J-PARC
ANNUALREPORT2 O 1 7Vol.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 18-04

MLF Annual Report 2017

Preface

PrefaceToshiji Kanaya
Division Head of Materials and Life Science Division, MLF
In fiscal year 2017, the operation of the Material and Life Science Experimental Facility (MLF) started with theneutron production mercury target (#2), which had an older design without helium bubbling system. The power was
limited to 150 kW, although the operation was very stable. In the summer maintenance period, we replaced the target
with a new one (#8) with helium bubbling system. On October 24, after the summer maintenance period, the operation started with power of 300 kW , which was increased to 400 kW in the beginning of 2018 to continue the stable
operation to the end of fiscal year 2017. The beam availability to the scheduled beam time in fiscal year 2017 was 92%.
The operation of the muon production target, replaced with a rotating design target in 2014, continued without major
problems. The great efforts of J-PARC MLF staffs ensured the stable operations of the neutron and muon targets. The
scientific results from the delivered beam of neutrons and muons, as well as the status report of the beamlines, spectrometers and the research environment, are provided in this Annual Report. In the coming years, we will make efforts
to achieve beam power of 1 MW, while keeping the operations stable.
Many activities were held in MLF in 2017. One of the most important international meetings was the 2nd collaboration workshop between the European Spallation Source (ESS) and J-PARC, held at ESS in Lund on January 18 and 19,
2018. The meeting was carried out under the Memorandum of Collaboration (MoC) in the field of spallation neutronrelated development between ESS and J-PARC. The extension signing ceremony of the MoC was held in Stockholm
on July 7, 2017 in the presence of Sweden’s Prime Minister Stefan Löfven and the Japanese Prime Minister Shinzō Abe.
Ten delegates from the J-PARC Center participated in the workshop to exchange information about management of
the organization, radiation and general safety issues, accelerator technology, neutron source, and neutron instruments
and data management. An important domestic meeting was the Quantum Beam Science Festa, which is a conference
for users of J-PARC MLF, also, the Institute of Materials Structure Science (IMSS) of High Energy Accelerator Research
Organization (KEK) was held in Mito, Ibaraki Prefecture, on March 2, 3 and 4, with 524 participants, to discuss the MLF
facility status, scientific results and developments, and the future plans for MLF. The details of the meetings are presented in the Annual Report.
Education of a new generation and invitation of new users are crucial for the sustainable development and research activities of the facility in the future. The 2nd Neutron and Muon School was jointly organized with the 9th AONSA
neutron school from November 16 to 20. The participants in the school included 49 young researchers and graduate
students from 13 countries: Korea, India, Australia, Thailand, China, Indonesia, Malaysia, Nepal, New Zealand, Russia,
Taiwan, Vietnam and Japan. They enjoyed neutron and muon lectures, a site tour to J-PARC and JRR-3, and handsexperiments with neutron and muon instruments at MLF.
I would like to introduce the reader to the research highlights and status reports of MLF in the fiscal year 2017 inthis annual report. For the development of neutron and muon science and technology in J-PARC MLF we will do ourbest in the future.

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

MLF Annual Report 2017

Preface

Hideaki Yokomizo
Director, CROSSCROSS has served as a Registered Institution of specific neutron beam Facilities of J-PARC appointed by theGovernment since 2011. We have been supporting the appropriate user program operation 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. In 2017, the number of science
coordinators at CROSS increased to four in order to encourage the industrial use and to help the management of theIndustrial Users Society for Neutron Application.
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 2017, we had to start with beam power of
150 kW using a spare target vessel, which had no protection from the pitting damage on the beam window. The beam
power was increased to 300–400 kW after the summer shutdown when a new target vessel equipped with pitting
protection system was installed. We accomplished a stable and highly reliable machine operation, which reached over
90% of the planned users’ time.
The special program for New User Promotion (NUP) started in 2016 to provide sufficient guidance and assistancefor scientists who are new to the neutron research. NUP has a preferential beam time allocation to first-time or novice
users in order to learn how to use the neutron facility. NUP is expected to cultivate new scientific field by conducting
their first experiments successfully with sufficient and generous support by our staffs. Another special program, theElementary Strategy Initiative, was completed successfully this year. In the 2017B proposal round, a new program
called Long-Term Proposal was started to select and approve the experimental plans that will be carried out in a periodof three years. Complementary Use is a program that encourages and facilitates the complementary and collaborativeuse 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 the 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
Crystal Structure of B-Site Defected 12L-Perovskites Ba2La2MW2O12 (M = Mn, Co, Ni, Zn) ······················································

2

Mechanical Synthesis and Structural Properties of the Fast Fluoride-Ion Conductor PbSnF4 ···············································

5

Inverse Pole Figure Mapping of Crystalline Grains by Bragg-dip Neutron Transmission Imaging ·······································

8

Stress Partitioning Behavior in Pearlitic Steels ········································································································································ 11
Behavior of Hydrogen in the Early Stage of Earth’s Evolution ··········································································································· 14
The Effect of Planar Rattling on Lattice Thermal Conductivity in LaOBiS2−xSex ··········································································· 17
Vibrational States of Atomic Hydrogen in Bulk and Nanocrystalline Palladium ········································································· 19
Dynamics of a Disease-causing Mutant of Troponin Studied by Quasielastic Neutron Scattering ····································· 21
Quasielastic Neutron Scattering Study of Microscopic Dynamics in Co-Crosslinked Rubber ··············································· 23
Quantitative Evaluation of Deformed Electron Density Distribution of Polydiacetylene Crystal on the Basisof the Organized Combination of X-ray and Neutron Diffraction Data ··················································································· 26
Role of Molecular Weight in Shish-Kebab Formation ··························································································································· 29
Structure and Mechanical Properties of Elastomer Thin Films Bound to Carbon Interface ···················································· 31
Analysis of Carbon Polygons by High-Resolution Pair Distribution Function Obtained from Neutron Diffraction ······· 34
Linking Spin-fluctuations in Ba0.75K0.25Fe2As2 to Electron Correlations ···························································································· 37
Tomonaga-Luttinger Liquid State in the Inequilateral Diamond-Chain Compound K3Cu3AlO2(SO4)4 ································ 40
Magnetic Excitations from Two-Dimensional Interpenetrating Cu Framework in Ba2Cu3O4Cl2 ············································ 43
Mono-Chiral Helimagnetism in CsCuCl3 ···················································································································································· 46
Polarized Neutron Reflectometry Probe of the Structural and Magnetic Interfacial Inhomogeneityof Epitaxial ε-Fe2O3/GaN Films ································································································································································· 48
3D Polarimetric Neutron Tomography (3DPNT) ····································································································································· 50First Muon Acceleration Using a Radio-Frequency Accelerator ········································································································ 52
μSR Study of Sr2−xLaxIrO4 Synthesized by Mechanical Alloying ········································································································· 54
Development of Ferromagnetic Fluctuations in Heavily Overdoped (Bi,Pb)2Sr2CuO6+δ Copper Oxides ···························· 56

Neutron Source
Progress of the Neutron Source Section ···················································································································································· 60
Progress of the Target Beam Window Cutting ········································································································································· 62
R&D of Electron Beam Welding on Moderator Vessel Fabrication ··································································································· 65
Replacement of the Proton Beam Window ·············································································································································· 67

Neutron Science
Neutron Science Section ················································································································································································· 70
BL01: 4D-Space Access Neutron Spectrometer 4SEASONS ················································································································ 72
Current Status of BL02 DNA in 2017···························································································································································· 74
Current Status and Future Plans of iBIX ····················································································································································· 76
Current Status of Accurate Neutron-Nucleus Reaction Measurement Instruments, ANNRI (BL04) ····································· 78
Status of Fundamental Physics Beamline BL05 (NOP) 2017 ··············································································································· 80
BL06: Commissioning Status of VIllage of Neutron ResOnance Spin Echo Spectrometers (VIN ROSE)······························ 82
Commissioning of a New 4K Cryostat at S-HRPD ··································································································································· 84
Current Status of Special Environment Powder Diffractometer, SPICA ·························································································· 87
BL10: NOBORU ···································································································································································································· 90
BL11: Development of High-P Experiments Using a Paris-Edinburgh Cell ··················································································· 92
Status of High Resolution Chopper Spectrometer, HRC, in FY2017 ································································································ 94
BL14 AMATERAS ································································································································································································· 96
Upgrading TAIKAN ····························································································································································································· 98
0.1 mm Focusing Elliptic Mirror with Large Area for Neutron Reflectometry at BL16 ······························································ 99
BL17: Current Status of Polarized Neutron Reflectometer, SHARAKU ···························································································· 102
Status of SENJU 2017 ························································································································································································ 104
Status of TAKUMI, BL19 ···················································································································································································· 106
The current status of the versatile neutron diffractometer, iMATERIA···························································································· 108
Status of the High Intensity Total Diffractometer (BL21, NOVA) ······································································································· 110
Present Status of the Energy-Resolved Neutron Imaging System RADEN ···················································································· 112
Commissioning Started on New Spectrometer POLANO ··················································································································· 115
Development of an in-situ Polarized 3He Neutron Spin Filter for POLANO ··················································································· 118
Development of the Magnetic Field Environment System for Polarized Neutron Experiments on POLANO ·················· 120
Improvement of the Computing Environment System on POLANO ······························································································ 122
Sample Environment at MLF ·········································································································································································· 124
Development of a Remote Data Access Based on the Cloud Environment·················································································· 126“Live Data Reduction” Project ········································································································································································ 128
Bump Cathode Element for Two-Dimensional Neutron Detector ··································································································· 131

Muon Science
Status of J-PARC MUSE ····················································································································································································· 134
Present Status of M2 Tunnel, the Central Part of MUSE························································································································ 136
Current Status of μSR Set Up at D1 ······························································································································································ 138
Status of D Line (D2 Area) Commissioning ··············································································································································· 139
Ultra Slow Muon Beam Commissioning ···················································································································································· 140
Completion of ARTEMIS spectrometer at S1 experimental area ······································································································ 141
H-Line Construction – Recent Progress······················································································································································ 144

MLF Safety
Research Safety ··································································································································································································· 148

MLF Operations in 2017
Beam Operation Status at MLF······································································································································································ 152
Users at the MLF ································································································································································································· 153
MLF Proposals Summary – FY2017 ······························································································································································ 154
MLF Division Staff 2017···················································································································································································· 156
CROSS Staff 2017 ································································································································································································ 159
Proposals Review System, Committees and Meetings ························································································································· 161
Workshops, Conferences, Seminars and Schools in 2017 ··················································································································· 164
Award List ············································································································································································································· 167
MLF Publication 2017 ······················································································································································································· 168

Editorial Board - MLF Annual Report 2017················································································································································ 174

Organization Chart

MLF Annual Report 2017

Organization Chart

Organizaon Chart of
J-PARC Center
Director, J-PARC Center

Organizaon Chart of
CROSS
CROSS is “Registered Instuon for facility Use
Promoon” for the public-access neutron
beam facilies at J-PARC.

Deputy Director (JAEA, KEK, Safety)
President
Safety Division
CROSS Head Oﬃce
Accelerator Division

Research Center for
Science and Society

Materials & Life Science Division

Director, Neutron Scienceand Technology Center

Neutron Source Secon

Science Coordinators

Neutron Science Secon

Safety Division

Neutron InstrumentaonSeconAdministraon Division

Muon Science SeconTechnology Development
SeconUlizaon Promoon
Division
Neutron R&D DivisionParcle & Nuclear Physics Division
Nuclear Transmutaon Division

The Role of CROSS
Cryogenics SeconInformaon System SeconAdministraon Division

Users Oﬃce

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 2017

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 2018

1m

Muon and Neutron Instruments
MLF Annual Report 2017

Research and Development
Highlights

Research and Development Highlights

MLF Annual Report 2017

Crystal Structure of B-Site Defected 12L-Perovskites
Ba2La2MW2O12 (M = Mn, Co, Ni, Zn)
1. Introduction
Low-dimensional magnetic materials have attracted a great deal of interest because of their anomalous
magnetic properties at low temperatures. In particular,
the antiferromagnetism on the two-dimensional triangular lattice has been extensively studied from the
aspects of geometrical frustration and quantum spin
liquid. In order to find further interesting magnetic behaviors, it is absolutely essential to explore new compounds with a triangular arrangement of magneticions.
Recently, we have focused on the Ba2La2MW2O12(M = Co, Mn, Ni, Zn). They have a B-site defected
12L-perovskite structure (Fig. 1(a)), in which the Mions form a two-dimensional triangular lattice in abplane. This structural feature is very similar to that of
the 6L-perovskites Ba2MSb2O9 whose low-dimensional
magnetic properties are attracting significant attention [1-3]; thus, the Ba2La2MW2O12 could be a new series of compounds showing further interesting physicalproperties.
For the crystal structure of Ba2La2MW2O12 and isostructural compounds, some structural models havebeen proposed [4-7], but have not yet been clearly determined. Therefore, we have carried out the powder
neutron diffraction measurements.

(a)

2. Experiments
The Ba2La2MW2O12 (M = Co, Mn, Ni, Zn) were prepared as polycrystalline samples by the solid-state
reaction. BaCO3, BaO, La2O3, CoO, MnO, NiO, ZnO andWO3 were used as starting materials. The mixture waspressed into pellets, and heated at 900°C for 12 h,
1100°C for 12 h, and 1200°C for 12 h × 2-3 in air (M =Co, Ni, Zn) or at 1200°C for 3 h in an evacuated silica ampoule and quenched by liquid nitrogen (M = Mn).
The powder x-ray diffraction (XRD) measurements
were performed at room temperature in the range 10°≤ 2θ ≤ 120° using a 2θ step size of 0.02° with Cu-Kα radiation on a Rigaku MultiFlex diffractometer.
The powder neutron diffraction (ND) profiles werecollected at room temperature. For M = Ni, the ND measurement (the neutron wavelength λ = 1.84843 Å) was
performed by HERMES [8], installed at the JRR-3M reactor in Japan Atomic Energy Agency (JAEA), Tokai. For
M = Zn, the time-of flight neutron diffraction (TOF-ND)
by Super HRPD (BL08), installed at the Material andLife Science Experimental Facility (MLF) of the Japan
Proton Accelerator Research Complex (J-PARC). The
data were analyzed by the Rietveld technique by using the program RIETAN-FP [9] for both XRD and ND,
and the Z-code program package [10,11] for the TOFND. The crystal structures were drawn by the VESTA
program [12].

(b)

MO6

WO6
La
Ba
Ba/La

c
a

a

Figure 1. Schematic crystal structures of Ba2La2MW2O12 and comparison between the two structural models:(a) space group R–3m with a disordered one in earlier reports and (b) R–3 with an ordered A-sitearrangement in this study.

