and doping dependence ofthe precession signals indicate that the muon takes aµ+ state in the insulating C12A7, most likely the [O-µ]−(= O2−-µ+) complex with the oxide ion O2− in the cage,
whereas it transforms into the negatively charged stateMu− as the electron doping proceeds by reduction (oxide ion removal) [3].
55Research and Development Highlights

1.0

MLF Annual Report 2016(a)Insulating C12A7
Zero-field 5 K

2

1
0.8

0.0

0.6
0.4

Transverse-field 5 mT
300 K
5K

-1.0
0

2

4
6
Time (µs)

810Figure 2.	Time evolution of the muon spin in insulating
C12A7 observed at a temperature of 300 and 5 K.
The precession frequency for the applied transverse
field (TF = 5 mT) exhibits the signature of charged
muon states (µ+ or Mu−). For Mu0 state, the frequency would have been 100 times faster [3].

To test the [O-µ] complex scenario in the insulating C12A7, the muon position was calculated within theframework of the density functional theory (DFT) for
electrons. The calculation shows that the [O-µ]− complex site is stable, and estimates the crystalline orientation dependence of the nuclear dipolar fields from
Al (Fig. 3). A qualitatively identical orientation dependence was observed by the muon measurement,
supporting the [O-µ]− complex formation [3]. By combining calculation at the KEK supercomputer and muon
measurement at MLF of J-PARC and other facilities (PSI
in Switzerland and TRIUMF in Canada), the muon (= hydrogen) electronic and positional states in C12A7 functional material were clarified.
This work was supported by MEXT Elements Strategy
Initiative to Form Core Research Center. The theoretical calculations were performed under the Large Scale
Simulation Program No.14/15-13 (FY2014-2015).
−

0.2
0

0

1

4

2

3
0.2

0.4

(b)

a

0.6

0.8

1

θ
Muon spin(001)µ+
sampleH = 20 mT

0.14
δn
Average

0.12

O

Ca

Al

b

-0.5

Relaxation rate (µs−1)

Gx(t), Gz(t)0.5−Hartree potential (eV)−12 −10 −8 −6 −4 −2 0

0.1
0.08

4

2

1

3

0.06
0.04
0.02
0

0

45

90
135
θ (Degree)180

Figure 3.	(a) Hartree potential calculation and stable muon
positions (1-4) in insulating C12A7, and (b) comparison of the angle dependence for the muon
spin relaxation rate between measurement (δn) andtheory (lines).

References[1] J. A. McLeod et al., Phys. Rev. B85, 045204 (2008).
[2] M. Kitano et al., Nature Chem. 4, 934 (2012).
[3] M. Hiraishi et al., Phys. Rev. B93, 121201(R) (2016).

M. Hiraishi1, K. M. Kojima1,2, M. Miyazaki1, I. Yamauchi1, H. Okabe1, A. Koda1,2, R. Kadono1,2, S. Matsuishi3, and H. Hosono3,4
Muon Science Laboratory and Condensed Matter Research Center, Institute of Materials Structure Science, High Energy Accelerator
Research Organization; 2Department of Materials Structure Science, The Graduate University for Advanced Studies (Sokendai); 3Materials
and Structures Laboratory, Tokyo Institute of Technology; 4Materials Research Center for Element Strategy, Tokyo Institute of Technology(MCES)
1

56

MLF Annual Report 2016

Research and Development Highlights

Chemical Environmental Effect on Negative Muon
Capture by an Atom Targeted to Gaseous Simple Carbon
Oxides: CO, CO2
1. Introduction
Muonic atom is an atomic system, where a negative muon (muon) replaces an electron. When a muonis stopped in a substance, it can be captured by the
Coulomb field of a nucleus and a muonic atom isformed. The captured muon’s individual quantum stateis like that of an orbital electron, and the muon is in ahighly excited state right after the muonic atom formation. The captured muon immediately cascades down
to muonic 1s state through characteristic X-ray (muonic
X-ray) and Auger electron emissions (muon cascading
process). The energies of the muonic X-rays are very
high due to muon’s heavy mass. The intensity of themuonic X-ray reflects the muon capture probabilityof the atom, and the X-ray structure reflects the initialquantum state (principal quantum number and angularmomentum quantum number) of the captured muon.
In this paper, such muonic atom formation is defined as
direct capture.
In hydrogen containing system, very unique muonic atom formation is occurred. When a muon is stopped
in hydrogen-containing substance, it is captured bya hydrogen atom, the only electron in the atom is replaced by the muon and a muonic hydrogen atom isformed. The muonic hydrogen atom can be regarded
as a tiny electrically neutral particle due to the strong
shielding effect of nuclear charge by the muon. In fact,
the muonic hydrogen atom can diffuse in the substanceeasily like a neutron. The muonic hydrogen atom canpenetrate an electron cloud without Coulomb repulsion and approach closely the nucleus of another atom.
When the muonic hydrogen atom reaches the heavier
nucleus (Z > 2), it transfers the muon to the deeper
atomic levels of the nucleus (muonic Z atom is formed).
This phenomenon is called muon transfer process. Since
the energy potential of the Z atom (muon accepter) is
more stable than that of the muonic hydrogen atom(muon donor), the muon transfer process progresses
spontaneously.
It is known that the muon capture processes arestrongly influenced by the structure of the muon capturing molecule. The muon capture probability of each
atom (muon capture ratio) and the initial quantum

state of the captured muon change drastically. For
example, the muon capture ratio of boron atom to nitrogen atom for boron nitride with a cubic structureis 20% smaller than that of a hexagonal structure [1].
This is known as the chemical environmental effect onmuon capture.
There are many studies related to muon capture
phenomena, but the chemical environmental effects
still have not been well investigated. Due to difficulties
in the experimental method, most of the previous studies have targeted only high-density samples, such as
solids, liquids and high-pressure gases. In such conditions, muon capture processes are quite complicated.
Since the muon cascading process and the electron refilling process compete with each other in high-density
materials, the muonic X-ray structure varies according
to the sample density. In fact, a previous study reported
that muonic X-ray structures are strongly influenced bysample’s density (density effect) [2]. Unless the density
effect is grasped precisely, the initial process of muon
capture cannot be understood from the muonic X-ray
structure.
To reveal the chemical environmental effect onmuon capture, we focused on low-pressure (below
100 kPa) gases. In these conditions, we can simplify themuon cascading process. Our group previously performed muon irradiations of simple gaseous molecules
containing nitrogen and oxygen atoms (NO, N2O andNO2) [3]. For this study, we chose molecules containing
carbon and oxygen atoms (CO, CO2) and their hydrogenmixture as muon irradiation samples.
2. Experimental
All muon irradiation experiments were performed
at D1-Port, Muon Science Establishment (MUSE) in MLF.
The experimental setup is shown in Fig. 1. Low-pressure
sample gases (40 kPa CO, 20 kPa CO2, 99 kPa H2 + CO(1%), and 99 kPa H2 + CO2 (1%)) were put into a gas
chamber and irradiated with low-momentum muon
beam (18.8 MeV/c). Muonic X-rays were measured by
germanium semi-conductor detectors. From a previous
experiment [3], we determined the sample pressuresthat ignorable the density effect.
57

Research and Development Highlights

MLF Annual Report 2016

Figure 1.	Schematic view of the setup for the muon irradiation experiment.

3. Results and discussions
Muonic X-ray spectra for CO and its hydrogen mixture(H2 + CO) are shown in Fig. 2. A high-purity muon beam
enabled us to obtain higher transition than Kγ X-rays.
The muonic X-ray structures (Kβ/Kα, Kγ/Kα … X-ray
intensity ratios to Kα) for muonic carbon, and muonic
oxygen, are shown in Fig. 3. The initial energy level ofthe captured muon can be estimated from the muonic
X-ray structures. In the case of direct muon captures for
CO and CO2, tremendous difference appears in the X-ray
structure of the muonic carbon (Fig. 3 a). This result implies that the initial capture level of the muon is different
between CO and CO2. Whereas, in the case of the muontransfer from muonic hydrogen, muonic X-ray structures
are almost the same between CO and CO2 (Fig. 3 c, d). This
result indicates that the molecular structure does not affect the initial quantum state of the muons captured bycarbon and oxygen atoms via the muon transfer process.
The muon capture probabilities of carbon and oxygen atoms can be obtained from the total intensity ofthe muonic Lyman X-ray series of each atom, since thecaptured muon finally de-excites to muon 1s state. The
experimental muon capture ratios per atom (A(C/O))
for CO, and CO2 molecules are determined as shown in
Table 1. In the case of direct muon capture, we foundmore than 30% difference in the muon capture ratios
between CO and CO2 [4]. Whereas, in hydrogen mixture
samples, we found the muon capture ratio A(C/O) of CO
to be similar to that of CO2 [5].
From the result of muonic X-ray structure and muon
capture ratio, we concluded the following: 1) The captured
muon undergoes a different cascade process depending on whether it is acquired by direct capture or muontransfer, 2) In this experimental condition, the effect of thechemical environment on the muon transfer process ismuch smaller than on the direct muon capture process.
58

Figure 2.	Muonic X-ray spectrum of a) CO 40 kPa, and b) H2+ CO 99 kPa, obtained by germanium semiconductor detector measurement. Higher transition thanKγ X-rays are observed in both spectra. Spectrum(a) is reflected muon direct capture, spectrum (b) isreflected muon transfer.

Figure 3.	
Muonic X-ray structure of CO and CO2 sample.
These graphs indicate the relative muonic X-ray intensity (per Kα) of each transition series. The tops oftwo spectra are reflected the direct capture and thevertical axis is log scale (a, b), the bottom two spectra reflect the muon transfer and the vertical axis islinear scale (c, d).

MLF Annual Report 2016

Table 1.	Relative muon capture probability of carbon to oxygen atom (muon capture ratio). These values arecorrected by the number of atoms in the molecule.

samplesA(C/O)

CO, 40 kPa

0.753 ± 0.021

CO, 20 kPa

0.549 ± 0.023

H2 + CO (1%), 99 kPa

0.649 ± 0.032

H2 + CO2 (1%), 99 kPa

0.656 ± 0.036

4. Conclusion
We performed negative muon irradiation to lowpressure gaseous samples (40 kPa CO, 20 kPa CO2,
99 kPa H2 + CO (1%), and 99 kPa H2 + CO2 (1%)) at D1port, MUSE, MLF, and determined the muon capture
ratio of carbon atom to oxygen atom and the muonic
X-ray structure of carbon and oxygen atoms. From theexperimental result, we found that the captured muon
undergoes a different cascade process depending onwhether it is acquired by direct capture or muon transfer. Also, we realized that the effect of the chemical environment on the muon transfer process is much smaller
than on the direct muon capture process.
5. Future Plans
The chemical environmental effect on muon capture has not been comprehended enough. We hopethat our study will be an important milestone in revealing the chemical properties of the muonic atom, andResearch and Development Highlights

will establish a whole new scientific field. Recently, we
performed muon irradiation for COS and CS2 gases,
and their hydrogen mixture. We also found that themuon capture ratio per atom (A(S/C)) changed after themuons were captured by COS and CS2 molecules via
muon transfer. Such a trend has never been reported
before, however, the results did not provide sufficient
statistics to confirm it. We expect to obtain enough statistical data in the next experiment, and start the new
discussion.
References[1] H. Schneuwly, M. Boschung, K. Kaeser, G. Piller, A.
Ruetschi, L. A. Schallcr and L. Schellenberg, Phys.
Rev. A27, 950 (1983).
[2] K. Kirch, D. Abbott, B. Bach, P. Hauser, P. Indelicato,
F. Kottmann, J. Missimer, P. Patte, R. T. Siegel, L. M.
Simons and D. Viel, Phys. Rev. A59, 3375 (1999).
[3] K. Ninomiya, W. Higemoto, T. U. Ito, T. Nagatomo, P.
Strasser, N. Kawamura, K. Shimomura, Y. Miyake, M.
Kita, A. Shinohara, K. Kubo, and T. Miura, KEK-MSL
Progress Report 2011 (2012) 31.
[4] G. Yoshida, K. Ninomiya, T. U. Ito, W. Higemoto, T.
Nagatomo, P. Strasser, N. Kawamura, K. Shimomura,Y. Miyake, T. Miura, M. K. Kubo and A. Shinohara, J.
Radioanal. Nucl. Chem. 303, 1277 (2015).
[5] G. Yoshida, K. Ninomiya, M. Inagaki, W. Higemoto,N. Kawamura, K. Shimomura, Y. Miyake, T. Miura, M.
K. Kubo, and A. Shinohara, Radioisotopes 65, 113(2016).

G. Yoshida1,2, K. Ninomiya2, M. Inagaki2, T. U. Ito3, W. Higemoto3, P. Strasser4, N. Kawamura4, K. Shimomura4, Y. Miyake4, T. Miura1,
M. K. Kubo5, and A. Shinohara2
1
Radiation Science Center, KEK; 2Graduate School of Science, Osaka University; 3Advanced Science Research Center, Japan Atomic Energy
Agency; 4Muon science laboratory, Institute of Materials Structure Science, KEK; 5College of Liberal Arts, International Christian University

59Research and Development Highlights

MLF Annual Report 2016

Metastable Hydrogen Configurations in the BaTiO3−xHx
Oxyhydride Associated with Hydrogen Exchange andTransport
1. Introduction
Oxyhydrides of perovskite titanates ATiO3-xHx (A =Ba, Sr, Ca) are a new class of hydrogen ion conductors,
obtained from ATiO3 by CaH2 reduction [1-3]. O2- ionsin the perovskite lattice are randomly substituted by Hions without creating any detectable amount of vacancies. The substitutional hydridic hydrogen in ATiO3-xHx
is in sharp contrast with the established hydrogen configuration in ATiO3, namely, interstitial protonic hydrogen H+ bound to an O2- ion. Macroscopic gas analysis
revealed that the hydrogen in the solid phase is mobileand exchangeable in its gaseous environment at a relatively moderate temperature of 400°C. Furthermore,
the CaH2 reduction turns the parent band insulators
into paramagnetic metals. These transport and hydrogen exchange characteristics make these materials
potentially suitable for application in mixed electron/hydrogen ion conductors and hydrogen membranes.
Several theoretical models have been proposed on
the stability of hydrogen ions in ATiO3-xHx and their dynamics [4-8]. These studies consistently concluded thatthe most stable configuration is the substitutional H- in
an n-type carrier-rich environment. On hydrogen kinetics, two types of scenarios have been proposed. One isbased on the idea of correlated migration of H-, O2-, andoxygen vacancy VO in the network of the anion site (typeI hydrogen migration) [1,4], as illustrated in Fig. 1(a).
The other model (type-II hydrogen migration) involves
two metastable hydrogen configurations, as shown in
Fig. 1(b). One is the interstitial H+, which supports rapid
proton diffusion [7]. The other is a hydrogen exchange
center composed of two hydrogen atoms trapped in anoxygen vacancy, which forms as a result of the interaction between a substitutional H- and an incoming interstitial H+. Two charge configurations (hydridic 2H- [6]and molecular H2 [7]) were proposed on this center.
In contrast to the theoretical advancements, the experimental insights into the mechanisms of hydrogentransport and exchange in ATiO3-xHx are still quite limited. Here we report microscopic insights from the m+ spinrotation and relaxation (m+SR) method on metastablehydrogen configurations related to the type-II hydrogen migration in a prototypical BaTiO3-xHx compound.
60

Figure 1.	Schematic illustrations of (a) the type-I and (b) the
type-II hydrogen migration models. The conversion
between the interstitial H+ and the hydridic 2H− in(b) involves an electron capture and release (n = 2).

2.	Experimental Insights into the Type-II Hydrogen
Migration Mechanism from μ+SR
m + SR measurements on powder samples of
BaTiO3-xHx (x = 0.1, 0.2, 0.3 and 0.5) were carried out
in the D1 area of J-PARC MUSE, Japan, and in Port 2 of
RIKEN-RAL, U.K., using a 4-MeV surface muon beam.
Spin-polarized positive muons implanted into a solid
lose their kinetic energy by electromagnetic interactions
with the host atoms and are then trapped in local potential minima, not necessarily at the global minimum.
The electronic structures of muonium (a hydrogenlike
m+-e- bound state: Mu) and its ionized species Mu+ and
Mu- in matter are supposed to be very similar to thoseof hydrogen. The as-implanted mixture of Mu states isfar from equilibrium and can involve metastable excitedstates. In BaTiO3-xHx, implanted muons are expected tobehave as incoming excess hydrogen and mimic excitedconfigurations involved in the type-II hydrogen migration model together with H- in the host lattice.
Figure 2(a) shows the time evolution of muon spinpolarization P(t) at 15 K in zero applied field (ZF) for
the x = 0.5 and x = 0.3 samples. The time scale of muon
spin relaxation indicates that it is mainly caused byquasistatic magnetic interactions between muons inMLF Annual Report 2016

Figure 2.	(a) ZF-μ+SR spectra of the x = 0.5 and 0.3 samples at
15 K. The solid curves show the best fits to the relaxation function in Ref. [9]. Partial contribution from theoscillating component is displayed by the dashedcurves. (b, c, d) x dependences of fd and d, p2S, Δ at
15 K in ZF. (e, f ) The most probable atomic configurations associated with the oscillating component and
the Gaussian component. In the model (f ), O2− at thethird nearest neighbor and further anion sites is randomly replaced by H− with a probability of x/3.

diamagnetic environment (Mu+ or Mu-) and surrounding nuclei. The P(t) curves have a damped cosine-likefeature superposed on a Gaussian relaxation curve. The
oscillating signal is a signature of the formation of an entangled two spin-1/2 system with a 1H nuclear spin thatis placed very close to the muon. On the other hand, theGaussian relaxation curve is usually ascribed to muonsthat interact with a large number of surrounding nuclei without creating such a special magnetic coupling.
The two components were tentatively assigned to themetastable configurations involved in the type-II model:
the oscillating component for the hydrogen exchange
center and the Gaussian component for interstitial Mu+,
as illustrated in Fig. 2(e) and (f), respectively. ZF spectra
at 15 K were analyzed based on this picture [9] and thex dependence of fitting parameters were obtained, as
shown in Fig. 2(b, c, d). fd is a characteristic frequencyof the oscillating component, which is a function of the
distance d between a muon spin and a strongly coupled
1H spin. Its average length of 1.64(1) Å agrees well with

Research and Development Highlights

the theoretical H-H distances of 1.67 and 1.64 Å for hydridic 2H- centers in SrTiO3-d [5], which have a slight difference in their local structure. This agreement suggeststhat a hydridic (Mu-, H-) configuration is more likely thana molecular MuH one with d = 0.74 Å. A linear increasein the fraction of the two-spin component p2S with theoscillating feature consistently supports this picture. D
is a Gaussian relaxation rate for the interstitial Mu+ component. The x dependence of D is reproduced well witha numerical calculation of the root-mean-square widthof the nuclear dipolar field at the interstitial Mu+ site, as
shown in Fig. 2(d) with a solid curve.
We also investigated temperature dependences ofthese parameters for the x = 0.5 sample up to 450 K andobtained evidence for interstitial Mu+ diffusion and retrapping at a deep defect [9]. This retrapping process is
not taken into account in the type-II hydrogen migration model and could be a rate-limiting step of macroscopic hydrogen transport in the BaTiO3-xHx lattice.
3. Conclusion and Outlook
We investigated metastable hydrogen configurations associated with the type-II hydrogen migration
mechanism in the BaTiO3-xHx lattice by the m+SR spectroscopy. Our experimental results are mostly in linewith the theoretical proposal involving the hydridic
2H- intermediate state, which would work as a hydrogen exchange center. On the other hand, our approachtells nothing about the type-I hydrogen migration inthis compound. The m-SR method, another branch ofmSR using negatively charged muons, may give us an alternative way to challenge this issue because it enables
to trace the diffusion of (muonic) oxygen ions closely
connected to that of hydride ions.
References[1] Y. Kobayashi et. al., Nat. Mater. 11, 507 (2012).
[2] T. Yajima et al., J. Am. Chem. Soc. 134, 8782 (2012).
[3] N. Masuda et al., J. Am. Chem. Soc. 137, 15315 (2015).
[4] X. Liu et al., J. Mater. Chem. A 5, 1050 (2017).
[5] Y. Iwazaki et al., J. Appl. Phys. 108, 083705 (2010).
[6] Y. Iwazaki et al., APL Mater. 2, 012103 (2014).
[7] J. Zhang et al., J. Phys. Chem. C 118, 17254 (2014).
[8] J. B. Varley et al., Phys. Rev. B 89, 075202 (2014).
[9] T. U. Ito et al., Phys. Rev. B 95, 020301(R) (2017).

T. U. Ito1,2, A. Koda2,3, K. Shimomura2,3,4, W. Higemoto1,2,5, T. Matsuzaki6, Y. Kobayashi7, and H. Kageyama7
Advanced Science Research Center, JAEA; 2Materials and Life Science Division, J-PARC Center; 3Institute of Materials Structure Science,
KEK; 4RCNP, Osaka University; 5Department of Physics, Tokyo Institute of Technology; 6Advanced Meson Science Laboratory, RIKEN;
7Graduate School of Engineering, Kyoto University

161Research and Development Highlights

MLF Annual Report 2016

Application of Profile-Fitting Method to Neutron
Time-of-Flight Protein Single Crystal Diffraction Data
Collected at the iBIX
1. Introduction
The neutron time-of-fight (TOF) method uses pulsed
neutrons with continuous wavelengths and is more efficient than the monochromatic method. The IBARAKI
Biological Crystal Diffractometer (iBIX) at the Japan
Proton Accelerator Research Complex (J-PARC), whichis installed on BL 03 at the Materials and Life Science
Experimental Facility (MLF) of J-PARC, is a neutron TOF
single crystal diffractometer used mainly for elucidating
the hydrogen, protonation, and hydration structures of
biological macromolecules in various life processes [1,2] (Fig. 1). The peak intensities of neutron diffraction
from protein single crystals are relatively weak because
neutron beam intensity is lower than X-ray synchrotron
intensity, and proteins have lower crystallinity than organic or inorganic compound crystals. Thus, iBIX has installed a H2 coupled moderator (CM). Some weak peaks
are hidden under the error of strong background generated by strong incoherent scattering of hydrogen atoms in the protein crystals. Therefore, effective methods
to determine accurate integrated intensities for weak
peaks are essential for TOF neutron protein crystallography structural analysis. It has been demonstrated thatthe application of profile-fitting methods to monochromatic X-ray diffraction data can provide more accurate
integrated intensities than summation-integration
methods, especially for weak peaks. The profile-fitting
method for the x and y detector positions has been implemented in monochromatic X-ray single crystal dataprocessing software such as DENZO, MOSFLM, and XDS.

Figure 1.	The inside view of iBIX. 30 two-dimensional detectors are installed. The active area of each detector is
133 × 133 mm and the distance from the sample tothe detectors is 490 mm (Taken from Ref. [7]).

62

To the best of our knowledge, one example of applying
profile-fitting methods in reciprocal space (Q space) to
the TOF single crystal analysis involved TOPAZ, which isinstalled on BL 12 at the SNS with a poisoned decoupledmoderator [3]. Because this case did not include protein
single crystals measured using a diffractometer with aCM, the same fitting function could not be applied to
the neutron diffraction data collected from the iBIX.
Thus, we attempted to find an appropriate fitting function and develop a profile-fitting algorithm for the integration method applicable to the full set of TOF neutron
protein diffraction data collected at the iBIX.
2. Evaluation of asymmetric fitting function
The TOF neutron diffraction data containing the
spatial position and TOF for each neutron are converted
to histogram data. The number of observed neutrons
at x, y, and t corresponding to the horizontal and vertical detector positions (x, y) and a time-of-flight channel (t) are recorded. Because the number of observed
neutrons at each pixel of the peak position of threedimensional (3D) data was insufficient to fit the functions accurately, we used projections of the 3D peakin the direction of the TOF axis to improve the statistical precision. Because the pulsed neutron shape wasasymmetric when using a CM, the projections of the 3D
peaks in the direction of the TOF axis were also asymmetric. Thus, asymmetric functions had to be used in
the profile-fitting method. In order to determine proper
fitting functions for the TOF diffraction data, four asymmetric functions were evaluated using strong intensity peaks, with no overlapping, of TOF diffraction datafrom ribonuclease A collected at the iBIX. These werea Gaussian convolved with two back-to-back exponentials, a pseudo-Voigt function convolved with two
back-to-back exponentials, a Gaussian convolved with
the Ikeda–Carpenter function derived from TOF profile
functions in the GSAS program suite [4], and a Gaussianconvolved with the Landau function. It is important topredict the peak positions and estimate the backgroundaccurately to determine the integrated intensity, especially for weak peaks. All four asymmetric functions
fit well with the strong intensity peaks and significant
differences were not found (Fig. 2). In order to reduceMLF Annual Report 2016

Research and Development Highlights

Figure 2.	Profile-fitting to the hkl = −8 1 0 peak from ribonuclease A crystal using four asymmetric functions. (a) Gaussian convolved
with two back-to-back exponentials fit. (b) Pseudo-Voigt function convolved with two back-to-back exponentials fit.
(c) Gaussian convolved with Ikeda–Carpenter function fit. (d) Gaussian convolved with Landau function fit. In panels (a–c),
SciPy was used to fit the functions and results were plotted by Gnuplot. In panel (d), because Gaussian convolved withLandau function contains convolution part in the equation, ROOT was used to fit the function and plot the results. Bothfour points of the outside regions of the integration region were used as the background region (Taken from Ref. [7]).

the processing time and the number of parameters, theGaussian convolved with two back-to-back exponentials was selected as the most suitable fitting function
and used in the profile-fitting method. This function isanalytical and has five parameters: A, α, β, σ, and Tph.
3. Implemented fitting function in profile fitting
Further details on the fitting function and its parameters are provided as follows.
H(∆T ) = ∫G(∆T - τ)E(τ)dτ= AN[eu erfc(y) + ev erfc(z)]where∞erfc(x) = 2 ∫ e-t dt.
√
π x
2

erfc(x) is an intrinsic function of the scipy.special package in SciPy.
Here,E(τ) = 2Neατ for τ < 0 and E(τ) = 2Ne-βτ for τ > 0,
where α and β are the rise and decay coefficients forthe exponentials. A is an intensity scale parameter. The
original function without A is normalized, and the integrated function area is 1. A refers to the integrated function area. The normalization factor, N, isN=

αβ2(α + β)The Gaussian function is

G(∆T - τ) =1 exp  - (∆T - τ)  , √2σ2 √2πσ2and the Gaussian variance is the coefficient σ2.
The coefficients u, v, y, and z areβ
u = α (ασ2 + 2∆T ), v = (βσ2 - 2∆T ),22y = ασ + 2∆T , and z =√2σ2βσ2 − ∆T.
√2σ2

ΔT is the difference in TOF between the peak position,
Tph, and the profile point, T.
∆T = T − Tph
The parameters α, β, and σ are related to the function profile and are not independent of each other.
4.	Correlation between fitting function parameters
related to profile and TOF
Two conditions for which the profile-fitting method
was accurate were proposed [5]. Firstly, peak positions
can be accurately predicted. Recently, detector parameters (distance between each detector and sample, detector position angles, etc.) and 3-axis goniometer offset
angles were accurately calibrated and accuracy of peak
position prediction was clearly improved. So, the first
condition was satisfied. Secondly, peaks located withina region of reciprocal space or detector space have thesame profile. This is the key assumption when determining weak peak profiles. A projection profile in the63Research and Development Highlights

MLF Annual Report 2016

direction of the TOF axis mainly depends on the TOF,
scattering direction, and crystal orientation with respect
to the beam. The active area of each detector is 133 ×
133 mm and the distance from the sample to the detectors is 490 mm. The maximum scattering angle difference among peaks within a detector is approximately
15°. iBIX contains 30 detectors and each of them measures different scattering angles. Because the maximum
scattering angle difference among peaks within a detector is approximately 15°, we assumed that peak profiles
at one crystal orientation and one detector change depending only on TOF. To prove this assumption, we investigated whether there is a correlation between fitting
function parameters related to profile and TOF. The parameters α, β, and σ are related to the profile. In order toreduce the parameter error values, α was fixed to a proper value and the A, β, σ, and Tph parameters were calculated by non-linear least square minimization. Peaks whoseI/σ(I) were over 5 and with lower parameter errors wereselected and the β and σ parameter values were plottedagainst TOF at one crystal orientation and one detector.
The result from the detector whose 2θcenter is 51° at one
crystal orientation is shown in Fig. 3 as an example. The
overall tendency regardless of detectors and crystal orientations is that β and σ are almost linearly dependent
on TOF. Adjacent TOF peaks have similar β and σ values.
Because β and σ are parameters related to profile shape,these plots show that adjacent TOF peaks have the sameprofile. Additionally, the maximum scattering angle difference among peaks within a detector is approximately
15°, so adjacent TOF peaks are located within a regionof reciprocal space or detector space. We could confirm
that the conditions of the profile-fitting method are satisfied. The weaker peaks with adjacent TOF have larger
parameter errors and the variances of β and σ in thesepeaks tend to be larger. To determine β and σ of weak
peaks more accurately, adjacent TOF and accurate peaks

were selected based on I/σ(I), peak intensity, and parameter errors. Accurate peaks with larger TOF occasionally
do not have similar β and σ values to Fig. 3a. Because
there are few weak peaks adjacent to those peaks, we
do not think this circumstance has a negative effect on
determination of the weak peak profiles.
5.	Application of profile-fitting method to a full setof protein neutron diffraction data
We developed a test program and applied it to a fullset of ribonuclease A neutron diffraction data with nonoverlapping peaks. The program could fit asymmetricfunctions to weak peaks as well as strong ones. Intensity
statistics, with peaks I/σ(I) larger than 0, were calculatedusing the iBIX data processing software STARGazer program [6], and joint refinements of neutron and X-ray
data were carried out using the PHENIX program. In order to evaluate the algorithm utility, the intensity andrefinement data statistics of the profile-fitting method
were compared to those of the summation-integration
method implemented in STARGazer by using the same
integration regions, peaks and initial refinement model.
A summary of the intensity data and refinement
results of ribonuclease A is provided in Tables 1. Moreobserved reflections could be used in the profile-fitting
method than in the summation-integration method. Thisimplies that the accuracy of a part of the negative intensity peaks on the summation-integration method was
improved by the profile-fitting method. The higher the
resolution, the lower the data quality indices Rmerge, Rpim,
Rwork, and Rfree were on the profile-fitting method thanon the summation-integration method. The greatest improvement in Rmerge, Rpim, Rwork, and Rfree was observed in
the highest resolution shell. The differences were 9.5%,
6.8%, 2.3%, and 1.7%, respectively. Because higher resolution shells contain a higher percentage of weak peaks,
it was shown that the profile-fitting method is effective

Figure 3.	Plots of parameters related to the peak profile against TOF in ribonuclease A neutron diffraction data. The peaks whoseI/σ(I) is over 5 and obtained by one detector located at 51° in 2θcenter and one crystal orientation were used. (a) Plot of parameter β against TOF. The peaks whose β errors are less than 1 were used. (b) Plot of parameter σ. The peaks whose σ errors
are less than 10000 were used (Taken from Ref. [7]).

64MLF Annual Report 2016

Research and Development Highlights

Table 1.	Statistics of neutron intensity data and X-ray and neutron joint refinement of ribonuclease A (Taken from Ref. [7]).

* Cell constants were calculated from X-ray diffraction data.

with weak peaks, as in previously reported results. Rmerge,
Rpim, Rwork, and Rfree in the overall resolution range wereslightly improved over the summation-integration method. On the other hand, as peak intensities are stronger
and background counts are relatively lower in the lower
resolution shell, it seems that there is hardly any difference of Rmerge, Rpim, Rwork, and Rfree between the profile-fitting method and summation-integration method.
In this study, we demonstrated for the first timethat the profile-fitting technique is also applicable tocomparatively weak peaks and high-background TOF
neutron protein diffraction data using a CM, and thatthe technique could improve data statistics [7].
The integration component with the profile-fitting
method has already been implemented in STARGazer
and its user manual has been updated. The software andits manual are available for distribution to the iBIX users.
6. Future plans
In the future, the accelerator power of J-PARC will

be increased to 1000 kW, and we will be able to collect
single crystal neutron diffraction data for larger unit cell
crystals, including membrane proteins. Because iBIX wasdesigned to measure samples with unit cells up to approximately 135 Å, problems caused by overlapping ofadjacent peaks are expected. To solve those problems,
we are attempting to apply the profile-fitting techniqueto separate overlapped peaks in the TOF direction.
References[1] Tanaka, I. et al., Acta Cryst. D66, 1194-1197 (2010).
[2] Kusaka, K., et al., J. Synchrotoron. Rad. 20, 994-998(2013).
[3] Schultz, A. J. et al., J. Appl. Cryst. 47, 915-921 (2014).
[4] Larson, A. C. & Von Dreele, R. B., Los Alamos National
Laboratory Report LAUR. 86-748 (2004).
[5] Pflugrath, J. W. Acta Cryst. D55, 1718-1725 (1999).
[6] Ohhara, T. et al., Nucl. Instr. Meth. Phys. Res. A600,
195-197 (2009).
[7] Yano, N. et al., Sci. Rep. 6, 36628 (2016).

N. Yano, T. Yamada, and K. Kusaka
Frontier Research center for Applied Atomic Sciences, Ibaraki University

65

Neutron SourceNeutron Source

MLF Annual Report 2016

Progress of Neutron Source Section
In fiscal year 2016, the important task of the
Neutron Source Section was to overcome two serious
problems that occurred in the previous year. The firsttask was to restore the performance of the cryogenichydrogen system for the moderators by taking proper
measures against abnormal increase of the differential
pressure at the heat exchangers and the adsorber ofthe helium refrigerator. The second was to fabricate aneutron production target vessel with robust structure
capable to withstand the thermal stress due to the repetitive beam trip during the operating period.
As it is described later, the fabrication of the target
vessel took more time to assure the feasibility of the new
fabrication method and welding condition throughvarious mock-up tests. This forced us to extend the useof the target vessel, which has been operated since
February 2016. Considering that the current target vessel does not have the gas micro-bubbles injection system to suppress the pitting damage, the beam power
was lowered from 200 kW to 150 kW after the summer
shutdown period to ensure reliable neutron production
while extending the operation for another year.
1.	Efforts to restore the performance of the helium
refrigerator of the cryogenic hydrogen system
The performance degradation of the helium refrigerator forced us to do the purification operation for
6 days after a 3-week operating period that started in
February 2016. After each operating period, we sampled
the helium gas from the heat exchanger and the adsober to measure the content of impurity elements in thegas with a quadrupole mass spectrometry. However, we
could not find elements composing water such as H2,O2 and H2O. After investigating the past events that resulted in performance degradation in the large helium
refrigerator at other facilities, oil contamination in theheat exchanger was suggested as a possible cause.
Therefore, in the summer maintenance period, weremoved the heat exchangers of the helium refrigerator
from the cold box and transported them to a factory forcleaning with Freon. We also replaced the adsorber witha new one (see Fig. 1). As a result, about 90 g of oil was
extracted from the heat exchanger and a felt in the adsorber. Furthermore, we replaced all filters of the oil separators of the helium compressor with new ones, where
the 300 kg of active charcoal was also exchanged. After
purifying the active charcoal for about 4 weeks, we restarted the operation of the helium refrigerator in the
68

Figure 1.	Photo of adsorber (left) and a felt (right) removed
from inside of the adsorber. Top layer of the felt was
yellowish because of incoming oil.

late October of 2016. Due to various efforts mentioned
above, the differential pressure between the heat exchanger and the adsorber never increased during theoperating period from November to March 2017, meaning that the reliable operation was restored.
2. Improvement of the design of the mercury target
Based on the lessons learned from the failure on
the water shroud of the target vessel that occurred during the 500 kW operation, we have been making efforts
to improve the mercury target vessel under the following plan: 1) minimizing the weld part and the bolt joint
between the water shroud and the mercury vessel, and
2) improving inspection technique to find cracks in theweld part on the multi-layer structure with a thicknessof 3 mm for the shrouds and 8 mm for the mercury
vessel.
We have made a step-wise design upgrade scenario, as shown in Fig. 2. In the first step, the front part of
the target, where the heat load is high during the beam
operation, was changed, so that the water shroud could
be integrated with the mercury vessel. The benefit wasthat the welding line could be reduced by more than30%. The change required us to employ a new fabrication procedure to cut out the integrated forepartstructure with coolant channels from a steel block bymeans of a wire-electron-discharge-machining (wireEDM) technique. The aim in the second step of the design was to make a constrain-free structure between
the water shroud and the mercury vessel in the forepartby removing the ribs. And finally, the water-shroud wasseparated from the mercury vessel completely.

MLF Annual Report 2016

Neutron Source

Figure 2.	Schematic horizontal cross-sectional views of mercury target vessel’s strategic step-wise design improvement. (a) previous
design, (b) target vessel with monolithic structure under fabrication since 2015, (c) constraint-free structure for fore-part,(b) entirely constraint-free type.

To apply the wire-EDM technique, many mock-up
tests were performed. It was time-consuming to cut thecomplicated big geometry with wire-EDM. We also tooktime to stabilize the welding condition to suppress thedeformation in the allowable range. Furthermore, we
increased the frequency for the radiographic and ultrasonic tests. As a result, in the end of March 2017, thefabrication of the target vessel was still on the way of
welding rear part of the mercury vessel to the forepartwith an integrated structure.
In fiscal year 2016, we have also started a structuraldesign of a target vessel with a constrain-free structurein the forepart (second step design). For the fabricationof this target, we employed a new electron beam welding technique for reducing the thermal stress in welding. To investigate the EBW welding condition for the
rib structure in the narrow gap of 3 mm between theouter and inner water shroud plates, some mock-up
tests were performed. The bid of fabrication contract
was awarded in January 2017.
3.	Efforts to shorten the time of target vessel
replacement
In J-PARC, it takes about 32 working days to replace
the target vessel, during which period, the target replacement itself, with remote handling tools, requires
10 days. The off-gas processing is a major cause for thelong time. It plays role in reducing the amount of radioactivity of gaseous radioactive materials of Xe-127

and tritium, generated in mercury via the spallation reaction, to an amount less than the value allowable forexhausting from the stack before removing the target
vessel from the mercury circulation pipes. It also collects helium gas filled into the mercury target system
for the leak check after installing a brand-new target
vessel.
In 2016, we took measures to double the volumeof the gas holders (see Fig. 3), aiming at shortening by
4 days in the helium gas process after the leak check.
As the next step, further improvement will be madeso that the processing and the gas release to the stackcloud be done at the same time.

Figure 3.	Photo of off-gas processing system with three newly installed gas holders.

H. Takada
Neutron Source Section, Materials and Life Science Division, J-PARC Center69

Neutron Source

MLF Annual Report 2016

Approaches to Improve the Robustness of the Mercury
Target Vessel
1. Introduction
During the proton beam operation at ca. 500 kW
in 2015, leakage of a small amount of coolant waterfrom the water shroud was detected in the fifth andseventh mercury target vessels. It was determined thatthe cause of the leakage was an initial welding defect,
which propagated because of repeated thermal stress.
To prevent such problems in the future, the structure of
the mercury target vessel was improved to reduce thenumber of the weld lines and the stress generated byproton beam injections in addition to testing of the fabrication process of the new mercury target vessel using
mock-up models prior to fabrication. Furthermore, radiographic and ultrasonic tests are added to strengthen
the welding inspection.
2. Structure improvement
A schematic of the mercury target vessel is shownin Fig. 1. The length, flange diameter, and total weight
are approximately 2 m, 1.2 m and 1600 kg, respectively.
The target vessel has a triple-walled structure consisting of the mercury vessel and the double-walled water
shroud. The fore part of the mercury vessel with a lengthof ca. 1 m is covered with a water shroud. The intermediate space between the mercury vessel and the water
shroud is filled with helium gas. The design pressure of

the mercury is 0.5 MPaG and that of the coolant waterand the helium gas is 0.2 MPaG.
The previous and the improved designs of the fore
part are shown in Fig. 2. The front-part, where the highheat is loaded during the beam operation, is cut out
from a large block using wire electric discharge machining (EDM) to achieve the monolithic structure tying
with ribs in the improved design. Plate parts of the water shroud of the rear part are cut out from thick plates
using the wire EDM. As a result, the total length of thewelding line is reduced by half.
The stresses of the mercury target vessel during
the beam operation at 1 MW were estimated using thenumerical analysis. The position and width of the ribs
between vessels were optimized to reduce the stress.
Tresca stress distribution on the inner surface of the external vessel caused by combination of internal pressure and thermal loading is shown in Fig. 3. The peakvalue of the thermal stress in the front part satisfies thecriteria of JIS B 8265 when elasto–plastic deformation
mode is taken into consideration. Therefore, new target
is available for the 1 MW beam operation.
ar

Re
nt

Fro

Coolant water
Mercury2m
rtpa

Proton beam

Mercury

Bolt

Vertical cross section

Bolt

External vesselof water shroud
Coolant waterInternal vesselof water shroud
Helium gas
Mercury vessel

Figure 1. Schematic of the mercury target vessel.

70(a) Previous design

1.2 m

re
Fo

Weld line

Vertical cross section(b) Improve design
Figure 2. Schematic of the fore part.

MLF Annual Report 2016

thin disks with a size of f22 × t1.5 mm by welding aftertightening the mercury vessel and the water shroud. Inorder to decrease an amount of the weld and prevent
weld defects, the suitable welding condition was determined using the mock-up model 3 with dimensions of
80 × 160 × 15 mm.

Internal vesselof water shroud

Q 452 MPa

Figure 3.	Tresca stress distribution in the inner surface ofthe external vessel due to the internal pressure
and thermal loading. Conventional finite element
method code; ANSYS R15.0 was used.
Thin disk

Beam windowof water shroud
Beam windowof mercury vessel
Front part

Bolt
Water shroud

Welding

Mercury vessel
Welding
Groove shape

Insert ring
Weld line
Mock-up model 1

Mock-up model 2

Neutron Source

Weld line
Mock-up model 3

Figure 4.	Mock-up models to confirm the fabrication process.

3.	Confirmation of the fabrication process using
mock-up model
The parts of the mercury vessel are joined by a gas
tungsten arc welding. Mock-up tests were conducted toconfirm the fabrication process shown in Fig. 4.
The many ribs connecting the vessels machinedusing the wire-EDM. The machining accuracy was confirmed using the mockup model 1 with dimensions ofapproximately 150 × 500 × 350 mm, because the thickness accuracy of the thin vessel affected the structural
strength.
The gradual changes in the wall thickness of thevessels’ side cause the concern that the side’s welding line may have a weld defect, which could result ina large deformation. In order to achieve a reliable full
penetration weld, the suitable groove shape with an
insert ring and welding procedure were determinedusing the triple-walled mock-up model 2 with a size of
120 × 350 × 200 mm.
In the rear part, upper area of bolt are covered with

4. Strengthening of inspection
The penetrant test and the pressurized test havebeen conducted as welding inspection. The radiographic test and the ultrasonic test were also added
to welding inspection to detect the small weld defect.
Against the repeated thermal stress in 1 MW operation,
the allowable size of the weld defect was estimated tobe less than 0.4 mm.
The detectable defect size of the radiographic
test is approximately 2% of thickness of the test subject. However, the result of the mock-up test showedthat the detection size in the multi-walled structure
decreases by scattering at the intermediate space between vessels. Therefore, the ultrasonic test should also
be conducted.
Since the JIS prescribes the ultrasonic method forplates with thickness of more than 6 mm, this method
can’t be used in the inspection of the water shroud with
3-mm thin wall. The water-immersion ultrasonic test using scanning ultrasonic system (Insight k.k, Flex Scan) isused, which is suitable for thin plates. The frequency of
the ultrasonic probe and the scan pitch are 50 MHz and
0.1 mm, respectively. The result with the mock-up test
showed that the detectable defect size is approximately
0.2 mm for a 3-mm plate (Fig. 5).
Schematic drawing

RT image

φ1.0
Voids

φ0.2 φ0.6 φ0.5
φ0.5 φ0.5
φ0.8 φ0.5

UT image

Figure 5.	Typical result of radiographic test (RT) and ultrasonic test (UT) on the specimen with artificial weld
defects.

T. Wakui, E. Wakai, H. Kogawa, T. Naoe, K. Haga, and H. Takada
Neutron Source Section, Materials and Life Science Division, J-PARC Center71

Neutron Source

MLF Annual Report 2016

The Status of the Cryogenic Hydrogen System
1. Introduction
At MLF, a cryogenic hydrogen system provides cryogenic hydrogen to the moderators at supercritical pressure of 1.5 MPa, with para-hydrogen concentration of
more than 99% and temperature lower than 20 K, generating high-performance pulsed cold neutron beams.
This system consists of a helium refrigerator system anda hydrogen circulation system, as shown in Fig. 1.
Since January 2015, the pressure differences at
the heat exchangers (HX-1 and HX-2) and an adsorber(ADS) increased gradually [1]. Various investigations
and measures were performed, but the problem was
not solved. In the 2016 summer maintenance period,
we decided to carry out cleaning of the inside heat exchangers, replacement of ADS, a check of the oil separators and an exchange of the filters on the assumptionthat oil accumulation may have caused the performance degradation [1].
He, H2 cylinder storage room

Compressor room
Liq. nitrogentankCompressor
Oilseparators

He buffer
tank

Activatecharcoal(OS-5)

3. Recovery measures during the summer outage
3.1 Cleaning of the inside heat exchangers
The heat exchangers (HX-1 and HX-2) with HX-3
were taken out from the cold box (Fig. 2). They weretransported to a cleaning factory in Hyogo. The Freon,
ASAHIKLIN AK-225G (c.a. 480 litters) was used to clean
the inside heat exchangers.
The cleaning procedure was as follows: filling with
Freon, circulating for 1 hour, circulating again withnitrogen gas bubbles for 1 hour, dipping overnight,
circulating again, and then removing the Freon. The extracted Freon (c.a. 350 ml) was analyzed to measure theoil content by the NVR (Non-volatile residue) method.
These procedures were repeated three times. We foundthat total amount of accumulated oil inside the heat exchangers was about 94 g. It seemed that the amount of
measured oil was roughly equivalent to the projected
one from the accumulation of oil contained in the helium gas (10 ppb), which was the design value.

He cylinders

Stuck

H2 cylinders
To blanket
To H2 loop

MLF building
Safety box
H2 pumps
Heater

TurbineCold box

N2 flow

HX3

He flow

HX1
HX2

Accumulator

Adsorber Heater(ADS)

Helium refrigeration system

72

Ortho-para
Hydrogenconverter

Moderators
C

H2-He
HX
H2 flow
Helium blanket

D

P

Hydrogen circulation system

Figure 1. The cryogenic hydrogen system.

Figure 2. Taking out the heat exchangers from the cold-box.

2. Operation until the summer outage
In order to keep the user beam schedule, which was
already planned until the end of June, we changed theoperation cycle of the cryogenic hydrogen system, to
3-week operation (up to the allowed maximum pressure difference) and a 1-week shutdown until the summer maintenance period. Because we found out thatafter every restarting operation, the pressure difference
dropped to its initial level in the previous operations.
We also reduced the helium flow by 25% to suppress
the oil exhaust from compressor to downstream. This
operation cycle worked well for the user schedule until
the end of June.

3.2 ADS replacement and analysis
The ADS was replaced with a new one because
most of the pressure difference was generated there.
The ADS was removed from the cold box, and then a
new one with the same design was installed in thesame position. The activated charcoal in the new ADS
was regenerated by nitrogen gas heated to 100°C in order to remove moisture.
We observed the inside of the inlet and outlet
area of used-ADS by fiber scope and ultraviolet light.
The surfaces of the inlet and outlet area were relatively
clean. There was little glistening oil that was illuminatedby ultraviolet light. The used-ADS was dismantled to its

MLF Annual Report 2016

components, such as felt and activated charcoal. We
found that the just surface (3 mm in thickness) of theupper felt, where the helium gas entered first, was yellowed, visually it resembled oil color. We measured theamount of oil in the felt. The oil concentration in the felt
and charcoal was analyzed by solvent extraction andinfrared spectroscopy. The upper and lower felts haveeight separate layers and the thickness of the felt is
4 cm. The analyzed results are shown in Fig. 3. The total
amount of accumulated oil was 48.0 g in ADS, however,
the total accumulated oil in ADS was also equivalent to
the projected one from accumulation of oil containedin helium gas. Almost all oil (45.6 g) was trapped in
the upper felt and even more surprisingly, 17.7 g of it
was accumulated in the first layer of the upper felt. It
seemed that the upper felt played the role of an oil filter. Generally, the felt was used not as an oil filter, but forholding the activated charcoal. We concluded that evenif small amount of oil builds up, the accumulated oil
forms a film on the surface of the felt that might causepressure difference during the cooling down process.

Neutron Source

The lowest piping that is an outdoor piping between the compressor and the cold box in this refrigerator was observed by a fiber scope and ultraviolet
light. As a result, no oil reaction was registered, oil did
not accumulate in the piping.
4. Recovery of the refrigerator performance
After the described measures taken during thesummer outage in 2016, the refrigerator could be operated for the total of over fifty days (November 1 to
December 20, 2016 and January 12 to March 8, 2017)
without any problem. During the operation, the differential pressure at the heat exchangers (HX-1 and HX2) and the ADS did not increase excessively, as shownin Fig. 4. The outlet temperature of the heat exchanger
HX-2 also did not increase.

Figure 4.	Trend of differential pressure at heat exchanger
HX-1 and HX-2 (ΔP1) and ADS (ΔP2) before and after the summer maintenance.
Figure 3. Result of the oil analysis of the used ADS.

3.3 Other maintenance
We have three oil separators (OS-2, 3, 4) and one oil
adsorber (OS-5) unit in order to separate the oil fromthe helium gas after going through the screw compressor. During the summer outage, we confirmed that theOS-2, 3, 4, and 5 were in their normal condition, without
any clogging or breakage of the filter. No problems were
found during the check. Although the filters had notreached the end of their lifetime, they were exchanged
new ones to maximize the oil separation capability.

5. Summary
The performance of helium refrigerator has been
restored by maintenance measures to remove oil, suchas cleaning the heat exchangers with Freon and replacing ADS. However, at this moment, we still have not
identified the cause of the incident. We will carry out
further investigations, including experiments and adding monitoring in order to reveal the phenomena.
Reference[1] T. Aso et al., MLF Annual Report 2015, 57-58, (2016).

T. Aso, M. Teshigawara, S. Hasegawa, H. Muto, K. Aoyagi, and K. Nomura
Neutron Source Section, Materials and Life Science Division, J-PARC Center73

Neutron Source

MLF Annual Report 2016

Present Status of the Spare Decoupled Moderator
Fabrication
1. Introduction
The structural material of the moderator and reflector,
such as aluminum alloy, will reach its design value (20 DPA)
around 2019 due to an accumulated-irradiation-damage.
The fabrication of a spare moderator and reflector ismoving ahead according to a 2013 plan to replace thesecomponents. This year, the fabrication of the decoupledmoderator was just completed, following the completionof the coupled moderator and reflector. Finally, the poisoned decoupled moderator will be fabricated in 2018. We
report the production status of the decoupled moderator.
2. Decoupled moderator fabrication
The Silver-Indium-Cadmium (Ag-In-Cd) decoupler
was used for producing neutron beams with sharp
pulse shape in the previous decoupled moderator andreflector. Gold (Au), instead of Ag, was selected to reduce dramatically the radioactivity of used components
without sacrificing neutronic performance. However,the bonding between Au-In-Cd (AuIC) and aluminumalloy (A5083), which is a part of the structural materialof the decoupler layer of the decoupled moderator, isrequired in terms of heat removal and thermal stress.
The issue is to develop decoupler layer with curved
curvature of AuIC and A5083 alloys (A5083 (1 mm) AuIC (3 mm) - A5083 (3 mm)) bonding material thathas a curved curvature for the decoupled moderator as
shown in Fig. 1. We applied a new casting technique to
produce AuIC plate with curvature and a Hot Isostatic
Pressing (HIP) technique to make bonding material between AuIC and A5083 alloys.

Since the Restriction of Hazardous Substances directive was enforced by the European Union in 2006,
it has become impossible to make new materials that
include Cd on an industrial scale in Japan. When a newalloy based on Cd is produced for research purposes,
we can only obtain it by developing it ourselves, andeven then it is only in laboratory amounts.
We could produce AuIC plates with curved curvature with thicknesses of 3 mm by casting an AuIC ingot(with diameter of 80 mm and thickness of 20 mm) inan alumina boat. The AuIC ingots were produced by anohmic heating method [1]. These plates were cut to thedesired shape using a wire electrical discharge machining (WEDM) method, and were spread along curved
curvature of aluminum mold as shown in Fig. 2. The
manufacturing tolerance was within ±0.3 mm, which
satisfied the required design. This small manufacturing
errors are very important to suppress the deformation
caused by the HIP process.
As mentioned above, the HIP process was applied
to obtain the bonding material between AuIC and
A5083 alloys. The optimal bonding condition (100 MPa
pressure, 535°C temperature and 1-hr holding time)
was already found for AuIC coin shaped small test piece(3 cm in diameter × 2 mm in thickness) by adopting a
HIP process [2]. We produced successfully a decoupler
with curved curvature based on this HIP process condition. Figure 3 shows the result of the ultrasonic reflection test. All reflections between AuIC and A5083 were
found in the ultrasonic reflection images, resulting inno separation between the AuIC and A5083 alloys.

AuIC

A5083

1 mt
3 mmt

Be

LH2

AuIC (3 mmt)

5 cm

Figure 1. Cutway view of decoupled moderator.

74

A5083

5 cm

Figure 2.	Preparation of HIP process parts with curved curvature (AuIC and A5083).

MLF Annual Report 2016

Neutron Source

AuIC
A5083

Invar joint

Decoupled moderator
head

Figure 3.	Ultrasonic reflection test after HIP and machining
process.

Figure 4.	Photograph of decoupled moderator head during
fabrication process.

In the spare moderator design, the invar joint withthe lowest thermal expansion was also adopted to improve the special fabrication, such as an asymmetricalsetting at an elbow-shaped bend in the cryogenic (hydrogen) pipe due to thermal shrinkage of aluminumand stainless steel (SS316L), which was employed forthe previous moderator design. The invar joints, such as
invar-A6061 and invar-SS316L joints were developed by
the friction weld method [3] to utilize in the cryogenic
pipe and implemented in the moderators, as shownin Fig. 4. The adoption of invar alloy ensured an easierfabrication due to the low thermal expansion in comparison with the previous one. Finally, many tests, suchas appearance inspection, dimensional check, welding
inspection, cooling test, etc. were performed before thedecoupled moderator fabrication was completed.

Acknowledgment
We are grateful for the cooperation of Metal
Technology Co. Ltd. in the fabrication of the sparedecoupled moderator. We also thank the Nippon
Advanced Technology Co., Ltd. staff for their help in the
Au-In-Cd material preparation.
References[1] M. Ooi, et al., Journal of Nucl. Mat. Vol. 431 (2012)
pp. 218-223.
[2] M. Ooi, et al., Journal of Nucl. Mat. Vol. 450 issue 1-3(2014) pp. 117-122.
[3] M. Harada, et al., Journal of Nucl. Mat. Vol. 450 issue
1-3 (2014) pp. 104-109.

M. Teshigawara, M. Harada, and M. Ooi
Materials and Life Science Division, J-PARC Center, JAEA

75

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MLF Annual Report 2016

Progress of the Proton Beam Transport (3NBT)
1. Introduction
In Japanese Fiscal Year (JFY) 2016, a beam for neutron
and muon production with power of 150 and 200 kW had
been steadily delivered by 3NBT, which is beam transport from the 3-GeV synchrotron (called Rapid Cycling
Synchrotron: RCS) to the target placed at the MLF. Since
the mercury target was not equipped with a helium bubbler to mitigate the pitting erosion, the high-power beam
operation was prohibited in JFY 2016. After the planned
replacement of the mercury target during the summer
outage in 2017, the beam operation with 300 kW will resume and the power will reach 1 MW in a few years. The
introduction of higher proton beam power to the target
will require attention to the beam operation to guarantee
the necessary safety level. To ensure a reliable beam operation, a beam tuning tool and beam loss monitor will be
required. Also, the increase of the radioisotope production
in cooling magnet’s water between the mercury target
and the muon production target will require treatment of
the water system.
2. Development of a beam tuning tool
Since the time for tuning of the beam was limited, an
efficient tuning tool was required. To mitigate the pitting
erosion at the mercury target, we developed nonlinear
beam optics [1] using octupole magnets. With the nonlinear beam optics, a low current density of the beam at
the mercury target can be achieved. However, the nonlinear optics complicates the beam tuning more than theconventional linear optics, in addition, the number of experts on beam commissioning at the MLF is limited, so anexpert system of beam tuning was required. Therefore, anexpert beam tuning system was developed, based on theStrategic Accelerator Design (SAD) [2] developed at the
KEK accelerator.
Since SAD implemented the Experimental Physics
and Industrial Control System (EPICS) [3], which was astandard control system used in J-PARC, the data monitor
can easily transfer to the SAD. Based on the measurementof the beam position with the monitor, the beam orbit was
immediately corrected by changing the steering magnet’s
current by the system. By the result of the beam width obtained by the Multi-Wire Profile Monitor (MWPM) [4], theemittance and the Twiss parameter of the beam can beobtained, as shown in Fig. 1. The present tool was also employed for diagnostics of the beam extracted by the RCS.
By tuning the phase advance between the octupole magnet and the target, the nonlinear optics parameters werealso obtainied to have a flat beam shape. By the result of
beam study with nonlinear optics [4], a desirable phaseadvance was found, which maximizes the efficiently of thebeam flatness and minimizes the beam loss due to deformation of the nonlinear optics.
Since a leakage field of the solenoid magnet for themuon U-line was found to affect about 4 mm verticalbeam position at the mercury target, an application wasdeveloped to correct the orbit automatically with respect
to the solenoid’s current. Also, the leakage field of thebending magnet transporting to the Main Ring (MR) was
automatically corrected by another application. The residual magnetic field of the pulse-bending magnet, which
delivered the beam with low repetition rate (0.4 Hz) to the

Figure 1. Screenshot of the expert system beam tuning of beam transport.

76MLF Annual Report 2016

Neutron Source

MR, was found to influence the horizontal beam orbit. A
collection magnet with a current pattern supply was introduced to the pulse-bending magnet to compensate theresidual field.
3. Beam loss
In the beam transport, the beam duct was activatedslightly. To observe precisely the beam loss, we installed
additional beam monitors of plastic scintillator to increase
the sensitivity. Whenever the beam delivery started, thebeam loss was carefully observed by the high-sensitivity monitor. With the new monitor, the beam loss dueto the scattering at the muon production target can becontrolled very well. Furthermore, we have developed adosimeter system with nanoDotTM [5] to observe the residual radiation dose due to the beam loss. Thanks to thenew beam loss monitors, the beam operation can be performed more confidently.
Although no loss was observed by the new beam loss
system, slight activation continued at downstream in frontof the muon target. Especially, the duct flange at the final
bending magnet was activated, which was placed at thefarthest downstream point in the beamline, at a distanceof 120 m from the mercury target. Since the neutrons produced from the target may activate the duct, to confirm
their intensity, a neutron detector was placed at the final
bending magnet. The experiment revealed that the intensity of the neutrons at the duct flangewas about 103
times higher than at other places around the flange. To
observe the spatial neutron distribution, a GafChromicTM
film, which can detect neutron by recoil proton in the film,
was placed. Figure 2 shows the result of the imagining. It
was found that a clear image of the neutron was obtainedwith shape of the beam duct, the duct flange and detector
holder. It can be concluded that the activation was causedby the interaction of neutrons from the target, which isinevitable in beam tuning. Even though the flight pathis very long (120 m) from the target, the neutrons can betransported the beam duct, which playes a role simular toneutron collimator. To avoid activation at the exit of thebeam duct, the duct’s thin window for extraction of neutrons will be utilized in the future.
4. Improvement of the water cooling system
In the previous year, copper was found to adhere
to the ceramic insulator placed in the water loop for the

Figure 2.	Image of GafChromicTM film placed at the final
bending magnet. Shade of the flange and detector
holder is shown.

magnet. We assumed that the copper presence was due
to erosion at the coil of the magnet. To minimize the magnet coil erosion due to the water flow, we installed a deoxidized system on the water system for the magnet, except
for the water around the muon production target. Afterinstalling the deoxidizer at the loop, the dissolved oxygen
concentration was drastically reduced to the order of subppb, and the amount of the copper adherence decreased.
Due to the radiation around the muon target causedby the interaction with the neutron target, the cooling water for the magnet between the muon and neutron target was activated and produced nuclides of 3H and 7Be.
Management of the cooling water between both targets
is one of the crucial issues in operating the MLF with highreliability. The problem has existed for a long time since
the first beam in 2008 and the water impurity was causedby the coil. To sustain high purity, the water was replaced
once in every two weeks.
The impurity caused by the coil contained a tiny
amount of antimony. In JFY 2015, activated antimony (Sb122) was detected in the disposal of the cooling water system. To control the activity, we have installed an additional
purification system using ion-exchanger. After applying
the additional ion-exchanger, the nuclide of 7Be and 122Sb
was found to be almost entirely removed, which cannot
be observed in the exit of the exchanger. To manage 3H,
we have added an extra tank in the water system.
References[1] S. Meigo, et al., HB2016 WEPM2X01 (2016).
[2] http://acc-physics.kek.jp/SAD/.
[3] http://www.aps.anl.gov/epics/.
[4] S. Meigo, et al., IBIC2015 WEDLA03 (2016).
[5] https://www.landauer.com/product/nanodot.

S. Meigo1, M. Ooi1, S. Fukuta1, T. Kawasaki1, M. Nishikawa1, and H. Fujimori2
Neutron Source Section J-PARC Center, JAEA; 2Muon Section J-PARC Center, KEK

177

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MLF Annual Report 2016

Neutron Science Section
1. User program
In 2016, the user program was negatively affectedby two target incidents of cooling water leakage that
happened in 2015. As a result, we decided to carry over
all experiments approved in 2015A but not executeddue to the problem. Because of that, the total available beamtime was reduced to 42 days for each of the
2016A and 2016B periods. After resuming the neutron
beam operation on February 20, 2016, by operating an
old-designed No.2 target with beam power of 200 kW,
we had to reduce the beam power to 150 kW from
November 2, to ensure a long stable operation of thetarget until the summer of 2017.
For the general-proposal submission period in
2016A, 85 neutron proposals were approved out of a total of 275 by the MLF Advisory Board after the Neutron
Science Proposal Review Committee. The competition
to be approved was so hard, 3.2 to 1. For 2016B, out of
234 submitted neutron proposals, 90 were approved sothat the competition was 2.6 to 1.
2. Instruments
The layout of the neutron instruments at MLF, as ofthe end of JFY 2016, is shown in Fig. 1.
The construction of the polarized neutron spectrometer POLANO at BL23 was still in progress. To examine radiation safety, POLANO accepted the first neutron beam.

Figure 1.	Layout of the neutron instruments at MLF as of JFY
2016. BL06 was in the commissioning phase. BL23
had its first neutron beam.

80

Figure 2.	Double-layered low-angle detectors of HRC.

On-beam commissioning will be started in FY2017.
In the backscattering instrument DNA at BL02, Si311 analyzer banks were installed to extend the energy-momentum space, and diffraction counters werere-installed with re-positioning.
Neutron Brillouin scattering (NBS), that is inelastic
neutron scattering close to the forward direction, is effective for observing coherent excitations, such as ferromagnetic spin waves and acoustic phonons in thefirst Brillouin zone from non-single-crystal samples. This
technique becomes feasible on the High Resolution
Chopper Spectrometer (HRC) at BL12. Since then, HRC
was improved to register the scattering intensities for
NBS experiments: the low-angle detectors were aligned
in a double layered configuration (Fig. 2), and the Fermi
chopper and the collimator were improved.
3. International activities
From June 1 to 2, sixteen scientists and engineers from the European Spallation Source (ESS) visited J-PARC facilities and we held the first ESS - J-PARC
Collaboration Workshop (Figs. 3 and 4). The ESS group
has obtained the information of J-PARC in a broad
range of fields, such as radiation safety issues, operation issues in accelerators, target handling, practicalconstruction of neutron shielding and neutron instruments. At the end of the workshop, it was decided thatthe second workshop will be held at ESS in 2018.
The first Neutron and Muon School was heldfrom November 22 to 26 (Figs. 5 and 6). That was the
new reorganized school, previously known as MLF
School, which was hosted by The Japanese Society for
Neutron Science, Society of Muon and Meson Scienceof Japan, J-PARC, CROSS, Materials Sciences ResearchCenter and the Nuclear Human Resource Development
Center of JAEA, The Institute for Solid State Physics ofMLF Annual Report 2016

Neutron Science

Figure 3.	Participants of the first ESS - J-PARC Collaboration
Workshop.

Figure 5.	Group photo at the first Neutron and Muon School.

Figure 4.	Prof. Yokoo explaining the inside structure of HRC
to the ESS participants.

Figure 6.	Prof. Kanaya, MLF Division Head, in discussion withstudents at a hands-on experiment at TAIKAN.

The University of Tokyo, Institute of Materials Structure
Science of KEK and Ibaraki Prefecture with the supportof The Graduate University for Advanced Studies and
KEK. 29 young researchers and graduate students from
Korea, Australia, Indonesia, India, Hong Kong, Taiwan,
United Kingdom, as well as Japan participated in theschool. From the neutron group, 8 neutron instruments
contributed to hands-on experiments and 25 of 29 participants took part in neutron experiments. We, members of Neutron Science Section, leaded successful startof the newly organized school.
We held the J-PARC Workshop entilted “Neutron
Biology for the Next Generation” on March 22. The purpose of the workshop was to promote investigations related to biology at MLF. At the workshop, we invited Dr.
Ralf Biehl from Forschungszentrum Jülich GmbH and
Dr. Frank Gabel from Institut de Biologie Structurale.
The future prospects of research in the field of biology
at MLF were discussed from both scientific and instrumental points of view.

resulted in more than 80 papers. The number includes
articles in influential journals such as Science, Nature
Communications and Scientific Reports.
The DNA beam line (BL02) group won the Technology
Prize of the Japanese Society for Neutron Science for thedevelopment of the high-energy resolution near-backscattering spectrometer (DNA).
The ANNRI beam line (BL04) group was awarded
the Culture, Sports, Science and Technology Minister’sCommendation of 2016 for the work of “Significant
innovation and application of neutron resonancespectroscopy”.
Development technology of high-performancetire technology by Sumitomo Rubber Industries, Ltd.
(ADVANCED 4D NANO DESIGN) was awarded as the 28thAward of The Society of Rubber Science and Technology,
Japan (June 6, 2016). The technology was confirmedthat atomic scale structure and dynamics of tire by neutron and X-ray and computer simulations could be used
to improve the inconsistent performances of car tires,namely, fuel consumption, gripping and wear resistance.
Based on this technology, a new tire product was commercialized (November 1, 2016).

4. Resultant outcomes
The research activities in neutron science at MLF

K. Nakajima1, Y. Kawakita1, S. Itoh1,2, and T. Otomo1,2
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Institute of Materials Structure Science, High Energy
Accelerator Research Organization, KEK

181

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MLF Annual Report 2016

BL01: 4D-Space Access Neutron Spectrometer
4SEASONS
1. Introduction and Statistics
4SEASONS is a thermal neutron Fermi-chopper
spectrometer for inelastic scattering measurements,and one of the Public Beamlines in MLF [1]. The momentum-energy region for this spectrometer occupies
the middle of the momentum-energy space coveredby all the MLF spectrometers [2]. In 2016, the number of the approved proposals was limited, because
the facility decided to decrease the beamtime for the
2016A and 2016B terms to accept the proposals postponed due to the facility troubles in 2014 and 2015.
Only 8 General Use proposals, 1 Urgent Use proposal, 1
New User Promotion proposal, were approved for BL01
in JFY2016, in addition to 2 Element Strategy Initiative
Use proposals and 1 Project Use proposal. Instead, 3
2014A General Use proposals and 7 2015A General Use
proposals were performed in the 2016A term. In addition, we were able to give beamtimes to 3 reserved
proposals. The number of international proposals
started to increase since 2014, and currently it reaches
about half of the total number of general proposals.
2. Detector Protection
3He detector is vulnerable to vibration, especiallywhile the electric power is supplied. As we reported lastyear, we have introduced an interlock system to prevent
detector damage caused by earthquakes. This system isconnected to seismometers placed in the experimental
halls. It cuts the electric power supply to the detectors,
once it detects an earthquake whose intensity is bigger
than some specified value (currently bigger than 4 on
the Japanese seismic scale). In addition, we replaced thepower supplies for the detectors with new ones, whichhave a better compatibility with the interlock system.
In 2016, this interlock system worked after being triggered by a real earthquake for the first time. Figure 1(a)shows the seismometer in Experimental Hall No. 1 of
MLF, whose red warning lamp lit up after detecting anearthquake with seismic intensity of 4 on November 22,
2016. It successfully cut off the power supply to the detectors, as shown in Fig. 1(b) [3].
3. Improvement in the Oscillating Radial Collimator
To reduce the background scattering from the sample environment, 4SEASONS can be equipped with an
oscillating radial collimator (ORC), which was developed82

Figure 1.	(a) Seismometer in MLF. (inset) The red alarm lamp
is on by detecting an earthquake. (b) The detector protection system and the new high-voltage
power supplies for detectors in the 4SEASONS
cabin [3].

by the Technology Development Section of MLF. It has
a number of thin shielding blades made of cadmiumplated aluminum sheets, which surround the space forthe sample environment device. The ORC is installed on
the vacuum scattering chamber, and it is usually oscillated horizontally to avoid uneven intensity distribution
on the detectors caused by shadows from the shielding blades [4]. However, this type of oscillation is not
simple, because the unevenness in intensity depends
on the oscillating speed and angle. Even after optimizing these parameters, we found that the shielding
blades inevitably made shadows when they stopped atboth ends of the oscillating angle to change the oscillating direction, even though the dead time was small(~20 ms). To solve this problem, we recently developed
a new oscillating mode, called “shift-mode”, which canshift the oscillating angle range gradually (Fig. 2). We
confirmed that by changing the angle range by 0.1° per
oscillation, we could obtain more even intensity distribution than in the normal oscillating mode [5].

MLF Annual Report 2016

Neutron Sciencecan visualize the data in real time, which gives us highflexibility in the 4D mapping measurements.

Figure 2.	Schematic illustration representing the shift-mode
operation. The angular separation between neighboring blades is assumed to be 2.5° in this figure [5].

4.	4D Mapping by Continuous Rotation of SingleCrystal Samples
One of the recent trends in the experiments on asingle crystal using a chopper spectrometer is to grasp
whole excitations in the 4D momentum-energy space byrotating the crystal over a wide angular range. Recently,
the MLF Computing Environment Group developed a
new measurement and analysis system, which enables
the 4D mapping of the reciprocal and energy space bycontinuously rotating a single crystal [6]. We introduced
this new measurement system on 4SEASONS this year.
Figure 3 shows the phonon spectra of a single crystalof copper measured by continuously rotating the crystal using the new system [3]. By rotating the crystal at areasonably fast speed (160°/h), we obtained the roughpicture at an early measurement stage (Figs. 3(a) and3(b)). The statistics improved with time by repeating
the rotation (Fig. 3(c)). With this new system, we do notneed to determine the rotation step size in advance andReferences[1] R. Kajimoto, M. Nakamura, Y. Inamura, F. Mi-zuno, K.
Nakajima, S. Ohira-Kawamura, T. Yokoo, T. Nakatani,
R. Maruyama, K. Soyama, K. Shibata, K. Suzuya, S.
Sato, K. Aizawa, M. Arai, S. Wakimoto, M. Ishikado,
S. Shamoto, M. Fujita, H. Hiraka, K. Ohoyama, K.
Yamada, and C. H. Lee, J. Phys. Soc. Jpn. 80, SB025(2011).
[2] H. Seto, S. Itoh, T. Yokoo, H. Endo, K. Nakajima,
K. Shibata, R. Kajimoto, S. Ohira-Kawamura, M.
Nakamura, Y. Kawakita, H. Nakagawa, and T.
Yamada, Biochim. Biophys. Acta, Gen. Subj. 1861,
3651 (2017).
[3] R. Kajimoto, M. Nakamura, Y. Inamura, K. Kamazawa,
K. Ikeuchi, K. Iida, M. Ishikado, N. Murai, H. Kira, T.
Nakatani, S. Ohira-Kawamura, R. Takahashi, N. Kubo,
W. Kambara, K. Nakajima, and K. Aizawa, J. Phys.:Conf. Ser., to be published.
[4] M. Nakamura, Y. Kawakita, W. Kambara, K. Aoyama,
R. Kajimoto, K. Nakajima, S. Ohira-Kawamura, K.
Ikeuchi, T. Kikuchi, Y. Inamura, K. Iida, K. Kamazawa,and M. Ishikado, JPS Conf. Proc. 8, 036011 (2015).
[5] M. Nakamura, W. Kambara, K. Iida, R. Kajimoto, K.
Kamazawa, K. Ikeuchi, M. Ishikado, K. Aoyama,
unpublished.
[6] Y. Inamura, T. Ito, and J. Suzuki, J. Phys.: Conf. Ser., tobe published.

Figure 3.	Phonon spectra of a single crystalline copper obtained by continuously rotating the crystal. The crystal was rotated horizontally at a rate of 160°/h. (a), (b), and (c) show the constant energy slices at 13 ± 1 meV, 15, 45, and 180 min after the startof the measurement, respectively [3].

R. Kajimoto1, M. Nakamura1, K. Kamazawa2, Y. Inamura1, K. Ikeuchi2, K. Iida2, M. Ishikado2, N. Murai1, T. Nakatani1, K. Aoyama1,
and W. Kambara1
1
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Neutron R&D Division, Neutron Science and Technology
Center, CROSS83

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MLF Annual Report 2016

BL02: Current Status of the Broadband micro-eV
Quasielastic and Inelastic Neutron Spectrometer DNA
1. Introduction
DNA, a time-of-flight (TOF) type near-backscattering spectrometer (n-BSS), is a unique instrument
among the world’s spallation pulsed neutron facilities
because it is n-BSS equipped with a high-speed pulseshaping disc-chopper [1]. The neutron beam from thecoupled moderator, which provides the most intense
yet broadest pulse among all three moderators in MLF,
is handled flexibly in pulse width by this chopper while
keeping its intensity and creating symmetrical pulse ina TOF spectrum. Si crystal analyzers, back-coated witha neutron absorber, reduce significantly the unfavorable background scattering of the instrument, reaching a signal-to-noise ratio of ~105. Those factors arehighly beneficial for expanding the application fields
into the dynamical behaviors of atoms and spins in biomolecules [2, 3], soft-materials and strongly-correlated
electron systems in nanosecond timescale or in the
micro-eV energy region.
Table 1. Instrumental specifications of DNA.
Items
Specification
Neutron source (NS) Coupled Liquid H2 Moderator
L1 (source-sample)
42 [m]
L2 (sample-analyzer) ~ 2.3 [m]L3 (analyzer-detector) ~2.0 [m]Pulse sharpening chopper (PS-chopper)
Max speed: 300 Hz at ~7.5 m from NS(Present max speed: 225 Hz by 4 slits on one disc)
Crystal analyzer
Crystal and reflection index
Si (111)Si (311) in test
Bragg angle of analyzers~87.5 [deg.]
Energy resolution~2.4 [meV]: Si (111) with 10 mm Slit @225 Hz~3.5 [meV]: Si (111) with 30 mm Slit @225 Hz~14 [meV]: Si (111) without PS-chopper~12 [meV]: Si (311) with 10 mm Slit @225 Hz
Momentum range 0.08 < Q < 1.86 [A-1]: Si (111)
1.0 < Q < 3.80 [A-1]: Si (311) in plan
Scan energy range:
Si (111): -40 < E/meV < 100: Single pulse scan around Ef-400 < E/meV < 600: Multi pulse scan around Ef-500 < E/meV <1500:
Without PS-chopper in second frame
Si (311): -150 < E/meV <300: Single pulse scan around Ef(Specifications obtained by the end of March 2017)

84

Figure 1. Photo of BL02 DNA (September 2016).

We made efforts to improve the instrumental activities, such as upgrading the data storage and data acquisition system, and rearranging the diffraction detector.
It should be also reported that our work on the construction and commissioning of DNA received an award
from the Japanese Society for Neutron Science (JSNS),
namely “The practical realization of the dynamics analysis spectrometer DNA by the construction group of the
dynamics analysis spectrometer DNA”.

Figure 2.	Photo from the award ceremony at the JSNS meeting (December 2016).

2. Instrumental activities
In FY2016, the following instrumental activities
were carried out:(1)	Commissioning and fabrication of a sample environments device.

MLF Annual Report 2016

	The heat-conduction part of a BL-common top
lording cryofurnace was improved. Also, a special sample stick for induced high voltage at the
sample was fabricated.
(2)	Upgrading the data storage and data acquisition system.
	During the summer shutdown period, the data
storage system was upgraded to the new Store
Next System. Also, the data acquisition system
was upgraded to new high-performance PC
servers.
(3)	Rearranging the diffraction detector.
	Three 8-pack 3He detector banks were moved tothe position at the high scattering angle in thevacuum scattering chamber for long-d diffraction measurements.
3. User program in the 2016A and 2016B periods
Proposals in a wide variety of research fields were
submitted for general use machine time on BL02 DNA.
In 2016A, 15 proposals were submitted and 6 of them
(28.0 days) were approved. In 2016B, 18 proposals were
submitted and 7 of them (32.0 days) were approved.
The 2 trial use proposals (4.0 days) and the 2 project
proposals (10.0 days) were also carried out in 2016A
and 2016B.
Other than that, the 10 proposals (2014B; 2 proposals (9.5 days) and 2015A; 8 proposals (27.0 days)) postponed due to some incidents that occurred in FY2014
and FY2015, were carried out in 2016A & 2016B. Finally,
all carry-forward proposals approved in 2014B and2015A, were carried out in the end of 2016B. Amongthe experiments, carried out in 2016A and 2016B,
were the following three proposals: 2015A0141 [2],2015A0143 [3], 2016A0048 [4], for which reports havebeen published.
On November 24th and 25th, 2016, a practice experiment was held as a part of lectures at the Neutronand Muon School 2016. Three students from Japan,
Australia and Taiwan, respectively, took part and carriedout measured and analyzed quasielastic neutron scattering (QENS) due to the proton conduction of Nafion
membrane on the BL02 DNA.

Neutron Science

Figure 3.	Photo of discussing students who were participated the Nafion QENS practice experiment on theBL02 DNA at the Neutron and Muon School 2016.

4. Future plans
The optimal combination of the major spectroscopic devices: pulse shaping chopper, Si crystal analyzer
and so on, made it possible to measure the S (Q, E) withmicro-eV high-energy resolution, high-beam intensity
at the sample position and quite low instrumental background. Taking advantage of this feature, the scientificresearch field of using DNA will be expanded not only
for quasi- elastic neutron scattering but also for inelastic
neutron scattering with very precise energy resolution.
References[1] Kaoru SHIBATA, et.al. JPS Conference Proceedings,
8, 036022 (2015).
[2] Tatsuhito Matsuo, Taiki Tominaga, Fumiaki Kono,
Kaoru Shibata and Satoru Fujiwara, BBA - Proteinsand Proteomics 1865 (2017) 1781–1789.
[3] Fujiwara Satoru, Chatake Toshiyuki, Matsuo
Tatsuhito, Kono Fumiaki, Tominaga Taiki, Shibata
Kaoru, Sato-Tomita Ayana, Shibayama Naoya,
Journal of Physical Chemistry vol. 121 (2017),
8069-8077.
[4] Bing Li, Yukinobu Kawakita, Yucheng Liu, Mingchao
Wang, Masato Matsuura, Kaoru Shibata, Seiko
Ohira-Kawamura, Takeshi Yamada, Shangchao Liu,
Kenji Nakajima and Shengzhong (Frank) Liu, Nature
Communications., DOI: 10/1038/ncomms16086.

K. Shibata1, Y. Kawakita1, H. Nakagawa1, W. Kambara1, Y. Inamura1, T. Nakatani1, T. Yamada2, M. Matuura2, T. Tominaga2,
M. Kobayashi2, and S. Kasai2
1
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Neutron R&D Division CROSS-Tokai

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MLF Annual Report 2016

BL03: IBARAKI Biological Crystal Diffractometer iBIX
1. Introduction
Single crystal neutron diffraction is one of thepowerful methods to obtain the structure information,
including that of the hydrogen atoms. The IBARAKI
biological crystal diffractometer called iBIX is a highperformance time-of-flight single crystal neutron diffractometer to elucidate the hydrogen, protonationand hydration structures of organic compounds andbiological macromolecules in various life processes [1].
In 2012, we upgraded the 14 existing detectors andinstalled 16 new detectors for the iBIX diffractometer(Fig. 1). The total solid angle of the detectors subtended by a sample and the average of detector efficiency
became 2 and 3 times larger, respectively [2]. The total
measurement efficiency of the present diffractometer
become 10 times larger from the previous one coupledwith the increasing of accelerator power. In the end of
2012, we were able to start the iBIX application in user
experiments for biological macromolecules. The final
specifications of the iBIX are shown in Table 1.