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MLF Annual Report 2017

3. Results and discussion
The title compounds Ba2La2MW2O12 (M = Mn, Co, Ni,
and Zn) were prepared as polycrystalline samples. TheirXRD data were well indexed by a rhombohedral unit cell(a ~ 5.7 Å, c ~ 27.4 Å). The Rietveld analysis was carriedout using the R-3m model proposed for Ba2La2MW2O12
and isostructural compounds [4-8] and this model wasa good fit for the data; however, we have found a bettermodel based on the results of neutron diffraction measurements which will be described below.
We have performed the neutron diffraction measurements for Ba2La2MW2O12 (M = Ni and Zn). Figure 2(a)shows the TOF-ND profile for Ba2La2ZnW2O12 and thecalculated profile obtained from the above R-3m model. It was found that this structural model was obviously
not suitable for the observed data. The reason for thediscrepancy was that the model was not suitable, i.e.,there are differences that cannot be well distinguishedin the XRD measurements, such as the space group,ordered/disordered arrangement of Ba/La ions, possibility of oxygen ion defects, and so on. Therefore, we
tried to analyze the ND data by using many structuralmodels, and finally found that a model with the spacegroup R-3 was adequate. The calculated profile is plotted in Fig. 2(b), which shows a good agreement withthe observed one. This model also gives good results
for the ND data for Ba2La2NiW2O12 and XRD data for allcompounds.

Research and Development Highlights

The structural parameters for Ba2La2ZnW2O12 were
determined by using the R-3 model, and the crystal
structures for both R-3m (old) and R-3 (new) models
are illustrated in Fig. 1. Both structures have the same
unit cell dimension but reflecting the loss of mirror
plane from R-3m to R-3, the crystallographic sites ofoxygen ions (O1 and O2) are different, which brings
about the tilting of connection of MO6 and WO6 octahedra. In addition, two kinds of A-site cations, Ba2+and La3+, adopt a fully ordered arrangement unlike
some earlier reports [4-7], and there are no oxygen
defects within the standard deviation. The BVS values
calculated from the structural parameters suggestthat the valence states of cations are represented as
Ba2+2La3+2M2+W6+2O12. In this crystal structure, the magnetic M2+ ions form a triangular lattice in ab plane, andeach plane is magnetically separated (~9 Å) by nonmagnetic layers consisting of Ba2+, La3+, and W6+ ions.
Therefore, in the view of the magnetism, the B-site defected 12L-perovskites Ba2La2MW2O12 can be regarded
as ideal candidates for the two-dimensional magnetically frustrated system.
Afterwards, the magnetic, thermal, and opticalproperties were measured for the title compounds, andthe DFT calculations based on above structural data
were carried out. The details have been published inanother paper [13].

Intensity (arb. unit)(a) R-3m model

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

1.5

2.0

2.5

3.0

3.5

4.0

(b) R-3 model

0.5

1.0

d (Å)
Figure 2. Time-of-flight powder neutron diffraction profiles for Ba2La2ZnW2O12, calculated by using (a) R–3m and(b) R–3 models. The blue line indicates the difference between the observed and calculated profiles.

3

Research and Development Highlights

MLF Annual Report 2017

4. Conclusion
The neutron diffraction measurements were
performed for the B-site defected 12L-perovskites
Ba2La2MW2O12 (M = Ni and Zn), and it was found thatthey adopt not the R-3m structure proposed in earlier
works but the R-3 one. Their detailed structural parameters were determined, and these results indicated thatthe magnetic M2+ ions form an ideal two-dimensional
triangular lattice.
References[1] Y. Doi, Y. Hinatsu, and K. Ohoyama, J. Phys.:
Condens. Matter, 16, 8923–8935 (2004).
[2] H.D. Zhou, E.S. Choi, G. Li, L. Balicas, C.R. Wiebe, Y.
Qiu, J.R.D. Copley, and J.S. Gardner, Phys. Rev. Lett.,
106, 147204 1–4 (2011).
[3] J.G. Cheng, G. Li, L. Balicas, J.S. Zhou, J.B.
Goodenough, C. Xu and H.D. Zhou, Phys. Rev. Lett.,
106, 197204 1–4 (2011).
[4] S. Kemmler-Sack, Z. Anorg. Allg. Chem., 461, 142–145 (1980).
[5] H.J. Rother, A. Fadini, and S. Kemmler-Sack, Z.

Anorg. Allg. Chem., 463, 137–143 (1980).
[6] R. Yu, M. Li, N. Xie, T. Wang, N. Xue, J. Am. Ceram.
Soc., 98, 3849–3855 (2015).
[7] R. Rawl, M. Lee, E.S. Choi, G. Li, K.W. Chen, R.
Baumbach, C.R. dela Cruz, J. Ma, and H.D. Zhou,
Phys. Rev. B, 95, 174438 1–9 (2017).
[9] K. Ohoyama, T. Kanouchi, K. Nemoto, M. Ohashi, T.
Kajitani, Y. Yamaguchi, Jpn. J. Appl. Phys., 37, 3319–
3326 (1998).
[10] R. Oishi, M. Yonemura, Y. Nishimaki, S. Torii, A.
Hoshikawa, T. Ishigaki, T. Morishima, K. Mori, T.
Kamiyama, Nucl. Instrum. Methods Phys. Res. A,
600, 94–96 (2009).
[11] R. Oishi-Tomiyasu, M. Yonemura, T. Morishima, A.
Hoshikawa, S. Torii, T. Ishigaki, T. Kamiyama, J. Appl.
Crystallogr., 45, 299–308 (2012).
[12] K. Momma and F. Izumi, J. Appl. Crystallogr., 41,
653–658 (2008).
[13] Y. Doi, M. Wakeshima, K. Tezuka, Y.J. Shan, K.
Ohoyama, S. Lee, S. Torii, T. Kamiyama, and Y.
Hinatsu, J. Phys.: Condens. Matter, 29, 365802 1–11
(2017).

Y. Doi1, M. Wakeshima1, K. Ohoyama2, S. Lee3, S. Torii3, T. Kamiyama3, and Y. Hinatsu1
Department of Chemistry, Faculty of Science, Hokkaido University; 2Graduate School of Science and Engineering, Ibaraki University;
3Neutron Science Section, Materials and Life Science Division, J-PARC Center, Institute of Materials Structure Science, KEK

1

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MLF Annual Report 2017

Research and Development Highlights

Mechanical Synthesis and Structural Properties of theFast Fluoride-Ion Conductor PbSnF4
1. Introduction
The all-solid-state rechargeable battery is a key
technology for large-scale applications such as electricvehicles, plug-in hybrid vehicles, and electrical energystorage systems in future smart grids. The use of solid
electrolytes is critical for improving the battery performance parameters: energy density, power capacity,
lifespan, and reliability. In the last decade, fluoride-ion
batteries (FIBs) have attracted much attention as alternative candidates for lithium-ion batteries, nickel-metal
hydride batteries, sodium-ion batteries, and so on [14]. The fluoride anion (F−) is considerably stable as acharge transfer ion in FIBs because it exhibits the highest electronegativity (3.98) of all elements. The chemical reaction of the fluoride anion with metals leads tothe formation of metal fluorides, which can release several electrons per metal atom. This masks the possibility
that the theoretical energy densities of FIBs outperform those of lithium-ion batteries. All-solid-state FIBs
based on the “metal (anode)/metal fluoride (cathode)”pair have been assembled experimentally and characterized using fluoride-ion conductors, for example,
La1−xBaxF3−x (as a solid electrolyte) [6]. The ionic conductivity of La0.9Ba0.1F2.9 (2.8 × 10−4 S/cm at 433 K) is sufficiently high, but not sufficiently high enough at room
temperature (RT). Therefore, all-solid-state FIBs basedon a metal/metal fluoride pair can work only at elevatedtemperatures. For the realization of all-solid-state FIBs
at RT, it is very important to explore new fast fluorideion conductors.
PbSnF4 exhibits the highest ionic conductivity(≈10−3 S/cm at RT) among the proposed fluoride-ion
conductors [7-9]. In spite of its narrow electrochemical stability window, the superior ionic conductivity
is also fascinating from the practical point of view. It
has been reported that PbSnF4 can be synthesized bymechanical milling (MM) of the two starting materials: SnF2 and α-PbF2 [12-14]. The ionic conductivity of
PbSnF4 obtained by MM is ≈10−3 S/cm at RT, which iscomparable to that obtained by the two conventional
methods. In the XRD measurements, several allotropic
forms such as β-PbSnF4 (tetragonal system, space group= P4 / nmm) and γ-PbSnF4 (fluorite-type structure, space–group: Fm3m) have been observed. However, the detailed crystal structure and the fluoride-ion conduction
mechanism are still unclear.

In the present work, γ-PbSnF4 was synthesized by
MM at RT, and β-PbSnF4 was obtained by aging it at
473 K. We discuss the fluoride-ion conduction mechanism in γ- and β-PbSnF4 from structural point of view.
2. Crystal structures of γ- and β-PbSnF4
Crystal structure analysis for γ- and β-PbSnF4 was
performed using neutron diffraction data. The neutron diffraction data were collected at BL09 (SPICA) in
MLF. The Rietveld refinement patterns for γ-PbSnF4 areshown in Fig. 1. First, the structure parameters were refined on the basis of the fluorite-type structure (space–group: Fm3m) with a single Sn/Pb site and a single F site(henceforth termed “Fγ(1) normal site”). Note that the
Sn/Pb atomic ratio is 1:1. As shown in Fig. 1(a), the fluoride ions were located at the four-fold coordinated sites(i.e., Fγ(1)[Sn/Pb]4 tetrahedral units) only. While a fairly
good agreement was obtained between the observedand calculated intensities, this was insufficient to refine
several Bragg reflections, such as (200) and (311). Next,
we employed an additional F site in the general position(henceforth termed “Fγ(2) interstitial site”), being consistent with the interstitial sites of PbF2 [15]. The change ofthe structure model achieved a meaningful improvement (see, Fig. 1(b)). In the figure, fluoride ions werelocated at the six-fold coordinated sites with off-center
displacement (i.e., Fγ(2)[Sn/Pb]6 octahedral units) in addition to the four-fold coordinated sites (i.e., Fγ(1)[Sn/Pb]4 tetrahedral units). The occupancies (g) at the Fγ(1)and Fγ(2) sites were less than 1, meaning that vacancies
exist at both sites. The ratio of the number of fluoride
ions at Fγ(1) to those at Fγ(2) was approximately 5:3. This
indicates that the fluoride ions have a preference for theFγ(1) normal site over the Fγ(2) interstitial site.
Figure 2 shows the Rietveld refinement patterns of
β-PbSnF4. The crystal structure of β-PbSnF4 was refinedon the basis of the tetragonal system (space group:
P4 / nmm). The model assumed a single Sn site, a single
Pb site, and three F sites: Fβ(1), Fβ(2), and Fβ(3). The Fβ(1)and Fβ(3) sites correspond to the F sites between Sn andPb layers (i.e., –SnPb–), and the Fβ(2) site corresponds
to the F site between the Pb layers (i.e., –PbPb–). The
F site between Sn layers (i.e., –SnSn–) was omitted inour refinement due to the Sn2+ lone pair [10, 11]. In fact,
the g value was close to zero when we assumed the Fsite between Sn layers together with the Fβ(1), Fβ(2),5Research and Development Highlights

MLF Annual Report 2017

1.0
0.8
311

0.6
0.4

Sn / Pb

200

Normalized Intensity

(a)

0.2

γ

F (1)

0.0
−0.2
1

2

3

4

d/Å

1.0
0.8

311

0.6
0.4

200

Normalized Intensity

(b)

0.2

Sn / Pb
γ

F (1)
γ
F (2)

0.0
−0.2
1

2

3

4

d/Å

Normalized Intensity

Figure 1. The crystal structure refinement for γ-PbSnF4 using neutron diffraction data

1.0
0.8
0.6
0.4
0.2

Sn
Pb
β
F (1)
β
F (2)
β
F (3)

0.0
−0.2
−0.4
1.0

1.5

2.0
2.5
d/Å

3.0

3.5

Figure 2. The crystal structure refinement of β-PbSnF4 using neutron diffraction data.

and Fβ(3) sites in the preliminary refinements. The Fβ(1)and Fβ(3) sites were found to be deficient, whereas theFβ(2) site was fully occupied, so that the g of the Fβ(2)site was fixed at unity in further refinements. The crystal
structure of β-PbSnF4 is illustrated in Fig. 2. The Fβ(1) andFβ(3) sites had g < 1, while the Fβ(2) site exhibited g = 1.
The ratio of the number of fluoride ions at Fβ(1), Fβ(2),and Fβ(3) was approximately 5:4:7. Thus, we concluded that fluoride ions prefer the Fβ(3) site (henceforth
termed “Fβ(3) interstitial site”), followed by the Fβ(1) site(henceforth termed “Fβ(1) normal site”), and the Fβ(2)site (henceforth termed “Fβ(2) normal site”). It is worth
noting that the Fβ(1) and Fβ(2) normal sites are the fourfold coordinated sites and the Fβ(3) interstitial site is a
six-fold coordinated site with off-center displacement(Fig. 2).

6

3. Fluoride ion pathway
Figure 3 presents the crystal structures of γ- and
β-PbSnF4, viewed down the a + b diagonal direction
and the a-axis, respectively. The relation between thelattice parameters of γ- and β-PbSnF4 is as follows: aβ ≈—(√ 2/2)aγ and cβ ≈ 2aγ. In the figure, the atomic arrangement of γ-PbSnF4 is similar to that of β-PbSnF4, although
the Fγ(1) normal site occurs as two sites: the Fβ(1) andFβ(2) normal sites, and the Fγ(2) interstitial site becomes
the Fβ(3) interstitial site. In particular, the number of fluoride ions at the F interstitial site appreciably increasedby the γ-to-β phase transition: 38.1% at Fγ(2) to 43.9% at
Fβ(3), from the g values for each F site.
In β-PbSnF4, the Fβ(2) normal site is fully occupied,
whereas the Fβ(1) normal site and the Fβ(3) interstitialsite are partially occupied, when we assume the absence of fluoride ions between the Sn layers due toMLF Annual Report 2017

(a)

(b)

γ-PbSnF4

Sn/Pb
Fγ(1)
Fγ(2)
Sn/Pb

Sn
Fβ(1)
Fβ(3)
Pb

Fγ(1)

Fβ(2)

β-PbSnF4

Figure 3. Crystal structures of (a) γ-PbSnF4 and (b) β-PbSnF4,
viewed down the a + b diagonal direction and thea-axis. The Fγ(1) normal site is divided into two sites:
the Fβ(1) and Fβ(2) normal sites; and the Fγ(2) interstitial site becomes the Fβ(3) interstitial site.

the Sn2+ lone pair. According to the vacancy diffusion
mechanism, it is sufficient to say that the “–Fβ(1)–Fβ(3)–Fβ(3)–Fβ(1)–” zigzag network with fluoride ions and vacancies on the ab-plane facilitates the two-dimensional
fast fluoride-ion conduction and there is no space available for migrating fluoride ions via the Fβ(2) normal sites
along the c-axis.
The electrical conductivity of β-PbSnF 4 (1.6 ×
10−3 S/cm at 298 K) is relatively higher than that of
γ-PbSnF4 (3.4 × 10−4 S/cm at 298 K). In the vacancy diffusion mechanism, σ can be represented by the following equation: σ = (Ze)nμ, where Ze is the valenceof the ion carrier (Z = 1 for Li+), n is the effective carrier
concentration, and μ is the mobility of ions. It is worth
noting that the “–Fβ(1)–Fβ(3)–Fβ(3)–Fβ(1)–” network isformed between the single Sn and the single Pb layers,
whereas the “–Fγ(1)–Fγ(2)–Fγ(2)–Fγ(1)–” network occurs
between the mixed Sn/Pb layers (see, Fig. 3). It seems
that the ordered framework of the single Sn and Pb layers in β-PbSnF4 plays an important role in improving μ(or σ). Furthermore, n depends directly on the numberof fluoride ions at the F interstitial site: 38.1% at Fγ(2) to43.9% at Fβ(3). It is most likely that n in the “–Fβ(1)–Fβ(3)–Fβ(3)–Fβ(1)–” network is optimized, compared with thatin the “–Fγ(1)–Fγ(2)–Fγ(2)–Fγ(1)–” network. More details
are provided in paper [16].