Figure 1. The iBIX diffractometer.
Table 1. Specifications of iBIX.
Moderator
Wavelength of incident neutron
Neutron intensity (@1 MW)
L1L2Solid angle of detectors
Detector covered region
Detector size
Detectors pixel size
No. of detectors

86

Coupled
0.7 ~ 4.0 Å (1st frame)
4.0 ~ 8.0 Å (2nd frame)
0.7 × 106 n/s/mm2
40 m
500 mm
19.5% for 4π+15.5 ~ +168.5 deg.
133 × 133 mm
0.52 × 0.52 mm
30

2. Current status
In 2016, the accelerator power of J-PARC become
150~200 kW. 6 organic compounds and 3 biologicalmacromolecules were provided for the diffraction experiments using iBIX. Some interesting scientific results
were obtained from these investigations by applying
neutron structure analysis.
We have tried to collect the data-set of a protein
crystal with the largest unit cell in the neutron diffraction experiment by using iBIX to estimate its own
performance. The crystal selected for the purpose was
Mn Catarase. The crystal volume was 2.0 mm3. The
cell parameters were a = 133.4 Å in a cubic form. The
measurement conditions were as follows: accelerator
beam power: 200 kW, range of wavelengths: 3.0~6.0 Å,
number of measurement settings: 10, exposure time:
30 hours/setting, total amount of measurement timefor full data-set: 12.5 days. Through data reduction andstructure refinement, we obtained successfully 2.4 Å
and reasonable structure with the information of hydrogen and deuterium atoms. These results show that
iBIX could achieve the maximum cell dimension of design specifications without any peak de-convolution
procedure.
The collection of a full data-set of biological macromolecules for neutron structure analysis by using iBIX
proceeded as follows under the 1 MW operation. The
maximum cell dimension was 135 × 135 × 135 Å3. The
average sample volume was about 2 mm3. The averagemeasurement time was about 2~4 days. We project that
iBIX will become one of the world’s best performing diffractometers under 1 MW operation.
3. Development
In order to improve the accuracy of the estimatedposition of Bragg reflections (= UB matrix) of TOF diffraction data for the integration procedure, we determined the detector parameters and the goniometer
offset angle (distance between sample and detector
surface, detector positions, tilted angles of the detector
surface, Dchi and Dphi offset angle) with a laser tracker
system. From the results, we found out that the centerof the diffractometer was not positioned at the centerof the beam line. We re-aligned the center of the diffractometer to the beam line and re-optimized the detector
parameters and the goniometer offset angle based on
the diffraction data-set from an inorganic compound.
More precise detector parameters could be obtained,MLF Annual Report 2016

and then the accuracy of the estimated position of the
Bragg reflections could be improved for protein crystals
with large unit cells.
A full data-set of a 2 mm3 protein sample by iBIX
can be obtained in about 2~4 days under 1 MW operation of accelerator power. However, the sample size is
still too large, and the measurement time is still too
long, which causes problems for the users. It is necessary to improve the measurement efficiency of theiBIX diffractometer. We started to develop a new scintillator unit with high sensitivity for the iBIX detector
system. The development aim for the new scintillator
unit is 1.4 times higher sensitivity than the previous
scintillator. We hope to demonstrate this increased
sensitivity by performing neutron experiments on atest piece.

Neutron Science

4. Future prospects
In the future, the accelerator power of J-PARC
will increase about 1 MW. iBIX should be available regularly for full data-set measurement of samples with thesize of 1 mm3. We will continue to develop the data
reduction software and the beam line instruments toimprove the accuracy of intensity data obtained fromsmall samples. Furthermore, we should plan to install
additional detectors looking toward an industrial use.
References[1] I. Tanaka, K. Kusaka, T. Hosoya, N. Niimura, T. Ohhara,
K. Kurihara, T. Yamada, Y. Ohnishi, K. Tomoyori andT.
Yokoyama, Acta Cryst. D66 (2010) 1194-1197.
[2] K. Kusaka, T. Hosoya, T. Yamada, K. Tomoyori, T.
Ohhara, M. Katagiri, K. Kurihara, I. Tanaka and N.
Niimura J. Synchrotron Rad. 20 (2013) 994-998.

K. Kusaka1, T. Yamada1, N. Yano1, T. Hosoya1, I. Tanaka1, T. Ohhara2, and M. Katagiri1
Frontier Research Center for Applied Atomic Sciences, Ibaraki University, Tokai; 2J-PARC Center, JAEA

1

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MLF Annual Report 2016

Measurement of the 133Cs(n,γ) Cross-Section Using a
New DAQ System at ANNRI
1. Introduction
Nuclear data on 135Cs will be vital to develop a system for transmuting nuclear waste products into stableor shorter-lived nuclides, reducing the environmental
impact of nuclear power. 133Cs is an unavoidable contaminant in the presently available samples of the long-lived
fission product 135Cs. High-quality data for 133Cs is necessary to analyze the experimental data of 135Cs.
Recently, a new data acquisition system (DAQ system) has been installed for the high-purity germanium(HPGe) detector array at the Accurate Neutron-Nucleus
Reaction Measurement Instrument (BL04-ANNRI) at the
J-PARC MLF, notably featuring much lower dead-timein comparison to the previous DAQ system. Using thisnew DAQ system, a measurement of the 133Cs(n,g) crosssection has been conducted at the J-PARC MLF.
2. Experiment
Neutrons, produced at the Hg target in the MLF,
travel a flight length of 21.5 m before interacting with asample, then the resultant gamma-rays are measured byan array of HPGe detectors. The neutron energy is determined via the neutron time-of-flight (nTOF) method.
The HPGe array consists of two clusters of 7 HPGe
detectors above and below the beamline, in addition to 8
co-axial detectors horizontally aligned with the beamline,
for a total of 22 detectors. However, due to noise on the
co-axial detectors, they were not used for this experiment.
Detector signals from the HPGe detectors are fed into a
pre-amp and then the pre-amp signal is digitized by CAEN
v1724 14-bit 100-MHz ADC boards [1]. The ADC boards arethen connected to a PC via optical-fiber cables for storingdata for offline analysis, as well as online monitoring.
The 133Cs sample was made by pressing 17.2 mg
Cs2CO3 into a pellet of diameter 5.04 mm and thickness
0.329 mm, and then sealed in FEP film. Additionally, a sample of Au was prepared for calibrating the nTOF parametersand determining the relative neutron energy spectrum inthe thermal energy range. A 10B sample was prepared for
determining the relative neutron energy spectrum in theepithermal to fast neutron energy range. A 208Pb sample
was measured to account for the effects of neutron scattering, and a blank sample of FEP film was used only tomeasure the background without sample influence.
The pulse-height and time-of-flight data from the
ADC were recorded event-by-event. See Fig. 1 for the raw
88

time-of-flight data from each sample.
A comparison of the time-of-flight spectrum surrounding the first and second resonances of 133Cs(n,g), using boththe current and previous DAQs, can be seen in Fig. 2. Under
the old DAQ system, large resonances suffer from severe
dead-time effects, and dead-time correction accounts
for nearly all of the information regarding the resonanceheight and shape. However, under the new DAQ system,
the dead-time effects are mostly negligible. Due to thecharacteristics of the CAEN v1724 boards, the dead-time
per event has been significantly reduced in comparison tothe old DAQ system, from 175.2 ms to 3.18 ms, a reduction
factor of approximately 55. Using the newly installed DAQ
system, it is possible to measure larger capture yields, foreither thicker targets or higher neutron fluxes, with higher
energy resolution and in higher energy regions.

Figure 1.	The measured time-of-flight spectrum for each sample. For the B sample, a pulse-height gate was placed
to only count events from the 478 keV photopeak.
Correspondingly, the analysis of the blank sample
was repeated also using the same pulse-height gate.

Figure 2.	A comparison of the time-of-flight spectra for measurements of the 133Cs(n,γ) reaction. Note that thebeam power in the new DAQ measurement is alsoroughly twice as strong in comparison to the experiment for the old DAQ.

MLF Annual Report 2016

3. Analysis
The pulse-height weighting technique [2] is applied
to convert the detector output pulse-height spectrum
in a given time-of-flight bin to neutron capture yield.
The pulse-height weighting function was calculated using the detector response, as simulated by GEANT4 [3].
The dead-time correction factor is calculated by tallying all detector events. Time-independent and timedependent background effects (including frame-overlap
effects) are deduced by using the time-of-flight data during the rest period when pulsed protons are sent to the
50 GeV synchrotron. The time-of-flight data are normalized to the total proton beam power of each measurement. Background counts without sample influence are
subtracted by using the blank sample data. The effects ofscattered neutrons from each measured sample are accounted for by subtracting the net 208Pb data multipliedby the ratio of the total neutron scattering cross-section
between 208Pb and each measured sample. A self-shielding factor is calculated using PHITS [4] and applied.
The above analysis produces the capture yield, proportional to ϕ(E)σ(E)N. In the energy region above 0.01 eV,
the relative neutron energy spectrum, proportional toϕ(E), is deduced from the number of 478 keV photopeak events from the 10B sample and the evaluated crosssection of 10B(n,ag) in JENDL-4.0 [5]. In the energy region
below 0.01 eV, the relative neutron energy spectrum isdeduced from the measured neutron capture yield fromthe Au sample and the evaluated cross-section of Au(n,g)
in JENDL-4.0. The reason for using Au in the thermal energy region is to avoid the large errors associated with
self-shielding effects in the 10B sample in the thermal energy region.

Figure 3.	The measured cross-section of 133Cs(n,γ) and comparison with previous measurements.

Neutron Science

The relative cross-section of 133Cs(n,g) was then derived by dividing the measured neutron capture yieldby the relative neutron energy spectrum. The measured
relative cross-section data for 133Cs(n,g) has been normalized to its evaluated value at 0.0253 eV in JENDL-4.0 of
28.90 b [5]. The measured cross-section of 133Cs(n,g) in
the energy range from 0.004 eV to 35 eV can be seenin Fig. 3, along with a comparison to previous measurements. The error analysis is ongoing.
4. Future plans
At the current stage of analysis, the measured crosssection of 133Cs(n,g) as a function of energy has been normalized to the evaluated value at 0.0253 eV in JENDL-4.0
of 28.90 b [4]. In the near future, we intend to deduce theabsolute capture cross section of 133Cs using the capture
yield of the Au sample and the same pulse height weighting technique, which greatly reduces systematic error.
We are also working on measurements for the crosssections of 135Cs(n,g) and 74,76,77,78,80,82Se(n,g) and publications of those results are expected shortly.
Acknowledgments
This work was funded by ImPACT Program of Council
for Science, Technology and Innovation (Cabinet Office,
Government of Japan).
References[1] http://www.caen.it[2] R. L. Macklin, J. H. Gibbons: Phys. Rev., 159 (1967), p.
1007.
[3] GEANT4: A Simulation toolkit - GEANT4 Collaboration(Agostinelli, S. et al.) Nucl.Instrum.Meth. A506 (2003)
250-303 SLAC-PUB-9350, FERMILAB-PUB-03-339.
[4] T. Sato, K. Niita, N. Matsuda, S. Hashimoto, Y. Iwamoto,
S. Noda, T. Ogawa, H. Iwase, H. Nakashima, T. Fukahori,
K. Okumura, T. Kai, S. Chiba, T. Furuta and L. Sihver,Particle and Heavy Ion Transport Code System PHITS,
Version 2.52, J. Nucl. Sci. Technol. 50:9, 913-923 (2013).
[5] K. Shibata, O. Iwamoto, T. Nakagawa, N. Iwamoto, A.
Ichihara, S. Kunieda, S. Chiba, K. Furutaka, N. Otuka,
T. Ohsawa, T. Murata, H. Matsunobu, A. Zukeran, S.
Kamada, and J. Katakura: “JENDL-4.0: A New Libraryfor Nuclear Science and Engineering,” J. Nucl. Sci.
Technol.. 48(1), 1-30 (2011).

B. Hales, A. Kimura, S. Nakamura, and O. Iwamoto

Nuclear Data Center, JAEA

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MLF Annual Report 2016

Status of Fundamental Physics Beamline BL05 (NOP)2016
1. Introduction“Neutron Optics and Physics (NOP/ BL05)” at MLF
in J-PARC is a beamline for studies in the field of fundamental physics. The beamline is divided at the upstream into three branches, which are the so-called
Polarized, Unpolarized, and Low-Divergence branches,used in different experiments in a parallel way [1-2].
A neutron lifetime measurement was performedat the Polarized beam branch with a spin flip chopper. Pulsed ultra-cold neutrons (UCNs) by a Doppler
shifter are available at the Unpolarized beam branch.
At the Low-Divergence beam branch, the search for
an unknown intermediate force is performed bymeasuring neutron scattering with rare gases. The
beamline is used also for R&D of optical elements anddetectors [3].
2. Measurement of the Neutron Lifetime
A neutron decays into a proton, an electron, andan antineutrino. The decay lifetime is an important parameter for the unitarity of the CKM matrix and also
for the primordial big bang nucleosynthesis. However,recently reported values for the neutron lifetime deviate significantly from the systematic uncertainties. An
experiment to measure the neutron lifetime with apulsed beam is ongoing at BL05 (NOP). The lifetime ismeasured as a ratio of the electron events of the neutron decay to the 3He(n,p)3H events caused by 3He gas
precisely doped in a time-projection chamber (TPC).
Physics data have been collected for about 4 weeks
by the TPC in 2016. The data were analyzed by using
Monte Carlo simulation [4].
3.	Time Focusing of Ultra-Cold Neutrons (Rebuncher)
Neutrons produced in a pulse source tend to
spread with time. We use this characteristic to distinguish neutron velocities by time of flight method,
but in other words, the neutron density is going to bediluted after production. We have been developing atime-focusing device, the so-called “rebuncher”, thatmakes it possible to re-focus neutrons on a certain position at a certain time to reproduce the initial densityof the pulse neutron source [5]. The rebuncer consistsof a gradient dipole magnet and a frequency variable
RF spin flipper. A neutron flipped in a magnetic field90

gains/loses its kinetic energy of 60 neV for 1 T. Then
we can increase or decrease the neutron kinetic energies by changing the frequency of the RF flipper withthe time of flight. We have demonstrated neutron
time focusing using UCN from the Doppler shifter at
the Unpolarized branch. The setup of the rebuncer
is shown in Fig. 1 [6]. UCNs from the Doppler shifter,
which were reduced to 0.5 Hz, transported to the rebuhcer were flipped in the RF coils in the gradient dipole magnet to control its velocity and focus it on a
detector position at the 3.2 m position downstream.
The maximum field of the gradient magnet was 1.0 T.
RF frequency was varied from 6 to 30 MHz, which correspond to 0.2 to 1.0 T, by synchronizing with time offlight of UCN to focus on time. TOF spectra of UCN withand without RF are shown in Fig. 2. It can be observedthat UCNs in 1,000–1,200 msec were swept out and focused at 1,250 msec [6].

Figure 1.	Experimental setup for the rebuncher for UCN [6].
UCNs from the Doppler shifter (0.5 Hz) throughUCN guide (1.2 m) come to the rebuhcer, which is
the RF coils in the gradient dipole magnet. Accelerated/decelerated UCN focuses on a UCN detector
after the UCN guide (3.2 m).

MLF Annual Report 2016

Neutron Science

Figure 2.	TOF spectra of UCN with and without RF are
shown in here. It can be observed that UCNs in
1,000-1,200 msec were swept out and focused at
1,250 msec [6].

Figure 3.	Gas handling system for the noble gas scatteringexperiment [7]. The circulation system with purifier
prevents outgas contamination in the noble gas
sample.

4.	S earch for Unknown Intermediate Force withRare Gas Scattering
Since then, many experiments have been performed to measure the deviation from the inversesquare law of Newtonian gravity down to tens of
micrometers. We are probing the short-range force inthe nanometer scale by measuring the neutron scattering with noble gases.
In the simplest case with an unknown particle witha Compton wavelength of λ, the Yukawa force is expected to add to the Newtonian force so that the potential
V(r) between masses of m and M can be de- scribed as
mM(1 + αe-r/λ)(1)
V(r) = -GNrmeasured 3 noble gases, He, Ar and Xe. The data arebeing analyzed.

where r is the distance between the masses, and GN
is the gravitational constant. Neutron scattering is aunique probe to measure the short-range forces because it has no charge and small polarizability. The extra forces described as eq. (1) increase forward angular
distribution in neutron scattering.
Thanks to regulation change of the radiation control at MLF in 2016, gases, which can be activated, canbe used as samples. For long-time measurement, wehave implemented a gas circulation system, shownin Fig. 3 [7]. The 300 cm3 of target gas with maximum
pressure of 200 kPa was circulated with a gas purifier to prevent outgas contamination in the noble
gas samples for long time measurements. We have

References[1] K. Mishima et al., “Design of neutron beamline
for fundamental physics at J-PARC BL05,” Nucl.
Instruments Methods Phys. Res. Sect. A, vol. 600, no.
1, pp. 342–345, 2009.
[2] K. Mishima, “J-PARC Neutron fundamental physics
beamline (BL05/NOP),” Neutron Netw. news, vol. 25,
no. 2, pp. 156–160, 2015.
[3] K. Mishima et al., NOP2017, “Fundamental physics
activities with pulsed neutron at J-PARC (BL05)”,2017. https://arxiv.org/abs/1712.06351[4] N. Nagakura et al, “Precise neutron lifetime experiment using pulsed neutron beams at J-PARC”, Proc.
Sci. 26th Int. Nucl. Phys. Conf. 2016, to be published.
arXiv:1702.03099.
[5] Y. Arimoto et al., “Demonstration of focusing by aneutron accelerator,” Phys. Rev. A - At. Mol. Opt. Phys.,vol. 86, no. 2, pp. 4–7, 2012.
[6] S. Imajo et al., NOP2017 P46, “Time-focus
Experiment of Ultracold Neutron by Improved UCN
Rebuncher at J- PARC/MLF” 2017.
[7] N. Oi et al., NOP2017 P47, “A Search for Possible
Deviations from Newtonian Gravity at the nm Length
Scale Using Neutron-Noble Gas Scattering”, 2017.

K. Mishima1,2 on behalf of NOP collaboration
1Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Institute of Materials Structure Science, KEK91

Neutron Science

MLF Annual Report 2016

BL06: Commissioning Status of VIllage of Neutron
ResOnance Spin Echo Spectrometers (VIN ROSE)
1. Introduction
Neutron spin echo spectroscopy (NSE) uniquely
enables us to explore the dynamics of various materials
spatiotemporally. NSE has already achieved the highest
energy resolution with neutrons as a probe [1], that is, themaximum Fourier-time has reached a submicrosecond.
Kyoto University and KEK have been installing two
types of neutron spin echo (NSE) spectrometers withneutron resonance spin flippers (RSFs) at BL06 since
FY2011, that is, a neutron resonance spin echo (NRSE)
instrument and a modulated intensity by zero effort(MIEZE) instrument. NSE with RSFs is a rather new approach [2]. Furthermore, the combination of NSE and apulsed neutron source makes it possible to scan a wide
spatiotemporal space very efficiently. The beam line has
been named “VIN ROSE” (VIllage of Neutron ResOnanceSpin Echo spectrometers), which will spawn a new fieldof spectroscopic methods [3].
In FY2014, the first neutron beam was accepted,
and the characteristics of the neutron guides were
quantitatively investigated [4]. The first MIEZE signal
was observed at the end of FY2014. Since then, various
improvements and developments for the public use of
BL06 have advanced.
(a)

In this report, the status of the MIEZE and NRSE
spectrometers at BL06 in FY2016 is summarized.
Figure 1 shows a recent photo of BL06.
2. Commissioning Status at BL06 in FY2016
Because the combination between time-of-flightneutron spectroscopy and MIEZE (TOF-MIEZE) is a
novel approach, the quantitative verification is fundamentally important. In FY2015, the TOF-MIEZE signals
were measured in various conditions, and comparedwith the theory [5]. The MIEZE signal with continuous
neutron sources suffers from geometric restriction andthis restriction can be relaxed by the TOF-MIEZE method, which was clearly shown experimentally with BL06.
Following these investigations, a 400-kHz MIEZE wassuccessfully generated [6]. In Fig. 2, the measured TOFMIEZE signal and the corresponding power spectrumwith 400 kHz is exhibited.
At the NRSE spectrometer, the two-dimensional
ellipsoidal neutron-focusing supermirrors are now under development in close collaboration with the RIKEN
center for advanced photonics. The ellipsoidal supermirrors are essential for NRSE with high-energy resolution, which will be installed before and after the sample
position symmetrically to correct the path difference.
The optical design is 1250 mm semi-major axis and65.4 mm semi-minor axis with 900 mm length. Sucha large ellipsoidal supermirror was unrealistic due tothe difficulties in both the supermirror deposition andthe substrate fabrication. Our strategy to develop suchlarge ellipsoidal supermirrors is to assemble the segments deposited by the supermirror, shown in Fig. 3.
We have established the necessary elemental technique [7], and achieved the reasonable characteristics
evaluated by neutron reflectivity measurements.

(b)

Figure 1. Current picture of BL06 (a), and a schematic top view of the MIEZE and NRSE beam line at BL06 (b).

92

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Neutron Science

Figure 3.	Top: 900 mm-length metallic substrate of elliptic
mirror connected with three segments. Bottom:
Segments with supermirror deposition.

a technical hurdle for the development of NRSE withhigh-energy resolution. Based on these successfulachievements, we will work intensely on the commissioning of NRSE in FY2017.
Figure 2.	
Top: Experimentally observed TOF-MIEZE signal
with effective 400 kHz. Bottom: corresponding
power spectrum by Fourier transformation.

3. Summary
This is a brief report about the current status of
BL06 VIN ROSE. The main progress in FY2016 was the
successful generation of a 400 kHz TOF-MIEZE signal.
This result is very important for the public use, whichis planned to start in FY2017. The other advancement
at NRSE is the development of two-dimensional ellipsoidal neutron-focusing supermirrors, which has been

References[1] F. Mezei ed., Neutron Spin Echo, Lecture Notes inPhysics, (Springer, Berlin) 128 (1982).
[2] R. Gähler and R. Golub, J. Phys. France, 49, (1988)
1195-1202.
[3] M. Hino, T. Oda, M. Kitaguch, N. L. Yamada, H.
Sagehashi, Y. Kawabata, H. Seto, Physics Procedia 42,(2013) 136.
[4] M. Hino et al., J. Nucl. Sci. Tech. accepted.
[5] T. Oda, Doctor Thesis, Kyoto University, (2016).
[6] T. Oda et al., J. Phys. Soc. Jpn. submitted.
[7] T. Hosobata et al., J. Phys. Soc. Jpn. submitted.

H. Endo1, M. Hino2, T. Oda2, N. L. Yamada1, H. Seto1, and Y. Kawabata2
Neutron Science Section, Materials and Life Science Division, J-PARC center, Institute of Materials Structure Science, KEK; 2Kyoto University
Research Reactor Institute193Neutron Science

MLF Annual Report 2016

Status Report on Super High Resolution Powder
Diffractometer, SuperHRPD

2. 14-Tesla Magnet commissioning
This 14-Tesla magnet is manufactured by Oxford
Instruments PLC., and is designed specifically for highresolution measurement for SuperHRPD [1].
First, the 14-Tesla magnet was installed in the sample chamber of SuperHRPD, and the background wasmeasured by empty sample. The proper adjustment of
the incident beam slit made it possible to eliminate reflections from the copper tube of variable temperature
inserts (VTI) in the immediate vicinity of the sample
position. After that, Rietveld analysis was performed
using standard powder sample (NIST Si SRM640d), andthe reliability of the structural analysis was evaluated.
Figure 1 shows the result of the Rietveld analysis of a30

standard sample. High-quality data with low background were obtained, and peak fitting allowed toobtain good results with Chi-square = 1.005734. Only
the middle part of the backward detector bank divided
into upper, middle and lower can be used from the window design of the magnet, the resolution Δd/d ~ 0.06%
could be obtained (Fig. 2).
The magnet excitation test at the BL08 beam line
was conducted in December 2016. Since it was the firstexcitation test after delivery, we spent considerable
1200

Intensity / arb.unit

1. Introduction
In fiscal year 2016, seven general proposals and apart of the S-type project of 2014S05 were carried out
at the BL08 beam line. The main activities included ahigh-temperature experiment using a vanadium furnace and a low-temperature experiment for magnetic
structure analysis. In the S-type project, the commissioning of the 14-Tesla magnet delivered last fiscal year
was conducted, and excitation test with neutron diffraction measurement could be carried out.

1000

resolution∆d/d = 0.0607920(2)%

800
600
400
200
0

91.2

91.3

91.4

91.5

91.6

TOF / µsec.

91.7 91.8 ×103

Figure 2.	Resolution calculation of NIST Si data. A high resolution of Δd/d ~ 0.06% was obtained.

NIST Si (SRM640d)
Chi-square = 1.005734

Intensity / arb.unit

ycal
yint

20

delta
yphase

10

0

20

40

60

80

100

TOF / µsec.

120

140

160

3

180 ×10Figure 1.	Result of the Rietveld analysis of a standard sample NIST Si. Despite installing the 14-Tesla magnet, very high-quality datawith low background were obtained.

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yint_80K_0Tesla
yint_80K_14Tesla

25

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004

Intensity / arb.unit

20%

20

0.05%

15
90

10

91

92

93

94
×103

5

40

60

80

100

120

TOF / µsec.

140

160

180 ×103

Figure 3.	Diffraction pattern of Co oxide. High-quality data were obtained in low background. It can be seen at a glance that the
004-reflection shifted by 0.05% and the 200-reflection decreased by 20% with intensity dependent on the magnetic field.

time allocating various wires or piping and devices. The
magnet has very large capacity, requiring one week
for pre-cooling with liquid nitrogen and transferring
liquid helium. An excitation experiment by on-beam
was also performed, and even in the excited state, thebackground was low and it was possible to collect highquality data (Fig. 3).
The volume of the magnet is so large, requiringa large amount of liquid nitrogen and helium for precooling, and it need to exchange and transport therefrigerant vessel so many times. Therefore, to open thismagnet for general users, it will take a little more time
because it is necessary to establish an environment for
efficient experiment preparation.
Reference[1] S. Torii, P. Miao, S. Lee, Y. Ishikawa, M. Yonemura
and T. Kamiyama, MLF Annual Report 2015, 79-80(2015).

S. Torii1,2, S. Lee1,2, and T. Kamiyama1,2
1
Neutron Science Section, Materials and Life Science Division, J-PARC center; 2Institute of Materials Structure Science, KEK

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BL09: Current Status of the Special Environment Powder
Diffractometer, SPICA
1. Introduction
SPICA is a dedicated beam line for battery study using the operando technique [1]. Over the last few years,
structure changes in electrode materials under operative conditions have been observed in various charge– discharge rates conditions, and they and their related investigations have already been reported [2-6]. In
FY 2017, the neutron intensity will increase to 300 kW
by a new structural mercury target. This higher neutron intensity will make it possible to collect operando
data with shorter time reaction. Neutron monitor data
is important to normalize TOF (Time-Of-Flight) diffraction data, especially related to short time-resolved data.
To keep the reliability of the operando diffraction data,a high-efficiency and high-count rate neutron monitor
detector is necessary. nGEM (Gas Electron Multiplier) detector [7] is one of the candidates for monitor detector,
which was installed in SPICA. Some test data was collected. The monitor intensity of nGEM was 102 times higher
than the one of the 3He gas detector (efficiency: 10-3)
with no counting loss against the direct beam of BL09.
2. Commissioning of the nGEM detector
The commissioning of the nGEM detector was carried out on SPICA. For the commissioning, the nGEM
detector was put on the sample position. As the initial step, the operating high voltage was determinedby counting rate scanning with changing the negative
high voltage. Figure 1 shows the counting rate response
against the high voltage scanning. The plateau region
was obtained from -2250 to -2400 V. From this result,the operating voltage was fixed at -2300 V.
The detection area was checked by observing a direct beam at the sample position. Figure 2 shows the

Figure 1.	The high voltage dependence of count ratings. The
counting rate was normalized with the number ofT0 frames.

96

(a)

(b)

Figure 2.	The beam profile at the sample position on SPICA.
The all TOF data was merged at each position. (a)X, Y-projection beam profile. (b) Two-dimensional
imaging map.

two-dimensional imaging data and the one-dimensional beam profiles. A beam size was defined by RegionOf-Interest (ROI) which the region of over 3% intensityof the maximum value in the X projection (Y projection)
distribution. In the condition of no beam shaping byslits, the beam size was 40.0 (W) × 77.6 (H) mm2. The
beam center was slightly shifted from the center of thedetector, however, it didn’t directly mean that the beam
center was misaligned since this shifted value included
the error of setting up the detector.
3. Installation of nGEM detector
SPICA had a 3He gas detector (efficiency: 10-5) as abeam monitor at the 48-m position from the decoupledpoisoned moderator. Figure 3(a) shows the geometry of
3He gas detector on the SPICA. This detector was located in a small cave at the last section of the downstream
radiation shields. The size of the cave was 400 (W) ×603 (H) × 550(D) mm3. And two quadrant slits were puton the upstream and downstream position from the
3He gas detector. A 10-mm sintered B C radiation shield,
4which decrees background from the upstream and has
a beam hall (100 (H) × 50 (W) mm2), was installed justoutside of the cave outlet.

MLF Annual Report 2016

Neutron Science

(a)

(b)

Figure 3.	The picture of the installed nGEM monitor at 48.5 m
position. (a) The geometry of each detectors locationon the SPICA beamline. The dark-colored area is in radiation shields. (b) The external view of nGEM detector component made by BBT under license by KEK.

Figure 3(b) shows the nGEM detector component.
This box contains the detector and an all-in-type electronic device to treat detection signals. The concave surface is the detector area. The size of the box is 50.5 (H)× 518.5 (W) × 254 (D) mm3. This box size was too large
to fit into the cave to substitute the 3He gas detector for
nGEM. Therefore, the nGEM (efficiency: 5 × 10-3) detector was installed on the outside of the cave (shown in
Fig. 3(a)). The position of nGEM detector was at 48.5 mfrom the moderator. As a result, the 3He gas detector
and the nGEM detector could be used as incident neutron monitor detectors at the same time on SPICA. Thisgeometrical setting was helpful for an ability test of thenGEM detector.
4.	Comparison between 3He and nGEM as monitor
detector
Figure 4 shows the incident direct beam profile
against TOF for 5 minutes of collection time. The intensities from each detector were consistent with theefficiency of detectors respectively. The data of nGEM
reached 10000 counts in the highest region and had ahigh amount of statics even within the 5 minutes. The

Figure 4.	Time-Of-Flight dependence of an incident neutron
beam on SPICA.

current goal of minimum time-resolved is 1 minute on
SPICA. This high static provides reliability for normalization of the operando diffraction data in 1 minute.
This new monitor detector will be expected to work
effectively on SPICA. In addition, reviewing nGEM as atransmission detector on SPICA for a small angle scattering has been considered. In the near future, anothernGEM detector will be installed at the downstream ofthe sample position.
Acknowledgement
This work was supported by the Research andDevelopment Initiative for Scientific Innovation of New
Generation Batteries (RISING2) project of the New Energy
and Industrial Technology Development Organization(NEDO). The neutron scattering experiment was approved by the Neutron Scattering Program Advisory
Committee of IMSS, KEK (Proposal No. 2014S10).
References[1] M. Yonemura, et. al., J. Phys. Conf. Ser., 502(1)Article# 012053 (2014).
[2] S. Shiotani, et. al., J. Power Sources., 325, 404-409(2016).
[3] S. Taminato, et. al., Scientific Reports., 6, Article#
28843 (2016).
[4] T. Matsunaga, et. al., Chem. Mater., 28(12), 41434150 (2016).
[5] K. Kino, et. al., Solid State Ionics., 288, 257-261(2016).
[6] T. Matsunaga, et. al., J. Phys. Chem. Lett., 7, 20632067 (2016).
[7] H. Ohshita, et. al., JPS Conf. Proc., 8 Article# 36019(2015).

M. Yonemura1,2,3, H. Ohshita1,2, Y. Ishikawa1,2, S. Torii1,2, and T. Kamiyama1,2,3
Institute of Materials Structure Science, KEK; 2Neutron Science Section, Materials and Life Science Division, J-PARC Center; 3Sokendai (The
Graduate University for Advanced Studies)1

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BL10: NOBORU
1. Introduction
In FY 2016, in addition to the postponed proposals
from FY 2015, 13 general use and 1 proprietary use proposals were carried out at NOBORU. There was no interruption of the user program due to the instrument trouble.
This year, we added two filters for resonance absorption experiments to the present filter exchanger [1]; one is a 2-mm thick cadmium (Cd) plate and theother one is a 50-µm thick tantalum (Ta) and indium(In) foils sandwiched by a couple of 1-mm thick copper(Cu) plates. Figure 1 shows the installed filters on theexchanger at around 7.4 m position of the beamline.

of the resonance calibration filter with the Cd filter.
Neutron transmission images of the test targets
made by gadolinium (Gd) and gold (Au) are shown on
the left and right of Fig. 3, respectively. The image of theGd was obtained by 10-minute irradiations with andwithout the target, then the former image was divided
by the latter. The transmission image of the Au target wasalso obtained by irradiations lasting 17 hours with thetarget and 15 hours without it. The detailed experimental procedures have been covered in the literature [3].
Although the image of the Au target was not as clear as
the Gd target due to lower statistics caused by the narrowenergy range, the improvement of the spatial resolution
was also significant in the resonance energy region. The
original spatial resolution of 3 mm (by pixel) was drastically improved by the center-of-gravity calculation using
event-recorded data of neutron detection. The estimatedspatial resolution of the LiTA12 system with the center-ofgravity calculation was 0.7 mm for the energy at 4.9 eV.

Figure 1.	Two newly installed filters for resonance absorption
experiments.

2.	Epicadmium neutron spectrum measurement
and imaging experiment using filters
Epicadmium neutrons, neutrons of kinetic energy
higher than the effective cadmium cut-off energy of
0.5 eV, are useful not only for radiography of thick objects due to its high-penetration power but also for elementary analysis using resonance absorption of nucleus.
Resonance absorption imaging, being used to visualize
a spatial distribution of elements and/or temperature
within a sample, is one of the important applications ofan intense short-pulse neutron source. To perform resonance absorption imaging, however, the efficiency ofthe epicadmium neutrons for the existing counting typetwo-dimensional (2D) detector is insufficient. The 2012
model lithium-6 time-analyzer neutron detector (LiTA12)
system [2], based on a lithium glass scintillator and multianode photomultiplier tube, has the highest neutron
efficiency among the detectors for pulsed neutron imaging. The LiTA12 system provides high count rate of up to
10M cps, as seen in Fig. 2, which shows measured spectra

Figure 2.	Measured resonance absorption spectra of Ta andIn with Cd filter using the LiTA12 system.

Figure 3.	Neutron transmission images of Gd (left) and Au(right) targets. The neutron energy ranges were lessthan 0.1 eV for Gd and 4.79 – 5.01 eV for Au.

References[1] M. Harada et. al., JPS Conf. Proc. 1, 014015 (2014).
[2] S. Sato et. al., Physics Procedia 60 (2014) 363.
[3] T. Kai et. al., submitted to Physica B (Proceedings of
ICNS2017).

K. Oikawa and T. Kai
Neutron Science Section, Materials and Life Science Division, J-PARC Center98

MLF Annual Report 2016

Neutron Science

BL11: in-situ Diffraction above 20 GPa with Diamond
Anvil Cell
1. Introduction
Since the start of the beamline operation at 2013,
developments to extend the accessible pressure andtemperature range have been conducted and now we
can routinely collect diffraction data up to 20 GPa. On
the other hand, data collection above 20 GPa is still difficult. This year, we were determined to overcome thislimit by using a diamond anvil cell (DAC) coupled withneutron optics, newly designed for it.
The diamond anvil cell is a high-pressure device, inwhich the sample is sandwiched and compressed by apair of single crystal gem diamonds. Thanks to the hardness of the diamond and the effective concentration of
the applied force to the sample, the device can generatepressures of more than 300 GPa despite its compactness (it is portable by one hand). Due to this advantage,
the device is widely used in many synchrotron facilities.
However, its use in neutron experiments is limited because the sample is so tiny (typically less than 0.01 mm3)that a significant signal cannot be detected. To overcome this problem, we have developed the followings:i) Increased the sample size by designing a new DAC
equipped with large diamonds.
ii) Increased the incident beam flux by focusing theneutron beam with a supermirror guide.
iii) Increased the quality of the diffraction pattern by
reducing the diamonds’ Bragg spots contamination using radial collimators with gauge length of
1.5 mm.
The details of each development are described in thefollowing sections.
2. Diamond anvil cell (DAC)
Figure 1 shows the diamond anvil cell, newly designed for time-of-flight (TOF) measurements. The sample is sandwiched between a pair of 0.35 carat diamonds(solid pink in the Fig. 1), which are conically supported
from the backside by sintered diamonds (shaded pink).
Both diamonds are kept coaxial during compression witha piston and a cylinder (blue). This assembly is encased ina load frame to apply force of maximum 100 kN (shaded).
The pressure is generated by rotating the breech of theload frame. The piston-cylinder assembly is removablefrom the load frame, so that we can load gas in the sample chamber prior to the compression with a gas-loading
system at the National Institute for Material Science.

Figure 2 shows the pressure generation curve whenusing diamonds with culet size of f1.5 mm. In this case,the sample size is typically 0.7 mm in diameter and0.14 mm in thickness. At present, we have succeeded ingenerating pressure of 30 GPa.

Figure 1. Cross section (top) and the photo (bottom) of DAC,
newly designed for TOF neutron diffraction.

Figure 2.	Pressure generation performance when using diamonds with culet size of ф1.5 mm.

3. Neutron optics
A focusing guide, newly designed for DAC, consistsof Ni/Ti supermirrors with critical index of m = 4.0. To
avoid unwanted degradation of the resolution of thediffraction pattern taken with horizontal scattering geometry, only the top and bottom glasses were coated99

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with Ni/Ti. The total length was 1.2 m and the focal
point was at 60 mm distance from the exit of the mirror. Figure 3 shows the performance of the mirror. The
effects on the intensity and resolution were evaluatedby collecting the diffraction pattern of a tiny nanopolycrystalline diamond (NPD) and Si power (NIST SRM
640d), respectively. When the newly designed focusing
mirror was used (see FD2 in the Fig. 3), the intensity increased by a factor of four at about d = 2 Å (corresponding to c.a. 20000 ms), compared to normal slits, while
the resolution decreased by a factor of 1.5.
A set of radial collimator with gauge length of
1.5 mm was also manufactured to reduce the intensity of diamonds’ Bragg spots, which contaminates thediffraction pattern. By coupling with the incident collimator with a hole of f0.7 mm, the volume contributing to diffraction can be defined into the dimension of
0.7 mm in diameter and 1.5 mm in thickness. Even byusing these optics, the contamination of the diamondpeak could not be avoided (Fig. 4), but the contamination degree was decreased.
Figure 5 shows the diffraction pattern of ice VII obtained by masking these spots. We have managed toobtain diffraction patterns of ice VII up to about 20 GPa.
Significant shift of the Bragg peaks was found at highpressures. Unfortunately, the peaks turned out to bevery broad, probably due to the inhomogeneous pressure distribution in the sample chamber. Besides, it
is known that the Bragg reflection of diamond anvils
causes significant loss of the incident beam at certain
energies (the so-called diamond dip) [1], which makes
the quantitative analysis of diffraction patterns difficult.
Now we are trying to fix this problem by collaboratingwith an author in Ref. 1.

Figure 4.	A two-dimensional pattern obtained with DAC.

Figure 3.	(Top) Diffraction patterns of NPD taken with different incident optics (4D: normal slit, FD2: newly
designed focusing device). (Bottom) Intensity gain
and resolution.

Figure 5.	Diffraction patterns of ice VII obtained with DAC after masking diamonds’ Bragg spots.

Reference[1] M. Guthrie, et al., J. Appl. Cryst., 50, 76 (2017).