Research and Development Highlights

4. Acknowledgement
TOF-ND experiments were approved by the Neutron
Scattering Program Advisory Committee of IMSS, KEK(Proposal No. 2014S10). This work was predominantly
supported by the Research and Development Initiative
for Scientific Innovation of New General Batteries 2(RISING 2) project, No. P16001, from the New Energy
and Industrial Technology Development Organization(NEDO), Japan. This work was partially supported by aGrant-in-Aid for Science Research (C), No. 15K06483,
from the Japan Society for the Promotion of Science(JSPS).
References[1] G.G. Amatucci, N. Pereira, J. Fluorine Chem. 128(2007) 243.
[2] N.I. Sorokin, B.P. Sobolev, Crystallogr. Rep. 52 (2007)
870.
[3] L.N. Patro, K. Hariharan, Solid State Ionics 239 (2013)41.
[4] C. Rongeat, M.A. Reddy, et al., ACS Appl. Mater.
Interfaces 6 (2014) 2103.
[5] F. Gschwind, G. Rodriguez-Garcia, et al., J. Fluorine
Chem. 182 (2016) 76.
[6] M.A. Reddy, M. Fichtner, J. Mater. Chem. 21 (2011)17059.
[7] J.M. Réau, C. Lucat, et al., Mat. Res. Bull. 13 (1978) 877.
[8] S. Vilminot, G. Perez, et al., Solid State Ionics 2 (1981)
87.
[9] R. Kanno, S. Nakamura, et al., Mat. Res. Bull. 26 (1991)
1111.
[10] G. Denes, Y.H. Yu, et al., Solid State Ionics 104 (1993)239.
[11] M. Castiglione, P.A. Madden, et al., J. Phys. Condens.
Matter 17 (2005) 845.
[12] A. Collin, G. Dénès, D.L. Roux, et al., Int. J. Inorg.
Mater. 1 (1999) 289.
[13] S. Suda, T. Eguchi, J. Kuwano, Key Eng. Mater. 181–
182 (2000) 203.
[14] M. Uno, M. Onitsuka, et al., Solid State Ionics 176(2005) 2493.
[15] K. Koto, H. Schulz, R.A. Huggins, Solid State Ionics 1(1980) 355.
[16] F. Fujisaki, K. Mori, et al., J. Solid State Chem.,
253(2017)287.

F. Fujisaki1, K. Mori2, M. Yonemura3,4, Y. Ishikawa3,4, T. Kamiyama3,4, T. Otomo3,4, E. Matsubara1, T. Fukunaga1 J. Suzuki1,2, Y. Inamura3,
T. Ito4, and T. Nakatani3
1
Ofﬁce of Society-Academia Collaboration for Innovation, Kyoto University; 2Institute for Integrated Radiation and Nuclear Science, Kyoto
University; 3Neutron Science Section, Materials and Life Science Division, J-PARC Center; 4Institute of Materials Structure Science, KEK

7

Research and Development Highlights

MLF Annual Report 2017

Inverse Pole Figure Mapping of Crystalline Grains by
Bragg-dip Neutron Transmission Imaging
1. Introduction
Mapping of crystalline grains and their crystal
orientations by using SEM-EBSD or X-ray diffraction
imaging is a powerful methodology for materials characterization. In general, neutrons have higher material
penetration ability than electrons and X-rays. Therefore,
analyses of bulk-averaged crystallographic information in a centimeter-sized polycrystalline material suchas steel are being performed by neutron diffraction
and Bragg-edge neutron transmission imaging [1].
Furthermore, recently, development projects of neutron diffraction imaging were launched using both
continuous [2] and pulsed [3] sources for the grain orientation analysis.
On the other hand, as described in this article, weare developing a grain orientation mapping method
based on pulsed neutron Bragg-dip transmission imaging [4]. This is because neutron transmission imaging
setup can achieve an imaging of large field-of-view withhigh spatial resolution around a few hundred micrometers. In addition, it is expected that Bragg-dip neutron transmission measurement for single crystal [5] isconvenient since the crystal-lattice direction along theneutron transmission direction can be deduced fromthe neutron wavelengths of Bragg-dips without sample
rotation [4]. This feature is efficient for imaging of grainorientation, even in the case of two-dimensional imaging. However, the orientation determination of eachgrain in a grain-overlapping material is quite difficult for
the least-squares fitting/refinement of a whole Braggdip pattern without a rough initial guess of crystallographic parameters of each single-crystal included in
the neutron transmission path. We developed a method to solve this difficulty.
In the present paper, we describe a new Bragg-dip
pattern analysis method, which can rapidly determine
the number of grains and their crystal-lattice directions
along the neutron transmission path. A demonstration
experiment applying this method was performed byusing a large-grained Si-steel plate at J-PARC MLF BL10“NOBORU”.
2. Experimental condition
Figure 1 shows a specimen photograph of 3.4wt%
Si-steel plate (BCC crystal structure, 5 mm thickness).
Grain boundaries can be observed on the surface with a8

6.90 cm

Field of viewThickness: 5 mm

6.75 cm

Figure 1. Photograph of the Si-steel specimen [1, 4].

naked eye. The grains have sizes ranging approximatelyfrom a millimeter to several centimeters. The observed
grain shapes were slightly different between the surface and the reverse face. This means that there are regions, where two or more stacked grains exist along thenormal direction of the plate.
During the experiment performed at NOBORU, theproton beam powers were 400 kW or 500 kW. The collimator ratio L/D was set at about 2400, and the neutron
flight path length was 14.26 m. In this experiment, a
GEM (gas electron multiplier) detector [6] was used formeasurements of position-dependent Bragg-dip neutron transmission time-of-flight spectra of the sample,
with an 800 μm pixel size. The distance between thesample and the detector was 4 cm. The measurement
time was about 7.2 hours for an open beam measurement and about 14.5 hours for a sample measurement,
respectively. Such a long time was required due to thelimitation in the counting rate of the detector.
3. Test of a new Bragg-dip pattern analysis method
Figure 2 shows an example of Bragg-dip neutrontransmission spectrum and an indexing result obtainedby the developed Bragg-dip pattern analysis method,
namely, the database matching method. An importantfeature of the developed analysis method is its speed
for determining the number of grains and their crystallattice directions along the neutron transmission path.
This method uses a database containing Bragg-dip
wavelength patterns about various crystal-lattice directions. Through the matching between wavelength

MLF Annual Report 2017

Spectrum from the most upper-right grain
Dip positions of the orientation [100 38 0]

0.9
0.8

0.5
0.4
0.3
0.20

0.25

(110)

0.6

(200) (101) (10-1)

0.7(211) (21-1)

Neutron transmission

1.0

0.30

0.35

0.40

0.45

Neutron wavelength / nm
Figure 2. Bragg-dip neutron transmission spectrum [4].

patterns of experimental Bragg-dips and the database,the most probable crystal-lattice direction along theneutron transmission direction is uniquely identified
for each grain.
The indexing result in Fig. 2 shows that the database matching method can reasonably determine thecrystal-lattice direction. This Bragg-dip transmission
spectrum is that of crystalline grain of the most upper right, and two integrated Bragg-dips are observed
at 0.213 nm and 0.268 nm. The former dip consists of

(a)

(b)

Research and Development Highlights

double dips of (211) and (21-1) according to the database matching and deepens in the experiment. The
latter dip consists of triple dips of (200) and (101) and(10-1) according to the database matching and becomes deeper in the experiment. Thus, there was nocontradiction between the experimental result and theanalysis result in terms of dip depth, although the dip
depth was not evaluated in the data analysis at all. It
seems that the crystal-lattice direction estimated by the
proposed method is correct.
4. Crystalline grain orientation imaging
Figure 3 shows inverse pole figure (IPF) maps ofthe crystalline grains included in the specimen. The
crystal-lattice directions indicated by IPF correspondto the normal direction of the plate (the neutron transmission direction). In Fig. 3 (a), “black” regions, except
for the most upper left, indicate the region, where two
grains are stacked along the neutron transmission path.
The crystal-lattice directions of such stacked grains arealso shown by Fig. 3 (b) and (c), respectively. In addition,note that these images can show the crystal-lattice directions of grains in the bulk or at the opposite surface,which cannot be detected by SEM-EBSD and X-ray diffraction imaging.

(c)5.90 cm

[111]

[001]
6.75 cm

6.75 cm[101]

6.75 cm

Figure 3. Inverse pole figure maps of bulk crystalline grains obtained by Bragg-dip neutron transmission imaging [4].

5. Conclusion and future works
We successfully demonstrated the IPF imaging ofbulk crystalline grains by combining the pulsed neutron
Bragg-dip transmission measurements and the newdata analysis method, which can rapidly and uniquely identify the crystal-lattice directions of each grain
along the neutron transmission path. This method will
provide new opportunities for the characterization ofcoarse grain-sized engineering materials, e.g. electromagnetic steels and turbine blades.
There are two issues for future research. One is crystal-lattice direction analysis along not only the normal
direction but also the perpendicular direction (full crystal orientation analysis). The other is real-space imaging
of grain structure with crystal orientation informationin three dimensions.
9Research and Development Highlights

MLF Annual Report 2017

References[1] H. Sato, J. Imaging 4 (2018) 7.
[2] S. Peetermans, A. King, W. Ludwig, P. Reischig and E.
H. Lehmann, Analyst 139 (2014) 5765-5771.
[3] A. Cereser, M. Strobl, S. A. Hall, A. Steuwer, R.
Kiyanagi et al., Sci. Rep. 7 (2017) 9561.

[4] H. Sato, Y. Shiota, S. Morooka, Y. Todaka, N. Adachi etal., J. Appl. Cryst. 50 (2017) 1601-1610.
[5] F. Malamud and J. R. Santisteban, J. Appl. Cryst. 49(2016) 348-365.
[6] S. Uno, T. Uchida, M. Sekimoto, T. Murakami, K.
Miyama et al., Phys. Procedia 26 (2012) 142-152.

H. Sato1, Y. Shiota2, S. Morooka3, Y. Todaka4, N. Adachi4, S. Sadamatsu5, K. Oikawa6, M. Harada7, S.Y. Zhang8, Y.H. Su9, T. Kamiyama1,
M. Ohnuma1, M. Furusaka1, T. Shinohara6, and Y. Kiyanagi2
1
Faculty of Engineering, Hokkaido University; 2Graduate School of Engineering, Nagoya University; 3Materials Sciences Research Center,
JAEA; 4Department of Mechanical Engineering, Toyohashi University of Technology; 5Graduate School of Science and Engineering,Kagoshima University; 6Neutron Science Section, Materials and Life Science Division, J-PARC Center; 7Neutron Source Section, Materials
and Life Science Division, J-PARC Center; 8Neutron Science and Technology Center, CROSS; 9Technology Development Section, Materials
and Life Science Division, J-PARC Center10

MLF Annual Report 2017

Research and Development Highlights

Stress Partitioning Behavior in Pearlitic Steels
1. Introduction
Pearlitic steels constitute a significant class ofcarbon steel because of their industrial applications,besides, their combined structure induces interesting mechanical properties. In situ neutron diffraction
measurements during deformation have revealed thesuperposition of various kinds of internal stresses for
pearlitic steels. Phase stress is accompanied by misfit
plastic strains between the ferrite and cementite phases both for ferrite-cementite lamellar [1] or cementitespheroidized specimens [2]. Furthermore, plastic flowin the individual ferrite grain depends on the crystallographic orientation, hkl plane, with regard to the tensile direction, as a result of the Schmid factor for theslip-system and strong elastic anisotropy of the BCC
crystal. This is generally known as “intergranular stress”
and should be referred to as “block stress” in pearlite.
Therefore, phase and block stresses are superimposedin a plastically deformed ferrite matrix, and potentiallyin cementite. Recently, a neutron diffraction peak profile reveals a heterogeneous deformation induced peakasymmetry [3-5]. It is argued that the asymmetry iscaused by stress partitioning among colonies.
2. Experimental procedures
The steel used in this study was created by induction heat melting in a vacuum, and the chemical compositions were 0.801C-0.01Mn-0.01Si-0.01P-0.01S (masspct). The steels were austenitized at 1103 K for 3.6 ks ina vacuum and then isothermally held at 673 K or 748 K
for 3.6 ks, in order to obtain full pearlite structures withdifferent lamellar spacings. Dog-bone-shaped specimens, with a diameter of 3 mm and a gauge length of
30 mm, were prepared.
The in situ neutron diffraction measurements were
performed using a high-intensity, high-resolution timeof-flight (TOF) neutron diffractometer, TAKUMI (BL19),
at the Materials and Life Science Facility of the Japan
Proton Accelerator Research Complex, J-PARC. A 20 kN
tensile tester was mounted on the diffractometer insuch a way that the loading axis was at a 45° angle tothe incident beam. Therefore, the diffraction profiles fortwo scattering vectors in terms of the axial (tensile) andtransverse directions were measured simultaneously
by two detector banks set at ±90° against the incident
beam. The specimens were deformed in tension atroom temperature step-by-step in the elastic deformation region, and subsequently in a continuous mannerin the elasto-plastic region, using a strain rate of 10−5 s−1.
The strain was measured and controlled using a strain
gauge that was glued onto the specimen surface. The
diffraction data were collected continuously using
event-recording mode during tensile deformation andtime-sliced with 0.9 ks intervals for analyses following
measurement.
3. Results and discussion
As typical examples, ferrite 200 axial and transverse
diffraction peaks are illustrated in Fig. 1(a). The diffraction peak profiles in the axial direction, obtained prior
to deformation and subsequently deformed by 4.7%
with an external tensile load, are compared in Fig. 1(a).
We particularly focus on the evolution of the peakasymmetry.
In order to compare the profile shape more clearly, these two profiles are normalized to be of identicalheights (see inserted figure). It shows that the broadening on the right-hand side is larger than that on theleft in the deformed case, which indicates asymmetry.
On the contrary, the diffraction profile of the deformed
specimen in the transverse direction exhibits slightly
larger broadening on the left-hand side; that is, thelarger broadening side is opposite in the tensile andtransverse directions. Such asymmetry becomes more
obvious with increasing plastic deformation. It is argued
that the peak asymmetry is caused by a distribution oflattice strain in different colonies. Therefore, the diffraction profiles were fitted according to double peaks
with different lattice spacings. The results for the axial
and transverse directions are presented in Fig. 1(b). The
hard colony (HC) peak (blue curve) shifts towards wider
lattice spacing, while the soft colony (SC) peak (green
curve) is narrower, and the magnitude of SC is lower
than that of HC in the axial direction. The strains of SC
and HC (εSC and εHC) were determined using the following equations:
εSC = (dShkl − d0hkl) / d0hkl
εHC = (dHhkl − d0hkl) / d0hkl
where dShkl, dHhkl, and d0hkl refer to the hkl plane spacing for SC, HC, and stress-free, respectively. Here, ferrite
110, 200, and 211 diffraction peaks were employed for
double peak fitting.
Figure 2(a) compares the SC and HC results for thecoarse pearlite. Firstly, the strains increase linearly withan increase in macroscopic strain near the yielding
point. Beyond yielding, colony strain of HC increases
11Research and Development Highlights

MLF Annual Report 2017

(a)

(b)

Figure 1. Examples of ferrite 200 diffraction peaks before and after deformation in axial and transverse directions (a).
The double peaks corresponding to the SC and HC in the axial and transverse directions (b).

Figure 2. Stress partitioning between hard and soft colonies (a) and change of relative FWHM with tensile deformation (b).
The embedded figure shows the average of the colony strain for 110, 200 and 211 reflections.

rapidly, but ceases to increase for the SC one, retaining
hkl dependence. Hence, in addition to the stress partitioning of phase and intergranular stresses, colonystress is overlapped.
The relative full width at half maximum (FWHM)
value, computed as the average of the FWHMs for 110,
200, and 211 reflections, is shown in Fig. 2(b). It can beseen that FWHM apparently increases in HC, but not
in SC, after yielding. In this case, FWHM is believed todepend mainly on dislocation density. It is speculated
that the pile-up of dislocations at the ferrite/cementite
interface is affected by lamellar alignment: in the caseof 45° in terms of the tensile direction (SC), the free

12

path for dislocation movement is large, and hence work
hardening must be low, due to poor accumulation andeasy dislocation annihilation. Furthermore, the increment of dislocation density is larger in fine pearlite of
HC constituent.
4. Conclusions
Colonies with different lamellar orientation exhibit
different work hardening capability, which is determined by the asymmetry of the diffraction peaks andthe lamellar spacing affects the stress partitioning ofcolony-unit deformation.

MLF Annual Report 2017

Acknowledgements
Neutron experiments were performed under proposal No. 2012P0102.
References[1] Y. Tomota, P. Lukáš, D. Heov, S. Harjo, Y.R. Abe, Acta
Mater., 51, 805-817 (2003).
[2] C. Zheng, L. Li, Y. Wang, W. Yang, Z. Sun, Mater. Sci.

Research and Development Highlights

Eng. A, 631, 181-188 (2015).
[3] T. Ungár, S. Harjo, T. Kawasaki, Y. Tomota, G. Ribárik,Z. Shi, Metall. Mater. Trans. A, 48, 159-167 (2017).
[4] S. Harjo, T. Kawasaki, Y. Tomota, W. Gong, K. Aizawa,
G. Tichy, T. Ungár, Metall. Mater. Trans. A, 48, 40804092 (2017).
[5] Y. Wang, T. Ohnuki, Y. Tomota, S. Harjo, T. Ohmura,
Scripta Mater., 140, 45-49 (2017).

Y. Wang1, T. Ohnuki2, Y. Tomota1, S. Harjo3, and T. Ohmura1
Research Center for Structure Material, National Institute for Materials Science; 2Tokyo Metropolitan College of Industrial Technology;
3Neutron Science Section, Materials and Life Science Division, J-PARC Center

1

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Research and Development Highlights

MLF Annual Report 2017

Behavior of Hydrogen in the Early Stage of Earth’s
Evolution

2. Neutron diffraction observation using a newly
developed anvil assembly
To reproduce the early stage of the Earth’s formation, the experiments were conducted for the ironhydrous mineral system. As a starting material, Fe rod(2.35 mmφ × 2 mmh) and an equimolar powder mixtureof SiO2, Mg(OD)2 (or MgO) were placed in a graphite capsule (3 mmφ × 4.5 mmh) in the molar ratio of 2:1. Thisinitial composition is a simple representation of the primordial materials of the Earth with/without water. We
used a multi-anvil 6-6 type (MA6-6) assembly [9] newly
developed for the neutron experiments to achieve large
sample volume, stable pressure(P)-temperature(T) generation and intense diffraction signals. In all three experimental runs, the pressures were initially increased
up to ~5 GPa, and then the temperatures were changed
as shown in Fig. 1. Diffraction data were collected for~10 hours in the PT region at ~4 GPa and ~700°C. The
14

Fe / FeHx

liquid1,700

δliquidγ(fcc)
1,200

1,200+ Water− Water+ Waterγ(fcc)
700

α(bcc)
α(bcc)

300
0

1

2

ε’(dhcp)3

4.8 4.94
5 5.4 67

8700Temperature (K)1,700Temperature (°C)

1. Introduction
The current Earth’s core consists mainly of iron alloy,
and seismological observations have reported that thedensity of the outer core is ~10% lower than that of pureiron. This density deficit is explained by the dissolutionof light elements, such as sulfur, silicone, oxygen, carbon, and hydrogen into the core, and experimental andsimulation studies have clarified the chemical species
and amounts of these light element(s). In particular, hydrogen, the most abundant element in the universe, is
expected to significantly affect density deficit. However,there have been few studies focusing on hydrogen due
to several experimental problems. First, the dissolutionof hydrogen into iron is quite limited (ppm order) at ambient condition and it only occurs under high pressure
above 3.5 GPa [1]. In conventional quench-experiments,
it has been impossible to detect hydrogen, although
the trace of included hydrogen was observed as many
bubbles in the recovered sample [2]. Second, in-situ
synchrotron X-ray diffraction observations [3-6] cannot
detect the lightest element and several assumptions
were needed for estimating the amount of dissolved hydrogen. In this study, we have conducted high-pressureand high-temperature in-situ neutron diffraction experiments using a multi-anvil apparatus with six independently acting 500-ton rams (ATSUHIME 6-axis press) [7]
installed at “PLANET” beamline (BL11) [8], MLF, J-PARC.

ε(hcp)
300
9

Pressure (GPa)Figure 1. Phase diagrams of pure Fe (black, solid line) andFeHx (red, dotted line) with the PT paths in the threeexperiments (with/without water). Phase boundaries are referred by [3-6]. The large and small circles
represent the PT conditions at which quick and longmeasurements (~10 h) were made, respectively.

incident beam was truncated into almost the same size
as iron for obtaining the diffraction patterns of ironalone. All the quenched samples were analyzed by X-ray
diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS).
3. Results
Figure 2 shows the temperature dependence of diffraction patterns. In the sample including water, mostof the peaks in the initial pattern were attributed toiron, while a few peaks of sample surrounding materials
were observed due to the divergence of the incident
beam. With increasing temperature, water was supplied
to iron by dehydration of Mg(OD)2 and the iron bcc-fcc
phase transition was observed subsequently. On cooling after the long exposure at 725°C, the bcc iron appeared again. On the other hand, in the experimental
run using MgO instead of Mg(OD)2, the phase transitionof pure iron was observed together with disappearanceof MgO and appearance of olivine phases.
When comparing the time dependence of the unit
cell volume of fcc iron between the experiments withand without water, a significant difference was observed (Fig. 3). The volume increased only in the sample
including water, suggesting the dissolution of deuterium into iron. Here, we could not observe the shrinkage of the cell volume due to the formation of superabundant vacancy (SAV), which had been reported by
Fukai et al. [4].

MLF Annual Report 2017with water

Research and Development Highlights

without water
2.8 GPa, RT

246°C

474°C
474°C

725°C
594°C

725°C

529°C

594°C

470°C
529°C

408°C
408°C

4.9 GPa, RT

4.8 GPa, RT

Ambient P, RT

5

10

15
TOF (μsec)

20

T up

Intensity (arbitrary unit)

246°C

T down2.9 GPa, RT

25×103

5

10

15

20

25×103

TOF (μsec)

Figure 2. Temperature dependence of the diffraction profiles at ~4 GPa in the experiments with and without water. In bothruns, iron bcc (black) -fcc (red) phase transformation occurred at ~600°C. In the run including water, Mg(OD)2 (marked
with vertical bars) disappeared due to dehydration at ~500°C. On the other hand, in the run without water, peaks of
MgO (triangle) disappeared and then olivine (cross) appeared instead. A bottom profile in the run without water was
obtained using a larger beam size to determine the lattice parameters of NaCl used as a pressure marker (asterisk).

Unit cell volume (Å3)

47.3

@ ~700°C

47.2

4.3 GPa

47.1
47.0
46.9

4.4 GPa

3.8 GPa

3.9 GPa

3.7 GPa

3.6 GPa

3.7 GPa

46.8
4.3 GPa

46.7
00:00

+ water– water+ water

4.4 GPa

03:00

06:00

09:00

12:00

Time (hh:mm)

Figure 3. Time changes of unit cell volume of fcc iron while keeping at ~700°C in three runs. Each data plot was calculatedusing the data obtained every hour. Uncertainty of the volume was estimated from standard deviation of the lattice
parameter refined by Rietveld analysis. Pressure variation was less than 0.05 GPa.

For the iron including hydrogen, the deuterium
content x was determined to be 0.19 (~0.7 wt.%) by
Rietveld refinement using an initial structure model offcc iron hydride (FeDx) with deuterium atoms occupying
both tetrahedral and octahedral sites [10]. This value
was small compared to previous neutron (2.24 wt.% at
6.3 GPa, 715°C for Fe-D2 system [10]) and XRD studies(x~1). It might be due to the differences in the experimental conditions, such as lower-PT, sample capsule,starting materials, and the reaction speed related tothe different formation process of FeDx in the current
iron-silicate-D2O system. SEM analyses of the recovered

samples supported this view (Fig. 4). In the recovered
sample containing water, a thin FeO layer was observedon the surface of the iron rod, as well as many small vacant holes within it, probably due to the degassed hydrogen on the release of pressure. Besides, Fe-rich (Fe,Mg)2SiO4 olivines existed around the iron rod, whereas
Fe-poor (Fe, Mg)SiO3 pyroxene was located far from it.
These results suggest that the reaction speed of hydrogenation of the iron rod is decreased by the existence of
the FeO layer, which was formed in the redox reaction:
2Fe + H2O → FeO + FeHx + (1−x/2)H2↑.

15

Research and Development Highlights

MLF Annual Report 2017(b) Px(a)and iron including light elements sank and formed thecore. To reveal the detailed process, further studies on
the partitioning of the multi-light elements between
silicates and iron hydride (not pure iron) are required.
This study suggests the importance of the effects ofhydrogen on the Earth’s mantle-core formation. Ourcontinuous research of the iron hydride-silicate-lightelements system is now in progress.

(c)
Ol
Fe
FeO

Fe

(d)

O

Si

Mg

Fe Px

Ol

Ol
FeO
Fe

Figure 4. Results of SEM analysis of the recovered sample including water. (a-c) Electron images with different
magnification, and (d) elemental maps on O, Mg,
Si and Fe. The iron contained many small vacantholes as the evidence of degassed hydrogen on
the release of pressure. The surface of an iron rod
was covered with a thin layer of FeO. Two silicates ofolivine (Ol) and pyroxene (Px) containing iron were
found in the area initially occupied by the mixtureof Mg(OD)2 and SiO2. Olivine with large Fe contents
is preferentially located close to the iron rod.

4. Implication for Earth’s evolution process
The results of our study indicate that hydrogen supplied from the hydrous minerals can dissolve into thesolid iron at much lower temperatures than its melting
point. This suggests that hydrogenation of iron could
have inevitably occurred in the very early stage of the
Earth’s history before the primordial materials weremolten with a magmatic ocean. Thus, other light elements might have been incorporated in the later process because they can dissolve only in the molten ironat much higher temperatures. In the end, it is likely thatsilicates (olivine and pyroxene) remained in the mantle,

References[1] Y. Fukai, Nature 308, 174 (1984).
[2] T. Okuchi, Science 278, 1781–1784 (1997).
[3] V. E. Antonov, I. T. Belash, E. G. Ponyatovsky, Scr.
Metal. 16, 203–208 (1982).
[4] Y. Fukai, K. Mori, H. Shinomiya, J. Alloys Compd.
348, 105–109 (2003).
[5] K. Sakamaki, E. Takahashi, Y. Nakajima, Y. Nishihara,
K. Funakoshi, T. Suzuki, Y. Fukai, Phys. Earth Planet.
Int. 174, 192 (2009).
[6] T. Yagi, T. Hishinuma, Geophys. Res. Lett. 22, 1933–
1936 (1995).
[7] A. Sano-Furukawa, T. Hattori, H. Arima, A. Yamada,S. Tabata, M. Kondo, A. Nakamura, H. Kagi, T. Yagi,
Rev. Sci. Instrum. 85, 113905 (2014).
[8] T. Hattori, A. Sano-Furukawa, H. Arima, K. Komatsu,
A. Yamada, Y. Inamura, T. Nakatani, Y. Seto, T. Nagai,
W. Utsumi, T. Iitaka, H. Kagi, Y. Katayama, T. Inoue,
T. Otomo, K. Suzuya, T. Kamiyama, M. Arai, T. Yagi,
Nucl. Instrum. Methods Phys. Res. A 780, 55–67(2015).
[9] R. Iizuka-Oku, T. Yagi, H. Gotou, T. Okuchi, T. Hattori,
A. Sano-Furukawa, Nature Commun. 8, 14096(2017).
[10] A. Machida, H. Saitoh, H. Sugimoto, T. Hattori, A.
Sano-Furukawa, N. Endo, Y. Katayama, R. Iizuka, T.
Sato, M. Matsuo, S. Orimo, K. Aoki, Nature Commun.
5, 5063 (2014).

R. Iizuka-Oku1, T. Yagi1, H. Gotou2, T. Okuchi3, T. Hattori4, and A. Sano-Furukawa4
Geochemical Research Center, Graduate School of Science, The University of Tokyo; 2Institute for Solid State Physics, The University ofTokyo; 3Institute for Planetary Materials, Okayama University; 4Neutron Science Section, Materials and Life Science Division, J-PARC Center,
Japan Atomic Energy Agency

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MLF Annual Report 2017

Research and Development Highlights

The Effect of Planar Rattling on Lattice Thermal
Conductivity in LaOBiS2−xSex
1. Introduction
Thermoelectric materials have attracted great attention in the field of energy conservation technology
as they can convert heat directly into electric power.
To realize the technology, further improvement of thethermoelectric performance is required. Thermoelectric
properties can be described by the dimensionless figure-of-merit (ZT) defined as ZT = S2T/ρκ where S is theSeebeck coefficient, ρ is the electrical resistivity and κ isthe total thermal conductivity. To achieve high thermoelectric performance, good electric conductivity andpoor thermal conductivity are required simultaneously.
This conflicting condition can be realized, for example, by large vibration of atoms, the so-called, rattling.
Rattling occurs in oversized cage compounds such as
clathrates and filled skutterudites.
Recently, we found out that rattling occurs also incompounds without oversized cages. LaOBiS2−xSex exhibits extremely low lattice thermal conductivity withvalue of about 1 W/mK around room temperature [1],which is lower than that of vitreous silica. The extremely
low lattice thermal conductivity positions LaOBiS2−xSex
as a promising thermoelectric material with the ZT value of 0.36 at T = 650 K. Crystal structure refinements revealed that Bi atoms located at the center of basal planeof BiS5-pyramid vibrate largely along c-axis [2]. We defined this as planar rattling to distinguish it from therattling in oversized cages. To clarify the dynamics ofplanar rattling and the mechanism of suppressing lattice dynamics with planar rattling, we studied phononsof LaOBiS2−xSex using inelastic neutron scattering [3].