T. Hattori1, A. Sano-Furukawa1, K. Funakoshi2, J. Abe2, and S. Machida2
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Neutron Science and Technology Center, CROSS

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HRC and Neutron Brillouin Scattering
1. Introduction
Neutron Brillouin scattering (NBS) is inelastic neutron scattering close to the forward direction, and iseffective for observing coherent excitations in non-single-crystal samples, such as ferromagnetic spin waves
in powder samples and acoustic phonons in liquids andpolycrystalline samples. In order to detect such excitations, access to the energy-momentum space near to(000) is required. Access to such energy-momentum
space can be achieved by using low-angle detectors,
high-energy neutrons and high resolution. For example, the scattering intensity from ferromagnetic spinwaves remains close to (000) only and rapidly decays
with increasing the momentum Q by the powder average. Since the first success of NBS on HRC [1], HRC
has been improved [2, 3]. Here, we describe recent improvement works for NBS on HRC [4].
2. Recent improvements for NBS on HRC
Since the solid angle of detecting area for NBS experiments is limited to very low scattering angles, improvements to gain scattering intensities are essential.
We made some efforts to gain the neutron flux in various ways.
(a)

The configuration of the detectors for NBS was improved. In the low-angle detector bank, detectors arealigned in a double-layered configuration to increase
the counting rate: the detectors in the front layer face
the sample and the detectors in the rear layer are placed
just at the lower stream of the front layer. The counting
rate for the double-layer configuration is increased by afactor of 1.4 to that for the single layer configuration for
the incident neutron energy of Ei = 100 meV as shownin Fig. 1(a). The detectors are mounted in the scattering
angle range of 0.6 – 5.1°.
The Fermi chopper is composed of a slit package,
which is a layered assembly of components of shielding plates and spacers sandwiched between curved
walls. The slit package of a vertical slit, a cross section
with dimensions 75 mm (width) × 64 mm (height) andlength of 100 mm, is inserted to the side of a cylindrical rotor, with diameter 125 mm, which rotates aroundthe vertical axis. The rotor and the slit package are distorted by the rotation stress at the frequency up to f
= 600 Hz. In the Fermi chopper in the previous setup,the slit package, where the sum of the widths of thecomponents equaled 75 mm, was inserted. In this assembly, a large distortion of the slit package is caused

(b)

(c)

4

p

d

2

100

2

La0.8Sr0.2MnO3
−1

1

0
−100

20
0
100
E (meV)

Intensity (arb.units)nIntensity (arb.units)

Intensity (arb.units)3

top

I (a.u.)side

50

Q = 0.225 Å

10

1

0

2

10

d

18

26

0
−4

2
−2 0
E (meV)

4

0
−10

−5

0
E (meV)

5

10

Figure 1.	Improvement for the NBS experiments on HRC. Blue and red marks indicate the present and previous setups, respectively.
(a) Detector configuration. Observed scattering intensities from a vanadium sample, which are integrated over the positions p along each detector, are plotted as a function of the detector number d, where d = 2 and 26 correspond to thescattering angles of 0.6 and 2.8°, respectively. Due to an incomplete mask for the sample, scattered neutrons spread from
low angles. The intensities at high angles (large d) show the actual intensity gain. (b) Improvement of Fermi chopper. Elastic profiles of the vanadium are plotted with curves fitted with Gaussian functions. The inset shows inelastic spectra fromthe vanadium observed at 4 m from the sample using the 1.5° collimator. (c) Total intensity gain. Ferromagnetic spin waves
in La0.8Sr0.2MnO3 were observed with the present and previous setups. The solid lines are curves fitted with the scatteringfunction for resolution-limited spin waves.

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by the rotation stress. At present, the slit package’s
width (the sum of the widths of the components) was
increased to 78.8 mm by increasing the number of thecomponents, then pressed to the width of 75 mm andinserted into the rotor. It was visually confirmed thatthe distortion after rotation up to 600 Hz was greatly
reduced. Figure 1(b) shows the inelastic spectra of theelastic scattering from a vanadium sample observed
for the present and previous setups with Ei = 100 meV,f = 600 Hz with the detectors located at 5.2 m from thesample, and with 0.3° collimator. This change improved
the energy resolution from DE = 2.0 meV to 1.9 meV,and the integrated intensity was increased by a factor of 1.1. In addition, the transmitted intensity at thehalf rotation of the Fermi chopper, which was observedat the energy transfer around E = 90 meV for the previous setup, disappeared in the present setup due toimproved slit structure, and therefore, the observableenergy-transfer range was also expanded.
The background noise was reduced at the scattering angles down to 0.6° for NBS experiments by using
a collimator with collimation of 0.3°. This collimator
composes a vertical slit of cadmium sheets with thickness of 0.1 mm. The collimation of w/L = 0.3° was realized with sheet spacing of w = 0.8 mm and collimator
length L = 150 mm. The transmission of the 0.3° collimator was only 20% of the designed value, because it wasvery hard to maintain the flat sheets of thin cadmium.
If the distortion of the cadmium sheet is constant, thetransmission should be increased for longer L with thecollimation w/L unchanged. A long collimator was introduced, where w = 1.55 mm, L = 295 mm. At present,
we can select one of the four: the new long 0.3° collimator, the previous short one, the 1.5° one, and the blank.
The 1.5° collimator is used for conventional experiments using detectors located at 4 m from the sample
and at the scattering angles down to 3°.
3. Measurement of improved performance
In order to evaluate the performance of the system

improved by the present works, an NBS experiment fora polycrystalline sample was performed. The sample is anearly-cubic perovskite ferromagnet La0.8Sr0.2MnO3 withferromagnetic transition temperature TC = 319 K [1]. The
measurement was performed at 245 K (< TC) with Ei =100 meV at f = 600 Hz, by using the double-layered detector system, the improved Fermi chopper, and thelong 0.3° collimator. Figure 1(c) shows an observed
spectrum, where the background measured with anempty can was subtracted. The spectrum is well fitted
to the scattering function for resolution-limited spinwaves [1]. Also, the observed spectrum in the same
condition but by using the single-layered detector system, the previous Fermi chopper, and the short collimator [1] is plotted in Fig. 1(c). This spectrum is also fitted
to the scattering function for resolution-limited spinwaves. From the intensity factors obtained by the fits,a factor of 2.4 was obtained as an intensity gain. Since
the gain for the double-layered detector system to thesingle one is 1.4 and the gain for the improvement of
the Fermi chopper is 1.1, the gain for the long collimator to the short one can be estimated to be 1.6.
4. Summary
By the success of NBS experiments on the HRC,
some scientific results have been obtained from studies
on spin waves and phononic excitations, mainly under
the initially realized conditions for NBS [1-3]. By using
the improved conditions, further results are expected.
The NBS option differentiates the HRC from other chopper spectrometers, and opens opportunities for contributing to the current science by measuring coherent
excitations from non-single-crystal samples.
References[1] S. Itoh et al., J. Phys. Soc. Jpn. 82 043001 (2013).
[2] S. Itoh et al., J. Phys. Soc. Jpn. 82 SA034 (2013).
[3] S. Itoh et al., AIP Conf. Proc. in press.
[4] S. Itoh et al., J. Phys.: Conf. Series, in press.

S. Itoh1,2, T. Yokoo1,2, T. Masuda3, H. Yoshizawa3, M. Soda3, M. Yoshida3, T. Hawai1,2, D. Kawana3, R. Sugiura3, T. Asami3, and Y. Ihata4
Institute of Materials Structure Science, KEK; 2Neutron Science Section, Materials and Life Science Division, J-PARC Center; 3Tne Institutefor Solid State Physics, The University of Tokyo; 4Technology Development Section, Materials and Life Science Division, J-PARC Center

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YUI and HANA: Control and Visualization Programs for
HRC
1. Introduction
We have constructed a computing system and software environment to control accessories and to handle
neutron signals from position sensitive detectors (PSD)
for High Resolution Chopper spectrometer (HRC), installed at BL12 in 2010 [1, 2]. In the software environment, the comprehensive-control program “YUI” andthe visualization program “HANA” play central roles [3].
In this report we describe their basic constructs andcharacteristic functions at present, and briefly explain
the future plans.
2. YUIThe comprehensive control program YUI (Yasashii
or Yoku-dekita User Interface) has three fundamental
functions: measurement by sequential operation of
DAQ middleware (DAQ-MW) [4], control of the devices,and logging of their status. The main window of YUI isshown in Fig. 1. All the related accessories are controlled
by YUI, although the communication protocols for theaccessories are different. As a key solution, we installeda “device server,” a virtual machine which intervenes
between YUI and the corresponding accessory. The installed device servers work for DAQ-MW, MLF-server,
Fermi chopper, Soller collimator, oscillating radial collimator, goniometer and temperature controller. Here,the MLF server is regarded as the accessory that gets the
proton number for the normalization of incident neutron numbers. The device servers of the last two are prepared for each sample-environment apparatus, such as
the GM-type refrigerator and 3He circulation-type refrigerator [5]. The device servers of the T0 chopper and thevacuum chamber controller are only for data logging.
Users can control the devices in either of two ways.
One is the manual control. For example, when setting
frequency and incident energy of the Fermi chopper,
users directly enter a command using the specialized
control graphical user interface (GUI) as shown in Fig. 2.
In this GUI, all the necessary functions on user-experiments are integrated and implemented. Such a GUI has
been prepared together with the installation of a newaccessory.

Figure 1.	Main window of YUI. It consists of three display areas: list of the activated device servers (top-left), sequence edited by users and its progress states (top-right), and messages communicated with devices, called system log (bottom).

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Figure 2.	GUI to control Fermi chopper.

The other way is the automatic control by executing
a macro of sequential commands. We prepared built-in
macros called “user-commands” for users to edit theirmacro. Users can perform their experiment by just arranging these user-commands in an xml file. One usercommand consists of a set of basic commands which areprepared for each device. For example, “DAQ Run” is oneof the typical user-commands. While users execute DAQ
Run, the basic commands of DAQ-MW: configure, begin,
DAQ wait, end, unconfigure, and increment run number
are executed in sequence. Furthermore, as an application of user commands, “Gonio-angle-scan” is a convenient user-command that consists of DAQ Run and aseries of basic commands related to goniometer control.
Set and current values of the devices are continuously monitored and recorded to the log files every
5 seconds. The obtained log data can be graphically displayed on a browser page named “Log-visualizer”. This
helps users to check the time variation of the current
values of the devices, such as stability of the phase of
the Fermi chopper.
After a measurement, a report file is created. Not
only the times of beginning and completion of themeasurement, i.e. begin and end times of DAQ-MW,
but also the set and monitored values of all activateddevices are recorded to the report file.
In addition, the effective measurement time andthe proton number, which is obtained from the server
in MLF intranet [6], are also recorded. The proton number is used for normalization of the measured intensity.
3. HANA
HANA (HRC ANAlyzer) is a data-reduction program
for the initial data handling and the data visualization.
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The basic flow is creation of intensity-histogram datafrom the event data, sequent reduction of the histogram data, and visualization of the dynamical structure
factor in four-dimensional space.
On HANA, one detected neutron is treated as a data
set labeled with three parameters of (d, p, t), where d, p,
and t denote the PSD number, position on the PSD, andtime of flight (ToF) of the neutron, respectively. Here, p
is given from the ratio of the electrical pulse heights at
the upper and lower ends [4]. The histogram data of theform (d, p, ω), where ω represents the energy transfer,is calculated by (d, p, t) and the incident energy Ei. Users
can determine the observed value of Ei by a fitting procedure on HANA.
Two types of the reductions of the histogram data
are available. One is for a single-crystal. The three dimensional momentum transfer Q is represented by thereciprocal-lattice coordinates of (Qa, Qb, Qc). Their directions are defined from the given lattice parameters.
Users can visualize a two-dimensional intensity map, on
which two of the four parameters Qa, Qb, Qc, and ω areselected as vertical and horizontal directions. The othercase is for a powder sample. The momentum transfer issimply regarded as |Q| = Q. Users can visualize an intensity map on the Q-ω plane.
The histogram data can be transformed to a data
format of the visualization program DAVE MSlice [7] forconvenience of the users. Furthermore, several histogram data with different measurement times can be
combined by normalization using proton number recorded by YUI.
The alignment support function is indispensable inthe beginning of single crystalline experiments. From a
Laue profile measured by a white beam, users can obtain the information of the relation between the coordinate of the crystal and that of the spectrometer with aneasy procedure.
As shown in Fig. 3, we have also developed the distribution version of HANA, for Mac and Windows, which
is distributed to users who want it. They are able to perform the data reduction process using event data on
their campus.
4. Future Plans
We have developed and improved YUI and HANA
day-by-day for convenience of users and instrument
staff members. Now we plan the installation of somenew devices for sample environment, as well as theircontrol from YUI in future. In HANA, we are planning to
implement an analysis function for four-dimensional

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Figure 3.	Distribution version of HANA.

data obtained from the continuously rotation scan ofa single crystal. Recently, the programs have also been
installed to the computing system in POLANO (BL23).
For example, the function of arithmetic calculations for
two intensity maps has been developed in HANA, inconsideration of the polarization analysis on POLANO.
Acknowledgement
The previous and present HRC staff members M.
Soda, S. Ibuka, M. Yoshida, T. Hawai, and S. Asai supported the operation checks of YUI and HANA, and T.
Asami and R. Sugiura supported their installations. We
would like to appreciate Bee Beans Technologies Co.,
Ltd. (Tsukuba, JAPAN) for gratefully supporting ourworks as partnership.

References[1] S. Itoh et al., Nucl. Instr. and Math. Phys. Res. A 631
90 (2011).
[2] S. Itoh et al., J. Phys. Soc. Jpn. 82 SA033 (2013).
[3] D. Kawana et al., submitted to Proc. on ICANS XXII(2017); see also arXiv:1710.00487 for details.
[4] S. Satoh et al., Nucl. Instr. and Meth. Phys. Res. A 600
103 (2009).
[5] S. Itoh et al., proc. of ICANS-XXI (JAEA-Conf 2015002/KEK Proc. 2015-7) 298 (2016).
[6] http://www-cont.j-parc.jp/MLF/, accessed on Oct.
11, 2017.
[7] R. T. Azuah et al., J. Res. Natl. Inst. Stand. Technol.
114 341 (2009).

D. Kawana1, T. Masuda1, H. Yoshizawa1, S. Itoh2,3, T. Yokoo2,3, and Y. Ikeda4
1
Neutron Science Laboratory, Institute for Solid State Physics, the University of Tokyo; 2Neutron Science Section, Materials and Life Science
Division, J-PARC Center; 3Institute of Materials Structures Science, KEK; 4Institute for Materials Research, Tohoku University

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BL14 AMATERAS
1. Introduction
FY2016 was the eighth year of operation of
AMATERAS [1, 2], a cold-neutron disk-chopper spectrometer. We continued the user program. As it happened in the previous year, in this fiscal year, we
encountered again some mechanical problems withthe equipment of AMATERAS. There were changes
in the staff of AMATERAS. A new research fellow, Dr.
Maiko Kofu joined AMATERAS in October. On the other
hand, Dr. Yukinobu Kawakita, who was engaged in both
AMATERAS and DNA, moved from AMATERAS to concentrate on DNA.
2. User program, international activities & out-comes
In FY2016, MLF was smoothly operated without
any seriously breakdowns. On AMATERAS, 20 general
proposals, four JAEA project proposals and one elemental strategy proposal were carried out. The numberof general proposals included 2014B and 2015A proposals, which were carried-over due to the interruptionof the user program in FY2015. Also, the portion of thebeam time of project proposals and elemental strategy
proposals, which were not used in FY2015, were spent
in FY2016. The number of general proposals submitted
for the 2016A and 2016B periods was 28 (accepted: 4,
reserved: 24) and 22 (accepted: 6, reserved: 16), respectively. As we will mention later, AMATERAS had several
serious problems with auxiliary devices, which, unfortunately, affected some of users’ experiments.
AMATERAS joined the first Neutron and Muon
School held in November. Three students took part in aquasi-elastic neutron scattering (QENS) experiment forionic liquids, which are attracting increasing attention
in many fields (Fig. 1). We gave a lecture on an overview
of AMATERAS and a TOF technique at the chopper spectrometer. They prepared the liquid samples, set them
to a cryostat, and conducted a measurement. Throughthe hands-on experiment, they learned how to analyze
the QENS data and how diffusive dynamics is examined
by QENS. We hope that neutron scattering will become
one of the experimental tools to be used in their future
research activities.
As it happened the last fiscal year, AMATERAS had aguest from Korea, Dr. Sungil Park (Korea Atomic Energy
Research Institute), in the framework of the Korea-Japan
collaboration program in neutron science. He carriedout a trial inelastic experiment on single crystals of 2D
organic-inorganic hybrid magnets.
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Figure 1.	(Top) Three students who participated in the first
Neutron and Muon School and staff members of
AMATERAS. From the left, Dr. T. Kikuchi (J-PARC), Mr.
Y. Ishii (Tohoku U.), M. Nakase (JAEA), Ms. N. I. P. Ayu(KEK), Dr. M. Kofu (J-PARC). (Bottom) They discuss
data analysis and results.

In 2016, four refereed papers reporting resultsfrom AMATERAS were published. Two master theses
including results from AMATERAS were written. Dr.
Minoru Soda (RIKEN) won the 14th Japanese Societyof Neutron Science Young Research Fellow Prize, which
was a recognition of his research work involving the useof AMATERAS.
3. Instrumental activities
Since one of the compressors that operate thecryopump system was broken last year, we replaced
several components, such as a displacer of the coldhead and an adsorber in the compressor this year.
However, the repaired systems still had a problem, anabnormal sound, when they were re-installed at the instrument just before the beam operation was resumed.
Then we took it back to the company again. Since we
had to operate cryostats in low vacuum due to the lackof a cryopump, we substituted our standard cryostat forMLF Annual Report 2016

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Figure 2.	Detector map images taken (a) before and (b) after the refurbishment of vanes between detector banks. Some of detector
pixels between the detector banks were hidden due to badly installed vanes before the refurbishment, which work correctly after the treatment.

other ones that can be commonly used at instruments.
The cryopump system came back in January, but one of
the three coldheads still has some failures. We decided
to stop its operation until the next summer.
Last year, a newly designed vane was partly installed as a trial at the vacuum scattering chamber.
Because it was quite effective, we replaced all the conventional vanes, which caused useless pixels in the data,with new ones. The data quality was improved after thisrefurbishment (Fig. 2).
In FY2016, we also made other improvements.
Minor modification on utilities around the experimentarea was done by in-house staff. More than half channels of high-voltage power supply have failed one after

another since the last year, and we replaced some ofthem.
References[1] K. Nakajima, S. Ohira-Kawamura, T. Kikuchi, M.
Nakamura, R. Kajimoto, Y. Inamura, N. Takahashi,
K. Aizawa, K. Suzuya, K. Shibata, T. Nakatani, K.
Soyama, R. Maruyama, H. Tanaka, W. Kambara,
T. Iwahashi, Y. Itoh, T. Osakabe, S. Wakimoto, K.
Kakurai, F. Maekawa, M. Harada, K. Oikawa, R. E.
Lechner, F. Mezei, and M. Arai, J. Phys. Soc. Jpn. 80,
SB028 (2011).
[2] K. Nakajima, RADIOISOTOPES 66, 101 (2017).

K. Nakajima1, S. Ohira-Kawamura1, M. Kofu1, T. Kikuchi1,2, and Y. Kawakita1
Neutron Science Section, Materials and Life Science Division, J-PARC center; 2Chemical Analysis Center, Research & Development HQ,
Sumitomo Rubber Industries, Ltd.

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Upgrading TAIKAN
1. Introduction
The small and wide angle neutron scattering instrument TAIKAN (BL15) has been developed and upgradedto analyze precisely and efficiently microstructures orhierarchical structures of substances in various scientific fields with a 1 MW spallation neutron source in
J-PARC [1]. In FY2016, it was upgraded further to perform measurements with a rheometer and middle-q
measurement.
2. Upgrading for measurements with a rheometer
A rheometer MCR-302 (Anton-Paar Co., Ltd.) witha double cylindrical cell was introduced for the RheoSANS measurement of surfactant solutions, ionic liquid,etc. (Fig. 1). The cell is composed of an outer cylinder
with 50 mm in inside diameter and an inner cylinder
with 48 mm in outside diameter. The gap between thecylinders is 1 mm. The sample volume is about 22 ml.
The rheometer has been used to measure viscoelasticity of a sample in torque of 1 nMm – 200 mNm at temperatures of -50°C – 150°C

3. Upgrading for middle-q measurement
The detector system of TAIKAN is composed of 5detector banks: the small-, middle-, high-, ultra-smallangle, and backward detector banks. On the middle-angle detector bank in the vacuum chamber, 288 3He PSD
tubes were additionally installed. The measurement efficiency of the middle-angle detector bank increased
twofold. The number of 3He tubes then increased to768, 592, 104, and 48 for small-, middle-, high-angle,
and backward detector banks, respectively. Figure 2
shows a photo of the small- and middle-angle detectorbanks after installing the 3He tubes.

Figure 2. Small- and middle-angle detector banks.

4. Future prospects
The improvement of measurement efficiency by
the installation of the detectors and the increase of
the beam intensity makes time-resolved measurement
easier. In the future, TAIKAN is expected to contributeto research not only of static phenomena but also oftransient phenomena related to microstructures or thehierarchical structures.

Figure 1. A rheometer on a sample stage of TAIKAN.

Reference[1] S. Takata, J. Suzuki, T. Shinohara, T. Oku, T. Tominaga,
K. Ohishi, H. Iwase, T. Nakatani, Y. Inamura, T. Ito,
K. Suzuya, K. Aizawa, M. Arai, T. Otomo and M.
Sugiyama, JPS Conf. Proc. 8, 036020 (2015).

J. Suzuki1, S. Takata2, K. Ohishi1, H. Iwase1, T. Morikawa1, Y. Kawamura1, and M. Sahara1
R&D Division, Neutron Science and Technology Center, CROSS; 2Neutron Science Section, Materials and Life Science Division, J-PARC
Center

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Detector Development for the SOFIA Reflectometer
SOFIA is a horizontal-type neutron reflectometer
constructed at Beamline 16 (BL16) of the Materials andLife Science Experimental Facility (MLF) of the Japan
Proton Accelerator Research Complex (J-PARC) [1, 2].
Owing to the high-flux beam of J-PARC, less than one
hour is needed for taking full Q-range data and only afew seconds for limited Q-range data in the case of asample with 3 inches (76 mm) in diameter; even though
the beam power is still one-third of the planned value,
1 MW. However, several hours are still needed for small
samples such as 10 mm × 10 mm, which is the typicalsize of a sample for X-ray reflectometry. For this purpose, we are developing a focusing mirror to use a highflux beam with a large beam divergence.
On the other hand, the diverged beam makes angular resolution worse because the distribution of anincident angle to the sample increases. To avoid thisproblem, a position-sensitive detector is strongly required because the incident angle of neutrons can be
distinguished by the reflection position under a specular condition. The angular resolution in this case is, however, limited by the spatial resolution of the detector. So
far, we are employing a scintillation detector consistingof a 6LiF/ZnS sheet and position-sensitive photomultiplier tube. Although the spatial resolution of the detector (about 1 mm) is acceptable for the purpose, there ismuch room for improvement in the counting efficiency(about 20% for thermal neutrons) and the counting rate(about 3000 count/s).
To upgrade the detector, we are developing a
detector based on a solid converter made of boronin combination with a GEM (Gas Electron Multipliers)
made of glass that we have already developed.
Upon absorption of a thermal neutron, 10B undergoes the following reactions:
10B + 1n → 7Li + 4He + 2.3 MeV [93%]10B + 1n → 7Li + 4He + 2.8 MeV [7%]In either case, these particles deposit some of
their energy in the surrounding gas, where a gaseous
ionizing-radiation detector can be used to determine
the time and position of the interaction. However, thethickness of the converter is limited (2 µm in an optimum condition) because the fission particles cannot
leave the converter due to the self-absorption. As only
5% of thermal neutrons can be captured in the pathof 2 µm even for enriched 10B, some solutions using
alternate stacking of converter layers and detection
layers are proposed. The systems, however, become

more complex and expensive, and unwanted scatteredneutrons in the front layers may contaminate data inbackward layers. To avoid these problems, we adopted
a simple way: increasing the effective thickness by illuminating a converter with grazing-incidence geometry.
Figure 1 presents a schematic illustration of the
new detector we are developing. Even though the converter is thin, the path length neutrons’ travel in theconverter becomes longer by the grazing-incidence geometry. Hence, the better the counting efficiency is, thesmaller the incident angle is. Besides, the spatial resolution becomes better whereas the total detection area
decreases effectively, since the incident angle is smaller.
Therefore, the tilt of the detector should be controlleddepending on the measurement condition.
To evaluate the effect of the grazing-incidence geometry on the counting efficiency, we made a prototype detector with a converter made of natural boron(Fig. 2). The natural boron with the thickness of 2 µm
was sputtered on a Si substrate, and 2 nm copper layer was sputtered on the boron layer for coating andagainst a charge-up. The converter was mounted in agas chamber with a GEM and readout board under aFigure 1. Schematic illustration of the new detector design.

Figure 2.	Photograph of a prototype converter made of natural boron with a valid area of 10 cm × 10 cm.

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Figure 3.	Counting efficiency of thermal neutrons with a prototype detector as a function of an incident angleof neutrons.

gentle flow of 1 bar Ar/CH4 (90:10). Figure 3 shows thecounting efficiency of thermal neutrons with wavelength of 0.18 nm, as a function of the incident angleof neutrons. As the incident angle decreases, the counting efficiency increases as expected. Since the amountof 10B in natural boron is 20%, this result indicates thatthe efficiency can reach approximately 50% with an incident angle of 50 mrad. Then, the effective detection
area is 25 mm × 100 mm, and the spatial resolution is
0.05 mm, if a readout pat with 1 mm pixels is employed.
Next, we made a second prototype detector withactual components. Figure 4 presents photographs ofthe converter, GEM and readout module. The converterwith the area of 10 cm × 10 cm is made of 10B and covered by 2 nm titanium film for protection. The valid areaof the GEM is the same as the converter, whose rims
on two sides are cut for placing GEMs with small gaps
of 0.5 mm. The readout module has a line and spacepattern with 96 channels per 100 mm. The neutron
signals are collected by the module and amplified bythree charge amplifiers for 32 channels independently.
The amplified signals are counted by time analyzers,
LiTA [3], based on a field-programmable gate array.
Figure 5 shows the beam intensity profile taken by
the second prototype, in which the beam width on thedetector was 0.70 mm. The profile shape is consistent
with the intensity distribution of neutrons although

Figure 4.	Photograph of an actual GEM made of glass, 10B
enriched converter, and readout module with thevalid area of 10 cm × 10 cm.

Figure 5.	Beam intensity profile taken by the second prototype detector.

one channel is dead. As the pitch of the channels is
100/96 mm, the full width of the signal is 27 mm, andthe incident angle is estimated to be 26 mrad. After
careful evaluation of the prototype, we plan to makethe final version of the detector with an area of 10 cm
× 50 cm by arraying five units, and replace the scintillation detector in use at the SOFIA.
References[1] N. L. Yamada et al., Euro. Phys. J. Plus 126, 108 (2011).
[2] K. Mitamura et al., Polymer J. 45, 100–108 (2013).
[3] S. Satoh, Physics Procedia 60, 363-368 (2014).

N. L. Yamada1,2, T. Fujiwara3, M. Hino4, and S. Sato1,2
Institute of Materials Structure Science, KEK; 2Neutron Science Section, Materials and Life Science Division, J-PARC center; 3ResearchInstitute for Measurement and Analytical Instrumentation, Advanced Industrial Science and Technology (AIST); 4Kyoto University Research
Reactor Institute, Kyoto University

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BL17: Current Status of the Polarized Neutron
Reflectometer, SHARAKU
1. Introduction
Neutron reflectometry (NR) is a powerful technique
to investigate the nanometric structure of surfaces andinterfaces in the depth direction of thin films. A neutron reflectometer at BL17 of MLF in J-PARC, SHARAKU,
was constructed to conduct the structural analysis using polarized neutrons. An NR with a polarized neutron
beam can probe not only a nuclear scattering lengthdensity (SLD) but also a magnetic SLD; therefore,
SHARAKU can be used to study the magnetic structure
in magnetic thin film samples. In SHARAKU, a two-dimensional neutron detector, multi-wired proportional
chamber (MWPC), is installed for the measurement ofoff-specular reflectivity and grazing angle incidence
small angle neutron scattering (GI-SANS), which areused to investigate the in-plane structure of the surfaces and interfaces of thin films. SHARAKU equips several
kinds of sample environments such as electromagnets
and refrigerators to enable the NR measurement in various environment conditions. While we continued theuser experiments in 2016, we developed the measurement system using MPWC and some sample environments. In this report, we describe the current status of
the MWPC and the sample environments.
2. Current status of MWPC
Figure 1 shows a photograph of the MWPC installedin SHARAKU. It has a neutron sensitive area of 128 ×
128 mm2 with 256 × 256 pixels, each of which has a sizeof 0.5 × 0.5 mm2. The spatial resolution is 1.8 mm. The
data acquisition system in MLF stores all information of

Figure 1. MWPC installed in SHARAKU.

each detected neutron: the time-of-flight (corresponding to wavelength) and the position, including the status of the sample environments. In the case of the NR
data obtained by a two-dimensional detector, various
kinds of data reduction should be performed from theexperimental data: a two-dimensional qx-qz map for an
off-specular reflectivity, a qx-qz map for GI-SANS, andso on. We implemented a data-reduction system forthe event data of the MWPC in UTSUSEMI, which is thedata analysis environment developed in MLF. Users canperform the data reduction in several formats with auser-friendly graphical interface.
Figure 2 (a) indicates the qx-qz map of an offspecular NR data for a Ni/Ti multi-layer thin film. The
(a)

(b)

Figure 2.	Off-specular NR measurement by MWPC. (a) qx-qz
map for an off-specular NR data obtained by MWPC.
(b) Comparison of the off-specular reflection spectra obtained by MWPC (red) and a 3He tube detector (blue).

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two-dimensional detection of the reflected neutron enabled the efficient measurement of a wide qx-qz range
in an acquisition time of 8 h. At qz = 1.25 nm-1 of thesecond Bragg reflection, a peak at qx = −0.025 nm-1 isclearly observed, which corresponds to the correlationof the lateral roughness of the Ni/Ti interface. Figure 2(b) compares the off-specular NR spectrum obtained by
the MWPC and that by a 0-D detector, which has been
employed for off-specular measurements in SHARAKU.
They are in good agreement with each other, indicating that the MWPC installed in SHARAKU can be used
for quantitative NR measurements.
3. Sample environments
SHRAKU is a powerful neutron reflectometer toanalyze the magnetic structure in thin film samples;
therefore, various sample environments for magnetic samples are installed: an electromagnet up toa magnetic flux density of 1 T, a super-conducting
electromagnet up to 7 T, and a refrigerator down to atemperature of 4 K. In 2016, we carried out the commissioning of another electromagnet with a magnetic
flux density of 4 T, which is equipped with a refrigerator at 1.2 K. Figure 3 (a) shows a photograph of the 4-T
magnet. With this magnet, the magnetic field is applied along the beam axis. This magnet can be used
for the NR measurement by highly polarized neutrons
with a polarization ratio of > 0.9 at a wavelength rangeof 0.2 – 0.8 nm. This magnet will be used for a contract
variation NR experiment by a dynamic nuclear polarization technique.
SHARAKU accepts user experiments not only for

(a)

(b)

Figure 3.	Sample environments installed in SHARAKU, a 4Telectoromagnet with refrigerator (a) and a liquid
immersion cell (b).

magnetic thin film sample but also for soft matterssuch as polymers and liquid crystals. A liquid immersion sample cell can be used for the NR measurementof a thin film sample immersed in a solvent. It has beenused in the studies on the swelling behavior of polymer thin films and the solvation structure of ionic liquids at a substrate surface, etc.
4. Summary
A two-dimensional neutron detector MWPC has
been installed for an off-specular NR and GI-SANS
experiments. The data-reduction functions for the
event data from the MWPC have been prepared in the
UTSUSEMI data analysis software system for the ease ofuse in the user experiments. A 4-T electromagnet withrefrigerator and a liquid environment cell has been
prepared for the needs of user experiments in various
research fields.

K. Soyama1, H. Aoki1, D. Yamazaki1, N. Miyata2, K. Akutsu2, T. Hanashima2, S Kasai2, and J. Suzuki2
Materials and Life Science Division, J-PARC Center, Japan Atomic Energy Agency; 2Neutron Science and Technology Center, CROSS

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Status of SENJU 2016
1. Introduction
SENJU is a TOF single-crystal neutron diffractometer designed for precise crystal and magnetic structure
analyses under multiple extreme environments such as
low-temperature, high-pressure and high-magnetic
field, as well as for taking diffraction intensities of small
single crystals with a volume of less than 1.0 mm3 down
to 0.1 mm3 [1]. Ever since SENJU was launched in 2012,
continuous commissioning and upgrading operations
have been carried out.
In 2016, we developed an oscillating radial collimator to reduce the background in measurements withsome extreme sample environment devices at SENJU.
We also upgraded the software for data processing,
STARGazer for SENJU.
2. Development of an oscillating radial collimator
One of the most important features of SENJU thatmakes the diffraction measurement of a small single
crystal possible is the low background achieved by aproperly designed vacuum sample chamber. However,when an MLF common extreme sample environment
device, such as 2 K cryostat or niobium furnace, was installed in the vacuum chamber, the incident neutrons
were scattered by a chamber or radiation shields of theinstalled device and consequently the background severely increased.

Figure 1. The oscillating radial collimator designed for SENJU.

To overcome this problem, we developed an oscillating radial collimator for SENJU. The collimator was
designed for installation in the vacuum sample chamber of SENJU and has a f400 mm MLF standard flange(Fig. 1). Slits were made by Gd2O3 coated mica and arranged with 2.0° repeating angle. The standard oscillating speed was 13 sec/deg and oscillating width was 2.0°
with 1.0° offset.
In the first half of FY2016, we fabricated the collimator with 78 Gd2O3-mica slits. In this setting, the detectors

Figure 2.	Diffraction image of a 0.1 mm3 single crystal and a 1-mm thick and ф161 mm aluminum cylinder with the oscillating radialcollimator.

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MLF Annual Report 2016at the north side of the direct beam (north detector bank)of SENJU was covered by the slits and the south detectorbank was not. To assess the collimator’s performance,
we installed it in the vacuum chamber of SENJU, put a
0.1 mm3 single crystal of an organic compound with a
1-mm thick and f161 mm aluminum cylinder in the sample position and took a diffraction image. Figure 2 shows
the obtained diffraction image. The background on thenorth detector bank (with slits) was drastically reduced
and Bragg peaks from the sample were clearly observed,
while huge background due to scattered neutrons fromthe aluminum cylinder was observed on the south bankburying the Bragg peaks.
In the second half of FY2016, after the preliminary
measurement described above, we added 57 Gd2O3mica slits to the collimator to cover the south detector bank. The collimator performs low-backgroundmeasurements with the MLF common extreme sample
environment devices at SENJU and will help us design
new sample environment devices for SENJU.
3.	U pgrading of the data processing software:
STARGazer for SENJUSoftware for data processing, i.e., making a reflection file (called “HKLF file”) from raw data and data visualization, is one of the essential components for asingle-crystal diffractometer. For SENJU, a program
called “STARGazer for SENJU” is used for data processing and visualization.
In FY2016, an update of STARGazer for SENJU including development of
1. data scaling by using the GateNET system

2.	integration of Bragg peaks at the edge of detectors,
was carried out.
The first one was developed to improve the reliability of the intensity-scaling process of several sets of diffraction data. In the previous version of STARGazer, theintensity-scaling was based on the number of T0 signals and consequently the influence of the accelerator
power fluctuation was ignored in the scaling. Recently,
we added “GateNET” modules, which produce a filethat includes the accelerator operation status and themonitor-event number of the DAQ system of SENJU.
Thus, we added a function to the STARGazer to read the
GateNET output file and scale the intensities of several
sets of diffraction data by using the information about
the accelerator operation and the monitor-event, including the accelerator power fluctuation.
The second one was developed to improve the efficiency of the diffraction measurement. In the previous version of the STARGazer, partially recorded Bragg
peaks at the detector edge region, usually 6 pixels fromthe edge, were ignored and consequently 1/3 of themeasured Bragg peaks were not processed. Thus, we
added a new function to the STARGazer to estimate theintensity of partially recorded Bragg peaks at the detector edge region by a profile-fitting technique using
Gaussian function. The evaluation of the effectivenessof this new function is in progress and we expect to recover more than half of the wasted Bragg peaks withthis technique.
Reference[1] T. Ohhara et al., J. Appl. Cryst., 49 120 (2016).

T. Ohhara1, R. Kiyanagi1, A. Nakao2, K. Munakata2, T. Moyoshi2, K. Moriyama2, and T. Kuroda2
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2R&D Division, Neutron Science and Technology Center,
CROSS

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BL19: 2D Detectors Installed to the Back-Scattering Bankof TAKUMIIn JFY 2016, a back-scattering detector bank,equipped with two-dimensional scintillator detectors
with wavelength-shifting fiber readout, was installedat the Engineering Material Diffractometer TAKUMI at
BL19. Thanks to the higher scattering angle of this bank,the diffraction peak resolution exceeded the existing±90° banks. Further, these detectors can evaluate theevolution of the texture in materials during mechanicaldeformation.
The back-scattering detector bank of TAKUMI
consists of three detector modules, as shown in Fig. 1.
The scattering angle of the center and the secondary
neutron flight path length of the detector bank are
2q = 155° and L2 = 1.75 m, respectively. Each detector
module has 64 × 64 pixels with the size of 5 mm × 5 mm
namely the size of the sensitive area of one detector is
320 mm × 320 mm. The details of the detector itself canbe found in reference [1].
Simple data reduction software based on the software of Utsusemi [2] and Manyo-Lib [3] was developed.
The two-dimensional intensity distribution of 221 reflection from La11B6 powder (in a vanadium can with adiameter of 6 mm) on the detectors is shown in Fig. 2.
A part of the Debye-Scherrer ring from La11B6 powder
was clearly observed and the S/N ratio of the diffraction
pattern was high enough for the engineering study at
TAKUMI. The time-focused diffraction pattern, in which
the d-spacing data for a particular scattering angle isgathered, of the whole TOF range of the La11B6 powder
is shown in Fig. 3. The diffraction peak resolution was
evaluated as DT/T = 0.15% from the positions and the
FWHMs of the peaks that were obtained through theGaussian fitting. This value is approximately half of thevalue of the ±90° banks for the same incident beam
condition. Hopefully, strain analysis with a resolution ofless than 0.01% can be achieved by this bank.

Figure 2.	Part of the Debye-Scherrer ring of 221 reflection
from La11B6 powder.

Figure 1.	Plane view of TAKUMI and a photograph of the back-scattering bank.

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Figure 3. Time-focused diffraction pattern of La11B6 powder and the ΔT/T of each peak in the pattern.

The detector bank is already available for use, andwill become a powerful tool for the engineering studies
at MLF.
This work was partly supported by JSPS KAKENHI
grant No. 15H05767.

References[1] T. Nakamura et al., Nucl. Instrum. Methods, A 686(2012) 64.
[2] Y. Inamura et al., J. Phys. Soc. Jpn., 82 (2013) SA031-1.
[3] J. Suzuki et al., Nucl. Instrum. Methods, A 600 (2009)
123.

T, Kawasaki1, S. Harjo1, T. Nakamura2, K. Aizawa1,3, and N. Tsuji4
Neutron Science Section, Materials and Life Science Division, J-PARC center; 2Neutron Device Section, Materials and Life Science Division,
J-PARC Center; 3Technology Development Section, Materials and Life Science Division, J-PARC center; 4Department of Materials Scienceand Engineering, Kyoto University

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The Current Status of the Versatile Neutron Diffractometer,
iMATERIA
1. Introduction
Ibaraki prefecture, local government of Japan’s area
where the J-PARC sites are located, has decided to build
a versatile neutron diffractometer (IBARAKI Materials
Design Diffractometer, iMATERIA [1]) to promote industrial applications for the neutron beam in J-PARC.
iMATERIA is planned to be a high-throughput diffractometer that could be used by materials engineers andscientists in their materials development work like thechemical analytical instruments.
The applications of neutron diffraction in materials
science are (1) to do structural analyses of newly developed materials, (2) to clarify the correlation between
structures and properties (functions), and (3) to clarify
the relation between structural changes and improvements of functions, especially for practical materials.
To achieve those purposes, a diffractometer with superhigh resolution is not required. The matching amongintermediate resolution around Δd/d = 0.15%, high intensity and wide d coverage is more important.
This diffractometer is designed to look at a decoupled-poisoned liquid hydrogen moderator (36 mm,
off-centered) (BL20), and to have the incident flightpath (L1) of 26.5 m, with three wavelength selection
disk-choppers and straight neutron guides with a total length of 14.0 m. The instrumental parameters arelisted in Table 1. There are four detector banks, including a low-angle and small-angle scattering detector

Figure 1.	IBARAKI Materials Design Diffractometer, iMATERIA
without detector for each bank and instrument
shielding. The high-resolution bank, special environment bank (90° bank), and low-angle bank, canbe seen from right to left. The small-angle detectorbank, which is not shown in the picture, is situatedin the low-angle vacuum chamber (left hand side of
the picture).

Table 1.	Instrumental parameters of iMATERIA. L2 is the scattered flight path. The d-range (q-range) for each bankis the maximum value for 2-measurement mode.
L1
Guide length
Position of Disk choppers

26.5 mHigh
Resolution
Bank
SpecialEnvironment
Bank
Low
Angle
Bank
Small
Angle
Bank

2θ
L2
d-range2θ
L2d-range2θ
L2d-range2θ
L2
q-range

Total 14 m (3section)
7.5 m (double)
11.25 m (single)
18.75 m (single)
150° ≤ 2θ ≤ 175
2.0 - 2.3 m
0.09 ≤ d(A°) ≤ 5.0°
80° ≤ 2θ ≤ 100°
1.5 m
0.127 ≤ d(A°) ≤ 7.2
10° ≤ 2θ ≤ 40°
1.2 - 4.5 m
0.37 ≤ d(A°) ≤ 58
0.7° ≤ 2θ ≤ 5°
4.5 m
0.007≤ q(A°-1) ≤ 0.6

bank. The angular coverage of each detector bank isalso shown in Table 1. The rotation speeds for the diskchoppers are the same with a pulse repetition rate of
25 Hz for the most applications (SF mode). In this case,the diffractometer covers 0.18 < d (Å) < 2.5 with Δd/d
= 0.16% and covers 2.5 < d (Å) < 800 at three detectorbanks of 90 degree, low angle and small angle with
gradually changing resolution. When the speed of
the wavelength selection disk-choppers is reduced to12.5 Hz (DF mode), we can access a wider d-range, 0.18
< d (Å) < 5 with Δd/d = 0.16%, and 5 < d (Å) < 800 with
gradually changing resolution with doubled measurement time from the SF mode.
2. Current status
All of the four banks, high-resolution bank (BSbank), special environment bank (90 degree bank), lowangle bank and small-angle bank, are operational. It
takes about 5 minutes (DF mode) to obtain a ‘Rietveldquality’ data in the high-resolution bank at 500 kW
beam power for about 1 g of standard oxide samples.
Figure 2 shows a typical Rietveld refinement pattern for LiCoO2 sample, cathode material for lithium ion
battery (LIB), at the high-resolution (BS) bank by themulti-bank analysis function of Z-Rietveld [2]. It takes
20 min at the DF mode to collect the available Rietveld
data, due to the high neutron absorption cross section
for natural Li (ssNat = 70 barn).
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Figure 2.	Rietveld refinement pattern for LiCoO2 at the highresolution bank of iMATERIA.

3. Sample Environments
The automatic sample changer is the most important sample environment for high-throughput experiments. Our automatic sample changer [3] consists ofsample storage, elevating system of two lines, two setsof pre-vacuum chambers and a sample sorting system.
We can handle more than 600 samples continuously atroom temperature without breaking the vacuum of thesample chamber.
The V-furnace (~900°C), the gas flow furnace(~1000°C), the cryo-furnace (4K) and the 1K cryo are
ready for experiments. Recently, the in-operando experiment system for LIB with a sample changer also became available in cylindrical and coin types of batteries.
References[1] T. Ishigaki et al., Nucl. Instr. Meth. Phys. Res. A 600(2009) 189-191.
[2] R. Oishi et al., Nucl. Instr. Meth. Phys. Res. A 600(2009) 94-96.
[3] A. Hoshikawa et al., J. Phys.: Conf. Ser. 251 (2010)
012083.

T. Ishigaki, A. Hoshikawa, Y. Yoshida, T. Matsukawa, and Y. Onuki
Frontier Research Center for Applied Nuclear Sciences, Ibaraki University

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Status of the High Intensity Total Diffractometer(BL21, NOVA)

2. Magnetic diffraction measurements
Since NOVA can cover longer d-range with long neutron wavelength, 8.3 Å, and its high neutron flux, NOVA is
suitable for magnetic diffraction measurements. Table 1
shows Q-ranges (d-ranges) of each detector bank andresolutions. The 90-deg bank of 0.6% resolution covers
up to 6.3 Å. The minimum magnetic moments observedby NOVA is about 0.3 mB for LaFeAsO0.55H0.45 (Fig. 1),
which was obtained during the research of Ref [1].
3. Sample environments
Table 2 shows the sample environments of NOVA.
To reduce the backgrounds, a radial collimator will be
installed in FY2017.
Table 1. Q-ranges (d-ranges) of NOVA.
Detectorbank

Scattering angle Q-resolution /Q-range(2q) / degree%(d-range) / Å
0.7~97(4~50)

0.03 ~ 8(0.8 ~ 209)

20-deg12.6~28

2. 5(1.7~3.9)

0.2 ~ 26(0.2 ~ 31)

45-deg33~57

1. 2(0.9~1.5)

0.4 ~ 50
(0.1 ~ 16)

90-deg72~1080. 6(0.5~0.7)

1 ~ 82(0.08 ~ 6.3)

High-angle

135~170

0. 3(0.3~0.35)

1.4 ~ 100(0.06 ~ 4.5)

Small-angle

Magnetic intensity(Simulation)

Net intensity(Observation)

1. Introduction
Total scattering is a technique to analyze non-crystalline structure in materials with atomic Pair Distribution
Function (PDF). NOVA was designed to perform total
scattering and is the most intense powder diffractometer with reasonable resolution (Dd/d ~ 0.5%) in J-PARC.
It is easy to adapt NOVA to a very wide variety of fields:
liquids, glass, local disordered crystalline materials, magnetic structure of long lattice constant and so on. The
observation of the hydrogen position in materials is oneof the most important scientific themes of NOVA.

d (Å)

Figure 1.	Magnetic diffraction of LaFeAsO0.55H0.45 (0.3 μB) measured with NOVA.

Table 2. Sample Environments of NOVA.
Apparatus

Specification

Sample Changer

sample: 10

Temperature controlled
Sample Changer

sample: 18
temp: 20〜500 (750) K

Top Load Cryostat

temp: 5〜700 K

Vanadium Furnace

temp: 〜1373 K

PCT

temp: 50〜473 K
press: 〜10 MPa H2/D2

2K Cryostat (MLF SE)

temp: 1.7～300 K

Impedance (under commissioning)

temp: 〜550 K
freq.: 4 Hz〜1 MHz

Acknowledgement
Operation and development of NOVA were performed under the S1-type program (2014S06) approved by the Neutron Scattering Program Advisory
Committee of IMSS, KEK.
Reference[1] M. Hiraishi et al., Nature Physics, 10, 300-303 (2014).

T. Otomo1,2, K. Ikeda1,2, T. Honda1,2, H. Ohshita1,2, N. Kaneko1,2, T. Seya1,2, and K. Suzuya2
Institute of Materials Structure Science, KEK; 2Neutron Science Section, Materials and Life Science Division, J-PARC Center

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Energy-Resolved Neutron Imaging System, BL22: RADEN
1. Introduction
A pulsed-neutron imaging instrument, named
Energy-Resolved Neutron Imaging System “RADEN”,
has been constructed at beam line BL22 in the Materials
and Life Science Experimental Facility (MLF) of J-PARC to
conduct pulsed neutron imaging experiments, such as
Bragg-edge, neutron resonance and polarized neutron
imaging [1]. Together with the commissioning studies,
RADEN started to accept user programs from FY 2015
and, in FY 2016, we have carried out 19 general-use programs and consequently about half of the total beamtime was utilized by the users. In this report, we will
cover the current status of RADEN’s activity, including
technical developments and application studies.
2.	Improvement of Neutron Imaging Detector Systems
Together with the user programs, the instrument
member of RADEN has performed development studies to improve imaging techniques. At first, the spatial resolution of the CCD camera-based detector was
improved, and it became possible to access less than
50 µm resolution by means of combining a thin scintillator screen and a brighter optical lens system. Second,by means of an EMCCD camera system, a short stroboscopic imaging synchronized with the accelerator
repetition of 25 Hz has been carried out. The shortest
exposure time was about 20 msec. With this technique,dynamic imaging of liquid flows in narrow channels ofan evaporator of an automotive air conditioning system
was successfully achieved.
In addition, a counting-type neutron imaging detector system using micro-pattern plane named µNID, which

Figure 1.	Wavelength dependent visibility of pulsed neutron
phase imaging experiment. Each visibility was obtained by horizontally scanning the last grating infive points.

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is used mainly for the energy-resolved neutron imaging
experiment, was improved to obtain higher count rate
performance. The count rate was limited due to the slow
data transfer speed of data acquisition electronics anddrift velocities of secondary particles generated after theneutron absorption by the 3He atom. Hence, we developed encoder modules with Gigabit Ethernet to achieve
fast data transfer. Also, we changed the stopping gas into
CF4 and optimized the gas mixture to speed up the drift
velocity. Owing to these upgrades, the count rate capacity was increased from 0.6 to 8 Mcps and the effective
maximum count rate was also increased to 1 Mcps [2].
3.	Development of a New Pulsed Neutron Imaging
Technique
The RADEN instrument is dedicated to energyresolved neutron imaging experiments using pulsed
neutrons, and recently we began the development of
the pulsed neutron phase imaging technique based on
the Talbot-Lau interferometry under ERATO Momose
Quantum Beam Phase Imaging Project [3, 4]. The neutron phase imaging technique has been developed
at steady neutron sources with a course wavelength
resolution of several tens percent, but the interference
phenomenon intrinsically depends on the neutron
wavelength and hence the phase imaging result also
depends on the neutron wavelength. Then, we conducted wavelength-dependent neutron phase imaging measurements in combination with Time-of-flightmethod using µNID detector.
In the Talbot-Lau interferometer, the self-image after the phase grating G1 is resolved as a moiré patternusing an additional absorption grating G2. The visibilityof this moiré fringe depends on the quality of the gratings and the wavelength resolution, and typical numbers
for the visibility obtained in previous works were around20%. On the other hand, the obtained visibility of moiré
fringe in the current work indicated a continuous change
against the neutron wavelength with a peak higher than
50% around 5 Å, which corresponded to the designed
number of our interferometer (Fig. 1). Figure 2 shows thedifferential phase imaging of three kinds of metallic rods,
Ni, Al and Ti. In this figure, the difference of signs of optical potentials between Al and Ti is clearly observed. This
becomes even more evident by looking at the line profile along the X direction with a fine wavelength resolution (Fig. 3). The calculated differential phases of Al andTi rods based on their optical values, indicated by solid

MLF Annual Report 2016lines in Fig. 3, reproduced correctly the experimental results. This suggests that it is possible to evaluate the optical potential of a sample by using this technique.

Figure 2. Result of a differential phase imaging experiment.

Figure 3.	Line profile of differential phase along X axis. The
solid lines are calculation results for Al and Ti metalrods using their optical potential values.

Neutron Science

4. Summary and Future Plans
Together with the user programs, improvementsof the imaging detector systems and development ofpulsed neutron imaging techniques have been conducted at the RADEN instrument. The increased countrate of the counting type imaging detector µNID is very
important for the effective energy-resolved neutron
imaging experiment, so a further upgrade is needed.
The pulsed neutron phase imaging has been demonstrated for the first time. We plan to develop a precise
phase measurement technique by using the wavelength resolved method and to apply polarized neutrons to phase imaging to observe magnetic potential
distribution.
Acknowledgement
This work was partially supported by JST ERATO
Momose Quantum Beam Phase Imaging Project andby Photon and Quantum Basic Research Coordinated
Development Program from the Ministry of Education,
Culture, Sports, Science and Technology, Japan.
References[1] T. Shinohara et al., J. Phys: Conf. Series 746 012007(2016).
[2] J.D. Parker et al., 2016 IEEE Nucl. Sci. Symp. Conf.
Rec. (2016).
[3] http://www.jst.go.jp/erato/momose/[4] Y. Seki et al., J. Phys. Soc. Jpn. 86 044001 (2017).

T. Shinohara1, T. Kai1, K. Oikawa1, M. Segawa1, T. Nakatani1, K. Hiroi1, Y. Su1, H. Hayashida2, J. D. Parker2, Y. Matsumoto2, Y. Seki1,
W. Ueno1, and Y. Kiyanagi3
1
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2R&D Division, Neutron Science and Technology Center,
CROSS; 3Graduate School of Engineering, Nagoya University

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Recent Progress on the Polarized Neutron Spectrometer
POLANO
1. Introduction
Since 2012, the POLANO team has persisted inits efforts to design and construct the POLANO spectrometer and its neutron devices. POLANO represents
the younger generation of spectrometers operating in
MLF [1‐3]. Three direct geometry chopper spectrometers are now part of the user program. They cover arather wide energy and momentum space for investigation of the dynamical structures in internal degrees
of freedom in materials. The POLANO was designed as
the same type of chopper spectrometer as the otherthree instruments, however, it has polarization analysis
capability. In the light of the recent discoveries in material science, many of the observed complex phenomena are largely due to the entangled physical degrees
of freedom (spins, charges, orbitals, and even lattice vibration). A unique, effective, and direct way to observe
these physical quantities separately is via the polarization analysis.
2. POLANO Specifications and Progress
Since the POLANO is located at the 23rd beam line
(BL23) in MLF, viewing the decoupled hydrogen moderator, reasonable resolution and neutron intensity
are achieved for the above purpose. With the specificgeometrical length parameters of the POLANO spectrometer, an energy resolution of ΔE/Ei = 3 to 5% (Ei:incoming neutron energy) and momentum resolutionof ΔQ/ki = 1 to 2% (ki: neutron’s initial wave number)are expected [3].
In 2016, many components of the spectrometer
were manufactured, installed, and adjusted. Most of
those major items are now ready for the start of theneutron beam operation. A set of position sensitive detectors (PSD) is one of essential components. In Fig. 1,
the installed PSD array in the large vacuum chamberand electronic modules out on the back of the chamber
are shown. For the range that interests us, we adopted
PSD with 60 cm effective length, 3/4” diameter, 10 atm
of 3He gas pressure, and SKYN2 feedthrough developedin MLF. 32 PSDs were positioned in a detector bank,covering a scattering angle of about 20°. In the verticaldirection, there were three layers of PSD arrays. In thehorizontal (central) layer, all the scheduled PSDs were
installed (from -20° to 120°).
Other devices were also installed. A remarkableachievement was the setup of magnetic devices [4] andsuper mirror analyzer. The magnetic devices are composed of several assembled permanent magnets, which
retain magnetic field along the neutron path called
guide field, with the purpose to prevent depolarizationof the neutron spins. These guide fields are on the orderof several tens of Gauss. Considering terrestrial magnetism and the interference with other fields, we optimized the combination of different types of magnets.
Particularly, the magnet after the sample should have awide acceptance for the scattered neutron beam. The
arc-shaped magnets were designed as minimizing the

Figure 1.	Detector systems of POLANO. (a) Electronic modules and cables set up in the back of the detector bank. (b) Installed position sensitive detector tubes.

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Figure 2.	Bending super mirror analyzer system.

shadow of magnet structure’s “dark-angle” and placedalong the scattering angle. The super mirror analyzer isalso one of the key devices. It can “analyze” the spin polarization of scattered neutrons via the reflection fromthe supper mirror. It is placed just after the arc-shaped
magnet in the vacuum chamber. As shown in Fig. 2, thisis the array of super mirror thin blades, currently covering 20° of the scattering angle. Since it is necessary tocover completely the designed scattering angle (from-20° to 120°), we designed a scanning mechanism forthe analyzer in the tank. It is rather heavy (about 80 kg),
magnetic (about 400 Gauss) and super expensive, so
we need careful designing, manufacturing and setup.
Also, it was very hard to build the scanning system withmechanical motors in the vacuum.
The data acquisition and device control system(YUI) and the data visualization and analyzing system(HANA) have been continuously developed for day-oneof the POLANO experiment [5]. The current versions of
YUI and HANA were set up in POLANO’s computing system, and their operation and network connection werechecked. The remote device control via the connection
will be a crucial technique for performing the polarization experiment in near future. We have to keep updating those controlling and analyzing systems for further

devices and new techniques of analyzing the polarization data sets.
3. Future Plans
We have so far focused on the designing and construction of devices and instruments. In the next year,
we will start commissioning using a real neutron beam.
Still, we must develop a few new devices, such as spin
flippers, controlling system of the correlation chopper,
high-performance polarization devices [6] and so on.
Therefore, our efforts target both developing and tuning instruments. Also, we are going to give more attention to the relationship with our community to ensure
future collaborations and scientific projects to be investigated at POLANO.
References[1] T. Yokoo et al., J. Phys. Soc. Jpn., 82 SA035 (2013).
[2] T. Yokoo et al., J. Phys.: Conf. Ser., 502 012046 (2014).
[3] T. Yokoo et al., EPJ Web Conf. 83 03018 (2015).
[4] K. Ohoyama et al., J. Phys. Conf. Series 711 012010(2016).
[5] Y. Ikeda et al., this annual report.
[6] T. Ino et al., J. Phys. Conf. Series 711 012011 (2016).

T. Yokoo1,2, S. Itoh1,2, M. Fujita3, Y. Ikeda3, N. Kaneko1,2, M. Ohkawara3, T. Ino1,2, K. Ohoyama4, S. Sugai1,2, and M. Sakaguchi1,2
Neutron Science Section, Materials and Life Science Division, J-PARC center; 2Institute of Materials Structure Science, KEK; 3Institute forMaterials Research, Tohoku University; 4Graduate School of Science and Engineering, Ibaraki University

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Development of an in-situ Polarized 3He Neutron Spin
Filter for POLANO
1. Introduction
A 3He neutron spin filter (NSF) is one of the essential devices in POLANO for polarization of the incident
neutron beam. It is operated in-situ to provide a stableneutron polarization, and the spin-exchange opticalpumping method is employed to polarize the 3He gas. A
compact in-situ 3He NSF system, suitable for the limited
space in POLANO, has been developed.

oven (Fig. 2), the 3He spin reversal and its NMR measurement are simultaneously performed in 100 ms. The 3He
polarization loss during the 3He spin reversal has been
confirmed to be less than 1 × 10-4 per flip.
The absolute 3He polarimetry for the in-situ 3He
NSF has been performed by measuring the Rb EPR frequency shift during the optical pumping [2], and a 3He
polarization of more than 80% was attained in a laboratory test.

2. NSF for POLANO
The in-situ polarized 3He NSF system for POLANO isshown in Fig. 1. All essential components are enclosed
for laser safety in an aluminum box, 60 cm long, 60 cm
wide, and 25 cm high.
The in-situ 3He NSF can reverse the 3He spins instantaneously by adiabatic fast passage (AFP) NMR [1]. By
sweeping the frequency of the oscillating magnetic field
generated by a cosine theta coil inside an aluminum

Figure 2.	A cylindrical 3He cell inside the AFP oven. The 3He
cell diameter is 60 mm, and the length is 60 – 100
mm. The 3He pressure varies from 2 to up to 3.5 atm.

3. Installation
The in-situ 3He NSF is almost ready to go and currently is being tested in a laboratory to check its performance and durability. It will be installed in POLANO
soon.
Figure 1.	A magnetically-shielded solenoid, a guide coil forpolarized neutrons, a laser diode array (LDA) with
optical components for the optical pumping of Rb,
and a low noise amplifier (LNA) for NMR are all in analuminum enclosure. An aluminum oven with a 3He
cell is at the center of the solenoid (not seen). The
neutron beam is shown as arrows.

References[1] A. Abragam, The Principles of Nuclear Magnetism,
Oxford University Press (1961).
[2] M. V. Romalis and G. D. Cates, Phys. Rev. A 58, 3004
(1998).

T. Ino1,2, M. Ohkawara3, T. Yokoo1,2, Y. Ikeda3, M. Fujita3, K. Ohoyama4, and S. Itoh1,2Institute of Materials Structure Science, KEK; 2Neutron Science Section, Materials and Life Science Division, J-PARC Center; 3Institute forMaterials Research, Tohoku University; 4Graduate School of Science and Engineering, Ibaraki University

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The Current Status of the Computing Environment on
POLANO
1. Introduction
As a new-generation pulsed-neutron instrument,
the polarized neutron spectrometer, POLANO, has been
designed with the ability to perform polarization analysis capable of handling a wide dynamic range of energy
and momentum transfer (E-Q) [1]. The construction of
the major equipment for POLANO has been alreadycompleted and now the commissioning is steadily under way. In this report, we present the current status of
the computing environment on POLANO.
2. Configuration of the computing environment
POLANO is a sister instrument of the High Resolution
Chopper spectrometer, HRC, installed at beam line 12 in
MLF [2, 3]. Specifically, part of the constituent devices
and data processing systems are almost the same as
those of HRC [4], and the data acquisition (DAQ) middleware [5] is also driven on Scientific Linux machines. The
schematic configuration of the computing environment
on POLANO is illustrated in Fig. 1. When neutrons aredetected at position sensitive detectors (PSD x352: x768
for full installation), the electronic signals are promptly
converted into the event data via the DAQ electronics(NeuNET x48, and Gateway x1). The colossal amount of
event data are processed by three DAQ servers (DAQ13; 2 TB x3) and stored into the network-attached storage (NAS) server of 30 TB with redundant arrays of

inexpensive disks (RAID60). At present, one NAS server(NAS1) is used for a main storage, while the other NAS
server (NAS2) is utilized as a backup machine of NAS1.
All installed devices (e.g. Fermi chopper, analyzer
mirror, and band-definition disk choppers, etc.) are controlled via the DAQ operation (DAQ-OP) server. Notethat users can easily control all devices via a terminal
machine (terminal1; Macmini) with YUI program. A general-purpose server (server1; 6 TB, RAID5) is utilized as alogging machine to monitor a current/previous condition of all running devices, e.g. the stability of the chopper frequency, the time dependence of the temperatureof a cryogenic system, etc. “FL net” is used to connect thecomputing system and the programable logic controller(PLC) of the vacuum chamber. This server is used to monitor the degree of vacuum in the scattering chamber andconfirm the condition of valves and pressure switches.
For data analysis, POLANO has one more server(server2; SSD 240 GB + HDD 3 TB) and a terminal machine (terminal2; Macmini) in the control room. The users can visualize experimental data with the terminal
machine via the HANA program.
3.	Intelligent control program YUI and data visualization program HANAThe YUI and HANA programs [4] are adopted asa user interface programs on POLANO as well as HRC.

Figure 1.	Schematic configuration of the computing environment on POLANO. Bold lines denote data flow, as shown in the bottom-right legend.

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Figure 2.	Additional functions of YUI on POLANO. Analyzer scan commands are available for polarization analysis.

Although the YUI and HANA programs on POLANO havealmost the same functions as the ones installed on HRC,
some additional functions are appended for polarization
analysis. For example, POLANO’s YUI has analyzer scancommands, as shown in Fig. 2. By using this function,
the users can effectively acquire data moving the supermirror analyzer. Furthermore, POLANO’s HANA supportsa basic arithmetic operation between two different histogram data for polarization analysis experiments.
4. Future plans
In the first commissioning with neutron beam, we
verified that there were no harmful defects, at least in
the major hardware of the computing environment, andsuccessfully acquired and visualized the event data. As
a next step, we will continue to work on refining specificdevices and programs (YUI and HANA) on POLANO. In
addition to the hardware preparation, further development of the control programs for SEOP devices, guidefield environment, and cryogenic systems is indispensable for the polarization analysis experiment.
Acknowledgement
We acknowledge the support of D. Kawana (ISSP),

KENS-DAQ group, and Bee Beans Technologies Co., Ltd.
(Tsukuba, Japan).
References[1] T. Yokoo, K. Ohyama, S. Itoh, J. Suzuki, K. Iwasa, T. J.
Sato, H. Kira, Y. Sakaguchi, T. Ino, T. Oku, K. Tomiyasu,
M. Matsuura, H. Hiraka, M. Fujita, H. Kimura, T. Sato,J. Suzuki, M. Takeda, K. Kaneko, M. Hino, and S.
Muto, J. Phys. Soc. Jpn. 82, SA035 (2013).
[2] S. Itoh, T. Yokoo, S. Satoh, S. Yano, D. Kawana, J.
Suzuki, and T. J. Sato., Nucl. Instr. and Math. Phys.
Res. A 631 90 (2011).
[3] S. Itoh, T. Yokoo, D. Kawana, H. Yoshizawa, T. Masuda,
M. Soda, T. J. Sato, S. Satoh, M. Sakaguchi, and S.
Muto, J. Phys. Soc. Jpn. 82 SA033 (2013).
[4] D. Kawana, M. Soda, M. Yoshida, Y. Ikeda, T. Asami, R.
Sugiura, H. Yoshizawa, T. Masuda, T. Hawai, S. Ibuka,
T. Yokoo, and S. Itoh, submitted to Proceedings on
ICANS XXII (2017); see also arXiv:1710.00487 for further information.
[5] S. Satoh, S. Muto, N. Kaneko, T. Uchida, M. Tanaka, Y.
Yasu, K. Nakayoshi, E. Inoue, H. Sendai, T. Nakatani,
and T. Otomo, Nucl., Instr. and Meth. Phys. Res. A
600, 103 (2009).

Y. Ikeda1, M. Sakaguchi2,3, T. Yokoo2,3, S. Itoh2,3, M. Fujita1, N. Kaneko2,3, and M. Ohkawara1
Institute for Materials Research, Tohoku University; 2Neutron Science Section, Materials and Life Science Division, J-PARC center, 3Instituteof Materials Structure Science, KEK

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Neutron Science

Development of Proton Filter for POLANO
1. Introduction
We will start the commissioning of POLANO withrelatively low-energy neutrons by using polarized 3He
gas for a spin filter. After the commissioning, we have aplan to polarize relatively high-energy neutrons, whoseenergies are several hundred meV.
To obtain a certain statistical variance in a shortmeasurement time, it is necessary to prepare a spin filter
with large P2T. Here P is the polarization of the neutron
beam transmitted through the spin filter and T is theneutron transmissivity of the spin filter. The neutron energy dependence of P2T for spin filters using polarized
3He or proton shows that proton filters are comparable
for neutrons with kinetic energy of several hundred
meV and superior for neutrons with energy larger thanabout 1 eV [1]. Therefore, we are considering preparing
a proton filter.
2. Test System
As a first step to develop a proton filter for POLANO,
we prepared a test system at KEK by using a cryostat
with a 5 T superconducting dipole magnet and a 1 K
4He evaporator. The diagram of this cryostat, used at
the University of Michigan, is shown in reference [2]. In
addition to the cryostat, we prepared a 213 MHz NMR
system to measure the proton polarization and a microwave generator with output power of 20 W and center
frequency of 140 GHz, to enhance the proton polarization by flipping the spin of the radicals that are dopedin the proton filter.
As the magnetic moment of a radical is much larger
than that of a proton, the thermal polarization of radicals, which is nearly equal to unity under the external

magnetic field of 5 T and at the temperature of 1 K,
is much larger than that of protons. Moreover, in flipping the radical spins, we can choose the microwave
frequency so that we can flip at the same time only the
proton spins that point to certain direction. In this situation, the polarization of the protons approaches thatof the radicals due to the much shorter spin relaxation
time of the radicals than that of the protons.
To test the system, we prepared a polyethylene
film, which contains many protons, doped with TEMPO,
which contains radicals. We put the film into the cryostat, applied static magnetic field of 5 T and cooled it
down to 1 K. Without irradiating the microwave to thefilm, we observed the small NMR signal of the protons in
the film, which corresponds to thermal proton polarization of 0.5%. The signal was increased by irradiating the
microwave to the film and reached saturation in about
an hour. As the signal is proportional to the proton polarization, we estimated it reached about 40% [1]. This
result clearly shows that we have successfully prepared
the test system.
References[1] K. Taketani, S. Itoh, T. Otomo, T. Yokoo, N. Kaneko, S.
Suzuki and S. Ishimoto, (2017). Proton filter for subeV neutron spectroscopy on POLANO, presented atthe 22nd meeting of the International Collaboration
on Advanced Neutron Sources, Oxford, UK.
[2] D. G. Crabb, C. B. Higley, A. D. Krisch, R. S. Raymond,
T. Roser and J. A. Stewart, (1990) Observation of a
96% Proton Polarization in Irradiated Ammonia,
Phys. Rev. Lett. 64, 2627.

K. Taketani1,2, S. Itoh1,2, T. Otomo1,2, T. Yokoo1,2, N. Kaneko1,2, S. Suzuki3, and S. Ishimoto3
Neutron Science Section, Materials and Life Science Division, J-PARC center; 2Institute of Materials Structure Science, KEK; 3Institute ofParticle and Nuclear Studies, KEK

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Sample Environment at MLF
1. Introduction
The sample environment (SE) team is in chargeof the preparation, maintenance and development of
the beamline (BL)-common SE equipment, and aids
the users in operating the equipment. The team has
14 members: 7 from JAEA, 5 from CROSS and 2 from an
outsourcing company, and is divided into sub-teams ofcryogenics and magnets, high temperature, high pressure, soft-matter, pulsed magnet and 3He spin filter, etc.
Light irradiation and hydrogen equipment are underdevelopment.
The status and activities of the SE team in JFY 2016
are summarized in this report.
2. Cryogenics and magnets
We had operated a superconducting magnet forusers’ experiments as equipment that has been commonly used at instruments until the last fiscal year. In
JFY2016, we introduced three new cryostats, which are
a top-loading 4He cryostat, a dilution refrigerator insert
and a bottom-loading 3He cryostat, after finishing theircommissioning. We supported nine experiment programs with these cryostats and this magnet in JFY2016.
We have upgraded the operation system for thesuperconducting magnet to enable users to control itwith the IROHA2, which is the common software framework for instrument control. In MLF, there is a rule thatat least one person has to monitor the magnet status
on-site when applying the magnetic field for superconducting magnets without a warning light, to finda magnet quench as soon as possible. The new system
on IROHA2 has a function to receive a quench signal
from the power supply and turn on the warning light.
Thus, the unmanned operation of this magnet has been
allowed. It is expected that the introduction of this system will reduce the users’ workload during experimentswith a superconducting magnet.
3. High temperature equipment
The high-temperature sub-team has developed
two furnaces as BL-common SE equipment.
3.1 Niobium furnace
The Niobium furnace was prepared for quasielastic
neutron scattering and inelastic neutron scattering measurements, in which niobium foils are used as a heating
element and radiation shields. It can be used with oscillating radial collimators to reduce the background of the128

elastic scattering from the niobium foils and the aluminum outer vacuum chamber. In 2016, we supported four
users’ experiments at BL14 and BL18 using the furnace.
We are also installing an automatic safety operation system for the furnace. In 2016, the automatic operation of
the sample stick rotation and the remote monitor of thetemperatures in the operation room were realized.
3.2	Furnace for small-angle neutron scattering andneutron reflectivity measurement
In 2016, the aluminum windows were improved toreduce the unwanted background in the small-angle
region, and the upgraded furnace (Fig. 1) was used forgeneral proposal experiments.

Figure 1.	Furnace for small-angle scattering and neutron reflectivity measurement.

4. A pulsed magnet system
The work of the SE pulsed magnet group started in
2014. We have developed a prototype of a general-use
pulsed magnet system, which consists of a solenoid coil,a sample stick and a pulsed power supply. The specifications are as follows: the maximum charging voltage
and output current are 2 kV and 8 kA, respectively; thecharging time of the power supply is approximately
30 seconds; the pulse width of the generated current is
2.65 msec at 50% of peak; the maximum magnetic field
is 30 Tesla; the maximum scattering angle is 30.6°. The
coil is immersed in liquid nitrogen and cooled at 77 K
not only to decrease the resistance of the coil, but also toMLF Annual Report 2016

remove the Joule heat generated by the pulsed current.
The repetition rate of this system is one pulse per several minutes. The first neutron scattering experiments using this system were carried out at HRC (BL12). However,a problem occurred in the insert, and the temperaturearound the sample did not decrease below 4.2 K during
the beam experiment. Currently, the insert is being improved and also a new one is being designed.
5. High pressure
To realize low temperature and high pressure (4 K,
10 GPa) experimental environment as a common SE
equipment at MLF, we have developed a special cryosystem coupled with a Paris–Edinburgh (PE) cell (MG63 Co.
Ltd., VX-5), as shown in Fig. 2. The PE cell is attached tothe second stage of the closed cycle Gifford–McMahon(GM) type cryocooler (Sumitomo Heavy Industry Co.
Ltd., RDK-415D). This is placed in a chamber for precooling with liquid nitrogen, which is surrounded by a radiation shield and an outer vacuumed chamber. While inuse, the press is initially precooled with liquid nitrogenand then cooled only by GM and the chamber is filled

Figure 2.	Newly constructed cryosystem for low-temperature and high-pressure experiments.

Neutron Science

with He exchange gas. This cryostat is mounted on thegoniometer for sample rotation. The designed size of
this system allows its installation in other beamlines
with a vacuum chamber whose inlet is nominal diameter 400A in JIS standard.
We have commissioned the system and found thatit took 6.5 hours to cool the sample to 6.5 K. In contrast,
it took more than 24 hours to raise the temperature to
room temperature, due to the large heat capacity of thePE cell. Thus, we are now planning to attach additional
heaters to the body of the cell to accelerate heating.
This system has been already installed in several beamlines and is used for inelastic and quasielastic scatteringexperiments.
6. 3He neutron spin filter
We have been developing a spin-exchange opticalpumping (SEOP) based polarized 3He neutron spin filter (3He-NSF) for efficient utilization of pulsed neutrons
at J-PARC. We are in the process of preparation of the
3He gas filling station for hybrid cell fabrication in the
J-PARC research building in 2016. For maintenance andpreparation of 3He-NSF, a laser lab was prepared in the
beam hall of MLF, and its operation started in May 2016.
As demonstrative experiments using 3He-NSF, weperformed the following measurements for the firsttime in 2016: 1) A polarized neutron single-crystal diffraction measurement at BL18 (SENJU). The sample wasa single-crystal iron, and the polarity-dependent Bragg
peaks from it were observed. The data analysis is inprogress. 2) A polarized neutron Imaging experiment at
BL22 (RADEN) with 2 on-beam SEOP setups at the sametime, where one was for the polarizer, and the otherone for the analyzer. The sample was an oriented soft
steel piece with a thickness of 0.35 mm, winded with amagnetic field coil to apply a magnetic field on it. It wasobserved that the polarization degree of the neutronstransmitted through the sample depended on the neutron wavelength and the incident beam position on thesample, reflecting the magnetic domain state within
the sample.

T. Oku1, M. Watanabe1, R. Takahashi1, S. Ohira-Kawamura1,2, M. Ishikado4, K. Ohuchi4, Y. Yamauchi5, M. Nakamura5, S. Isomae5,
K. Munakata4, T. Hattori2, S. Takata1,2, Y. Sakaguchi4, H. Kira4, K. Sakai1,3, T. Aso1,3, and K. Aizawa1
1
Technology Development Section, Materials and Life Science Division, J-PARC Center; 2Neutron Science Section, Materials and Life Science
Division, J-PARC Center; 3Neutron Source Section, Materials and Life Science Division, J-PARC Center; 4R&D Division, Neutron Science andTechnology Center, CROSS; 5Nippon Advanced Technology co.

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MLF Annual Report 2016

Present Status of IROHA2
1. Introduction
Since 2015, the upgraded instrument control software framework “IROHA2” [1, 2] has been introduced
and used in several neutron instruments at MLF, J-PARC.
IROHA2 consists of four servers, which are the device
control, the instrument management, the sequence
management and the integrate control. One of themain features of IROHA2 is that users cooperate to use
these servers with a web browser to carry out their experiments [3]. In this year, we have implemented two
new functions to IROHA2. One is the support for the
MLF common sample environment devices, which are
the 7T magnet, the Nb furnace and the Signal Light by
the IROHA2 device control server. The other is the remote experimental status monitoring system on the
IROHA2 integrate control server. An experimental status is a web service for monitoring from the Internet the
progression status of experiments conducted at MLF.
Since the facility staff and users cannot monitor the experiment at the instrument all the time, this service isneeded to reduce their workload in an experiment. We
have developed the system for providing the experimental status in stages as a part of promoting environmental improvement of the remote access at MLF.
2.	New device modules for common sample environment devices
We have developed the device modules of the
IROHA2 device control server for the 7T magnet, the Nb
furnace and the Signal Light, which are the common
sample environment devices at MLF. The 7T magnet isthe sample environment device that creates the magnitude of a strong magnetic field to be applied on thesample with the superconducting magnet. The 7T magnet is a complex device composed of a power supply
producing a current to be applied on the superconducting magnet, refrigerators for the sample and thesuperconducting magnet, helium liquid level gauge
and rotation controller for the sample. The Nb furnace
is a device, which heats up a sample to a high temperature by electric heat. The Nb furnace is monitored
through reading out the status from the programmable
logic controller (PLC) and the recorder. The Signal Lightis a device monitoring an apparatus generating hightemperature, high pressure, strong magnetic field, andso on. The Signal Light consists of a PLC and red, yellow,
green and blue lights. When something is wrong withthe apparatus, the Signal Light indicates it by red and130yellow lights according to the incident level. The green
and blue lights indicate remote control and unattended
operations.
The device module for the 7T magnet operates
independently the power supply (Mercury iPS-M), therefrigerators (LakeShore 218 and 340), the helium liquid level gauge (Scientific Magnetics Helium Level
Meter) and the rotation controller (Mclennan Single
Axis Stepper System); it also operates sequentially thepower supply and the refrigerator when the magnetic
field changes. The users can carry out their automatic
measurements composed by IROHA2 from the instrument data acquisition system and the 7T magnet.
The device module for the Nb furnace monitors
various parameters like the present and set temperatures, the heater power (current and voltage), the vacuum pressure and so on from the PLC (KEYENCE KV-5000)
and the recorder (CHINO KR2160MN2A). During theirexperiments, the users can monitor the status and record the parameters by using IROHA2.
The device module for the Signal Light monitors
the alarm status of the apparatus connected to the
Signal Light from PLC (DEC PFXLM4301TADDK). The
module can also switch the remote control ON/OFF.
Currently, the Signal Light is used for monitoring thebaking system of the 3He spin filter chamber in the
J-PARC research building.
3. Experiment status monitoring system
Figure 1 shows screenshots of the experimental
status. It is possible to browse the experimental list andthe experimental status of each neutron instrument.
The system consists of servers for status collection
from neutron instruments and web service of the experimental status. The status collection server createsHTML files, which include only static contents considering the security risk caused by the dynamic contents,
based on the status information collected from eachneutron instrument. By accessing the web server, thefacility staff and users can browse the status information of their experiments transferred from the statuscollection server.
At the early stage of the system, it was possible tomonitor only the states of the DAQ system, such as thestate of each DAQ component, event counts and run
number, and browse the experimental status within
only J-PARC intranet. In this system, anyone could
browse the experimental status without authentication.

MLF Annual Report 2016

(a)

(b)

Figure 1.	The screenshots of the list of experiments (a) andthe experimental status (b).

After that, the system has been improved to cooperate with IROHA2, making it possible to monitor an
integrated experimental status, including the status of
the beam control apparatus and sample environment
devices in addition to DAQ, which are made by IROHA2
integrate control server. Furthermore, the system canbe accessed from the Internet by cooperation with an
integrated authentication system based on an LDAP

Neutron Scienceat MLF. However, this access was limited only to thefacility staff. This is because the system was not able
to ensure access control for each experimental group.
Since the status information includes details about theexperiment, such access control is essential to provide
Internet access with facility users while retaining theuniqueness of the experiment.
Recently, we have updated the experimental status and IROHA2, enabling the access control for eachexperimental group by means of a one-time password(OTP). The IROHA2 integrate control server creates OTP
and access control file as well as the status information
file in HTML form. The status collection server creates
list of experiments and OTP based on the set of files
collected from each neutron instrument. Finally, theselists and each static HTML file are transferred to the web
server to be able to access from Internet. When an experimental group accesses its experimental status, theaccess controls are performed based on the OTP.
4. Conclusion and future plans
By these developments, users of the instruments,
where IROHA2 has been introduced, can carry out theirexperiments with devices easily integrated in the common sample environment and the data acquisition
system, while monitoring the experimental status fromthe Internet. In FY2017, we will start using the devices
for users’ experiments with IROHA2 and offering an
Internet access to the facility users of several neutron
instruments such as BL18 and BL21 and plan to expand
the access to the instruments in stages.
References[1] T. Nakatani, Y. Inamura, T. Ito and T. Otomo,
Proceedings of the ICANS-XXI, 493 (2014).
[2] T. Nakatani, Y. Inamura, T. Ito and K. Moriyama,
Proceedings of NOBUGS2016, 76 (2016).
[3] T. Nakatani, Y. Inamura, T. Ito and T. Otomo, JPS
Conference Proceedings, 8, 036013 (2015).