2. Experimental details
Polycrystalline samples of LaOBiS2−xSex (x = 0, 0.2,
0.4, 0.6, 0.8, and 1) were synthesized by solid-state reactions. Inelastic neutron scattering measurements
were conducted using AMATERAS. The incident neutron energy was Ei = 10.5 meV. The energy resolution
at elastic scattering was 0.69 meV. The temperature was
T = 300 K. The data were processed using the Utsusemi
visualization software. Phonon calculations based on
density-functional theory and plane-wave basis set
were performed to identify the phonon modes.
3. Results and discussion
Figure 1 shows contour maps of the scattering intensity of LaOBiS2 at T = 300 K. The observed intensity
is well reproduced by phonon calculations. Acoustic
and optical phonon modes with steep and flat dispersions were observed, respectively. Phonon calculations
revealed that the optical phonon modes around E =6 meV were associated dominantly with large vibration of Bi atoms. To clarify the Se doping dependencesof the Bi rattling modes, the contour map was sliced in
the Q range of 2.75 – 2.85 A−1. The energy spectra demonstrate that well-defined optical phonon peaks softenwith Se doping (Fig. 2). This suggests that anharmonicity is enhanced with the doping. According to crystal
structure refinements, Se doping induces in-planechemical pressure to Bi atoms [2]. That is, the chemicalpressure can enhance the Bi rattling. This is in contrast
with the rattling in oversized cage compounds, wherelarger free space enhances the rattling motions [4-8].

Figure 1. Contour maps of the scattering intensity of LaOBiS2 at T = 300 K. (a) Observed map. (b) ab initio calculation
convoluted with instrumental energy resolution. Reproduced from [3], with the permission of AIP Publishing.

17

Research and Development Highlights

MLF Annual Report 2017

Figure 3 shows rattling energy vs. lattice thermal
conductivity (κL). The rattling energy softens linearlywith decreasing κL, demonstrating that κL is suppressedby the Bi rattling modes. The results indicate that planarrattling is an essential factor for suppressing κL as rattling in oversized cage compounds.
4. Summary
We studied the phonon dynamics of LaOBiS2−xSex,
which exhibits extremely low κL. We observed that Bi
planar rattling modes soften with decreasing κL, suggesting that the rattling modes are responsible for thelow κL. In-plane chemical pressure enhances the planarrattling, in contrast with that in oversized cage compounds, where free space is essential.

Figure 2. Se doping dependence of energy spectra of phonons at T = 300 K in the Q range of 2.75 to 2.85 A−1
for LaOBiS2−xSex. Solid lines are Gaussian fits. Reproduced from [3], with the permission of AIP Publishing.

Figure 3. Bi rattling mode energy vs. lattice thermal conductivity at T = 300 K for LaOBiS2−xSex. Reproduced
from [3], with the permission of AIP Publishing.

References[1] A. Nishida, O. Miura, C. H. Lee, and Y. Mizuguchi,
Appl. Phys. Express 8, 111801 (2015).
[2] Y. Mizuguchi, A. Miura, A. Nishida, O. Miura, K.
Tadanaga, N. Kumada, C. H. Lee, E. Magome, C.
Moriyoshi, and Y. Kuroiwa, J. Appl. Phys. 119, 155103(2016).
[3] C. H. Lee, A. Nishida, T. Hasegawa, H. Nishiate, H.
Kunioka, S. Ohira-Kawamura, M. Nakamura, K.
Nakajima, and Y. Mizuguchi, Appl. Phys. Lett. 112,023903 (2018).
[4] K. Suekuni, M. A. Avila, K. Umeo, H. Fukuoka, S.
Yamanaka, T. Nakagawa, and T. Takabatake, Phys.
Rev. B 77, 235119 (2008).
[5] Y. Takasu, T. Hasegawa, N. Ogita, M. Udagawa, M. A.
Avila, K. Suekuni, I. Ishii, T. Suzuki, and T. Takabatake,
Phys. Rev. B 74, 174303 (2006).
[6] C. H. Lee, H. Yoshizawa, M. A. Avila, I. Hase, K. Kihou,
and T. Takabatake, J. Phys.: Conf. Ser. 92, 012169(2007).
[7] C. H. Lee, H. Yoshizawa, M. A. Avila, I. Hase, K. Kihou,
and T. Takabatake, J. Phys. Soc. Jpn. 77, 260 (2008)
Suppl. A.
[8] C. H. Lee, I. Hase, H. Sugawara, H. Yoshizawa, and H.
Sato, J. Phys. Soc. Jpn. 75, 123602 (2006).

C. H. Lee1, A. Nishida2, T. Hasegawa3, H. Nishiate1, H. Kunioka1, S. Ohira-Kawamura4, M. Nakamura4, K. Nakajima4, and Y. Mizuguchi2
National Institute of Advanced Industrial Science and Technology (AIST); 2Graduate School of Science and Engineering, Tokyo Metropolitan
University; 3Graduate School of Integrated Arts and Sciences, Hiroshima University; 4Neutron Science Section, Materials and Life Science
Division, J-PARC Center

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MLF Annual Report 2017

Research and Development Highlights

Vibrational States of Atomic Hydrogen in Bulk andNanocrystalline Palladium
1. Introduction
The behavior of hydrogen in metals has attracted
significant attention in fundamental and applied research areas. Palladium hydride (PdHx; x < 1) is a typical metal-hydrogen system, which had been intensively
studied for many decades. Pd has remarkable abilities
to absorb plenty of hydrogen and to catalyze a broad
range of chemical reactions. Metal nanoparticles areof current interest owing to their unique properties ascompared with bulk materials. It has been demonstrated that the H absorption property of Pd nanoparticles
is markedly different from that of bulk Pd and strongly
depends on their size, shape, and surface structure. A
key issue in metal hydride nanoparticles is to clarify thethermodynamic state and structure of the subsurface(a few layers below the surface), which are closely connected with the H absorption ability and the high catalytic performance.
We have investigated the structure [1] and diffusion [2] of hydrogen atoms by means of neutron scattering techniques for both bulk and nanocrystalline PdHx/
PdDx. Neutron diffraction (ND) data of nanocrystalline
PdD0.36 (nano-PdD0.36), taken on NOVA at MLF, suggested that hydrogen atoms were accommodated both atthe octahedral (O) sites (1/2, 1/2, 1/2) and the tetrahedral (T) sites (1/4, 1/4, 1/4) in the face-centered cubic(fcc) lattice of Pd (see Fig. 1). This is in contrast to bulk
PdH0.7 with the occupation of only O sites [1]. It was also
reported by our quasielastic neutron scattering (QENS)
study that an additional fast diffusion process of the Hatoms appeared in nano-PdH0.47 [2]. It indicates that the
H atoms diffuse faster near the surface, probably via theT sites. In this work, vibrational states of H atoms in bulk

Figure 1. Interstitial hydrogen sites in an fcc Pd lattice: octahedral (O) and tetrahedral (T) sites.

and nano-PdHx were examined in a wide energy region0 ≤ ħω ≤ 300 meV by inelastic neutron scattering (INS),to gain insight into the shape of a potential well aroundthe H sites [3].
2. ExperimentHigh-quality Pd nanocrystals with a narrow size distribution (8.0 ± 0.9 nm) were used in this work. They werebasically the same as those in previous studies [1-2]. The
INS spectra of bulk PdH0.73, nano-Pd, and nano-PdH0.42
were recorded at 10 K using a time-of-flight Fermi chopper spectrometer, 4SEASONS. The frequency of the
Fermi chopper was set to 600 Hz and the phase wasconfigured to select an Ei set of 942, 331, and 168 meV.
3. Results and discussion
Figure 2 shows the INS spectra of bulk PdH0.73 andnano-PdH0.42 at Q ≈ 10 Å-1 and T = 10 K, taken with Ei of
331 meV. In bulk PdH0.73, multiphonon processes up to
4th order (n = 4) are clearly visible. The excitation energy and intensity against n, estimated by multi-peakfitting, are roughly described by the quantum harmonic
oscillator (QHO) model. In the model, the excitation energy is given by n(ħω0) and the fundamental energy ħω0is estimated to be 68 meV.

Figure 2. Inelastic neutron scattering spectra of (a) bulk
PdH0.73 and (b) nano-PdH0.42 at 10 K.

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Research and Development Highlights

MLF Annual Report 2017

The INS spectrum of nano-PdH0.42 is different fromthat of PdH0.73. We have analyzed the spectrum with the
combination of the spectrum of bulk PdH0.73 and the
additional excitations, because the previous ND and
QENS works suggest that most H atoms (70 – 80%) occupy the O sites and their behavior resembles the one
observed in bulk. The additional excitations were foundat energies above 80 meV (Fig. 2(b)). The energies andintensities of the additional states were not explainedby the QHO model but were reasonably described as vibrations in a highly anharmonic trumpet-like potential(Fig. 3). The estimated ħω0 was 122 meV that was significantly larger than that of bulk PdH0.73. Such a remarkable change in ħω0 cannot be explained by the small

Figure 3. Potential energy as a function of the atomic displacements relative to the equilibrium position of
the H atom.

change in the lattice constant. In fact, the vibrationalenergy for the T site with the short H-Pd distance is expected to be higher than that for the O site. Therefore, it
is reasonable to conclude that the additional vibrations
are attributed to the H vibrations in the T sites near thesurface of nanocrystals.
4. Conclusion
We investigated the vibrational spectra of hydrogen atoms in bulk and nanocrystalline Pd. The H vibrations in bulk PdH0.73 are roughly described by the QHO
model. In PdH0.42 nanocrystals, the excess excitations
were found at higher energies in addition to the excitations, which resemble those observed in bulk PdH0.73.
The excess excitations are attributed to the hydrogenvibrations in a highly anharmonic trumpet-like potential, which is realized at the T sites in the near-surface
region where the potential energy is substantially modified by surface strain/distortion effects.
Finally, our ND [1], QENS [2], and INS [3] works provided self-consistent results and would be the first comprehensive neutron scattering studies to gain insight
into the behavior of H atoms in metal nanoparticles.
Our findings can provide important information in awide range of research fields, including hydrogen storage, surface science, and catalytic chemistry.
References[1] H. Akiba, M. Kofu. H. Kobayashi, H. Kitagawa, K.
Ikeda, T. Otomo and O. Yamamuro, J. Am. Chem.
Soc., 138 10238 (2016); MLF Annual Report 2016,11-12 (2016).
[2] 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).
[3] M. Kofu, N. Hashimoto, H. Akiba, H. Kobayashi, H.
Kitagawa, K. Iida, M. Nakamura and O. Yamamuro,Phys. Rev. B, 96 054304 (2017).

M. Kofu1, N. Hashimoto1, H. Akiba1, H. Kobayashi2, H. Kitagawa2, K. Iida3, M. Nakamura4, and O. Yamamuro1
Institute for Solid State Physics, University of Tokyo; 2Department of Chemistry, Kyoto University; 3Neutron Science and Technology Center,
CROSS; 4Neutron Science Section, Materials and Life Science Division, J-PARC Center

1

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MLF Annual Report 2017

Research and Development Highlights

Dynamics of a Disease-causing Mutant of TroponinStudied by Quasielastic Neutron Scattering
1. Introduction
In the cardiac muscle, force generation is regulated
in a Ca2+-dependent manner by the protein, troponin(Tn), consisting of three subunits, TnC, TnI, and TnT. The
main regulatory part of Tn is called the Tn core domain(Tn-CD), which consists of TnC, TnI, and TnT2 (TnT183-288)(Fig. 1). Upon Ca2+-binding to TnC, a series of structuralchanges occur within Tn, thereby transmitting the Ca2+binding signal to the other regulatory protein, tropomyosin (Tm). These Ca2+-induced changes then allow
interactions between actin and myosin, leading to force
generation.
To date, more than 70 mutations in Tn are identified as causes of familial hypertrophic cardiomyopathy(HCM), which is associated with heart failure and/or
sudden cardiac death [1]. These mutations modulate
Ca2+-sensitivity of force generation and/or the maximum force. While these mutation-induced functionalaberrations have been widely studied, their detailed
molecular mechanisms are poorly understood. Since
the structural dynamics of Tn is crucial for the regulatory function [2], it is important to reveal the dynamics
changes of Tn caused by these mutations.
While the time scale of the structural dynamics ofproteins spans more than ten orders of magnitude fromfemtosecond vibrational modes to millisecond domain
motions, picosecond dynamics serves as a lubricant forslower structural changes and thus an essential process
for expressing protein function [3].
Quasielastic neutron scattering (QENS) is a powerfultool to study the picosecond dynamics of proteins. Dueto large incoherent scattering cross-section, motions of

Figure 1. Structure of the human cardiac Tn core domain(Tn-CD). TnC, TnI, and TnT2 are shown in red, blue,
green, respectively. The mutation site is represented by orange spheres. A Ca2+ ion bound to TnC isshown in a grey sphere.

hydrogen atoms are observed. Since hydrogen atoms
are distributed quasi-uniformly in proteins, atomic motions averaged over a whole molecule are detected by
QENS. In this study, we investigated how the dynamics
of Tn is modulated by a HCM-causing mutation K247R
of TnT, which increases the maximum force withoutchanging the Ca2+-sensitivity, using QENS [4].
2. Materials and Methods
The subunits of the human cardiac Tn-CD, expressed in E. coli, were purified, and reconstituted into
the Tn-CD complexes containing the wild-type TnT2
(wtTn-CD) or the mutant of TnT2 (mtTn-CD). The D2Osolutions of the wtTn-CD and mtTn-CD were preparedat ~20 mg/ml in both the −Ca2+ and +Ca2+ states. The
QENS measurements were carried out using the BL02
near-backscattering spectrometer DNA at an energy
resolution of 12 μeV at 300 K.
3. Results and Discussion
The measured QENS spectra S(Q, ω) (Q and ω aremomentum transfer and energy transfer, respectively)
were fit by the following equation:
S(Q, ω) = [A(Q)δ(ω) + {1 − A(Q)}Llocal(Q, ω)]⊗ Lglobal(Q, ω) ⊗ R(Q, ω) + B(Q),(1)

where A(Q)δ(ω) is the elastic component with A(Q) being the elastic incoherent structure factor (EISF), fromwhich amplitudes of local atomic motions are obtained,and δ(ω) being the Dirac delta-function. Llocal(Q, ω) and
Lglobal(Q, ω) are the Lorentzian functions describing the
local motions and the global diffusive motions of protein molecules, respectively. From the Q2-dependenceof the widths of Lglobal(Q, ω) and Llocal(Q, ω), the apparent diffusion coefficient including translational androtational motions of the entire molecules, and theresidence time of local motions are obtained. R(Q, ω)
denotes the instrumental resolution function and B(Q)
denotes the background.
Figure 2 shows an example of the measured spectra with the results of the fit using Eq. 1. The dynamics
parameters obtained from these fits are summarized inFig. 3. While there was no change in the apparent diffusion coefficients by either Ca2+-binding or the mutation(data not shown), dynamics changes were observed for21

Research and Development Highlights

MLF Annual Report 2017

Figure 2. Examples of the QENS spectra. Those of the wtTnCD in the +Ca2+ state at Q = 1.375 [Å−1] are shown.
The measured data points are denoted by the grey
open squares. The total fit, the elastic component,
and the Lorentzian component are denoted byblack, green and red solid lines, respectively. The
resolution function is shown in black broken lines.

Figure 3. Summary of the dynamics parameters. (a) Residence times obtained from the QENS spectra. (b,c) Amplitudes of local atomic motions in the Tn-CD
obtained from the EISF analysis. Asterisks show statistically significant differences at 95% confidence
level by the Student’s t-test.

local motions. In the case of the wtTn-CD, the residence
time decreased upon Ca2+-binding, suggesting thatthe frequency of the local motions increases by Ca2+binding (Fig. 3 (a)). On the other hand, the residence
time of the mtTn-CD in the −Ca2+ state was smaller thanthat of the wtTn-CD in the corresponding state and did
not show any change upon Ca2+-binding. This increased
frequency of local motions caused by the mutation suggests that the Tn-CD molecules are destabilized by the
disruption of hydrogen bond network around the mutation site.
Figure 3 (b, c) show the amplitudes of local motions obtained from the EISF analysis. Here, two kindsof populations of atoms moving inside spheres of radii of a1 and a2 were assumed. Both amplitudes of the
wtTn-CD showed a decrease upon Ca2+-binding. The
amplitudes of the mtTn-CD in the −Ca2+ state weresimilar to those of the wtTn-CD in the corresponding
state. Upon Ca2+-binding, however, the amplitudes ofthe mtTn-CD increased and as a result they exceeded
those of the wtTn-CD. This suggests that the atoms ofthe mtTn-CD can explore larger conformational spacethan those of the wtTn-CD. Since the functional aberration is observed in the +Ca2+ state, these larger amplitudes should be related to the pathogenesis of HCM.
We have previously shown that the main effectof the K247R mutation on Tn structure is in the orientation of TnT183-225 region, which is connected to the
Tm-binding region [5]. The large fluctuations of the
mtTn-CD in the +Ca2+ state detected here imply that theconformation of the mtTn-CD with the altered orientation of TnT183-225 is unstable and thus Tn-Tm interactions
are disturbed by the mutation. Since Tn-Tm interactions are crucial for the regulation of force generation,
the disturbance of these interactions would modulate
their abilities to control interactions between actin
and myosin, leading to an increase in maximum force
as observed for the K247R mutation. The present study
has demonstrated that the dynamics of the Tn-CD is altered by Ca2+-binding and a disease-causing mutation,emphasizing the importance of picosecond protein dynamics in both healthy and pathological conditions.
References[1] Q.W. Lu et al., J. Geriatr. Cardiol., 10 91-101 (2013).
[2] A. Metskas & E. Rhoades, J. Mol. Biol., 428 2965-2977(2016).
[3] G. Zaccai. Science, 288 1604-1607 (2000).
[4] T. Matsuo et al., Biochim. Biophys. Acta., 1865 17811789 (2017).
[5] T. Matsuo et al., Biophys. Physicobiol., 12 145-158(2015).

T. Matsuo1, T. Tominaga2, F. Kono1, K. Shibata3, and S. Fujiwara1
1
Quantum Beam Science Research Directorate, QST; 2Neutron Science and Technology Center, CROSS; 3Neutron Science Section, Materials
and Life Science Division, J-PARC Center

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MLF Annual Report 2017

Research and Development Highlights

Quasielastic Neutron Scattering Study of Microscopic
Dynamics in Co-Crosslinked Rubber

2. Experimental
We prepared a mixture of BR, ZDA, and dicumyl peroxide (DCP) as samples. ZDA monomer possesses carbon-carbon double bond (C=C) at its both ends. Firstly,
the ZDA monomer was grafted to BR by reacting one
C=C to BR, then ZDA aggregates with the size of several
nm were subsequently formed by chain transfer reaction

between the ZDA monomers. Secondly, the crosslinking of BR proceeded through further chemical reaction
between other C=C end of ZDA and BR. DCP was used
as an initiator for crosslinking reaction. Samples consisted of 0, 2.7, 5.3, 10.1, and 14.4 volume % of ZDA werenamed ZDA(0), ZDA(3), ZDA(5), ZDA(10), and ZDA(14),respectively. Figure 1 shows the relationship between
the elastic modulus obtained by dynamic viscoelasticity
measurements and the volume fraction of ZDA at 303 K.
The elastic modulus increases dramatically above thevolume fraction of 0.05. For clarity, we also added a solidline, which only holds for low ZDA contents in Fig. 1.
QENS measurements were carried out with an inverted geometry time-of-flight spectrometer (BL02
DNA) [5], installed at the Materials and Life Science
Experimental Facility (MLF) in J-PARC, Tokai, Japan. Theenergy resolution (δE) defined as the full width at half
maximum (FWHM) was estimated to be 4.0 ± 0.2 μeV for
an elastic scattering spectrum measured at lowest temperature. The scattering contribution of each component
was estimated based on the scattering cross section. For
ZDA(14), which contained the highest volume fraction of
ZDA among the investigated samples, the proportionsof the total scattering cross-sections of BR, ZDA, and DCP
were estimated to be 94.7:5.0:0.3. The large scattering
contribution of BR were mainly due to the large incoherent scattering cross section of hydrogen atoms. Thus, theobservable scattering intensity for ZDA/BR in this QENS
study, would be dominated by the BR.

120
100
Elastic modulus (MPa)

1. Introduction
Rubber materials utilized in various industrial products are indispensable in the industries and our daily
life. Fillers or functional agents are used to enhance theproperties of pure rubber, such as mechanical strength,abrasion resistance, and deterioration resistance.
Mechanical properties of rubber materials can be enhanced by an addition of crosslinking agents or reinforcing fillers, such as carbon black, silica, or clay [1]. The
mechanical strength of polybutadiene rubber (BR) reinforced with zinc diacrylate (ZDA) (ZDA/BR) is known tobe considerably higher than that of the typical carbon
black or silica reinforced rubber [2]. Among them, themechanism underlying the high mechanical strength
attained using ZDA remains unknown despite the extensive studies. It has been conjectured that the failure
to elucidate the reinforcement mechanism in ZDA/BR
originates mainly from the lack of detailed information
about both its static and dynamic structures. To overcome this shortcoming, first, we studied the structureof ZDA/BR through the complementary use of smallangle X-ray scattering (SAXS) and small-angle neutron
scattering (SANS) techniques [3, 4]. In addition to thehierarchical structures of the ZDA aggregates and BR
matrix, a hierarchical BR structure possessing a higher
crosslinking density (HC-BR) than that of the BR matrix
was observed for ZDA/BR. Furthermore, it was expectedthat such HC-BR region was mainly segregated on thesurface of the ZDA aggregates.
In this work, we try to study the effect of concentration of reinforcing material (ZDA) on dynamics of ZDA/
BR, which exhibit high mechanical strength throughquasielastic neutron scattering (QENS). At present, the research of the concentration dependency of the reinforcing agent has been insufficient, due to various controllingparameters. Hence, tuning the concentration of the reinforcing agent, which depends on the specific fields where
the BR product is used, is vital for its industrial application.

80
60
40
20
0
0.00

0.05

0.10

0.15

Volume fraction of ZDA
Figure 1. Relationship between the elastic modulus and volume fractions of zinc diacrylate (ZDA) [8].

23MLF Annual Report 2017

3. Results and discussion
Figure 2 shows the dynamic scattering laws S(Q, ω)
normalized by the peak intensity of the elastic scattering from different ZDA volume fractions at 310 K in therange of the scattering vector Q = 1.48 Å−1. The increase
in ZDA volume fraction, a narrowing of the S(Q, ω) is
observed. To extract the parameters describing dynamical information from the S(Q, ω), we performed
curve fitting to the observed S(Q, ω) at different ZDA
volume fractions using an appropriate model function
described by the Kohlrausch-Williams-Watts (KWW)
equation [6].
S(Q, ω) = A((1 − ecf) F{exp[−(t/τ)β ]} + ecfδ(ω)⊗R(Q, ω)(1)where A, ecf, τ, and β are the amplitude of the relaxation
function, the elastic component fraction, the relaxation
time, and the distribution of the relaxation function, respectively. KWW function is defined in the time domain,necessitating that we adopt the Fourier-transformed
KWW function (F (KWW)) in the frequency region [7].
R(Q, ω) indicates the instrumental resolution function.
In Fig. 3(a), the elastic fraction ecf increases with theZDA volume fraction, suggesting that the elastic fraction mainly originates from the immobile region mediated by the cross links formed by the addition of ZDA.
In addition, the deviation from the linear dependenceof ecf above the volume fraction of ZDA of 0.05 wasseen. Qualitatively, this tendency corresponds to thatof the elastic modulus as seen in Fig. 1, indicating thatthe high ecf value observed at high ZDA content was
related to high mechanical strength. As seen in Fig. 3(b),the average relaxation time <τ> increases with the volume fraction of ZDA. At the same time, the parameter β,which represents the width of the distribution of relaxation time, decreases with increasing the ZDA volume
fraction, implying the broadening of the distributionof relaxation time. In other words, the samples become
dynamically heterogeneous with the increment of ZDA
volume fraction.
To construct a plausible physical picture that could
explain consistently the evaluated parameters, we referred to the structural information revealed in our previous work on SAXS and SANS [3, 4]. From small-angle
scattering studies, the coexistence of BR regions having low and high crosslinking densities was revealed.
In the above discussion on S(Q, ω), we used the mobile

0.25

(a)

0.20
0.15
ecf

Research and Development Highlights

0.10
0.05

6

2

0.05

0.10

0.15

Volume fraction of ZDA

(b)

1

200

8

<τ>
β

0.45

6
4

150

2

0.1

0.40
β

<τ> (ps)

S (Q, ω) (a.u.)

0.00
0.00

ZDA(0)_310K
ZDA(3)_310K
ZDA(5)_310K
ZDA(10)_310K
ZDA(14)_310K
Resolution function

4

100

8
6

0.35

50

4

-20

0

20

40

60

Energy transfer (μeV)

Figure 2. Dynamic scattering laws S(Q, ω) for ZDA(0) (‫)ۑ‬,
ZDA(3) (‫)ۍ‬, ZDA(5) (‫)ڧ‬, ZDA(10) (‫ )ڹ‬and ZDA(14)(‫ )ۃ‬normalized at the peak top at 310 K in therange Q = 1.48 Å−1. The line indicates the instrumental resolution function [8].

24

0
0.00

0.30
0.05
0.10
Volume fraction of ZDA

0.15

Figure 3. The volume fraction of ZDA dependence of (a) ecf(‫)ڸ‬, (b) <τ> (‫ )ڧ‬and β (‫ )ڦ‬at 310 K in the range Q= 1.48 Å−1 [8].

MLF Annual Report 2017

region and the immobile region for the low crosslinking density region and the highly crosslinked region,
respectively. Based on this assumption, we reasoned
that the mobile region originates from the low crosslinking density region (LC-BR) and the immobile region
originates mainly from the high crosslinking density
one (HC-BR), which is still in a glassy state in the present temperature range. As an increase in the elastic
fraction was observed with the increasing ZDA volume
fraction, a physical picture that assumes the coexistence of mobile and immobile regions in the ZDA/BR, isseemingly applicable to the observed dynamics. If themobile and immobile regions are dynamically homogeneous for the ZDA/BR, the evaluated relaxation times
or distributions of relaxation times must be constant,regardless of the volume fraction of ZDA. However, aslight increase in the relaxation time or broadening of
the distribution of relaxation time with the increase in
the volume fraction of ZDA was observed (see Fig. 3(b)).
Thus, a contributing factor other than the coexistenceof mobile and immobile component must be present
in the ZDA/BR system. It is expected that the dynamics of BR near the HC-BR regions would be strongly
perturbed by the HC-BR region in the glassy state, resulting in slower dynamics than that of neat BR. With
increases in the volume fraction of ZDA, the contributions from such interfacial regions near HC-BR would
increase. Thus, due to the gradient of dynamics mediated by the ZDA aggregates, more heterogeneous andslower dynamics are observed for ZDA/BR than thoseof the neat BR. The schematic representation of the
ZDA/BR system, obtained from the results of our previous work and this QENS study, is shown in Fig. 4. In

Research and Development Highlights

Figure 4. Schematic representation of the ZDA/BR system [8].

the case of ZDA/BR, the existence of chemical bonds
between the BR and ZDA contributed to the effective,
strong interaction between the BR and the reinforcement agents. Thus, tougher network-like structure isformed in ZDA/BR. Forming such network-like structure
has also clearly supported the resulting dynamics as afunction of ZDA concentration. Consequently, a higher
mechanical strength was realized for ZDA/BR at a given
volume fraction of reinforcement agents. The details of
the present work can be obtained from reference [8].
References[1] Y. Fukahori, Rubber Chem. Technol., 80, 701 (2007).
[2] Y. Tsujita, et al., Macromolecules, 34, 2220 (2001).
[3] R. Mashita, et al., Polymer J., 48, 239 (2016).
[4] R. Mashita, et al., Polymer J., 45, 57 (2013).
[5] K. Shibata, et al., JPS Conf. Proc. 8, 036022 (2015).
[6] D. Richter, et al., J. Non-Cryst. Solids, 287, 286 (2001).
[7] F. Alvarez, et al., Phys. Rev. B, 44, 7306 (1991).
[8] R. Mashita, et al., Soft Matt., 13, 7862 (2017).