T. Nakatani1 and K. Moriyama2
Technology Development Section, Materials and Life Science Division, J-PARC Center; 2Neutron Science and Technology Center, CROSS

1

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A Large Area, Position-Sensitive Scintillation Neutron
Detector
1. Introduction
The recent world-wide shortage of 3He gas encouraged us to develop an alternative detector technology
to replace the conventional 3He gas-based detectors.
To ameliorate this situation, we have developed a large
area, position-sensitive scintillation neutron detectors
for pulsed neutron scattering instruments [1, 2]. To
make it usable for practical applications, the detector
should be equipped with modularity and a large area,
as well as superior detector performance comparable tothose of the 3He PSDs. It should be noted that the detector manufacturing costs should also be economically efficient because the detectors will cover more than a few
m2 required for typical neutron scattering instruments.
2. The large area, two-dimensional detector
A neutron­-sensitive scintillator / wavelength-shifting fiber technology has been used to develop thelarge area detector. This technology has several advantages over the conventional clear-fiber one. They areits simple structure and flexibility of the pixel size. The
detector comprises wavelength-shifting (WLS) fibers
arrays in x and y directions and flat scintillator screens.
The WLS fibers are placed at a regular pitch with an air
gap between each other. By adjusting the length anda pitch of each WLS fiber, the area and the pixel sizeof the detector can be designed depending on the requirements. In order to make a large area detector, forexample with a size over 50 × 50 cm several detector
technologies have been developed and incorporated
into the design. One of the important techniques isreading a scintillation light from both ends of the fiber.
By introducing this, the light collection yield increases
by 1.8 hold compared to the conventional one-side readout. This method positively compensates for the loss ofcollected light suffered while propagating through WLS
fibers, ensuring a stable detector operation, as well as
improved detection efficiency and count uniformity.
Figure 1 shows prototype detectors that have neutron-sensitive areas of 32 × 32 and 64 × 64 cm (denoted
as Det 32 and Det 64 in the figure). The pixel size is designed to be 2 × 2 cm for both detectors: and can be reduced to 5 mm. The Det 64 detector is one of the largest

Figure 1.	Prototype detectors with neutron-sensitive areas of
32 × 32 and 64 × 64 cm (Det 32 and Det 64) [2].

Figure 2.	Spatial count distribution measured with the Det
64 under a food neutron illumination (1 ch. = 2 cm).
Four 25.6 × 25.6 cm screens are implemented tentatively [2].

two-dimensional detector modules of this type everbuilt in the MLF. Figure 2 shows a spatial count distribution measured with the Det 64 under a flood illumination from a 252Cf source. The count uniformity over thedetector area is evaluated to be 10% (= s/mean) (Countdip appeared in cross is due to juncture part of the four
scintillator screens). The detector exhibits detection
efficiency of 40–50% for thermal neutrons with a 60Co
gamma-ray sensitivity of ~10-6.
References[1] T. Nakamura, J. of Phys. Conf. Ser. 528 (2014) 012042.
[2] T. Nakamura, et. al., in the proceedings of 2015 IEEE
NSS conference record (2015).

T. Nakamura, K. Toh, N. Tsutsui, and K. Sakasai
Neutron Instrumentation Section, Materials and Life Science Division, J-PARC Center132

MLF Annual Report 2016

Neutron Science

A Scintillator / Wavelength-Shifting Fiber Coil Detector
1. Introduction
A detector technology, alternative to the 3He-gas
based detectors, should produce similar or even better detector performances than the conventional onesin terms of a neutron-sensitive area, detection efficiency, gamma-ray sensitivity, count rate capability, etc.
Recently, we have proposed a scintillator / wavelength
fiber coil (SFC) detector as one of the promissing solutions [1-3]. This new detector technology would pave
the way to install high-performance scintillation neutron detectors into a high vacuum vessel to replace theconventional tubular 3He PSDs in future.
2. The SFC detector
Figure 1 shows a photograph and a schematic viewof the SFC element. The idea of the SFC structure is tocreate a detector element with a rolled WLS fibre coilsandwiched between cylindrical scintillator screens.
With this unique element structure, the total thicknessof the 6Li:ZnS scintillatior screen can be effectively increased without loss in the collected light yield fromthe opaque scintillator. An incident neutron experiences four layers of scintillation screens, where the neutron
absorption probabilty corresponds to that of a 6-bar
1-inch diameter 3He PSD. Hence, the detector enhances
its potential to exhibit a high-detection efficiecy.
A linear position-sensitive neturon detector canbe built by alignining many elements in a row. Figure 2
shows a photograph and a schematic view (inside)of the small prototype detector. 14 SFC elements are
implemented in the cylindrical aluminum tube. The tubular detector can be installed easily in a high vacuum
vessel (<10-3 Pa) mechanically. It is also possbile to tile
many detectors side by side with a negligible gap similarly to the array of tubuler 3He PSDs. Each neutron-sensitive element has two fiber outputs for light read out.
These fibers are penetrating through the tube towards
the end to connect with photomultiplier tubes. By coicidence measurement of the two fibers, the detector
can identifly the lit element (position sensitivity). This
readout method makes the detector pixelated in principle, hence assuring a high global count rate capability, which would exceed that of a conventional tubular
3He PSD. Figure 3 shows beam profile meaurementwith a 28-element detector by using a 252Cf source.

Figure 1.	(a) Photograph of an SFC element and (b) a schematic view of the SFC element [2].

Figure 2.	A 14-element prototype detector. (a) Photographand (b) a schematic view of the detector.

Figure 3.	Cd-masked beam profile measured with a 28-element detector. One element has a width of 2 cm.

The detector measured the Cd-shielded neutron profile clearly with a spatial resoluiton of 2 cm. This result
demonstrates the position senstivity of the proposed
detector.
References[1] T. Nakamura, et. al., US patent No.9268045, 2016.
[2] T. Nakamura, et. al., Nucl. Instr. and Meth. A 741(2014) 42.
[3] T. Nakamura, et. al., in the proceedings of the 2016
IEEE NSS conference record.

T. Nakamura, K. Toh, N. Tsutsui, and K. Sakasai
Neutron Instrumentation Section, Materials and Life Science Division, J-PARC Center

133Muon ScienceMuon Science

MLF Annual Report 2016

Status of J-PARC MUSE: Overview
Because of the problems with the water leakage
from the neutron target, we had to adopt the No.2 neutron target, which is not equipped with Helium bubbling function, so it cannot accept beams with intensity
higher than 300 kW.
Finally, we managed to restart the MLF operationin the end of February 2016 with the restricted proton
intensity of 200 kW. Since the beginning of October
2016, the proton intensity was restricted to less than
150 kW. Although the proton beam intensity was lessthan 200 kW, we ensured a rather stable operation at
the MLF MUSE.
1. D-LineThe D-line, a superconducting decay/surface channel with a modest-acceptance (about 40 mSr) pion
injector, was originally constructed with the re-usedsuperconducting magnet, which had been used at KEKMSL for more than 30 years, having cold bore (inner bore
radius of f 12), therefore it has beam windows at the inlet and outlet. In the summer shutdown period of 2015,
we replaced the re-used superconducting magnet witha new one with a warm bore (inner bore radius of f 20),
therefore it has no beam window, with the purpose to extract lower momentum intense negative muons, which
otherwise are stopped at the beam windows. We havebeen having beam commissioning to extract muons
with lower momentum of decay. The beamline commissioning was further accelerated by installing an automatic tuning program, the so-called ForTune, providing
the beamline parameters to deliver at the sample position a muon beam, which is well-focused and has a narrower momentum byte. Consequently, we managed to
extract a negative muon beam with a momentum as low
as 3.7 MeV/c (65 keV). The details of the beam commissioning results will be introduced in another document.

2. S-line
At the S-line, we extracted successfully not only
surface muons, but also negative cloud muons witha momentum between 24 and 32 MeV/c, and thenby installing Kalliope mSR detectors assembled in the
spectrometer, we started actual users’ runs even at theS1-area in fiscal year 2016, although, officially the use
was expected to start in the begging of April 2017.
3. U-LineAt the U-line, we observed successfully ultra-slow
muons on February 21, 2016. As many as 35 ultra-slow
muons per second by laser resonant ionization of muoniums evolved from hot tungsten (2000 K) were experimentally detected by a MCP, which is higher thanthat developed by KEK and RAL (20 m+/s) at the RIKEN/
RAL. We have been making efforts to enhance the yieldof ultra-slow muons, by replacing 3N W to 4N W, installing axial focusing superconducting magnets in the
U-line, and by developing an YGAG AMP crystal for thesolid-state laser system.
4. H-LineAt the H-line, we installed successfully the frontend components near the muon production target,
H-line beamline elements up to the H1 area and theiron shielding, including that for the H1 area experiments. The safety inspection of the MLF was successfully conducted, and the certificate was issued on
November 7, 2016, from the Radiation Management
Institute, Inc. The inspection items included the shielding construction prepared for a new muon beam line
and the radiation dose measurements around it in
MLF, particularly, for the muon beam line up to the H1
area.

Y. Miyake1,2Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK); 2Muon Science
Section, Materials and Life Science Division, J-PARC center

1

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Muon Science

Recent Developments of Monitoring Systems and Remote
Handling Devices for Muon Production Target at J-PARC
MLF MUSEAt J-PARC MLF, a muon rotating target made of anisotropic graphite is located at 30-m upstream of a neutron mercury target. In the summer maintenance period of 2014, the spent fixed target was replaced with arotating target [1].
1) Diagnosis of the rotating system and temperatures
The muon rotating target is consumable with a finite lifetime. Rotary supports, bearings and shafts of themuon rotating target are exposed to very intense radiation and high heat by the pulsed 3-GeV proton beam irradiation. The radiation damage of the graphite is dispersedby rotation. We are developing a monitoring system for
multiplexing of the interlock system, life prediction andabnormality portent of the muon rotating target.
It is predicted that the life time of the muon rotatingtarget is determined by the failure of the rotary support.
We are monitoring the torque of the rotary motor in order to diagnose the condition of the rotation system. The
number of rotations from the first introduction into theproton beamline up to the present time (March 2017) isaround 5 million rounds (5400 hours). Service life time of
the bearing using a solid lubricant made of a tungsten
disulfide is around 100 million rounds. The torque of the
motor has not changed since the initial introduction.
Recently, a motor-acoustic diagnosis by a microphonehas been initiated. Currently, we have a directional microphone installed near the rotating motor, and the motor
sound is the subject of analysis. The frequency analysisof the recorded sound indicated in Fig. 1 shows that the
acoustic components include the electric noise, driving
sound due to cooling water and the air conditioner andthe sound of the rotary motor and transmissions. It is
possible to measure selectively the sound of the rotation.
Currently, we ordinarily monitor the amplitude and peakfrequency of the sound during rotation.
It is not possible to measure the temperatures ofthe muon rotating target by direct contact because athermometer cannot be attached to the rotating body.
Thermocouples are attached to the cooling jacket tomeasure the temperature rise due to thermal radiationfrom the muon target. However, the proton beam cannot be stopped rapidly in this monitoring system, incase of excessive temperature rise. We are developing

Figure 1.	Sound pressure level as a function of frequency ofthe sound during rotation (red) and stop (blue).

a real-time two-dimensional radiation thermometer tomonitor the temperature. The major problem in introducing the infrared camera is that the camera breaks
down due to radiation. We measured the radiation dosewith glass dosimeters at the M1 tunnel where the camera
will be installed. The measured dose at 312 hours of 0.15MW beam operation was 20 mSv. This value corresponds
to 1 Sv when operated for 1 year (2000 hours) with 1 MW
operation. Since the infrared camera (ULVVIPS-04171SL
made by Vision-Sensing Co., Ltd.) to be introduced withstands up to 5 Sv by irradiation with gamma rays, it is estimated to be usable for more than 5 years. The radiation
hardness against neutrons and fast charged particles is
unknown, and we plan to conduct a radiation tolerance
test by installing a test machine in the future.
2) Remote-controlled commissioning for volume reduction
The muon target will be so highly activated thathands-on maintenance cannot be conducted. The
muon fixed or rotating target is rigidly fabricated into aTarget rod. The Target rod is integrated into a stainlesssteel plug shield through four screws. The assembled
component is called target assembly. The used target
rod on the target assembly is replaced with a new target rod and the plug shield is reused. In the Hot cell,
the replacement is performed by remote handling devices, such as a plug stand, an exchange device, a cutting device, a power manipulator, several master slave
manipulators, and an in-cell crane. The exchange device gives up-down motion, left-right motion, forwardbackward motion and rotation to dismount the Target
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rod from the plug shield. The cutting device has two
holding mechanisms and a cutter. The whole two holding mechanisms can be rotated with 90° toward the HLLT storage vessel. The two holding mechanisms can be
moved with up-down motion independently. Only theupper holding mechanism can be moved with left-rightmotion and forward-backward motion. The target assembly with the replacement of the Target rod is transported to the beam line and installed again.
The upper and lower holders of the Target rod areheld by the upper and lower supports of the exchange
device, respectively. The fixing screws are loosened remotely by a power-manipulator. Finally, the Target rod
is dismounted from the plug shield by the upward motion and the backward motion of the exchange device.
The dismounted Target rod is stored in a storage facility
outside of the MLF facility. However, the volume of thehighly radioactive part from the Target rod must be reduced to save space for storage.
The Target rod is remotely cut into three pieces by
the cutting device. The most radioactive part (1–2 Sv/h
at surface) is stored in a vessel with functions of support and enclosure, because they are not self-standing
and radioactive. Because that vessel is transported toanother facility for long-term storage, it is called highlevel (HL) long-term (LT) storage vessel. The moderately-radioactive part (20–40 mSv/h at the surface) and the
low-radioactive part (100–200 mSv/h at the surface) isstored in another vessel with functions of support andbrief enclosure. The vessel is called middle-level (ML)long-term (LT) storage vessel. Both storage vessels canbe transported remotely by the in-cell crane. Figure 2
shows pictures of the HL-LT storage vessel.
For volume reduction, the HL-LT storage vessel without a hat-shaped lid is set on a base table of the cutting
device. The dismounted Target rod is given to the cutting
device from the exchange device. The holding mechanism grasps the Target rod and is rotated with 90° toward
the HL-LT storage vessel. The holding mechanism is lowered and inserted into cutting position of the storage vessel. After cutting by the cutter, the high-level part of theTarget rod is stored in the HL-LT storage vessel. Figure 3
shows a picture of the mock-up Target rod held by the
cutting device from the exchange device on the left anda picture of the mock-up Target rod in the HL-LT storage
vessel just after cutting by the cutting device. Then the

Figure 2.	A picture of the HL-LT storage vessel.

Figure 3.	A picture of the mock-up Target rod held by the
cutting device from the exchange device on theleft and a picture of the mock-up Target rod in the
HL-LT storage vessel on the right.

holding mechanism is removed from the upside of thestorage vessel. The hat-shaped lid is set on the storage
vessel and the fixing screws are tightened by the powermanipulator. Finally, the integrated HL-LT storage vessel
is transported to a temporary storage position. As of the
ML-LT storage vessel, the holding position of the Target
rod is changed with the assistance of the in-cell crane.
Then the moderately radioactive part is stored in the MLLT storage vessel with procedures similar to those of the
HL-LT storage vessel. The lowly radioactive part can also
be stored in the ML-LT storage vessel by the in-cell crane.
Using mock-ups of the Target rod, the commissioning
tests of volume reduction in the Hot cell was successfullycompleted in 2014 and 2016.
Reference[1] S. Makimura et al., Development of Muon Rotating
Target at J-PARC/MUSE, Journal of Radioanalyticaland Nuclear Chemistry 305 (2015) 811-815.

S. Matoba1,2, S. Makimura1,2, N. Kawamura1,2, Y. Matsuzawa3, H. Aoyagi3, H. Kondo3, S. Sakata3, M. Meguro3, and M. Tabe1,2
Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK); 2Muon Science
Section, Materials and Life Science Division, J-PARC center; 3Nippon Advanced Technology Co., LTD (NAT)1

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MLF Annual Report 2016

Muon Science

Present Status of D-line
In FY2015, during the summer shutdown period, the
new solenoid was installed into an existing beamline.
This solenoid is a warm-bore type, and requires no foils
for protection from thermal radiation. The inner radiusof the coils was increased from 12 to 20 cm. Thus, a drastic improvement of the low energy muon (~100 keV) intensity is expected. To determine this low-energy decay
muon, two new experimental tools were prepared.
Firstly, we used a new type of beam profile monitor,
which was made using a plastic scintillator surroundedby optical fiber, as shown in Fig. 1. The muon beam passes through the plastic scintillator, and the beam profile
is obtained by a CCD camera downstream; in addition,
the photons collected by the optical fiber, which areconverted to electrical signals by a photo diode, provide
information about the incoming time and total intensityof a beam.
Next, an automatic optimization program for beamline components, such as magnetic bends and quadrupoles (named FORTUNE), was developed, based on the
TRIUMF beam tuning program. In this tuning, the time
gated signal of muons, which is obtained by an opticalfiber of the beam profile monitor, was adopted as inputs
into the D2 area.
After commissioning these apparatuses, we spent
several days performing beam tuning; finally, the muon
intensity that was obtained was more than 100 times
larger than that at 5 MeV/c at momentum (~120 keV inenergy). Therefore, the expected intensity of the negative muon is ~3 × 103 muon/s @1 MW.
We also performed a slit and beam profile at thefocusing point optimization using the same apparatus and at this stage, its parameters were, horizontally
10 mm, vertically 30 mm with a narrow momentum

Figure 1. Beam profile monitor at the D2 area.

width (Fig. 3). Further improvement is expected prior tonext year’s commissioning.
In the D1 area, we also performed dedicated tuning
in an almost identical way, and got a beam profile smaller than the previous one, as shown in Fig. 4. In addition,
to reduce the noise component, a flypast chamber was
installed The flypast chamber is a long vacuum pipe, anda sample is mounted in the flypast chamber as shown in
Fig. 5. Using the flypast chamber, 16% (Maximum) of theasymmetry can be obtained with a 5 × 5 mm2 sample.
Several kinds of refrigerators are available at D1. The
lowest temperature is obtained by using a top-loading
dilution refrigerator (DR). In a common dilution refrigerator, the dilution unit should be warmed up to room
temperature in order to change the sample. Therefore,
it takes a few days to change and cool down a sample.
Meanwhile, in our top-loading DR, the sample can bechanged by unloading or loading only the sample
holder. This feature is quite useful for μSR experiments.

Figure 2.	Comparison of the muon intensity with the old (cyanand purple) and new (red and green) solenoid.

Figure 3.	Beam profile of decay muon at the D2 area focusing
point.

139

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MLF Annual Report 2016

Figure 4. Example of the beam profile of surface muon at D1.

Figure 5. Flypast chamber installed at D1.

Furthermore, the cooling system of the DR is based on
the pulse-tube type refrigerator, and liquid Helium is not
required to cool down the system. Currently, the DR canbe used only at the D1 area. The cooling down of thesystem, including the pre-cooling process, can be performed automatically by using an integrated operation
program. After evacuation of the vacuum can to highvacuum, it takes roughly 1.5 days to reach the lowest
temperature from room temperature. The changing ofa sample requires 0.5 day. The dimensions of the sample
area are 40 × 40 mm2. A specimen is mounted on thepure silver plate using Apiezon N grease or GE varnish,
and is covered by thin Ag (10 μm) foil.

Helium 4 cryostats are also available at D1. The mostpopular one is “Minicryo” which can be used down to 4 K
within a few hours. In minicryo, the sample is placed in
vacuum and a silver sample holder is used.
A high-temperature infrared furnace is also available at D1. In the furnace, a sample can be warmed up
from room temperature to 1000 K.
The muon kicker system is used to separate a double pulse muon beam into two single pulses and to feedthem to two experimental areas (D1, D2) simultaneously. The beam operation with the kicker system started
successfully in the winter of 2011. It was found, however,that the kicker noise to the particle detector system appeared to be associated with the ignition of the kicker
power supply. The amplitude of the noises ranged froma few tens to several hundreds of millivolts, and the frequency was between 6 and 10 MHz. The noises were radiated into the air, and/or dispersed through the AC lines,
the detector signal lines and the ground lines. The kicker
noise level was drastically improved by RF-shielding withcopper sheets of the transmission lines and by reinforcing both the ground lines of the kicker system and thedetectors. Measures with bypass capacitors at the New
D1-μSR spectrometer were also successful.
Further improvements were required for the negative muon experiments at the D2 area, and for the ultra-slow muon at the U1A area. Therefore, we tried toinsulate electrically the kicker chamber from the beamducts and its base, and reduce the ground impedance.
However, despite that, the radiation noises increased.
A method to utilize a saturable inductor (SI) was also
tested to suppress the surge current at the ignition.
However, it was not successful because of the non-linear
response of SI: the magnitude of the surge current was
too high to suppress. This time, a Low-Pass-Filter (LPF)
using only linear elements is tested instead of the SI.
The pi-type LC filter was tested as a low-pass filter toeliminate the kicker noise to the particle detector usedin the negative muon experiments at the D2 experimental area. The filter filtered successfully the surge current
produced at the kicker ignition. However, the noises tothe detector were not mitigated. The noise frequency
ranged between 1 and 3 MHz, which coincided withthe dominant frequency component of the kicker pulse
whose width was 1 μs.

H. Fujimori1,2, Y. Irie1,2, K. Kojima1,2, Y. Ikedo1,2, T. Adachi1,2, M. Tampo1,2, K. Hamada1,2, S. Doiuchi1,2, W. Higemoto3, S. Sakata4,
M. Meguro4, N. Kawamura1,2, A. Koda1,2, N. Kurosawa5, P. Strasser1,2, K. Shimomura1,2, and Y. Miyake1,2
1Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK); 2Muon Science
Section, Materials and Life Science Division, J-PARC center; 3Advanced Science Research Center, Japan Atomic Energy Agency (JAEA);
4Nippon Advanced Technology Co., Ltd. (NAT); 5Cryogenics Science Center, High Energy Accelerator Research Organization (KEK)140

MLF Annual Report 2016

Muon Science

The Status of the U-line
Ultra-Slow Muon beamline
Compared to the conventional “surface” and “decay”
muon beams, the Ultra-Slow Muon beams have specificfeatures, such as low kinetic energy, small beam-size,and short time distribution. Thus, there is a need for a
new magnetic probe to investigate the material properties of subsurfaces, interfaces and small-size samples.
Initially, the generation of Ultra-Slow Muon involves the emission of muonium (Mu) with thermal energy from tungsten foil (2000 K) into vacuum. Then, Mu
is excited and is ionized by 122-nm light (Lyman-α ofMu) and 355-nm light.
In February 2016, we observed Ultra Slow muons
for the first time in J-PARC. Since then, we continued
to perform the beam commissioning to increase thebeam intensity and to optimize the beam properties.
The generation rate of Ultra-Slow Muon was gradually
increased to 55 µ+/s by increasing the intensity, and optimized for the alignment and position of laser lights(Fig. 1). Considering the detection eﬃciency of the microchannel plates, the rate was estimated to be morethan 100 µ+/s.
Another development in the U-line was the increaseof the intensity of the surface muon beam incident on the
Mu production target using an Axial Focusing Solenoid
No. 3 and No. 4. An axial Focusing Solenoid is a pair of superconducting coils in a cryostat with a warm bore. Six
sets of Axial Focusing Solenoids are designed to transportand focus surface muon beams on the Mu production
target. However, Axial Focusing Solenoid No. 3 and No. 4
were not used because of the instability of the high voltage power supply for positron separators, which is a Wien
Filter type supply that is used to eliminate positrons frommuon beams, was enhanced by applying the magnetic
field of an Axial Focusing Solenoid. In November 2016,
we restarted the aging of the separator in condition by
exciting Axial Focusing Solenoid No. 3 and No. 4. Then,
we found the condition of applying a high voltage at
the separator with the solenoid field. Figure 2 shows thetime structure of an Ultra-Slow Muon with and without asolenoid field at the separator. It is clearly seen that the
Ultra-Slow Muon rate was increased by ∼30% comparedwith the case when not using Axial Focusing Solenoid
No. 3 and No. 4. We continue to conduct beam commissioning to realize a more intense Ultra-Slow Muon andto optimize further the beam properties. In addition toincreasing the laser intensity, Ultra-Slow Muon spin rotation experiments will be performed in the near future.

Figure 1.	Ultra-Slow Muon generation rate to vary the timing of 355-nm light with respect to the Lyman-α of
muonium.

Figure 2.	Ultra-Slow Muon generation rate to vary the timing of 355-nm light with respect to the Lyman-α of
muonium.

Laser system for Ultra-Slow Muon generation
Ultra-Slow muons can be generated in resonant
optical ionization by the simultaneous irradiation of
122.09-nm-wavelength light, which is the muonium
Lyman-α resonance wavelength and corresponds to
the 1S-2P transition of muonium, and 355-nm light.
Therefore, the high-energy coherent Lyman-α lightsource is a very important element for the eﬃcient generation of high-power Ultra-Slow muons.
In order to generate intense Lyman-α light, wechose the two-photon resonance four-wave-mixing
scheme in krypton. A 212.556-nm pulse for two-photon excitation and a tunable near-infrared pulse are
required for this method. The tunable near-infrared
source can tune the wavelength around 820.649 nm
and 845.015 nm to generate a resonant Lyman-α for a
muonium and a hydrogen atom, respectively.
The output pulses at 212.556 nm and near-infraredfrom all-solid-state laser and subsequent wavelength141

MLF Annual Report 2016

conversions were independently loosely focused andcoaxially superposed in the middle of a 1-m long krypton-argon mixture gas cell to achieve a long interaction
length and suitable mode-matching. The Kr and Ar gas
mixing ratio was adjusted to satisfy phase matching infour-waves because Kr gas has a negative dispersion in
the Lyman-α wavelength region. The Lyman-α laser system is described in Ref. 1.
In our last report, we showed that by installing agas mixer into a system, the ratio of the experimentally
suitable Ar/Kr mixed gases was in agreement with thetheory [2]. However, the Lyman-a intensity gradually decreased after it was filled with the gas mixture. Moreover,the gas-exchange procedure influenced the degree towhich the intensity of the Lyman-α fell. It was recognized that the intensity of the Lyman-a fell to around
20–30% just after the introduction of the gas mixture
over about 18 h. The depredate intensity of Lyman-α
is shown in Fig. 3. The reason for such a degradation is
being investigated using a time- history analysis of gas
contaminations. In any case, we improved a gas mixer
and vacuum control device to enable it to exchange thegas mixture automatically. In this way, we performed
gas exchange every few hours, which corresponded tothe muon-beamline separator shut down, and we wereable to maximize the beam-commissioning time.
Another major improvement in the laser system
was the shape of the spectrum. To realize eﬃcient ultraslow muon generation by laser ionization, the synchronization between the spectrum shapes of the laser
with the Doppler broadening of the thermal muonium(∼230 GHz) is very important when significant laser power is provided. The spectrum shape of Lyman-α is determined by the spectrum shape of the seed laser, which isbased on the wavelength-tunable Ti:sapphire laser. The
spectrum shape of the seed laser had comb- like discrete
spectrum due to the output coupler of the Ti:sapphirelaser cavity. To improve the spectrum shape, the output
coupler was replaced by a new one. The spectrum shape
was successfully smoothed, as shown in Fig. 4. The obtained broad spectrum has a ∼90-GHz bandwidth full
width at half maximum (FWHM) that corresponds to one
third of the band width of thermal muonium Doppler
broadening. The complete band width matching will be

Figure 3.	Long term evolution of Lyman-α intensity measured by NO gas ionization signal.

BeforeIntensity (arb. units)

Muon Science

After

Omega2 wavelength (nm)Figure 4.	The spectrum shape of the seed laser before theoutput coupler (blue line) was replaced and after(red line).

achieved using a spectrum filter in the Ti:sapphire cavity.
In conclusion, we have successfully installed an automatic gas exchanger to improve the stability of the
Lyman-α intensity. Then, we successfully operated thelaser system to generate ultraslow muons and subsequent beamline tuning for a long time. In addition, thelaser spectrum was improved for eﬃcient Ultra-Slowmuon generation.
References[1] N. Saito et. al.. Opt. Exp. 24 (2016) 7566-7574.
[2] O.A. Louchev et. al.. Phys. Rev. A 84 (2011) 033842(1-9).

T. Adachi1,2, Y. Oishi1,2, A. D. Pant1,2, Y. Ikedo1,2, H. Fujimori1,2, J. G. Nakamura1,2, T. Iwashita3, P. Strasser1,2, T. U. Ito2,4, W. Higemoto2,4,
K. Shimomura1,2, R. Kadono1,2, Y. Miyake1,2, E. Torikai4,5, M. Iwasaki5, N. Saito5, and S. Wada5
1
Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK); 2Muon Science
Section, Materials and Life Science Division, J-PARC center; 3Nippon Advanced Technology Co., Ltd. (NAT); 4Advanced Science Research Center,
Japan Atomic Energy Agency (JAEA); 5Integrated Graduate School of Medicine, Engineering, and Agricultural Sciences, University of Yamanashi

142

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Muon Science

Experimental Area S1: from Beam Commissioning
to Sample Environment and Autorun of ARTEMISSpectrometerA new surface muon beamline (S-line) is being
constructed in the Materials and Life Science Facility(MLF) building at J-PARC. This beamline is designed toprovide high-intensity low-energy muon beams, typically surface muons with a momentum of 28 MeV/c,that will be used mainly for materials and life science(μSR) experiments. The S-line will eventually comprisefour beam legs and four experimental areas (namely
S1–S4) that will share the double-pulsed muon beam.
However, so far, the secured funding was sufficient toconstruct and operate the beamline toward only one of
the four planned experimental areas, i.e., area S1.
Since the first beam delivery on October 29,
2015 [1], the beamline commissioning has been extensively performed by using the μSR spectrometer ARTEMIS [2], fabricated by the Element Strategy
Initiative project for Electronic Materials. An automatic
beam tuning program, named “ForTune” and developed
specifically at MUSE, was used to obtain a well-focusedmuon beam at the sample position by observing μ–e
decay events counted by Kalliope detectors assembled
in the μSR spectrometer. The beamline parameters
were optimized to achieve an optimum muon flux witha good S/N ratio within a small sample size (∼20 mm).
The tuning of the beamline slits led also to the suppression of positron contamination in the muon beam
and a narrower beam spot size at the target position. A
beam collimator with a diameter of 40 mm was placedat the end of the beamline just in front of the sample
position to reduce the beamline related background.
Smaller collimator sizes were also available to further

(b)

(c)
80 mm

(a)

reduce the beam size. The typical surface muon flux fora beam size of ϕ20 mm after significant tailoring (including narrowing slits) was 8.5 × 104 μ+/s at the sample position obtained at 150-kW proton beam power
operation.
A muon beam profile monitor developed to diagnose pulsed muon beams at MUSE [3] was used tomonitor the muon beam shape and size at area S1.
Muons stopped in a scintillation screen produce lightthat is captured by a large aperture lens and sent toa gated image intensifier connected to a cooled CCD
camera. Figure 1 shows muon beam profiles observed
at S1 with (a) beamline slits wide open, and (b) after significant tailoring by narrowing down the width of theslits (ϕ40-mm beam collimator was used in both cases).
The optimized beam spot (Fig. 1b) has a Gaussian shapewith a FWHM of 22 mm horizontally and 25 mm vertically. For comparison, the beam spot with slits open
(Fig. 1a) has a FWHM of 34 mm horizontally and 26 mm
vertically, respectively.
The commissioning of the new electric kicker system SK12 [4] that delivers a single-pulsed muon beam
to areas S1 and S2 was also performed. The results showthat all four kicker modes can send the muon beam to
S1 without any significant changes in the beam spot
size or shape (same FWHM). Figure 1c shows the observed beam profile at S1 with the electric kicker SK12(1313-mode) that should be compared to Fig. 1b when
the switchyard magnet SSY12 is used. The only difference is that the muon yield is 4–5% smaller when using
the kicker.

80 mm

Figure 1.	Muon beam profiles observed at area S1 with (a) beamline slits wide open, (b) after significant tailoring by narrowing
down the slits, and (c) same condition as in (b) but using the electric kicker SK12 (1313-mode) instead of the switchyard
magnet SSY12.

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Negative muon beam commissioning was realized
by using cloud-negative muons at S1. Muon asymmetry
was measured in a highly oriented pyrolytic graphite(HOPG) sample with size 50 × 50 mm2 in an open geometry with beam slits fully open (see Fig. 2). In contrast
to the surface muons that are 100% polarized, cloud
muons are produced by the lowest energy pions emitted from the muon target (cloud like) from a mixtureof backward and forward decay, leading to a negative
muon beam with lower polarization. The measured
negative muon polarization was 0.38(1) at 28 MeV/c,and decreased with increasing muon momentum andintensity. A figure of merit, calculated by multiplying theasymmetry by the square-root of the spectrometer coincidence rate, showed that a momentum of ∼32 MeV/c(maximum at S-line) is better as a measurement condition for μ−SR, as only a data acquisition 30 times longer is needed to achieve a precision comparable tothat of μ+SR. This figure of merit depends on the negative muon residual polarization in the sample [5], andAsymmetry(a)Surface µ+

0.2

Cloud µ−0

Cloud µ+

-0.2
0

2

4

Time (µs)

6

8

10

Figure 2.	Negative muon commissioning at area S1 showing
muon asymmetry measured in a HOPG sample with
28 MeV/c cloud μ− (black square), and compared to
28 MeV/c surface μ+ (red circle) and 32 MeV/c cloudμ+ (green triangle), respectively.

Time (µs)

Figure 3.	Photo induced relaxation of Silicon as reproduced
at the light illumination attachment of ARTEMIS.

144

needs to be adjusted to other elements. For carbon, it
is slightly higher (∼20%) compared to most other elements (∼16%).
The ARTEMIS spectrometer [2] is equipped withsample environment (SE) and autoruns. We have prepared: (1) flypast chamber to reduce the backgroundsignal originating from the muons stopped anywhereoutside of the sample [3], (2) flash-lamp light illumination setup and pulse-wise light on/off histogram recording (red/green mode) of data acquisition, (3) microtransverse-field coil (μTC) with an inner bore of 130 mm,
which can apply 50 mT horizontal field perpendicular tothe beam and muon spin with a minimum shifting of
the muon beam trajectory. Figure 3 shows a commissioning result of the photo-induced muon spin relaxation of silicon [6], as reproduced at ARTEMIS.
In Fig. 4a, the μTC setup and vertical helium flow
cryostat as installed in ARTEMIS are shown. In order tomeasure the anisotropy of the hyperfine parameter ofthe shallow hydrogen-like state of muons, such as in(b)(c) ZnO

H//0001 = 25 mT
T = 2.5 K

Figure 4.	(a) Micro transverse-field coil (μTC) together withvertical helium flow cryostat installed in ARTEMIS.
(b) Rotating samples rods: the rod with the smaller
disk is automated by a stepping motor, and is computer controlled. (c) Fast Fourier Transform spectrum of ZnO shallow muonium state as measured
at ARTEMIS.

MLF Annual Report 2016

ZnO [7] and rutile TiO2 [8], an automated sample rotating rod, with rotation axis parallel to the beam axis has
been prepared (Fig. 4b); with the μTC and vertical helium flow cryostat, the angle dependence measurementof the hyperfine coupling parameter is now fully automated. An example of an FFT spectrum of the shallow
state (side bands) in ZnO is shown in Fig. 4c.
Autorun sequence system to run a series of measurements, together with a remote monitoring systemof the running measurement is incorporated with the
IROHA2 system developed for MLF [9]. The histogram
data of the μSR measurement are also available on a
KEK server with a password protection for each set ofexperimental numbers. The histogram data files may
be downloaded upon request from the histogram data
viewer in a format readable by the major analysis programs, such as musrfit, msrfit and WiMDA.
Experimental area S1 has been opened to theuser program since February 2017. With area D1 at the
D-line, two experimental areas at MUSE are now available to μSR users to perform condensed matter physics
experiments.

Muon Science

Acknowledgement
The development of the ARTEMIS spectrometer
was financially supported by MEXT Elements Strategy
Initiative to Form Core Research Center at Tokyo
Institute of Technology.
References[1] A. Koda et al., KEK-MSL Report 2015, 16 (2016) and
MLF annual report 2015; P. Strasser et al. to appear
in JPS Conf. Ser. (2017).
[2] K. Kojima et al., J. Phys: Conf. Ser., 551 (2014) 012063;
MLF annual report 2015, 133 (2016); to appear in
JPS Conf. Ser. (2017).
[3] T. U. Ito et al., Nucl. Instr. Meth. A 754, 1 (2014).
[4] P. Strasser et al., KEK-MSL Report 2013, 14 (2014).
[5] V. R. Akylas and P. Vogel, Hyperfine Interact. 3, 77(1977).
[6] R. Kadono et al., Phys. Rev. Lett., 73, 2724, (1994).
[7] K. Shimomura et al., Phys. Rev. Lett., 89, 255505,(2002).
[8] K. Shimomura et al., Phys. Rev. B92, 075203, (2015).
[9] T. Nakatani et al., Proceedings of ICALEPCS2009,
676 (2009).

P. Strasser1,2, A. Koda1,2,6, K. M. Kojima1,2,6, T. U. Ito2,3, H. Fujimori1,2, Y. Irie1,2,4, M. Aoki5, Y. Nakatsugawa1,2, W. Higemoto2,3, M. Hiraishi1,
H. Li1,6, H. Okabe1,2, S. Takeshita1, K. Shimomura1,2, N. Kawamura1,2, R. Kadono1,2, and Y. Miyake1,2
1Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK); 2Muon Science
Section, Materials and Life Science Division, J-PARC center; 3Advanced Science Research Center, Japan Atomic Energy Agency (JAEA) ;4Accelerator Laboratory, High Energy Accelerator Research Organization (KEK); 5Graduate School of Science, Osaka University; 6Open
Source Consortium of Instrumentation (Open-It)

145

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MLF Annual Report 2016

Present Status of the H-line
A brand-new beam line, H-line, is planned to beconstructed as the fourth beam line in MUSE. The newbeam line is designed to have a large acceptance, momentum tunability, as well as the ability to use a kicker
magnet and a Wien filter. This beam line will provide
an intense beam for experiments that require high statistics, and need to occupy the experimental areas for
relatively long periods. Several experiments in the fieldof fundamental physics have been proposed pertaining
to the H-line [2-4].

completed in 2012 and the remainder finished in 2014,as shown in Fig. 2.

HGV1

HB1

φ600 pillow seal

HS1a

HS1b

Figure 2.	Installed front-end devices in the H-line.

H-lineH1 exp. area
HB2

S-lineFigure 1.	A layout plan of experimental hall #1 in the firstphase of the H-line construction.

In the primary stage of the MUSE construction,
only the D line and the front-end magnets in the S line
were installed, then the front-end magnets in the U line
were installed in 2009. In the H-line, temporary radiation-shield blocks were placed. J-PARC has been in operation since 2008, and thus the activation around themuon production target has become more serious withevery passing year. According to the evaluation usinga Monte-Carlo code [5], the dose rate near the target
chamber was estimated to be close to 1 Sv/h, and thesummer shutdown in 2012 was the actual deadline for
installation of the front-end magnets in the H-line. Thus,
the installation of the front-end devices was almost
146

In the other high-intensity beam line, the U line, we
adopted only axial focusing magnets to obtain hightransmission efficiency [6]. However, in the H-line, thebeam captured by an axial focusing large-aperture solenoid magnet is transported through bending magnets,
although these non-axial focusing magnets increase
the beam loss. To compensate for this and achieve ahigh transmission efficiency, large-aperture magnets
and other devices are adopted in the H-line.
The conceptual design work for the major components in the experimental hall, i.e. magnets, vacuum
components, etc., has been almost completed for the
first phase of the H-line, where the beam-line was constructed up to the first experimental area, as shown in
Fig. 1.
The design work for the radiation shield was performed in the same manner as in the other beamlines [5]. Along the beam-line, a few meters-thick concrete shield will be required to enclose the streaming
neutrons and other radiation sources. Because large aperture devices were adopted, the effect of the streaming neutrons will be more serious than in the otherbeam lines. The evaluation of the streaming neutrons
is important not only for radiation safety but also to determine its effect on the detectors and other devices inthe experimental area. Figure 3 shows a typical resultof the simulation. During the proton beam operation,

MLF Annual Report 2016

Muon Science

the dose rate in the experimental area is expected toreach 100 mSv/h, and no one can enter this area even
if no muon beams are being delivered. By inserting abeam blocker made of a 40-cm thick copper block, thedose rate is decreased by about 1/10. Using the beam
blocker as well as switching off the bending magnet,
HB2, can guarantee radiation safety. Herewith, a personal protection interlock system can be introduced.

(a) blocker out(b) blocker in

100 µSv/h

10 µSv/h

Figure 4.	The radiation shield of the H-line assembled in experimental hall #1.

blocker
H line extension

Figure 3.	A typical simulated result of the radiation dosearound the H-line.

In 2014JFY, supplemental budget was secured toreinforce the radiation shield against a 1-MW protonbeam. A part of the H-line shield was designed and fabricated to unite the reinforcement shield in experimental
hall #1. These shield blocks were delivered in the end of
March 2015. Then, during this fiscal year, we assembled
all of these blocks into the H-line up to the first experimental area, the H1 area, which is covered with deep
blue shield blocks, as shown in Fig. 4. Although the assembly was completed about 10 days behind schedule,
the work was done without any major problems.
The application for change in the shield was accepted by the regulatory agency after the inspection in early November, just after restarting the beam operation.
Early completion of the H-line construction is anticipated by the usercommunity. We aim to deliver the beam
to the first experimental area in the first phase of the construction. After that, during the second phase, the H-line
will be extended for g-2/EDM measurement and also forthe transmission muon microscope, as shown in Fig. 5.

Figure 5. Beamline layout in the second phase.

[1] N. Kawamura et al. 2013 Journal of Physics: Conference
Series 408 012072.
[2] K. Shimomura et al. ibid.
[3] N. Saito et al. ibid.
[4] S. Mihara et al. ibid.
[5] N. Kawamura et al. 2009 NIM A 600 114.
[6] K. Nakahara et al. 2010 AIP Conf. Proc. 1222 420.

N. Kawamura1,2, MuHFS collab., DeeMe collab., and g-2/EDM collab.
1Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK); 2Muon Science
Section, Materials and Life Science Division, J-PARC center

147

MLF Safety

MLF Safety

MLF Annual Report 2016

Research Safety(Radiological License Upgrade)
The two applications for radiological license upgrades in FY2016 were approved on September 27,
150

2016, and February 2, 2017.
Updated items on September 27, 2016:(1)	Change of the contamination survey areas for
preparation to apply the 1st-class radiationcontrolled area in the MLF experimental halls(2)	Added storage and usage of several sealed radioisotopes (6 Cs-137)(3)	Preparation of the H-line installation of Muon
beam line (change of shield structures)(4)	Change of the drainage equipment for radioactive liquid waste (position change of the connection to the tank lorry)
Updated item on February 2, 2017:(1) Added gas folders in the off-gas system.
2. Chemical safety
The usual chemical safety checks of user-broughtchemical materials, such as specimen and reagents, toevaluate their toxicity and the stability of their actual
physical state – powder, solid, liquid or gas, were performed successfully by the chemical-safety team, alongwith approval of the actual materials for use by individual beamline staffs. As a result, the experiments were
performed without serious problems. Figure 1 showsa trend for the number of chemical materials for safety
check. As for the form of the sample, solid was usedmost frequently, then powder, liquid, and gas. Fromthe viewpoint of organic or inorganic matter, inorganic
matter was used more frequently. In 2016, because of
stably available beam time (approximately 153 days),
the total number of chemical materials was increased,compared with 2015 (approximately 62 days), that was
the highest number ever.

7000

Number of chemical materials

1. Radiation safety(Adopting “low-surface contamination area” at the MLF
Experimental halls)
To prepare for the upcoming high-beam-power operation of MLF, a new classification of the radiation-controlled-area at the MLF experimental halls, “low-surface
contamination area”, was adopted in November 2016.
Its purpose is to avoid surface-contamination problems
caused by a sample, an environmental atmosphere,
contamination and so on, and to expand the flexibilityof the experimental conducted at MLF.
The low-surface contamination area is defined in
the local radiation protection rule of J-PARC and is included in the 1st-class radiation-controlled area. In thearea, a concentration of surface contamination equal
to or lower than the standard value (0.04 Bq/cm2 foralpha-emitting radioisotopes and 0.4 Bq/cm2 for nonalpha-emitting radioisotopes) should be kept. If thecontamination in the area exceeds the standard value,
it should be removed immediately. An operation withany surface contamination in the area can’t be planned.
However, any accidental contamination is acceptable(and of course, it should be removed immediately). The
limitation of gas and liquid used in the experiment is mitigated. And challenging experiments can be conducted
more easily. The low-surface contamination area is notapplied to the BL11 experimental room and the 3rd experiment preparation room because the contamination
is assumed during the experiment or the operation.
To introduce the low-surface contamination, a monitor for take-out articles and 2 hand-foot-clothes monitors were installed. More than 20 survey meters wereprepared and can be used at each neutron instrument
due to easy operation by users and staffs. Lockers wereprepared in the locker room to reduce the number of articles brought to the experimental halls. Users and staffs
can always take an article out of the radiation controlledarea, excluding irradiated articles and sample becauseof the installed monitor for articles that are being takenout. Periodic survey service (once a day) to take out large
articles also started. In the summer maintenance period,
the classification of the radiation-controlled area at theexperimental halls temporarily changes to 2nd class tomake it easy to maintain the instruments.

6000
5000
4000
3000
2000
1000
0

2009 2010 2011 2012 2013 2014 2015 2016
Year

Figure 1.	Trend of chemical materials for chemical safety check.

MLF Annual Report 2016

A Deuteration laboratory of P1 class has been under construction for several years. Currently, the rules
for safety use are discussed, and it is scheduled for test
operation from the next fiscal year.
3.	Alarm indication system for instrument condition
monitoring
We started installing alarm indication systems on individual beamlines in experimental halls. This system consists of signal line of equipment to monitor, connection
box, controller, signal light and PC via J-LAN. The schematic of the system is shown in Fig. 2. The status of the equipment of an individual beamline, collectively monitored, isdisplayed at a monitoring room by using this system.
One of the purposes of the system is to ensure an
unattended operation of various kinds of sample environment equipment, for example, cryo-furnace, by observation in the monitor room. Therefore, the burden
on the users is alleviated for some of the equipment.
On the other hand, an application possibility of the system for unattended operation of the high temperature
furnace under maximum temperature of more than
1273 K is being discussed now. This year, the systems
were installed at BL01, BL02, BL14 and BL22. Figure 3
shows the systems installed at BL01 and BL02.
The top red light indicates status of warning or normal-operation by blinking or by lighting, respectively at
any time. The orange light in the middle indicates statusof caution of equipment, when the equipment signals
potential malfunction, the light glows. The bottom lightindicates the operation status, when the equipment isworking in unattended operation mode, the light is

LAN

BL01

BL02

MLF Safety

blue and when it is working in remote operation mode
via IROHA2, which is the standard computational environment in MLF, the light turns green. A buzzer sounds
when the status requires a warning.
Next year, the systems will be installed sequentiallyat other beamlines, including the muon beamline.

(a)Blinking : warning
Lighting : operation
CautionOperation status
Blue : unattended operation
Green : remote operation
Buzzer(b)
Figure 3.	(a) alarm indication system at BL01 and BL02, (b)signal light.

+RVW3&0RQLWRULQJURRP-/$1

6LJQDOOLJKW&RQWUROOHU

BL䞉䞉

&RQQHFWLRQER[(TXLSPHQW

Figure 2. Schematic of the alarm indication system.

151

MLF Annual Report 2016

4. Crane safety
There are 2 cranes in each experimental hall (experimental hall No.1 and experimental hall No.2). These
cranes are used to change the experimental setup during beam time and to perform summer maintenance by
the technical staffs or constructors. Figure 3 shows thestatistics of the total crane usage in both experimental halls as a function of every month. There was a total of 241 cases of use. The statistics for 2015 indicatedhigh use in December and March, because of the performance of many experi-ments, based on the stablebeam operation.
As usual, the safety measures and the effective
schedules of crane usage were planned by the cranesafety team. Also, the crane safety team checked
monthly the mechanical sling, lifting sling, etc. andreplaced the old ones with new ones when necessary. Furthermore, a crane operator, who wants to use
the cranes in the experimental halls, needs to attend
hands-on training by the crane safety team staff before
the actual operation. As of the work team, according

to the rules, it must include a crane operator, slinging
operator, and observer.
As a result, there were no serious problems with thecrane operations.

25

in-house staff
constructor

20
Number of crane usage

MLF Safety

15
10
5
0

4

5

6

7

8

9 10 11 12
Month

1

2

3

Figure 4. Trend of the total crane usage in one year.

M. Harada1, M. Ooi1, M. Sekijima1, K. Kawakami2, K. Aizawa2, A. Hori2, N. Kubo2, W. Kambara2, M. Sawabe2, K. Suzuya3, N. Kawamura4,
Y. Sakaguchi5, Y. Yamaguchi5, and K. Soyama6
1
Neutron Source Section Materials and Life Science Division, J-PARC Center; 2Technology Development Section, Materials and Life Science
Division, J-PARC center; 3Neutron Science Section, Materials and Life Science Division, J-PARC center; 4Muon Science Section, Materials andLife Science Division, J-PARC Center; 5Neutron R&D Division, CROSS-Tokai; 6Materials and Life Science Division, J-PARC center

152

MLF Operations in 2016

MLF Operations in 2016

MLF Annual Report 2016

Beam Operation Status at MLF
In Japanese Fiscal Year (JFY) 2016, the beam operation was planned to start on April 11, after the refreshment of the cryogenic for the neutron moderator,
which was performed from April 4 to 10. On April 4, abeam collimator placed at 3-GeV synchrotron malfunctioned causing a leak into the vacuum of the beam
duct. It took until April 13 to fix the issue, then the beam
operation for JFY 2016 started. Like in the previous fiscal year, the beam power was maintained at 200 kW toavoid damage to the mercury target. In February 2016,
we replaced the target with a new one (Target #2).
Since this target was not equipped with a helium bubbler to mitigate cavitation erosion at the target vessel,
the beam power was lowered below 200 kW. The useof such beam power was decided in the previous plan,
according to which we had to replace the target during outage period from June to October 2016. However,
because the design and fabrication of next robust target, which can withstand a high-power operation, took
longer than expected, the target could not be changedin the summer as scheduled. To maintain the beam operation without the failure of Target #2, we decided toreduce the beam power to 150 kW for an expanded annual service from November to June 2017.
Table 1 shows the scheduled time and availability
in JFY 2016 with a subtotal of records for the periods of
2016A and 2016B, which are switched on January 30. In
JFY 2016, there were no severe failures, so the achieved
availability was high at 90%. One of the reasons forsuch a high availability was the reduction of the beam
power. The availability was very low in JFY 2015 due tothe failure of the target on two occasions. These records
show that the development of a target with robustness
to accept high-power beams is crucial to achieving
such high availability. Another reason for that achievement was that the cryogenic of the moderator was successfully cleaned up during the summer maintenanceperiod. Figure 1 shows the trend of the beam power
and its availability during JFY 2016. A significant failure
was the malfunction of the timing system on June 21,
which took a few days to fix and resume the operation.
Due to this failure, the daily availability was limited at
the end of June. Since this failure occurred shortly afterradiation inspection of the beam to extend the usageof the facility, this failure did not affect the schedule ofradiation inspection. After November 2016, very stablebeam operation was achieved.

Figure 1.	Beam power trend (shown in blue line) at MLF andavailability per day (shown in red line).

Table 1. Run cycle, scheduled time and availability.

*1
*2

154

Run

Duration

Scheduled time (h)Actual time (h)Availability (%)

68
69
70
71
72A
2016A*1

Apr 10 – May 28
Jun 3 – Jun 29
Nov 1 – Nov 16
Nov 18 – Dec 21
Jan 14 – Jan 30
Apr 10 – Jan 30

891
564
322
708
363
2848

744.3
458.6
307.2
671.3
355.8
2537.2

83.5
81.3
95.4
94.8
98.0
89.1

72B
73
74
2016B*2

Jan 30 – Mar 30
Mar 16 – Mar 30
Mar 31 – Apr 1
Jan 30 – Apr 1

802
312
12
1126

766.7
297.8
11.73
1086.2

95.6
95.4
97.8
95.6

Overall

Apr 10 – Apr 1 2017

3974

3613.590.9: Subtotal record for 2016A: Subtotal record for 2016B

MLF Annual Report 2016

MLF Operations in 2016

Users at the MLF
In the fiscal year 2016, the beam power was reduced to150 kW, but was steadily delivered all throughthe period.

The stable operation of MLF regained the numberof users to the level of FY2014 and higher, as summarized in Table 1.

Table 1. The number of domestic and foreign users in the period of fiscal year.
FY2008Domestic
Users
Neutron

FY2009Foreign
Users

Domestic
Users

12

303

107

0

38

Foreign
Users

Domestic
Users

113

476

13

59

FY2014

Neutron

432

824
711
78

FY2011

Foreign
Users

Domestic
Users

44

238

476

2

42

Foreign
Users

Domestic
Users

83

744

10

83

432

20
01
10
FY 2010

399

449

56
2

50
61

46

10

50

11

Foreign
Users

99
16

Neutron (Japanese)

Neutron (Foreigners)

Muon (Japanese)

Muon (Foreigners)

46
80

2
21
21

628

2011
FY 2011

13

16

900

78
113

83

750

11
50
50

10

108

600

59
83

450

711

399

238
FY 2009
2009

80

708

Foreign
Users

108

42
44

303

Domestic
Users

852

8

12
95
FY
Y 2008
2008
00

628

21

10

18

21

FY2013ForeignUsers

FY201669

38
14

Domestic
Users

23
8

559

2

FY2012Foreign
Users

259

50

FY2015

91

Muon

14
40

18

Domestic
Users

Domestic
Users

317

95
18

Muon

FY2010Foreign
Users

476

744

300
150

201
01
12
FY 2012201
13FY 2013F 2014
2014
FY

2015
FY 2015

0
Y 2016FY

Figure 1. The number of domestic and foreign users in the period of fiscal year.

155

MLF Operations in 2016

MLF Annual Report 2016

MLF Proposals Summary – FY2016
Table 1. Breakdown of Proposals Numbers for the 2016 Rounds.
2016A

Beamline

2016A

Full Year

Submitted Approved Submitted Approved

Instrument

GU

GU

GU

GU

Submitted
PU/S

IU

Approved
ES

IU

ES

BL01 4D-Space Access Neutron Spectrometer - 4SEASONS

11(1)

5(1)

15(0)

5(0)

3

1

2

3

1

2

BL02 Biomolecular Dynamics Spectrometer - DNA

16(1)

7(1)

19(1)

8(1)

2

1

0

2

1

0

(100-b)‡

8

1

6

0

0

0

0

0

0

0

†

2

2

0

0

18

0

0

18

0

0

9

3

12

3

2

1

0

2

1

0

BL03 Ibaraki Biological Crystal Diffractometer - iBIX(b)

Accurate Neutron-Nucleus Reaction Measurement
BL04
Instrument - ANNRI
BL05 Neutron Optics and Physics - NOP

6

2

2

2

1

0

0

1

0

0

BL06 Neutron Resonance Spin Echo Spectrometers - VIN ROSE

0

0

0

0

1

0

0

1

0

0

BL08 Super High Resolution Powder Diffractometer - S-HRPD

11

3

12

6(0)

1

0

0

1

0

0

BL09 Special Environment Neutron Power Diffractometer - SPICA

0

0

0

0

1

0

0

1

0

0

Neutron Beamline for Observation and Research Use NOBORU

11

5

8

7

3

1

0

3

1

0

BL10

BL11 High-Pressure Neutron Diffractometer - PLANET

12(0)

8(0)

12(0)

8

0

1

0

0

1

0

BL12 High Resolution Chopper Spectrometer - HRC

12

4

9

3

1

0

0

1

0

0

BL14 Cold-neutron Disk-chopper Spectrometer - AMATERAS

28

4

22

6

4

1

1

4

1

1

Small and Wide Angle Neutron Scattering Instrument BL15TAIKAN

29(3)

9(3)

17(2)

9(2)

4

3

1

4

3

1

19

10

7

7

0

0

0

0

0

0

18(2)

8(2)

10(1)

4(1)

1

1

1

1

1

1

23(1)

4(1)

16(0)

5(0)

2

3

1

2

3

1

23

5

25

7

3

1

2

3

1

2

13

4

19

4

0

0

0

0

0

0

44

24

20

20

15

0

0

15

0

0

BL16

High-Performance Neutron Reflectometer with a horizontal
Sample Geometry - SOFIA

BL17 Polarized Neutron Reflectometer - SHARAKU
BL18

Extreme Environment Single Crystal Neutron Diffractometer SENJUBL19 Engineering Diffractometer - TAKUMI
BL20

Ibaraki Materials Design Diffractometer iMATERIA(100-b)(b)†‡

BL21 High Intensity Total Diffractometer - NOVA

19

7

17

7

1

0

0

1

0

0

BL22 Energy Resolved Neutron Imaging System - RADEN

18

6(0)

11(0)

7(0)

2

2

0

2

2

0

BL23 Polarization Analysis Neutron Spectrometer - POLANO

0

0

0

0

1

0

0

1

0

0

D1

Muon Spectrometer for Materials and Life Science
Experiments - D1

17(0)

6(0)

18(0)

1(1)

3

1

0

3

1

0

D2

Muon Spectrometer for Basic Science Experiments - D2

13

6

15

7

1

1

0

1

1

0

U

Muon U
Total

0

0

0

0

0

0

0

0

0

0

362

133

291

125

69

18

8

69

18

8

GU : General Use
PU : Project Use or Ibaraki Pref. Project Use
S : S-type Proposals
IU : Instrument Group Use
ES : Element Strategy† : Ibaraki Pref. Exclusive Use Beamtime (β = 80% in FY2016)‡ : J-PARC Center General Use Beamtime (100-β = 20% in FY2016)( ) : Proposal Numbers under Trial Use Access System or P-type proposals (D1,D2) in GU

156

PU/S

MLF Annual Report 2016

MLF Operations in 2016

800
700

Proposals

600

142

500
400

45

20

200
100
0

34
67

214

FY2008FY2009309

FY2010293

395
Not Approved

126

42

300

278

460

422

469

FY2012FY2013

FY2014255
FY2011

Approved

321

353

FY2015FY2016

Proposal Round

Figure 1. MLF Proposal Numbers over Time.

JAEA, 91, 14%

KEK,
45, 7%

Universies (Japan)
Universies (Japan),309, 49%

Foreign Organizaons,
82, 13%Companies (Japan)
Research Instutes (Japan)
Foreign Organizaons
JAEA
KEK

Research Instutes (Jappan),
65, 10%Companies (Japan),45, 7%
Figure 2. Origin of Submitted Proposals by affiliation - FY2016.

Figure 2. Origin of Submied Proposals by affiliaon - FY2016

Q1, 17, 3%
P9, 13, 2%
P7, 26, 5%

Q2, 46,8%
P1, 103, 18%
P2, 59, 10%

P6, 59, 10%
P5, 170, 29%

P3, 89, 15%

P1 :Materials Science and Engineering
P2 :Energy Science and High-Pressure ScienceP3 :Soft Matter, Biomaterials and Liquids
P4 :(Reserved)
P5 :Magnetism and Strongly Correlated Electron Systems
P6 :Fundamental and Nuclear Physics, Instrumentation, Imaging
P7 :Industrial Applications
P8 :(Reserved)
P9 :Trial Use Access Program
Q1 :Electronic Properties of Matter
Q2 :Hydrogen in Matter & General Applications

Figure 3. Submitted Proposals by Sub-committee/Expert Panel – FY2016.

Figure 3 : Submied Proposals by Sub-commiee/Expert Panel – FY2016

157

MLF Operations in 2016

MLF Annual Report 2016

MLF Division Staff 2016
Head

Toshiji Kanaya

Deputy Head

Hideki Seto		

Kazuhiko Soyama

Neutron Source Section

*: additional duties<JAEA>
Hiroshi Takada (Leader)

Yuko Kato

Ken-ichi Oikawa *Katsuhiro Haga (Sub-Leader)

Tomoyuki Kawasakii

Kenji Sakai

Katsuhiro Aoyagi

Yoshinori Kikuchi

Masakazu Seki

Tomokazu Aso

Hidetaka Kinoshita

Mitsuaki Sekijima

Shinpei Fukuda

Hiroyuki Kogawa

Motonori Takagi

Kouhei Hanano

Kazuma Maekawa

Makoto Teshigawara

Masahide Harada

Shin-ichiro Meigo

Toshitsugu Uchida

Shoichi Hasegawa *Hideki Muto

Hiroyuki Uehara

Mitsunori Hirane

Takashi Naoe

Eiichi Wakai

Miyuki Hoshino

Norio Narui

Takashi Wakui

Masato Ida

Masaaki Nishikawa

Zhihong Xiong

Kenji Imahashi

Kazutaka Nomura

Shizuka Yoshinari

Tetsuya Kai *Motoki Ohi

Neutron Science Section

*: additional duties<JAEA>

158

Kenji Nakajima (Leader)

Yasuhiro Inamura

Masato Kubota *Yukinobu Kawakita (Sub-Leader)

Hideaki Isozaki

Kazuo Kurihara *Motoyasu Adachi * (QST)

Tetsuya Kai

Bing Li

Kazuya Aizawa *Ryoichi Kajimoto

Tatsuhito Matsuo * (QST)

Hiroyuki Aoki

Wataru Kambara *Satoshi Morooka *Kazuhiro Aoyama

Kouji Kaneko *Naoki Murai

Satoru Fujiwara * (QST)

Chiho Katagiri

Hiroshi Nakagawa *Hideo Harada *Seiko Kawamura

Shoji Nakamura *Masahide Harada *Takuro Kawasaki

Mitsutaka Nakamura

Takeshi Harada

Naoko Kawase

Takashi Ohhara

Stefanus Harjo

Tatsuya Kikuchi

Mariko Ohtake

Takanori Hattori

Atsushi Kimura *Kenichi Oikawa

Yuu Hirano * (QST)

Ryoji Kiyanagi

Asami Sano

Kousuke Hiroi

Maiko Kofu

Mariko Segawa *Miho Igarashi

Fumiaki Kono * (QST)

Yoshichika Seki

MLF Operations in 2016

MLF Annual Report 2016

Kaoru Shibata

Hiroshi Suzuki *Katsuaki Tomoyori *Naoko Shimizu

Kentaro Suzuya

Yousuke Tou *Rumi Shimizu * (QST)

Shin-ichi Takata

Wakana Ueno

Takenao Shinohara

Tarou Tamada * (QST)

Masao Watanabe *Yuhua Su

Itaru Tamura *Dai Yamazaki *Shinichi Ito (Sub-Leader)Takashi Kamiyama

Kaoru Taketani

Hideki Seto

Naokatsu Kaneko

Shuki Torii

Hitoshi Endo

Kenji Mishima

Norifumi Yamada

Takashi Honda

Fumiya Nemoto

Testuya Yokoo

Kazutaka Ikeda

Hidetoshi Oshita

Masao Yonemura

Takashi Ino

Toshiya Otomo<KEK>

Technology Development Section

*: additional duties<JAEA>
Kazuya Aizawa (Leader)

Wataru Kambara

Kaoru Sakasai *Takayuki Oku (Sub-Leader)

Kazuhiro Kawakami

Masaki Sawabe

Tomokazu Aso *Hiroyuki Kogawa *Kentaro Suzuya *Chikako Doda

Naoya Kubo

Ryuta Takahashi

Wu GongKazuo Kurihara * (QST)

Shin-ichi Takata *Katsuhiro Haga *Mitsutaka Nakamura *Tarou Tamada * (QST)

Masahide Harada *Tatsuya Nakamura *Kazue Tanaka

Yuu Hirano * (QST)

Takeshi Nakatani

Katsuaki Tomoyori * (QST)

Yasuhiro Inamura *Motoki Ohi *Masao Watanabe

Tetsuya Kai *Kenji Sakai *<KEK>Masataka Sakaguchi

Naritoshi Kawamura *Tomohiro Seya

Hiroshi Fujimori *Kenji Kojima *Kaoru Taketani *Takashi Ino *Shunsuke Makimura *Shuki Torii *Naokatsu Kaneko *Setsuo Sato

Testuya Yokoo *Neutron Instrumentation Section

*: additional duties<JAEA>
Kaoru Sakasai (Leader)

Ryuji Maruyama

Noriaki Tsutsui

Noriko Amezawa

Tatsuya Nakamura

Dai Yamazaki

Masumi Ebine *Kentaro Toh

159

MLF Operations in 2016

MLF Annual Report 2016

Muon Science Section

*: additional duties<KEK>
Ryosuke Kadono (Leader)

Akihiro Koda

Koichiro Shimomura

Naritoshi Kawamura (Sub-Leader)

Kenji Kojima

Patrick Strasser

Taihei Adachi

Shunsuke Makimura

Masato Tabe

Pant Amba Datt

Shiro Matoba

Soshi Takeshita

Hiroshi Fujimori

Yasuhiro Miyake

Yutaka Taniguchi

Koji Hamada

Junpei Nakamura

Motonobu Tanpo

Masatoshi Hiraishi

Yohei Nakatsugawa

Shogo Doiuchi

Li HuaYasuhisa Nemoto

Tatsuhiko Tachibana

Yutaka Ikedo

Yu OishiYasuo Kobayashi

Hirotaka Okabe<JAEA>
Wataru Higemoto *160

Takashi Ito *MLF Operations in 2016

MLF Annual Report 2016

CROSS Staff 2016
Director

Hideaki Yokomizo

Science Coordinators
Kazuhisa Kakurai

Makoto Hayashi

Yoshiaki Fukushima

Research & Development Division*: additional duties

Jun-ichi Suzuki (Head)<BL15 Group><Technical Support Group>

Kenichi Funakoshi (Deputy Head)

Kazuki Ohishi (Leader)

Koji Kiriyama (Leader)

Jun-ichi Suzuki *Takayoshi Ito (Sub-Leader)

Hiroki Iwase

Yoshifumi Sakaguchi<BL01 Group>

Yukihiko Kawamura

Kazuya Kamazawa (Leader)
Kazuhiko Ikeuchi<BL17 Group>

Hiroshi Kira

Kazuki Iida

Jun-ichi Suzuki *(Leader)Motoyuki Ishikado

Noboru Miyata (Sub-Leader)

Nobuo Okazaki<BL02 Group>

Kazuhiro Akutsu

Makoto Kobayashi

Masato Matsuura (Leader)

Takayasu Hanashima

Satoshi Kasai
Toshiaki Morikawa

Takeshi Yamada<BL18 Group>

Hideyuki Hiramatsu

Akiko Nakao (Leader)

Yutaka Ebara<BL11 Group>

Koji Munakata

Kentaro Moriyama

Kenichi Funakoshi *(Leader)

Taketo Moyoshi

Tetsuya Kuroda

Taiki Tominaga

Keiichi Ohuchi

Jun AbeShinichi Machida<BL22 Group>

Masae Sahara

Hirotoshi Hayashida (Leader)

Tazuko Mizusawa *Joseph Don Parker
Yoshihiro Matsumoto
Shuoyuan Zhang

Health and Safety Division*: additional duties

Yasuhiro Yamaguchi (Head)

Yukihiko Kawamura *Koji Kiriyama *Rei Ohuchi *161MLF Operations in 2016

MLF Annual Report 2016

Utilization Promotion Division*: additional duties

Junichi Sato (Head)

Megumi Kawakami

Sayaka Suzuki

Tsukasa Miyazaki (Deputy Head)

Asuko Ariga

Miho Kawato

Kenichi Funakoshi *(Deputy Head)

Tazuko Mizusawa

Rei Ohuchi

Junko Ohta

Atsuko Irie

Toshiki Asai

Rie Suzuki

Administration and Finance Division

162

Michihiko Murasawa (Head)

Takashi Hikita

Yoshitaka Yasu

Mika Gunji

Mutsumi Shiraishi

MLF Annual Report 2016

MLF Operations in 2016

Proposals Review System, Committees and Meetings

Proposal Review System
The JAEA-KEK-CROSS Agreement of Cooperaon on the Promoon of Public Ulizaonof the Specific Neutron Beam Facilies at J-PARC (Enacted on 1 April 2011)
Director General
KEK

President
JAEA

J-PARC
CenterDirector
J-PARC

President
CROSS
CollaboraonCommiee

(JAEA/KEK)

Muon Science
Proposal Rev. Comm.

RegisteredInstuon(CROSS)All except Public Beamlines Public Beamlines Only

MLF Advisory
Board

Muon Instrument
Proposal Rev. Comm.

Director
CROSS-Tokai

SeleconCommieeTask Forces

All except Contract
Beamlines

Contract Beamlines
Only

All except Public
Beamlines

Public Beamlines Only

Neutron Instrument
Proposal Rev. Comm.

Contract Beamline
Evaluaon Comm.

Neutron Science
Proposal Rev. Comm.

Proposal
Evaluaon Comm.

Joint Meeng

Muon
Instrument
Proposals

Joint Meeng

Neutron Instrument
Proposals

Public Beamlines Only
All except Public Beamlines
JAEA Research
CROSS Development
Neutron Program
Proposal Advisory Proposal Evaluaon
Advisory
CommieePanelCommiee
Joint MeengMuon Program
Advisory Comm.

Muon Scienfic Proposals

Neutron Scienfic Proposals

Unified
Access Point

ALL Proposals submied via the J-PARC Users Office
Figure 1. Proposals Review System Framework.

Materials and Life Science Facility Advisory Board
Kazuya Aizawa

Japan Atomic Energy Agency, Japan

Jun Akimitsu

Okayama University, Japan /Hiroshima University, Japan

Hiroshi Amitsuka

Hokkaido University, Japan

Masaki Fujita

Tohoku University, Japan

Kenya Kubo

International Christian University,
Japan

Tetsurou Minemura

Ibaraki Prefecture, Japan

Yasuhiro Miyake

High Energy Accelerator Research
Organization, Japan

Atsushi Nakagawa

Osaka University, Japan

Kenji Nakajima

Japan Atomic Energy Agency, Japan

Toshiya Otomo

High Energy Accelerator Research
Organization, Japan
High Energy Accelerator Research
Organization, Japan

Michihiro Furusaka

Hokkaido University, Japan

Masatoshi Futakawa

Japan Atomic Energy Agency, Japan

Ryosuke KadonoHigh Energy Accelerator Research
Organization, Japan

Hideki Seto

Takashi Kamiyama

High Energy Accelerator Research
Organization, Japan

Mitsuhiro Shibayama The University of Tokyo, Japan

Toshiji Kanaya

High Energy Accelerator Research
Organization, Japan

Kazuhiko Soyama

Japan Atomic Energy Agency, JapanJun Sugiyama

Toyota Central R&D Labs., Inc., Japan

Yuji Kawabata

Kyoto University, Japan

Jun-Ichi Suzuki

Yukinobu Kawakita

Japan Atomic Energy Agency, Japan

Yoshiaki Kiyanagi

Nagoya University, Japan

Comprehensive Research
Organization for Science andSociety, Japan163

MLF Operations in 2016

MLF Annual Report 2016

Masayasu Takeda

Japan Atomic Energy Agency, Japan

Toshio Yamaguchi(Chair)Fukuoka University, Japan
Term: through March 31, 2017

Neutron Instrument Proposal Review Committee

Takashi Kamiyama

High Energy Accelerator Research
Organization, Japan

Toshiji Kanaya

High Energy Accelerator Research
Organization, Japan

Ryoji Kanno

Tokyo Institute of Technology, Japan

Yukinobu Kawakita

Japan Atomic Energy Agency, Japan

Stephen King

Rutherford Appleton Laboratory,
U.K.

Masatoshi Futakawa

Japan Atomic Energy Agency, Japan

Toru Ishigaki

Ibaraki University, Japan

Seung-Hun Lee

University of Virginia, U.S.A.

Takashi Kamiyama

High Energy Accelerator Research
Organization, Japan

Masaaki Matsuda

Oak Ridge National Laboratory,
U.S.A.

Hiroyuki Kimura

Tohoku University, Japan

Tetsurou Minemura

Ibaraki Prefecture, Japan

Yoshiaki Kiyanagi

Nagoya University, Japan

Yukio Morii

Yukio Morii

Radiation Application Development
Association, Japan

Radiation Application Development
Association, Japan

Atsushi Nakagawa

Osaka University, Japan

Kenji Nakajima

Japan Atomic Energy Agency, Japan

Kenji Nakajima

Japan Atomic Energy Agency, Japan

Toshiya Otomo

High Energy Accelerator Research
Organization, Japan

Yukio Noda

Tohoku University, Japan

Toshiya Otomo

Yasuhiro Sakemi

Tohoku University, Japan

High Energy Accelerator Research
Organization, Japan

Konoe Sato

Yokohama City University, Japan

Anna Paradowska

Hideki Seto

High Energy Accelerator Research
Organization, Japan

Australian Nuclear Science andTechnology Organization, Australia

Je-Geun Park

Seoul National University, Korea

Kazuhiko Soyama

Japan Atomic Energy Agency, Japan

Vanessa Peterson

Masaaki Sugiyama

Kyoto University, Japan

Australian Nuclear Science andTechnology Organization, Australia

Jun-Ichi Suzuki

Comprehensive Research
Organization for Science andSociety, Japan

Hideki Seto

High Energy Accelerator Research
Organization, Japan

Shinichi Shamoto

Japan Atomic Energy Agency, Japan

Ichiro Tanaka

Ibaraki University, Japan

Hirohiko Shimizu

Nagoya University, Japan

Naoya Torikai

Mie University, Japan

Masaaki Sugiyama

Kyoto University, Japan

Hideki Yoshizawa

The University of Tokyo, Japan

Jun-Ichi Suzuki

Comprehensive Research
Organization for Science andSociety, Japan

Keiji Tanaka

Faculty of Engineering, Kyushu
University, Japan

Yo Tomota

Research Center for Strategic
Materials, Japan

Albert Young

North Carolina State University,
U.S.A.

Term: through March 31, 2017

Neutron Science Proposal Review Committee

164

Koichi Akita

Japan Atomic Energy Agency, JapanKen Andersen

European Spallation Source, Sweden

Takahisa Arima

The University of Tokyo, Japan

Samrath Chaplot

Bhabha Atomic Research Centre,
India

Yoshiaki FukushimaComprehensive Research
Organization for Science andSociety, Japan

Michihiro Furusaka(Chair)Hokkaido University, Japan

Makoto Hayashi

Ibaraki Prefecture, Japan

Shinichi Itoh

High Energy Accelerator Research
Organization, Japan

Kazuaki Iwasa

Ibaraki University, Japan

Michael James

Australian Synchrotron, Australia

Ryosuke KadonoHigh Energy Accelerator Research
Organization, Japan

Hiroyuki Kagi

The University of Tokyo, Japan

Term: through March 31, 2017

Neutron Program Advisory Committee
Shinichi AdachiHigh Energy Accelerator Research
Organization, Japan

Masaki Azuma

Tokyo Institute of Technology, Japan

Hazuki Furukawa

Ochanomizu University, Japan

Masatoshi Futakawa

Japan Atomic Energy Agency, Japan

Yasushi Idemoto

Tokyo University of Science, Japan

Shinichi Itoh

High Energy Accelerator Research
Organization, Japan

Takashi Kamiyama

High Energy Accelerator Research
Organization, Japan

MLF Annual Report 2016

Toshiji Kanaya

High Energy Accelerator Research
Organization, Japan

Mikio Kataoka

Nara Institute of Science andTechnology, Japan

Yukinobu Kawakita

Japan Atomic Energy Agency, Japan

Yasuhiro Miyake

High Energy Accelerator Research
Organization, Japan

Yutaka Moritomo

University of Tsukuba, Japan

Youichi MurakamiHigh Energy Accelerator Research
Organization, Japan

Masato Ohnuma

Hokkaido University, Japan

Toshiya Otomo (Chair) High Energy Accelerator Research
Organization, Japan
Yasuhiro Sakwmi

Tohoku University, Japan

Taku Sato

Tohoku University, Japan

Hideki Seto

High Energy Accelerator Research
Organization, Japan

Mitsuhiro Shibayama The University of Tokyo, JapanMLF Operations in 2016

Muon Science Proposal Review Committee
Kenta Amemiya

High Energy Accelerator Research
Organization, Japan

Hiroshi Amitsuka

Hokkaido University, Japan

Masaharu Aoki

Osaka University, Japan

Alan Drew

University of London, U.K.

Masatoshi Futakawa

Japan Atomic Energy Agency, Japan

Takayuki Goto

Sophia University, Japan

Wataru Higemoto

High Energy Accelerator Research
Organization, Japan

Ryosuke KadonoHigh Energy Accelerator Research
Organization, Japan

Toshiji Kanaya

High Energy Accelerator Research
Organization, Japan

Yoji Koike

Tohoku University, Japan

Kenji Kojima

High Energy Accelerator Research
Organization, Japan

Kenya Kubo (Chair)International Christian University,
Japan

Hirohiko Shimizu

Nagoya University, Japan

Masaaki Sugiyama

Kyoto University, Japan

Roderick Macrae

Marian University, U.S.A.

Toshio Yamaguchi

Fukuoka University, Japan

Yasuyuki Matsuda

The University of Tokyo, Japan

Takashi Miyake

National Institute of Advanced
Industrial Science and Technology,
Japan

Yasuhiro Miyake

High Energy Accelerator Research
Organization, Japan

Term: through March 31, 2017

Muon Instrument Proposal Review Committee
Kazuya Aizawa

Japan Atomic Energy Agency, Japan

Koichiro Asahi

Tokyo Institute of Technology, Japan

Seiji Miyashita

The University of Tokyo, Japan

Masatoshi Futakawa

Japan Atomic Energy Agency, Japan

Yuichiro Nagame

Japan Atomic Energy Agency, Japan

Wataru Higemoto

High Energy Accelerator Research
Organization, Japan

Kenji Nakajima

Japan Atomic Energy Agency, Japan

Yasuo Nozue

Osaka University, Japan

Masahiko Iwasaki

RIKEN, Japan

Chihiro Ohmori

Ryosuke KadonoHigh Energy Accelerator Research
Organization, Japan

High Energy Accelerator Research
Organization, Japan

Toshiya Otomo

Toshiji Kanaya

High Energy Accelerator Research
Organization, Japan

High Energy Accelerator Research
Organization, Japan

Hideki Seto

Kenji Kojima

High Energy Accelerator Research
Organization, Japan

High Energy Accelerator Research
Organization, Japan

Tatsushi Shima

Osaka University, Japan

Kenya Kubo

International Christian University,
Japan

Koichiro Shimomura

High Energy Accelerator Research
Organization, Japan

Yoshitaka Kuno

Osaka University, Japan

Yoko Sugawara

Kitazato University, Japan

Yasuhiro Miyake

High Energy Accelerator Research
Organization, Japan

Yoichi Yanase

Kyoto University, Japan

Nobuhiko Nishida

Toyota Physical and Chemical
Research Institute, Japan

Hiroyuki Nojiri

Tohoku University, Japan

Toru Ogitsu

High Energy Accelerator Research
Organization, Japan

Koichiro Shimomura

High Energy Accelerator Research
Organization, Japan

Kazuhiko Soyama

Japan Atomic Energy Agency, Japan

Yasunori Yamazaki

RIKEN, Japan
Term: through March 31, 2017

Kazuyoshi Yoshimura Kyoto University, Japan
Term: through March 31, 2017

Muon Program Advisory Committee
Kenta Amemiya

High Energy Accelerator Research
Organization, Japan

Hiroshi Amitsuka

Hokkaido University, Japan

Masaharu Aoki

Osaka University, Japan

Masatoshi Futakawa

Japan Atomic Energy Agency, Japan

Takayuki Goto

Sophia University, Japan165

MLF Operations in 2016

MLF Annual Report 2016

Wataru Higemoto

High Energy Accelerator Research
Organization, Japan

Ryosuke KadonoHigh Energy Accelerator Research
Organization, Japan

Toshiji Kanaya

High Energy Accelerator Research
Organization, Japan

Yoji Koike

Tohoku University, Japan

Kenji Kojima

High Energy Accelerator Research
Organization, Japan

Kenya Kubo

International Christian University,
Japan

Yasuyuki Matsuda

The University of Tokyo, Japan

Takashi Miyake

National Institute of Advanced
Industrial Science and Technology,
Japan

Yasuhiro Miyake(Chair)High Energy Accelerator Research
Organization, Japan

Seiji Miyashita

Fukuoka University, Japan
Term: through March 31, 2017

Proposal Evaluation Committee (CROSS)
Ken Andersen

European Spallation Source, Sweden

Takahisa Arima

The University of Tokyo, Japan

Samrath Chaplot

Bhabha Atomic Research Centre,
India

Yoshiaki FukushimaComprehensive Research
Organization for Science andSociety, Japan

Michihiro Furusaka(Chair)Hokkaido University, Japan

Makoto Hayashi

Comprehensive Research
Organization for Science andSociety, JapanThe University of Tokyo, Japan

Kazuaki Iwasa

Ibaraki University, Japan

Yasuo Nozue

Osaka University, Japan

Michael James

Australian Synchrotron, Australia

Chihiro OhmoriHigh Energy Accelerator Research
Organization, Japan

Hiroyuki Kagi

The University of Tokyo, Japan

Toshiya Otomo

High Energy Accelerator Research
Organization, Japan

Ryoji Kanno

Tokyo Institute of Technology, Japan

Stephen King

Hideki Seto

High Energy Accelerator Research
Organization, Japan

Rutherford Appleton Laboratory,
U.K.

Seung-Hun Lee

University of Virginia, U.S.A.

Tatsushi Shima

Osaka University, Japan

Masaaki Matsuda

Koichiro Shimomura

High Energy Accelerator Research
Organization, JapanOak Ridge National Laboratory,
U.S.A.