R. Mashita1, R. Inoue2, T. Tominaga3, K. Shibata4, H. Kishimoto1, and T. Kanaya5
SUMITOMO Rubber Industries, LTD.; 2Institute for Integrated Radiation and Nuclear Science, Kyoto University; 3Neutron Science andTechnology Center, CROSS; 4Neutron Science Section, Materials and Life Science Division, J-PARC Center; 5Material and Life Science
Division, J-PARC Center, KEK

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MLF Annual Report 2017

Quantitative Evaluation of Deformed Electron Density
Distribution of Polydiacetylene Crystal on the Basis of theOrganized Combination of X-ray and Neutron Diffraction Data
1. Introduction
Generally, it is quite difficult to obtain the accurate
crystal structure information for semicrystalline synthetic
polymers, which is indispensable for the prediction ofphysical property, because of the poor X-ray diffraction
data. However, in a lucky case, a giant single crystal of a few
mm size can be prepared in a solid-state polymerization reaction of the original monomer single crystal by the irradiation of γ-ray beam [1]. Polydiacetyele (PDCHD) with bulky
carbazoryl side groups is treated here as the most typicalcase [2]. This polymer is electronically conjugated among
the single, double and triple CC skeletal bonds. The accurate crystal structure analysis may determine the electron
density distribution ρ(x) along the skeletal chain, usefulfor understanding the physical property from the electronlevel. Since the electrons of the covalently-bonded atoms
Rinteract with each other, ρ(x) deviates|
more or less from the original atomic − [−C=C−C≡C−]−|
nucleus positions. The quantitativeRevaluation of the deformed electronR=CH2
density distribution Δρ(x) may provideNdetails about the chemical bonding
along the polydiacetylene chain.
The Δρ(x) is estimated by subtracting the density ρο(x)of the isolated atoms from the X-ray-analyzed density distribution ρ(x).
Δρ(x) = ρ(x) − ρο(x) = (1/V)Σqj [FobsX(qj) − FcalcX(qj)]eiqjx (1)(2)
Here, FcalcX(q) = Σj fjX(q)exp(-iqxXj)exp(-iqUXj)
is the structure factor calculated using the atomic scattering factors fjX(q) of the isolated and non-interacting atoms
without bondings. In the actual calculation the atomic
positions (xXj) and thermal parameters (UXj) estimated by
the X-ray analysis are assumed to be equal to those of theatomic nuclei. However, this assumption sometimes leads
to an abnormal result of Δρ(x) due to the so-called asphericity shift effect [3]. The X-ray diffractions mainly generated
from the valence (or outer-shell) electrons do not locate
the exact positions of the nuclei, but they give information
about the center of gravity of the electron clouds, which is
not equal to the coordinates of the atomic nuclei. The exact
positions of the atomic nuclei are obtained experimentallyby analyzing the wide-angle neutron diffraction data. In
this case, the Δρ(x) can be calculated as(3)Δρ(x) = (1/V)Σqj [FobsX(qj) − FcalcN(qj)] eiqjx
26

where FcalcN(qj) is the structure factor calculated from theisolated-atom X-ray scattering factors fjX(q) combined withthe parameters of nuclear positions xNj and thermal parameters UNj determined by neutron diffraction data analysis:(4)
FcalcN(q) = ΣjfjX(q)exp(-iqxNj)exp(-iqUNj).
Thus, the combination of the X-ray and neutron diffraction data provides accurate information of Δρ(x). This
technique is called X – N method. We evaluated successfully the Δρ(x) of polydiacetylene single crystal using thismethod in our experiments [1]. Although various papers
had been published about the application of the X – N
method, most of them treat the inorganic and organic crystals of low molecular weight [3]. The present study is thefirst successful research of the synthetic polymers [1]. So far
the electron state of the polymer substance was studied
mainly using electron spectroscopy and quantum chemical calculation. The experimentally-obtained informationof the electron density distribution is useful for interpretation of the physical properties of polymer from the electronlevel. This method is also useful for validation of the quantum chemical theoretical calculation.
2. Measurements and analysis<Sample> A giant single crystal of PDCHD was prepared by irradiating 40 MRad γ-ray to the single crystal of
1,4-dicarbazoryl diacetylene (DCHD) monomer at room
temperature.
<X-ray Diffraction Data> X-ray diffraction measurements were performed at room temperature by utilizing a
Rigaku R-Axis Rapid II X-ray diffractometer with a graphitemonochromatized Mo-Kα line. The full-matrix least-squares
refinement was performed to determine the final crystal
structure based on 1882 observed reflections (R factor
4.29% and wR 11.5%).
<Neutron Diffraction Data> Neutron diffraction measurement was performed at room temperature using 2
systems: (A) BIX-3 (high resolution neutron diffractometerdedicated to biological macromolecules [4]), which is installed at the JRR-3 reactor hall of JAEA in Tokaimura, Japan.
The 2D-detector used was a cylindrical imaging plate camera of 40 cm diameter. The neutron beam with wavelengthof 1.51 Å was incident on the sample. The diffraction data
were analyzed for all atoms including the H atoms. (B) iBIX
(Ibaraki Biological Crystal Diffractometer) installed in beam

MLF Annual Report 2017line 03 at the Material and Life Science Experimental Facility(MLF), J-PARC, Tokaimura, Japan [5]. The pulsed neutron
beam was incident to the sample at 25 Hz. The proton acceleration power was 200 kilowatt. The wavelength rangeof the thus generated neutron was 0.7 ~ 4 Å. The 20 2-dimensional position-sensitive detectors were set aroundthe sample for the TOF measurements. The crystal structure
analysis was performed using the program SHELX-2013 (R10.45% for all the observed diffraction spots).

Research and Development Highlights

the X – N method. The agreement between the observedand calculated results is excellent.
3.3 Evaluation of Δρ(x) by X-ray analysis
The Δρ(x) was calculated using only the X-ray analyzed
result. The Δρ(x) was estimated using the atomic coordinates (XX) and thermal parameters (UX) derived by the X-ray
data analysis. This method can be called the X – X method.
As shown in Fig. 3, the maxima are observed for Δρ(x), in
particular around the CC triple bond. As it is known fromthe comparison of structural parameters between X-ray
and neutron data analysis, the atomic coordinates obtained by these two methods are slightly different fromone another, resulting in a non-negligible difference in C-C,
C=C and C≡C bond lengths. Then, a slight discrepancy occurs between the center positions of electron clouds andthe atomic nuclear positions. The thermal parameters arelarger for the X-ray results than the neutron ones. Figure 4
illustrates schematically how the abnormal density distribution is generated. In case of the X- N method, the relatively small electron density spheres are drawn at the nuclear
positions. The thus-drawn ρο(x) are subtracted from thewhole electron density ρ(x), then the maxima of Δρ(x) are
generated on the middles of bonds. The result corresponds
well to that shown in Fig. 2. In case of the X – X method, thespheres ρο(x) are drawn at the centers of X-ray-derived electron density, where the radii of these spheres are relatively
large because of the larger thermal parameters. Besides
the CC distance is shorter (1.203 Å), resulting in the remarkable overlap of ρο(x) between the neighboring spheres. The
rest of electron density or Δρ(x) becomes almost zero in the
middle part of C≡C bond. The Δρ(x) is rather higher in thecenter of C-C bond. These results give the abnormal distribution shown in Fig. 3. Thus, the usage of atomic nucleus
positions revealed by the neutron data analysis is indispensable for the calculation of Δρ(x).

3. Results and discussion
3.1 Crystal structure of PDCHD
Figure 1 shows the crystal structure and molecular conformation of PDCHD obtained by the X-ray data
analysis. The unit cell parameters are a = 12.8525(4) Å, b =4.88680(10) Å, c = 17.3393(6) Å and γ = 108.3690(10)°, andthe space group is P21/c- C2h5. The almost fully-extended
planar-zigzag chains with bulk side groups are packed side
by side in the unit cell. Neutron structure analysis was performed separately for the data collected with the BIX-3 andiBIX systems. The crystal structures derived by these methods displaced essentially the same accuracy of the atomic
nuclear coordinates.
3.2 Evaluation of Δρ(x) by the X – N method
By utilizing the results of X-ray and neutron diffraction
analyses, the X – N method was applied to evaluate Δρ(x)as shown in Fig. 2 (a). The 1-dimensional curve of Δρ(x)traced along the skeletal chain axis is shown in Fig. 2 (b).
The electron density maximum is detected around thecenter positions of triple CC bonds. The lower but similar
maxima are observed also on the single and double CCbonds. The Δρ(x) was calculated in parallel by the density
functional theory (DFT) using a DMol3 software (Materials
Studio 8.0, Biovia). Figure 2 (b) compares the 1-dimensionalΔρ(x) curve obtained by the DFT calculation with that by
(a)

(b)

4

1.4
1.2

2

1
0.8
0

0.6

−2

0.4
0.2

−4

0
−0.2
−4

Figure 1. Crystal structure of PDCHD(copyright permission granted
by ACS [1]).

−2

0

2

4

Figure 2. Deformed electron density distribution Δρ(x) and 1D profile along the
PDCHD chain axis (copyright permission granted by ACS [1]).

27Research and Development Highlights

MLF Annual Report 2017

How can we evaluate the correct Δρ(x) using the X –X method? The X-ray atomic scattering factor consists ofthe contributions from core and valence electron clouds.
The relative weight of diffraction from the core electronsis overwhelmingly large in the higher-angle region. If
the X-ray diffractions in such high-angle region are usedpreferably in the analysis of electron core positions, theabovementioned asphericity shift might be removed aswell. So, even the X – X method might give us a reasonableevaluation of Δρ(x): the X-ray diffraction data collected in
the lower-angle range reveals the whole electron density
distribution ρ(x) and the X-ray diffraction data in the higher-angle range shows the positions of the atomic coresor ρο(x). Of course the effect of the atoms’ thermal vibrations must be erased for drawing of smaller spheres ρο(x).
A diffraction measurement at adequately low temperatureis required for it. In summary, the quantitatively accurate
evaluation of Δρ(x) by the X – X method needs the highlyaccurate X-ray diffraction analysis with the diffraction datacollected at a wide-diffraction angle and at a low temperature. The actual trial to PDCHD was made using a synchrotron X-ray beam [6].
3.4 Application of the X – N method to general polymers
At present, the X – N method (and also the X – X method) is actually impossible to apply to the general partiallycrystalline polymer substances, since the total number ofobserved diffraction spots is too small and the accurate
evaluation of the diffraction intensity is also difficult [7].
So far the structure-property relation of polymers has
been discussed mainly from the atomic level at best. It is
0.2
0.15
0.1
0.05
0
−0.05
−0.1

Figure 3. Deformed electron density distribution Δρ(x) of
PDCHD derived by the X – X method (copyright
permission granted by ACS [1]).

Figure 4. Schematic illustration to obtain the deformed electron density distribution of PDCHD (copyright permission granted by ACS [1]).

desirable to shift this type of discussion toward the electron level for more precise interpretation of characteristic
property of polymers. The concerted combination of X-ray
and neutron diffraction methods is indispensable for thispurpose as described in this report.
References[1] K. Tashiro, K. Kusaka, T. Hosoya, T. Ohhara, M. Hanesaka,
Y. Yoshizawa, H. Yamamoto, N. Niimura, I. Tanaka, K.
Kurihara, R. Kuroki and T. Tamada, Macromolecules, 51,
3911-3922 (2018).
[2] V. Enkelman, Adv. Polym. Sci., 63, 91-136 (1984).
[3] P. Coppens, P. X-ray Charge Densities and Chemical
Bonding. Oxford University Press Inc. (UK) (1997).
[4] N. Niimura, T. Chatake, A. Ostermann, K. Kurihara, I.
Tanaka, J. Z. Kristallogr., 218, 96-107 (2003).
[5] K. Kusaka, T. Hosoya, T. Yamada, K. Tomoyori, T.
Ohhara, M. Katagiri, K. Kurihara, I. Tanaka, N. Niimura, J.
Synchrotron Radiat., 20, 994-998 (2013).
[6] B. Bagautdinov, H. Tanaka, C-H. Shih, K. Sugimoto, S.
Sasaki, K. Tashiro, M. Takata, Acta Cryst., A67, C27-28(2011).
[7] K. Wasanasuk, K. Tashiro, M. Hanesaka, T. Ohhara, K.
Kurihara, R. Kuroki, T. Tamada, T. Ozeki, T. Kanamoto,
Macromolecules, 44, 6441-645 (2011).

K. Tashiro1, K. Kusaka2, T. Hosoya3, T. Ohhara4, M. Hanesaka1, Y. Yoshizawa1, H. Yamamoto5, N. Niimura3, I. Tanaka3, K. Kurihara4,
R. Kuroki4, and T. Tamada4
1
Department of Future Industry-Oriented Basic Science and Materials, Toyota Technological Institute; 2Frontier Research Center for Applied Atomic
Sciences, Ibaraki University; 3Department of Biomolecular Functional Engineering, College of Engineering, Ibaraki University; 4Research Unit for
Quantum Beam Science Initiative, Japan Atomic Energy Agency; 5Aichi Synchrotron Radiation Center, Aichi Science and Technology Foundation

28

MLF Annual Report 2017

Research and Development Highlights

Role of Molecular Weight in Shish-Kebab Formation
1. Introduction
Polymer materials are crystallized under various
kinds of flow during processing, such as fiber spinning,
injection molding and extrusion. In flow-induced crystallization processes, the so-called shish-kebab structures are often observed, which consist of a long central
core (shish: extended chain crystal) surrounded by lamellar crystals (kebabs). The modulus and strength become higher as the number of shish-kebab structures
increases. Therefore, it is believed that shish-kebab
structures are the structural origin of ultrahigh strengthand modulus of fibers. Extensive studies have been conducted to elucidate the shish-kebab morphology andmechanism of formation. The modulus and strength
become higher when ultrahigh molecular weight components are added to the fibers, thus indicating that theultrahigh molecular weight components enhance theformation of the shish-kebab structures.
In our previous paper [1] we have examined the effects of high molecular weight components on shishkebab formation for polyethylene (PE) using small-angle
neutron and X-ray scattering (SANS and SAXS) to conclude that the ultrahigh molecular weight component
was mainly included in the shish. However, in the samemonth (May 2007), a completely opposite experimental
result was published with blends of deuterated and hydrogenated isotactic polypropylene (d-iPP and h-iPP)
by Sumitomo Chem. Co. group [2]. Their findings indicated that more of the low molecular weight component was included in the shish than the high molecularweight component. To disclose the contradiction, we
conducted SANS and SAXS experiments on drawn PE
blends of deuterated and hydrogenated PE (d-PE andh-PE) with various molecular weights.
2. Experimental section
d-PE with an average molecular weight of Mw =600,000 and molecular weight distribution of Mw/Mn= 2 and h-PE with various molecular weights of Mw =58,000, 300,000 and 2,000,000 and Mw/Mn = 8∼12 wereused in this experiment. The blend films were drawn at
three drawing rates of 6 μm/s, 400 μm/s and 2.4 cm/s
at 125°C.
SANS measurements were carried out using two
machines. The first one was TAIKAN in MLF at J-PARC
and the other one was a 40 m SANS machine at the
HANARO reactor in Korea. SAXS and WAXS measurements were conducted using BL40B2 at SPring-8.