Tetsurou Minemura

Ibaraki Prefecture, Japan

Yoko Sugawara

Kitazato University, Japan

Yukio Morii

Yoichi Yanase

Kyoto University, Japan

Radiation Application Development
Association, Japan

Atsushi Nakagawa

Osaka University, Japan

Yukio Noda

Tohoku University, Japan

Anna Paradowska

Australian Nuclear Science andTechnology Organization, Australia

Je-Geun Park

Seoul National University, Korea

Vanessa Peterson

Australian Nuclear Science andTechnology Organization, Australia

Hirohiko Shimizu

Nagoya University, Japan

Masaaki Sugiyama

Kyoto University, Japan

Jun-Ichi Suzuki

Comprehensive Research
Organization for Science andSociety, Japan

Keiji Tanaka

Faculty of Engineering, Kyushu
University, Japan

Yo Tomota

Research Center for Strategic
Materials, Japan

Albert Young

North Carolina State University,
U.S.A.

Kazuyoshi Yoshimura Kyoto University, Japan
Term: through March 31, 2017

Selection Committee (CROSS)
Jun Akimitsu

Okayama University, Japan /Hiroshima University, Japan

Masaki Fujita

Tohoku University, Japan

Michihiro Furusaka

Hokkaido University, Japan

Yasuhiro Iye (Chair)Japan Society for Promotion of
Science, Japan

Yuji Kawabata

Kyoto University, Japan

Hiroyuki Kishimoto

Sumitomo Rubber Industries, LTD.,Japan

Naoki Kishimoto

Research Center for Strategic
Materials, Japan

Yoshiaki Kiyanagi

Nagoya University, Japan

Tetsurou Minemura

Ibaraki Prefecture, Japan

Atsushi Nakagawa

Osaka University, Japan

Mitsuhiro Shibayama The University of Tokyo, Japan

166

Toshio Yamaguchi

Jun Sugiyama

Toyota Central R&D Labs., Inc., Japan

Shinji Tsuneyuki

The University of Tokyo, Japan

Term: through March 31, 2017

MLF Annual Report 2016

MLF Operations in 2016

Neutron Advisory Committee (NAC)
NAC convened 20-21 February, 2017 at the J-PARC Research Building, TokaiGroup photo of NAC

Neutron Advisory Committee (20-21 Feb. 2017)

Robert McGreevy (chair)

Rutherford Appleton Laboratory

Bertrand Blau

Paul Scherrer InstituteMark Wendel

Oak Ridge National Laboratory

Yoshiaki Kiyanagi

Nagoya University

Christiane Alba-Simionesco

Laboratoire Léon Brillouin

Jamie Schulz

Australian Nuclear Science and Technology Organisation

Dimitri Argyriou

European Spallation Source

Chang Hee Lee

Korea Atomic Energy Research InstituteMitsuhiro Shibayama

The University of Tokyo

Masaaki Sugiyama

Kyoto University

Muon Advisory Committee (MAC)
MAC convened 22-23 February, 2017 at the KEK Tokai Campus, TokaiGroup photo of MAC

Muon Advisory Committee (22-23 Feb. 2017)

Francis Pratt (Chair)

Rutherford Appleton Laboratory

Toshiyuki Azuma

RIKEN

Klaus Jungmann

University of Groningen

Kenya Kubo

International Christian University

Andrew MacFarlane

The University of British Columbia

Yasuo Nozue

Osaka University

Prokscha Thomas

Paul Scherrer InstituteJun Sugiyama

Toyota Central R & D Labs. Inc.

167

MLF Operations in 2016

MLF Annual Report 2016

Workshops, Conferences, Seminars and Schools in 2016
Conferences held jointly by J-PARC MLF andCROSSWorkshop for Neutron Inelastic Scattering (BL12)
14 Nov. 2016, KEK Tokai Campus, Ibaraki

2016 Meeting on J-PARC MLF Industrial Use
21-22 July 2016, Akihabara Convention Hall, Tokyo

Workshop for Polarized Neutron Scattering (BL23)
15 Nov. 2016, KEK Tsukuba Campus, Ibaraki
Workshop for Neutron Total Scattering (BL21)
21 Nov. 2016, KEK Tokai Campus, Ibaraki
7th Workshop for Muon and Accelerator Research
5-7 Jan. 2017, RIKEN, Saitama

Photo of the 2016 Meeting on J-PARC MLF Industrial Use

2016 Quantum Beam Science Festival (The 8th MLF
Symposium and The 34th PF Symposium)
14-15 Mar. 2017, Tsukuba International Congress
Center, Ibaraki

Workshops held by CROSS
The 18th CROSSroads Workshop“Polarized Targets and Neutron Polarization
Techiques”
15 June 2016, IBARAKI Quantum Beam ResearchCenter, Ibaraki

Group photo of CROSSroads 18
Group photo of the 2016 Quantum Beam Science Festival

Workshops held by KEK

The 19th CROSSroads Workshop“Neutrons and Muons for Interface Investigations”
13 Feb. 2017, IBARAKI Quantum Beam Research Center,
Ibaraki

7th Progress Report Meeting of J-PARC MUSE
29 May 2016, KEK Tokai Campus, Ibaraki
Joint Workshop for CMRC and TRIMN
8 July 2016, KEK Tokai Campus, Ibaraki
Workshop for Negative Muon Research
11 July 2016, KEK Tokai Campus, Ibaraki
Workshop for Neutron Optics and Physics (BL05)
9 Aug. 2016, Nagoya University, Aichi

168

Group photo of CROSSroads 19

MLF Annual Report 2016

MLF Operations in 2016

Workshops and Seminars held by CROSS andother organizations

2016 Workshop on Soft Matter Neutron Scattering
17 Nov. 2016, Essam Kanda Hall, Tokyo

Potential of Neutrons in Interfacial Nano Electron
Chemistry
15 July 2016, KANTO KAGAKU, Tokyo

Seminar on Industrial Applications of Neutrons in
Saitama
11 Dec. 2016, Cultural Center “Sanazeria”, Saitama

2016 1st Workshop on Residual Stress and Strain
22 Aug. 2016, KENKYUSHA EIGO Center, Tokyo

2016 Workshop on Neutron Science
14 Dec. 2016, Essam Kanda Hall, Tokyo

3rd Symposium on the Collaborative Use of Large
Research Institutions and the KEI Super Computer
2016
1 Sep. 2016, Akihabara UDX, Tokyo

1 st Workshop on the Collaborative Use of Large
Research Institutions and the KEI Super Computer2017
10 Jan. 2017, RIST, Hyogo

Photo of the 3rd Symposiumon the Collaborative Use of Large ResearchInstitutions and the KEI Super Computer 2016

Photo of the 1st Workshopof the Collaborative Use of Large ResearchInstitutions and the KEI Super Computer 20172016 1st Workshop on Structural Biology
2 Sep. 2016, KENKYUSHA EIGO Center, Tokyo

2016 Workshop on Magnetic Materials
19 Jan. 2017, Essam Kanda Hall, Tokyo

13th Seminar on Industrial Applications at SPring-8
7-8 Sep. 2016, Hyogo Arts & Culture Association, Hyogo

2016 Workshop on Battery Materials
25 Jan. 2017, KENKYUSHA EIGO Center, Tokyo

2016 Workshop on Surfaces and Interfaces
28 Sep. 2016, KENKYUSHA EIGO Center, Tokyo

2016 Workshop on Non-destructive Visualization
and Analysis Methods
15 Feb. 2017, KENKYUSHA EIGO Center, Tokyo

2016 Workshop on Materials Science
29 Sep. 2016, Essam Kanda Hall, Tokyo
2016 Workshop on Analytical Methods In Small
Angle Scattering
1 Nov. 2016, Essam Kanda Hall, Tokyo

3 r d S e m i n a r o n t h e Co m p l e m e n t a r y U s e o fSynchrotron Radiation and Neutrons
17 Feb. 2017, KENKYUSHA EIGO Center, Tokyo
Photo of the 3rd Seminar on the Complementary Use of
Synchrotron Radiation and Neutrons

2016 Workshop on Metallographic Structure
11 Nov. 2016, Essam Kanda Hall, Tokyo
Ibaraki Society for the Promotion of the Use of
Neutrons“2016 Meeting on Magnetic Materials”
14 Nov. 2016, Essam Kanda Hall, Tokyo

169

MLF Operations in 2016

MLF Annual Report 20162016 Z-Code Training Course
27-28 Feb. 2017, LMJ Tokyo, Tokyo

Hello Science from J-PARC: Chocolate Science
21 Jan. 2017, Food court at AEON Tokai, Ibaraki

2016 2nd Workshop on Residual Stress and Strain
8 Mar. 2017, KENKYUSHA EIGO Center, Tokyo
2016 Workshop on Liquids and Amorphous Materials
13 Mar. 2017, Essam Kanda Hall, Tokyo
2016 2nd Workshop on Structural Biology
29 Mar. 2017, KENKYUSHA EIGO Center, Tokyo

Schools in 2016
KEK-Summer Challenge Beam Experiment12-13 Nov. 2016, J-PARC Center and KEK Tokai Campus,
IbarakiPhoto of the
KEK-Summer Challenge Beam Experiment

The Neutron and Muon School
22-26 Nov. 2016, J-PARC Center, Ibaraki
Group photo of the Neutron and Muon School

170

Photo of Hello Science from J-PARC:
Chocolate ScienceMLF Annual Report 2016

MLF Operations in 2016

Award List
AESJ Best Paper Award (Atomic Energy Society ofJapan)Development of microbubble generator for suppression ofpressure waves in mercury target of spallation source
H. Kogawa, T. Naoe, and H. Kyotoh (2017-03-28)
Young Scientist Award of Societry of Muon and
Meson Science of Japan
Research of Iron-based superconductors using muon spinrotation and relaxation
M. Hiraishi (2017-03-19)
Scientist Award of Societry of Muon and Meson
Science of Japan
Research of spin-orbit coupling induced Mott insulatorsand their superconductivity using muon spin rotation andrelaxation
H. Okabe (2017-03-19)
Tire Technology of the Year
Advanced 4D Nano Design
Sumitomo Rubber Industries (2017-02)
JAEA President’s Awards 2016, Research andDevelopment Prizes
Completion of design, construction and leading researchof Engineering Materials Diffractometer in J-PARC
S. Harjo, A. Moriai, T. Kawasaki, K. Sakasai, T. Nakamura,
T. Ito, J. Abe, H. Arima, W. Gong, T. Iwahashi, andK. Aizawa (October 2016)

The Japan Institute of Metals and Materials The Best
Paper Award
Relation between Vickers Hardness and Bragg-Edge
Broadening in Quenched Steel Rods Observed by Pulsed
Neutron Transmission Imaging
H. Sato, T. Sato, Y. Shioda, T. Kamiyama, A.S. Tremsin,
M. Ohnuma and Y. Kiyanagi (2016-09-21)
The Society of Polymer Science Research Award
Conformational analysis of single polymer chains bysuper-resolution optical microscopy
H. Aoki (2016-09-15)
Fellowship of the Royal Society of Chemistry
A. Takahara (2016-07)
The 28th Award from The Society of Rubber Scienceand Technology, Japan
Combined analysis of Rubber material using SPring-8,
J-PARC, K-Computer
H. Kishimoto, Y. Masui, F. Kaneko, Y. Shinohara, and
Y. Masubuchi (2016-05)
Science Technology Award of MEXT in FY2016
Advance in Neutron Resonance Spectroscopy andApplication Researches
S. Harada, A. Kimura, and Y. Toh (2016-04-20)
The 10 th Young Scientist Award of the PhysicalSociety of Japan, Magnetism (Region 3)
M. Soda (2016-03-21)

The 11 th Young Scientist Award of the PhysicalSociety of Japan, Beam Physics Region
Pulsed ultra-cold neutron production using a Doppler
shifter at J-PARC
S. Imajo (2016-10-16)

171

MLF Operations in 2016

MLF Annual Report 2016

MLF Publication 2016
1

2

3

4

5

6

8

7

9

10

1

2

3

4

5

6

7

8

9

10

H. Kawaura, M. Harada, Y. Kondo, H. Kondo, Y. Suganuma, N.
Takahashi, J. Sugiyama, Y. Seno, and N. L. Yamada
Operando Measurement of Solid Electrolyte Interphase Formation
at Working Electrode of Li-ion Battery by Time-slicing Neutron
Reflectometry
ACS Appl. Mater. Interfaces 8 9540-9544 (2016)
S. Tsukui, F. Kimura, K. Kusaka, S. Baba, N. Mizuno, and T. Kimura
Neutron and X-ray single-crystal diffraction from protein microcrystals
via magnetically oriented microcrystal arrays in gels
Acta Crystallographica Section D-Biological Crystallography 72
823-829 (2016)
H.-J. Jhuo, S.-H. Liao, Y.-L. Li, P.-N. Yeh, S.-A. Chen, W.-R. Wu, C.-J. Su,
J.-J. Lee, N. L. Yamada, and U-S. Jeng
New Processing Route with a Novel Additive 1-Naphthalenethiol for
Efficiency Enhancement of Polymer Solar Cells
Adv. Funct. Mater. 26 3094-3104 (2016)
O. A. Louchev, N. Saito, Y. Oishi, K. Miyazaki, K. Okamura, J.
Nakamura, M. Iwasaki, and S. Wada
Photoionization pathways and thresholds in generation of Lyman-α
radiation by resonant four-wave mixing in Kr-Ar mixture
AIP Advances 6 95018 (2016)
T. Matsuo, T. Arata, T. Oda, K. Nakajima, S. Ohira-Kawamura, T.
Kikuchi, and S. Fujiwara
Difference in the hydration water mobility around F-actin and myosin
subfragment-1 studied by quasielastic neutron scattering
Biochemistry and Biophysics Reports 6 220-225 (2016)
S. Nishimura, Y. Suzuki, J. Lu, S. Torii, T. Kamiyama, and A. Yamada
High-Temperature Neutron and X-ray Diffraction Study of Fast
Sodium Transport in Alluaudite-type Sodium Iron Sulfate
Chemistry of Materials 28 2393–2399 (2016)
T. Matsunaga, H. Komatsu, K. Shimoda, T. Minato, M. Yonemura, T.
Kamiyama, S. Kobayashi, T. Kato, T. Hirayama, Y. Ikuhara, H. Arai, Y.
Ukyo, Y. Uchimoto, and Z. Ogumi
Dependence of Structural Defects in Li2MnO3 on Synthesis
Temperature
Chemistry of Materials 28 4143-4150 (2016)
Y. Tsuchiya, K. Takanashi, T. Nishinobo, A. Hokura, M. Yonemura, T.
Matsukawa, T. Ishigaki, and N. Yabuuchi
Layered NaxCrxTi1-xO2 as Bi-Functional Electrode Materials for
Rechargeable Sodium Batteries
Chemistry of Materials 28 7006–7016 (2016)
T. Niizeki, S. Nagayama, Y. Hasegawa, N. Miyata, M. Sahara, and K.
AkutsuStructural Study of Silica Coating Thin Layers Prepared from
Perhydropolysilazane: Substrate Dependence and Water Penetration
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Coatings 6 64 (2016)
T. Masuda, J. Arase, Y. Inagaki, M. Kawahata, K. Yamaguchi, T.
Ohhara, A. Nakao, H. Momma, E. Kwon, and W. Setaka
Molecular Gyrotops with a Five-Membered Heteroaromatic Ring:
Synthesis, Temperature-Dependent Orientation of Dipolar Rotors
inside the Crystal, and its Birefringence Change
Crystal Growth & Design 16 4392-4401 (2016)

Electrochemistry 84 802-807 (2016)
12

12

K. Sasaki, T. Mizutani, M. Iio, T. Mibe, T. Ogitsu, N. Saito, K.
Shimomura, and T. Obata
Study of Magnetic Field Measurement System for g-2/EDM
Experiment at J-PARC
IEEE Trans. Appl. Supercond. 26 0605604 (2016)

13

13

T. Matsukawa, H. Hoshima, A. Hoshikawa, C. Otani, and T. Ishigaki
Temperature Dependence of Crystal Structure and THz Absorption
Spectra of Organic Nonlinear Optical Stilbazolium Material for HighOutput THz-Wave Generation
Infrared Milli. Terahertz Waves 37 540-550 (2016)

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M. Inukai, S. Horike, T. Itakura, R. Shinozaki, R. Ogiwara, D.
Umeyama, S. Nagarkar, Y. Nishiyama, M. Malon, A. Hayashi, T.
Ohhara, R. Kiyanagi, and S. Kitagawa
Encapsulating Mobile Proton Carriers into Structural Defects in
Coordination Polymer Crystals: High Anhydrous Proton Conduction
and Fuel Cell Application
J. Am. Chem. Soc. 136 8505-8511 (2016)

14

15

H. Akiba, M. Kofu, H. Kobayashi, H. Kitagawa, K. Ikeda, T. Otomo,
and O. Yamamuro
Nanometer-Size Effect on Hydrogen Sites in Palladium LatticeJ. Am. Chem. Soc. 138 10238-10243 (2016)

15

16

A. S. Tremsin, S. Ganguly, S. M. Meco, G. R. Pardal, T. Shinohara, andW. B. Feller
Investigation of dissimilar metal welds by energyresolved neutron
imaging
J. Appl. Cryst. 49 1130-1140 (2016)

18

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T. Ohhara, R. Kiyanagi, K. Oikawa, K. Kaneko, T. Kawasaki, et al.
SENJU: A new time-of-flight single-crystal neutron diffractometer at
J-PARC
J. Appl. Cryst. 49 120-127 (2016)16

18

Y. Onuki, A. Hoshikawa, S. Sato, P. Xu, T. Ishigaki, Y. Saito, H.
Todoroki, and M. Hayashi
Rapid measurement scheme for texture in cubic metallic materials
using time-of-flight neutron diffraction at iMATERIA
J. Appl. Cryst. 49 1579-1584 (2016)17

19

Y. Oba, S. Morooka, K. Ohishi, N. Sato, R. Inoue, N. Adachi, J. Suzuki, T.
Tsuchiyama, E. P. Gilbert, and M. Sugiyama
Magnetic Scattering in the Simultaneous Measurement of SmallAngle Neutron Scattering and Bragg Edge Transmission from SteelJ. Appl. Cryst. 49 1659-1664 (2016)20

Y. Noda, S. Koizumi, T. Masui, R. Mashita, H. Kishimoto, D.
Yamaguchi, T. Kumada, S. Takata, K. Ohishi, and J. Suzuki
Contrast variation by dynamic nuclear polarization and time-of-flightsmall-angle neutron scattering. I. Application to industrial multicomponent nano composites
J. Appl. Cryst. 49 2036-2045 (2016)

21

K. Akutsu, T. Niizeki, S. Nagayama, N. Miyata, M. Sahara, A.
Shimomura, M. Yoshii, and Y. Hasegawa
Investigation of structure of a thin SiO2 layer as an antifouling andcorrosion-resistant coating
J. Ceram. Soc. Jpn. 124 172-176 (2016)

22

N. Kitamura, K. Kaneko, H. Kamagata, N. Ishida, and Y. Idemoto
Hydrothermal synthesis of lanthanum silicate nanopowder and film
preparation by electrophoretic deposition method

19

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20
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Y. Idemoto, A. Horie, N. Ishida, and N. Kitamura
Crystal Structure Analysis in the Charge and Discharge Process of Liion Battery Cathode-material LiNi0.8Co0.2O2

MLF Annual Report 2016

J. Ceram. Soc. Jpn. 124 29-33 (2016)
23
21

M. Hirayama, T. Shibusawa, R. Yamaguchi, K.-S. Kim, S. Taminato, N.
L. Yamada, M. Yonemura, K. Suzuki, and R. Kanno
Neutron reflectometry analysis of Li4Ti5O12/organic electrolyte
interfaces: characterization of surface structure changes and lithium
intercalation properties
J. Mater. Res. 31 3142-3150 (2016)

Electronic Structure of Hydrogen Donors in Semiconductors andInsulators Probed by Muon Spin Rotation
J. Phys. Soc. Jpn. 85 091013 (2016)
35

T. Okuda, H. Hata, T. Eto, S. Sobaru, R. Oda, H. Kaji, K. Nishina, H.
Kuwahara, M. Nakamura, and R. Kajimoto
Effects of Mn Substitution on the Thermoelectric Properties andThermal Excitations of the Electrondoped Perovskite Sr1-xLaxTiO3J. Phys. Soc. Jpn. 85 094717 (2016)36

Y. Togawa, Y. Kousaka, K. Inoue, and J. Kishine
Symmetry, structure, and dynamics of monoaxial chiral magnets
J. Phys. Soc. Jpn. 85 112001/1-37 (2016)37

T. Kawasaki, K. Kaneko, A. Nakamura, N. Aso, M. Hedo, T. Nakama, T.
Ohhara, R. Kiyanagi, K. Oikawa, I. Tamura, A. Nakao, K. Munakata, T.
Hanashima, and Y. Ōnuki
Magnetic Structure of Divalent Europium Compound EuGa4 Studied
by Single-Crystal Time-of-Flight Neutron Diffraction
J. Phys. Soc. Jpn. 85 114711 (2016)

38

T. Adachi, A. Takahashi, K. M. Suzuki, M. A. Baqiya, T. Konno, T.
Takamatsu, M. Kato, I. Watanabe, A. Koda, M. Miyazaki, R. Kadono,
and Y. Koike
Strong electron correlation behind the superconductivity in Ce-freeand Ce-underdoped high-Tc T’-cuprates
J. Phys. Soc. Jpn. 85 114716 (2016)

39

K. Iwasa, R. Higashinaka, Y. Aoki, S. Ohira-Kawamura, and K.
Nakajima
Broad Excitation Spectra between Crystalline-Electric-Field Levels
Associated with Non-Kramers Doublet Ground State of f Electrons in
PrNb2Al20
J. Phys. Soc. Jpn. 85 123704 (2016)40

M. Soda, Y. Honma, S. Takamizawa, S. Ohira-Kawamura, K.
Nakajima, and T. Masuda
Spin Model of O2-based Magnet in a Nanoporous Metal Complex
J. Phys. Soc. Jpn. 85 34717 (2016)41

M. Miyazaki, I. Yamauchi, and R. Kadono
Quest for the Origin of Heavy Fermion Behavior in d-Electron Systems
J. Phys. Soc. Jpn. 85 91009 (2016)

42

K. Kodama, K. Ikeda, M. Isobe, H. Takeda, M. Itoh, Y. Ueda, S.-I.
Shamoto, and T. Otomo
Local Structural Analysis of Half-Metallic Ferromagnet CrO2
J. Phys. Soc. Jpn. 85 94709 (2016)

43

H. Hazama, S. Tajima, Y. Masuoka, and R. Asahi
Transport properties of the Cu2ZnSnS4 bulk systems: Effects ofnonstoichiometry and defect formation
Journal of Alloys and Compounds 657 179–183 (2016)

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A. F. Gubkin, E. P. Proskurina, Y. Kousaka, E. M. Sherokalova,
N. V. Selezneva, P. Miao, S. Lee, J. Zhang, Y. Ishikawa, S. Torii, T.
Kamiyama, J. Campo, J. Akimitsu, and N. V. Baranov
Crystal and magnetic structures of Cr1⁄3NbSe2 from neutron
diffraction
Journal of Applied Physics 119 13903 (2016)38

45

Y. Sakaguchi, H. Asaoka, Y. Uozumi, K. Kondo, D. Yamazaki, K.
Soyama, M. Ailavajhala, and M. Mitkova
Silver photo-diffusion and photo-induced macroscopic surface
deformation of Ge33S67/Ag/Si substrate
Journal of Applied Physics 120 55103 (2016)

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K. Yoshida, T. Yamaguchia, T. Yokoo, and S. Itoh
Collective dynamics measurement of liquid methanol by inelastic
neutron scattering
Journal of Molecular Liquids 222 395 (2016)

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Y. Sekine, H. Endo, H. Iwase, S. Takeda, S. Mukai, H. Fukazawa, K. C.
Littrell, Y. Sasaki, and K. Akiyoshi
Nanoscopic structural investigation of physically crosslinked nanogels
formed from self-associating polymers
J. Phys. Chem. B 120 (46) 11996–12002 (2016)25

Y. Kameda, S. Ebina, Y. Amo, T. Usuki, and T. Otomo
Microscopic Structure of Contact Ion Pairs in Concentrated LiCl- and
LiClO4-Tetrahydrofuran Solutions Studied by Low-Frequency Isotropic
Raman Scattering and Neutron Diffraction with (6)Li/(7)Li Isotopic
Substitution Methods
J. Phys. Chem. B 120 4668-4678 (2016)

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T. Minato, H. Kawaura, M. Hirayama, S. Taminato, K. Suzuki, N.
L. Yamada, H. Sugaya, K. Yamamoto, K. Nakanishi, Y. Orikasa, H.
Tanida, R. Kanno, H. Arai, Y. Uchimoto, and Z. Ogumi
Dynamic Behavior at the Interface between Lithium Cobalt Oxide
and an Organic Electrolyte Monitored by Neutron Reflectivity
Measurements
J. Phys. Chem. C 120 20082–20088 (2016)

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K. Miwa, T. Sato, M. Matsuo, K. Ikeda, T. Otomo, S. Deledda, B.C.
Hauback, G. Li, S. Takagi, and S.-I. Orimo
Metallic Intermediate Hydride Phase of LaMg2Ni with Ni–H Covalent
Bonding: Precursor State for Complex Hydride Formation
J. Phys. Chem. C 120 5926-5931 (2016)
T. Matsunaga, H. Komatsu, K. Shimoda, T. Minato, M. Yonemura, T.
Kamiyama, S. Kobayashi, T. Kato, T. Hirayama, Y. Ikuhara, H. Arai, Y.
Ukyo, Y. Uchimoto, and Z. Ogumi
Structural Understanding of Superior Battery Properties of Partially
Ni-Doped Li2MnO3 as Cathode Material
J. Phys. Chem. Lett. 7 2063-2067 (2016)
S. Saito, H. Watanabe, Y. Hayashi, M. Matsugami, S. Tsuzuki, S. Seki,
J. N. C. Lopes, R. Atkin, K. Ueno, K. Dokko, M. Watanabe, Y. Kameda,
and Y. Umebayashi
Li(+) Local Structure in Li-Tetraglyme Solvate Ionic Liquid Revealed
by Neutron Total Scattering Experiments with the (6/7)Li Isotopic
Substitution Technique
J. Phys. Chem. Lett. 7 2832-2837 (2016)
Y. Ikeda, S. Suzuki, T. Nakabayashi, H. Yoshizawa, T. Yokoo, and S.
Itoh
Inelastic Neutron-Scattering Study of Stripe and Over-Doped
Checkerboard Ordering in Layered Nickel Oxide Nd2-xSrxNiO4
J. Phys. Soc. Jpn. 85 023701 (5 pages) (2016)

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36

48
31

T. Haku, M. Soda, M. Sera, K. Kimura, S. Itoh, T. Yokoo, and T. Masuda
Crystal Field Excitations in Breathing Pyrochlore Antiferromagnet
Ba3Yb2Zn5O11
J. Phys. Soc. Jpn. 85 034721 (2016)

32

W. Higemoto, Y. Aoki, and D. E. MacLaughlin
Spin and time-reversal symmetries of superconducting electron pairs
probed by the muon spin rotation and relaxation technique
J. Phys. Soc. Jpn. 85 091007 (2016)

33

J. Sugiyama
Study on Hydrogen Storage Materials
J. Phys. Soc. Jpn. 85 091012 (2016)

34

K. Shimomura and T. U. Ito

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MLF Operations in 2016

MLF Annual Report 2016

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T. Naoe, H. Kogawa, T. Wakui, K. Haga, M. Teshigawara, H. Kinoshita,
H.Takada, and M. Futakawa
Cavitation damage prediction for the JSNS mercury target vessel
Journal of Nuclear Materials 468 313-320 (2016)

41

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T. Naoe, X. Zhihong, and M. Futakawa
Gigacycle fatigue behaviour of austenitic stainless steels used for
mercury target vessels
Journal of Nuclear Materials 468 331-338 (2016)

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S. Itoh, Y. Endoh, T. Yokoo, J.-G. Park, Y. Kaneko, K. S. Takahashi, Y.
Tokura, and N. Nagaosa
Weyl fermions and spin dynamics of metallic ferromagnet SrRuO3Nature Communications 7 11788 (2016)

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Q. Wang, Y. Shen, B. Pan, X. Zhang, K. Ikeuchi, K. Iida, A. D.
Christianson, H. C. Walker, D. T. Adroja, M. Abdel-Hafiez, X. Chen, D.
A. Chareev, A. N. Vasiliev, and J. Zhao
Magnetic ground state of FeSe
Nature Communications 7 12182 (2016)

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N. Yabuuchi, M. Nakayama, M. Takeuchi, S. Komaba, Y. Hashimoto,T. Mukai, H. Shiiba, K. Sato, Y. Kobayashi, A. Nakao, M. Yonemura, K.
Yamanaka, K. Mitsuhara, and T. Ohta
Origin of stabilization and destabilization in solid-state redox reactionof oxide ions for lithium-ion batteries
Nature Communications 7 13814 (2016)

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Y. Kato, S. Hori, T. Saito, K. Suzuki, M. Hirayama, A. Mitsui, M.
Yonemura, H. Iba, and R. Kanno
High-power all-solid-state batteries using sulfide superionic
conductors
Nature Energy 1 16030 (2016)

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65

S. Takahashi, N. L. Yamada, K. Ito, and H. Yokoyama
Inclusion Complex of α-Cyclodextrin with Poly(ethylene glycol) Brush
Macromolecules 49 6947-6952 (2016)

R. Maruyama, T. Bigault, A. R. Wildes, C. D. Dewhurst, K. Soyama,
and P. Courtois
Study of the in-plane magnetic structure of a layered system using
polarized neutron scattering under grazing incidence geometry
Nucl. Instrum. Methods Phys. Res. A 819 37-53 (2016)

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A. Zarei-Hanzaki, M. A. Mohtadi-Bonab, Y. Onuki, R. Basu, A.
Asghari, and J. A. Szpunar
Grain-orientation-dependent of γ–ε–α’ transformation and twinningin a super-high-strength, high ductility austenitic Mn-steel
Materials Science and Engineering A 674 514-528 (2016)

T. Fujiwara, U. Bautista, Y. Mitsuya, H. Takahashi, N. L. Yamada, Y.
Otake, A. Taketani, M. Uesaka, and H. Toyokawa
Microstructured boron foil scintillating G-GEM detector for neutron
imaging
Nucl. Instrum. Methods Phys. Res. A 838 124-128 (2016)

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Y. Su, K. Oikawa, S. Harjo, T. Shinohara, T. Kai, M. Harada, K. Hiroi, S.
Zhang, J. D. Parker, H. Sato, Y. Shiota, Y. Kiyanagi, and Y. Tomota
Time-of-flight neutron Bragg-edge transmission imaging of
microstructures in bent steel plates
Materials Science and Engineering A 675 19-31 (2016)

S. Takeda, Y. Yamagata, N. L. Yamada, M. Hino, T. Hosobata, J. Guo, S.
Morita, T. Oda, and M. Furusaka
Development of a large plano-elliptical neutron-focusing supermirror
with metallic substrates
Opt. Express 24 12478-12488 (2016)

68

68

N. Saito, Y. Oishi, K. Miyazaki, K. Okamura, J. Nakamura, O. A.
Louchev, M. Iwasaki, and S. Wada
High-efficiency generation of pulsed Lyman-α radiation by resonant
laser wave mixing in low pressure Kr-Ar mixture
Opt. Express 24 7566 (2016)

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N. D. Khanh, N. Abe, H. Sagayama, A. Nakao, T. Hanashima, R.
Kiyanagi, Y. Tokunaga, and T. Arima
Magnetoelectric coupling in the honeycomb antiferromagnet
Co4Nb2O9
Phys. Rev. B 93 075117 (2016)76

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S. Torigoe, Y. Ishimoto, Y. Aoishi, H. Murakawa, D. Matsumura, K.
Yoshii, Y. Yoneda, Y. Nishihata, K. Kodama, K. Tomiyasu, K. Ikeda, H.
Nakao, Y. Nogami, N. Ikeda, T. Otomo, and N. Hanasaki
Observation of all-in type tetrahedral displacements in nonmagnetic
pyrochlore niobates
Phys. Rev. B 93 085109 (2016)

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M. Hiraishi, K. M. Kojima, M. Miyazaki, I. Yamauchi, H. Okabe, A.
Koda, R. Kadono, S. Matsuishi, and H. Hosono
Cage electron-hydroxyl complex state as electron donor in mayenite
Phys. Rev. B 93 121201(R) (2016)

M. Tabuchi, H. Kageyama, K. Kubota, H. Shibuya, K. Doumae, and R.
Kanno
Structural change during charge–discharge for iron substituted
lithium manganese oxide
Journal of Power Sources 318 18–25 (2016)
S. Shiotani, T. Naka, M. Morishima, M. Yonemura, T. Kamiyama, Y.
Ishikawa, Y. Ukyo, Y. Uchimoto, and Z. Ogumi
Degradation analysis of 18650-type lithium-ion cells by operando
neutron diffraction
Journal of Power Sources 325 404-409 (2016)
K. Ninomiya , M. Inagaki, M. K. Kubo, T. Nagatomo, W. Higemoto,N. Kawamura, P. Strasser, K. Shimomura, Y. Miyake, S. Sakamoto, A.
Shinohara, and T. Saito
Negative muon induced elemental analysis by muonic X-ray andprompt gamma-ray measurements
Journal of Radioanalytical and Nuclear Chemistry 309 65-69 (2016)
D. Habu, Y. Masubuchi, S. Torii, T. Kamiyama, and S. Kikkawa
Crystal structure study of dielectric oxynitride perovskites La1xSrxTiO2+xN1-x (x = 0, 0.2)
Journal of Solid State Chemistry 237 254–257 (2016)

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Y. Wang, Y. Tomota, S. Harjo, W. Gong, and T. Ohmura
In-situ neutron diffraction during tension-compression cyclic
deformation of a pearlite steel
Materials Science and Engineering: A 676 522-530 (2016)

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K. Fukuda, Y. Tomota, S. Harjo, W. Gong, W. Woo, B. S. Seong, Y.
Kuwahara, and F. Ikuta
Residual stresses in steel rod with collar formed by partial diameterenlarging technique
Materials Science and Technology 33 172-180 (2016)

58

58

H. Nishijima, Y. Tomota, Y. Su, W. Gong, and J. Suzuki
Monitoring of Bainite Transformation Using in Situ Neutron Scattering
Metals 6(1) 16 (2016)

59

59

S. Nakano, S. Konno, N. Tomita, G. Matsuba, T. Tominaga, and S.
TakataGelation process of polyacrylonitrile solutions as studied using smallangle neutron scattering techniques
Microsystem Technologies 22 57-63 (2016)

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Nakajima, S. Ohira-Kawamura, Z. Yamani, Y. Yoshida, H. Eisaki, S.-W.
Cheong, A. L. Chernyshev, and J.-G. Park
Spontaneous decays of magneto-elastic excitations in noncollinear
antiferromagnet (Y,Lu)MnO3
Nature Communication 7 13146 (2016)

J. Oh, M. D. Le, H.-H. Nahm, H. Sim, J. Jeong, T. G. Perring, H. Woo, K.

MLF Annual Report 2016

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M. Ruminy, M. Núñez Valdez, B. Wehinger, A. Bosak, D. T. Adroja,
U. Stuhr, K. Iida, K. Kamazawa, E. Pomjakushina, D. Prabakharan,
M. K. Haas, L. Bovo, D. Sheptyakov, A. Cervellino, R. J. Cava, M.
Kenzelmann, N. A. Spaldin, and T. Fennell
First-principles calculation and experimental investigation of latticedynamics in the rare-earth pyrochlores R2Ti2O7 (R=Tb,Dy,Ho)
Phys. Rev. B 93 214308 (2016)
S. Lee, Y. Ishikawa, P. Miao, S. Torii, T. Ishigaki, and T. Kamiyama
Novel magnetoelastic coupling forbidden by timereversal symmetry:Spin-direction-dependent magnetoelastic coupling on MnO, CoO,
and NiO
Phys. Rev. B 93 64429 (2016)
M. Ruminy, E. Pomjakushina, K. Iida, K. Kamazawa, D. T. Adroja, U.
Stuhr, and T. Fennell
Crystal-field parameters of the rare-earth pyrochlores R2Ti2O7 (R =Tb, Dy, and Ho)
Phys. Rev. B 94 024430 (2016)
D. Hu, Z. Yin, W. Zhang, R. A. Ewings, K. Ikeuchi, M. Nakamura, B.
Roessli, Y. Wei, L. Zhao, G. Chen, S. Li, H. Luo, K. Haule, G. Kotliar, and
P. DaiSpin excitations in optimally P- doped BaFe2(As0.7P0.3)2
superconductor
Phys. Rev. B 94 094504 (2016)
H. Sim, S. Lee, K.-P. Hong, J. Jeong, J. R. Zhang, T. Kamiyama, D. T.
Adroja, C. A. Murray, S. P. Thompson, F. Iga, S. Ji, D. Khomskii, and J.G. Park
Spontaneous structural distortion of the metallic Shastry-Sutherland
system DyB4 by quadrupole-spinlattice coupling
Phys. Rev. B 94 195128 (2016)
T. Hayakawa, Y. Toh, M. Huang, T. Shizuma, A. Kimura, S. Nakamura,
H. Harada, N. Iwamoto, S. Chiba, and T. Kajino
Measurement of the isomer production ratio for the 112Cd(n,γ)113Cd
reaction using neutron beams at JPARC
Phys. Rev. C 94 055803-1-6 (2016)
Y. Sakaguchi, H. Asaoka, Y. Uozumi, Y. Kawakita, T. Ito, M. Kubota, D.
Yamazaki, K. Soyama, G. Sheoran, and M. Mitkova
Processes of silver photodiffusion into Ge-chalcogenide probed byneutron reflectivity technique
Physica Status Solidi (a) Applications and Materials Science 213
1894-1903 (2016)

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N. Tomioka, T. Okuchi, N. Purevjav, J. Abe, and S. Harjo
Hydrogen sites in the dense hydrous magnesian silicate phase E: apulsed neutron powder diffraction study
Physics and Chemistry of Minerals 43 267-275 (2016)

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S. Fujiwara, K. Araki, T. Matsuo, H. Yagi, T. Yamada, K. Shibata, and H.
Mochizuki
Dynamical Behavior of Human α-Synuclein Studied by Quasielastic
Neutron Scattering
PLoS ONE 11(4) e0151447 (2016)

81

81

A. Izumi, Y. Shudo, T. Nakao, and M. Shibayama
Cross-link Inhomogeneity in Phenolic Resins at the Initial Stage ofCuring Studied by 1H-pulse NMR Spectroscopy and Complementary
SAXS/WAXS and SANS/WANS with a Solvent-swelling Technique
Polymer 103 152-162 (2016)

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R. Mashita, H. Kishimoto, R. Inoue, A. Koda, R. Kadono, and T.
KanayaDynamics of polybutadiene reinforced with unsaturated carboxylatestudied by muon spin relaxation (mSR)
Polymer 105 510-515 (2016)
S. Shimomura, M. Inutsuka, N. L. Yamada, and K. Tanaka
Unswollen layer of cross-linked polyisoprene at the solid interface

MLF Operations in 2016

Polymer 105 526-531 (2016)
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84

S. Imajo, K. Mishima, M. Kitaguchi, Y. Iwashia, N. L. Yamada, M. Hino,
T. Oda, T. Ino, H. M. Shimizu, S. Yamashita, and R. Katayama
Pulsed UCN Production using a Doppler Shifter at JPARC
Prog. Theor. Exp. Phys. 2016 013C02 (2016)85

85

A. Mukunoki, T. Chiba, Y. Benino, and T. Sakuragi
Microscopic structural analysis of lead borate-based glass
Progress in Nuclear Energy 91 339–344 (2016)

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G. Yoshida, K. Ninomiya, M. Inagaki, W. Higemoto, N. Kawamura, K.
Shimomura, Y. Miyake, T. Miura, M. K. Kubo, and A. Shinohara
Chemical environmental effects on muon transfer process in lowpressure H2+CO and H2+CO2 gases
RADIOISOTOPES 65 113-118 (2016)

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Editorial Board

MLF Annual Report 2016

Editorial Board - MLF Annual Report 2016

Chief Editor

Kenji M. Kojima

Kenichi Oikawa
Neutron Science Section

Muon Science Section

Naritoshi Kawamura

Joseph Parker

Muon Science Section

CROSS

Kenji Mishima

Kaoru Sakasai

Neutron Science Section

Neutron Instrumentation Section

Takashi Naoe

Taiki Tominaga

Neutron Source Section

CROSS

Kazue Tanaka
Neutron Science Section and Muon Science Section

176

J-PARCHigh Energy Accelerator Research Organization (KEK)
Japan Atomic Energy Agency (JAEA)

J-PARC ANNUAL REPORT 2016

Japan Proton Accelerator Research Complex

Vol.2: Materials and Life Science Experimental Facility

http://j-parc.jp/
Materials and Life Science Division
J-PARC Center

http://j-parc.jp/MatLife/
http://www.cross-tokai.jp/

J-PARC 17-07

J-PARC Center

Comprehensive Research Organization for Science and Society