3. Results and discussion
On the basis of our previous experimental results,
we considered a possible scenario for shish-kebab formation in which the low molecular weight component,
rather than the high molecular weight component, wasthe major constituent of the shish. In the scenario, we
also expected that the slower the drawing rate, themore of the polymer chains were included in the shish.
On the basis of the considerations, we sought to confirm the scenario by using SANS and SAXS on drawn
films of d-PE and h-PE with various molecular weights.
From the experimental results, we had to distinguishbetween the two types of PE at the nanometer scale.
Therefore, we used SANS and SAXS measurements forthis experiment.
Figure 1 shows the 2D SAXS and SANS patterns forthe drawn PE blend films. The 2D SAXS patterns showed
weak two-spot patterns along the drawing direction
corresponding to the distance between the kebabs(or lamellar crystals). The 2D SAXS patterns were very
similar, thus suggesting that the small amount of added
h-PE (3 wt%) did not affect the whole structure of the PE
blends and functioned as a tracer. In contrast, in the 2D
SANS patterns, streak-like scattering was observed normal to the drawing direction. Streak-like scattering corresponding to scattering from the h-PE was observed inaddition to the two-spot pattern, thus suggesting thatthe shish mainly consisted of h-PE. At the same drawing rate, the streak-like scattering was enhanced as themolecular weight of the h-PE decreased. These results
suggested that the low molecular weight component
was more easily merged into the shish than the highmolecular weight component. Furthermore, for thesame molecular weight of h-PE (e.g., Mw = 58,000), thestreak-like scattering was enhanced as the drawing rate
decreased. The observed results qualitatively supported the picture predicted in the scenario.
To carry out a quantitative analysis, we evaluatedthe 1D SAXS and SANS intensities in the directions normal and parallel to the drawing direction. The SANS
contrast in the present samples arises from the scattering length density difference due to the mass density
difference and the scattering length density difference
between the hydrogen (H) and deuterium (D). The form
factor for the streak-like scattering normal to the drawing direction was approximately obtained as the difference between the SANS and SAXS intensities. The
intensity differences are shown in Fig. 2.
29

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MLF Annual Report 2017

Figure 1. 2D SAXS and SANS patterns for the drawn PE blends containing 3 wt% h-PE with different molecular weights.
The draw ratio is 7.0 for all samples.

Figure 2. (a) Intensity differences between the SANS and SAXS results in the normal direction for the PE blends containing
h-PE with different molecular weights. The solid curves are the results of the fits using the multicore-shell cylindermodel. The dashed lines show the contributions of the large shell. (b) Volume fraction of the core (shish) as afunction of the radius of the core (shish).

The multicore-shell cylinder model was applied toanalyze the intensity differences in the normal direction.
The illustration of the model can be found in Fig. 5 inref. [1]. The results of the fitting are shown as black solidlines in Fig. 2. These results suggested that the observed
results can be qualitatively explained with the scenario.
As mentioned in the introduction, this work was
motivated by two contrary experimental results on theflow-induced crystallization of PE and iPP. Though wehave not studied iPP or other flow conditions, it is clearthat there are various mechanisms for shish-kebab formation that depend on factors such as the type of flow
field, flow rate, type of polymer, temperature, molecularweight and molecular weight distribution. In various
cases, the shish would be formed by either high-molecular or low-molecular weight components.
References[1] T. Kanaya, et. al., Macromolecules, 40, 3650 (2007).
[2] S. Kimata, et. al., Science, 316, 1014 (2007).

T. Kanaya1,2, M. Murakami1, T. Maede1, H. Ogawa1,3, R. Inoue1,4, K. Nishida1, G. Matsuba5, N. Ohta3, S. Takata6, T. Tominaga7,
J. Suzuki7, Y.-S. Han8, and T.-H. Kim8
1
Institute for Chemical Research, Kyoto University; 2Material and Life Science Division, J-PARC Center; 3Japan Synchrotron Radiation
Research Institute; 4Research Reactor Institute, Kyoto University; 5Department of Polymer Science and Engineering, Yamagata University;
6
Neutron Science Section, Material and Life Science Division, J-PARC Center; 7Neutron Science and Technology Center, CROSS; 8Korea
Atomic Energy Research Institute, South Korea

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MLF Annual Report 2017

Research and Development Highlights

Structure and Mechanical Properties of Elastomer Thin
Films Bound to Carbon Interface
1. Introduction
The interface between polymers and inorganic
materials is of pivotal academic and industrial interest. An example is the interphase in nanocomposites,a class of materials composed of polymers (matrix) andinorganic nanopowders (fillers). In general, the performance of a nanocomposite strongly depends on not
only the physical properties of the matrix but also theinteraction between the matrix and the filler material. It
is noteworthy that the physical response of a composite
can be modulated via the interactions resulting fromthe attachment/detachment of polymers on fillers. Thismeans that an understanding of the interfaces between
the polymer matrix and inorganic fillers is essential toconstruct highly functionalized nanocomposites.
A specific example are tire materials; because therubber for tires consists mainly of a polymer elastomer
matrix and carbon black fillers, an understanding of
the interface between the polymer and carbon is important for quality improvement. It is well known thata nanometer-thick polymer layer, the so-called boundrubber layer (BRL), is formed on carbon fillers, and it isresistant to dissolution even in a good solvent for thepolymer. As in the case of other nanocomposites, it isempirically known that the BRL plays an important rolein improving the tensile strength, tear strength, fatigue
resistance, and wear resistance of tires [1].
There have been significant efforts in the industry to manufacture well-performing tires by making asurface-modified filler. As the structure and/or thermalmolecular motion of the polymer at the filler/polymer
interface are affected by the interactions with the filler, it is believed that surface modification changes theproperty of the BRL, resulting in better tire performance.
However, this is still a hypothesis because the evidence
is still insufficient and the empirical data, especiallyabout the influence of surface modification on the BRL,
is not enough, moreover, the relationship between the
BRL and the tire performance needs to be evaluated todevelop a guiding principle to improve the tire performance. To answer this question, hydrophilization treatment of carbon is performed to change the surface freeenergy (γ), and investigate the influence of an elastomer bound to the surface, model BRL, on the structure
and mechanical properties.

2. Experimental method
1,4-cis polybutadiene (PB) with a number-averagemolecular weight (Mn) of 190 kg/mol and molecularweight distribution of 2.3, and monodispersed deuterated 1,4-cis PB (d-PB) with a Mn of 90 kg/mol wereused. The glass transition temperature (Tg) of PB andd-PB evaluated by differential scanning calorimetry
were 170 K and 173 K, respectively. Si wafers were usedas substrates, and carbon films were prepared on the
Si wafers by plasma-enhanced chemical vapor deposition. Then, the carbon films were irradiated with alow-pressure mercury lamp with a wavelength (λ) of
185 nm and 254 nm in steam atmosphere at room temperature to change γ. To investigate the effect of thesurface modification, three kinds of carbon layers wereprepared. The γ of the carbon films were approximately
30, 45, and 58 mJ·m−2 (here we call these carbon layers
carbon-30, carbon-45, and carbon-58), respectively. PB
films were spin-coated on the carbon layers from a toluene solution and dried under vacuum for more than
12 h at room temperature. After that, the PB films wererinsed with a large amount of toluene 5 times to obtain residual layers (RLs) adhering on a carbon surface,which are model BRLs. Then, the specimens were dried
under vacuum for more than 8 h at room temperature.
Interfacial diffusion of polymeric chains between
the RLs and d-PB films on the RLs was examined byneutron reflectivity (NR) measurements with the SOFIA
reflectometer installed at BL16. For the measurements,
the d-PB films with a thickness of ca. 100 nm were spincoated on the RLs from the toluene solution and dried
under vacuum for more than 12 h at room temperature. After the measurements for the dried samples, thespecimens were annealed under vacuum for more than
8 h at 453 K, and NR measurements were performed after annealing. Incident neutrons with a λ ranging from0.25 to 0.88 nm were guided into the specimen. The reflectivity profiles depending on the scattering vector, q= (4π/λ)·sinθ, were analyzed by fitting based on the scattering length density profile along the depth direction
using the parratt32 software.
The normal force of the RLs was measured based onforce-distance curves derived from atomic force microscopy (AFM) observations. A cantilever made of Si with aspring constant and Young’s modulus of 1.6 N·m−1 and
169 GPa, respectively, was used to evaluate the normal
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Research and Development Highlights

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force, and an approach-retract scan was performed ata speed of 20 nm·s−1. To avoid contamination of thecantilever by the PB films, each measurement was performed using a fresh cantilever.
3. Results and discussion
Figure 1 shows the NR profiles of the RL/d-PB bilayers on the carbon films before and after annealing at
453 K for more than 8 h. For clarity, each data set of thebilayers is offset by two decades. The schematic fitting
model is illustrated in Fig. 1(c). Here, we focused on the
scattering length density (b/V) of RL, (b/V)RL, and the interfacial roughness between RL and d-PB, σint. Table 1
summarizes the (b/V)RL and σint values before and after
annealing. For comparison, (b/V) of the RL before adding d-PB calculated from the mass density obtained
from X-ray reflectivity of RLs are also listed in Table 1.
First, (b/V)RL of the RL on carbon-58 after the formationof a d-PB layer was larger than that of the RL without
the d-PB layer, and it increased upon annealing. This
indicates that a part of the d-PB chains has alreadypenetrated the RL during spin coating of the d-PB layer, and the intermixing of the molecules between the
RL and d-PB layers is enhanced by the annealing. In

contrast, no change in (b/V)RL was observed and only
σint increased upon annealing in the case of the RL on
carbon-45 and carbon-30 (the change in the NR profiles
was mainly caused by the change in the roughness ofthe d-PB surface, σd-PB, for all the cases). Note here that
σint of carbon-45 increased more than that of carbon-30;
that is, the PB molecules in the RL on the carbon-45
were slightly more mobile than those on carbon-30.
These results suggest that the mobility of the PB molecules in the RLs is strongly suppressed depending on
the γ of the carbon films.
Figure 2 shows the force-distance curves of the RLs.
In the case of the RL on carbon-58, the normal force
slightly increased immediately after contact with the
RL surface on approach, the slope becomes graduallysteeper with closer contact, and the force curve presents a large hysteresis upon retraction. This suggeststhat the cantilever first detected the normal force of theRL, which has a thickness of 6.3 nm in the rubbery state;it then detected that of the carbon under the RL uponfurther contact and finally detected the one modulated by the rubbery RL adhesion upon retraction. In
contrast, the slope of the force-distance curves immediately increased for the RLs on carbon-45 and carbon-30.

Figure 1. NR curves of (RL/d-PB) bilayer on the carbon film (a) before and (b) after annealing. Solid curves show calculated reflectivities based on model scattering length density profiles. (c) Schematic illustration of the model used for the bilayer.

Table 1. Scattering length density of RLs (b/V)RL and interfacial roughness of (RL/d-PB) interface σint before and after annealing.

RL without d-PB layer−2−2(b/V)RL / nm

32

Before annealing(b/V)RL / nm

After annealing

σint / nm(b/V) RL / nm−2σint / nm

RL(carbon-58)(0.43 ± 0.08) × 10

(1.02 ± 0.05) × 10

1.3 ± 0.3

(2.28 ± 0.06) × 10

2.6 ± 0.5

RL(carbon-45)(0.47 ± 0.05) × 10

(0.47 ± 0.05) × 10

1.4 ± 0.2

(0.48 ± 0.05) × 10

2.4 ± 0.4

RL(carbon-30)(0.50 ± 0.06) × 10

(0.50 ± 0.05) × 10

0.9 ± 0.3

(0.50 ± 0.05) × 10

1.2 ± 0.4

−4
−4
−4

−4
−4
−4

−4
−4
−4

MLF Annual Report 2017

Figure 2. Force-distance curve of RL on carbon films. Downwards arrows denote positions where slope between
Normal force and Z-sample position were obtained.

The slopes (m) of carbon-45 (m = 0.31 ± 0.02) and carbon-30 (m = 0.31 ± 0.02) were less than that of the carbon film (m = 0.38 ± 0.02) but obviously more than thatof the rubbery PB (m = 0.03 ± 0.01). This increment of
the slope, in other words, the enhancement of the stiffness for RL on the hydrophobic carbons, implies thatthe elevation of Tg is far above the bulk one. So far, thechange in the polymer dynamics at various interfaces
has been intensively studied and many experimental
works have reported the increase in Tg and the suppression of the dynamics above the bulk Tg. To the best of
our knowledge, the molecular orientation of the phenyl rings of a polystyrene (PS) film at an interface witha sapphire substrate did not change at 100 K above thebulk Tg [2], but our result suggests a greater elevationof the Tg. As a complete study of the elevation of the Tg
at the interface lies outside the scope of this work, weleave these details for a future study, focusing insteadon the mechanical properties of the RLs here.
4. Conclusion
Interfacial layers of PB films on bare andResearch and Development Highlights

surface-modified carbon films and RLs on the carbon
films were examined. Figure 3 is a schematic representation of the experimental results. An interfacial layer
of PB was present near the carbon layer, with density
and thickness identical to those of the RL after rinsing,in which case, a denser layer with more hydrophobic
surface was formed on the carbon. The thermal diffusion between the RL and d-PB top layer, investigated by
NR, indicated that the denser layer did not intermix significantly with the top layer. A consistent result was obtained for normal stress measurements based on AFM:
the RLs on hydrophobic carbons were not in a rubbery
state but presumably in a glassy state, whereas thoseon hydrophilic carbon were in a rubbery state. If the RLs
on the hydrophobic carbons were glassy at room temperature, the transition temperature increased by morethan 120 K [3].

High density bound rubber
on hydrophobic carbon

Low density bound rubber
on hydrophilic carbon

Figure 3. Schematic illustration of residual layers on hydrophobic and hydrophilic carbon.

Acknowledgement
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.
References[1] S. T. Palinchaket al., Rubber Chem. Technol., 31, 374(1958).
[2] K. S. Gautamet al., Phys. Rev. Lett., 85, 3854 (2000).
[3] K. Hori et al., Langmuir, 33, 8883, (2017).

K. Hori1,2, N. L. Yamada2,3, Y. Fujii4, T. Masui1, H. Kishimoto1, and H. Seto2,3
Chemical Analysis Center, Research & Development HQ. SUMITOMO RUBBER INDUSTRIES, LTD.; 2Neutron Science Section, Materials
and Life Science Division, J-PARC Center; 3Institute of Materials Structure Science, KEK; 4Department of Chemistry for Materials, Graduate
School of Engineering, MIE UNIVERSITY

1

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MLF Annual Report 2017

Analysis of Carbon Polygons by High-Resolution Pair
Distribution Function Obtained from Neutron Diffraction
1. Introduction
Graphene is a basic building block for a variety of
2-carbon architectures with different dimensions: zesp
ro-dimensional (0D) fullerene C60 [1], 1D single-walledcarbon nanotube [2, 3], 2D single-layer graphene [4, 5].
Moreover, it has been theoretically predicted that graphene is capable to form 3D frameworks (Fig. 1) known
as Mackay crystals [6] or carbon Schwarzites [7]. A zeolite-templating method is expected to synthesize such
imaginary 3D graphene frameworks as real materials [8,9]. By replicating zeolite 3D nanochannels (Fig. 2) withcarbon, zeolite-templated carbons (ZTCs) can be obtained, and the framework topology of ZTC accords tothat of the zeolite nanochannels.
It is beneficial to understand how sp2 carbons canbe assembled into three-dimensional graphene-based
frameworks in ZTC, towards the realization of carbon
Schwarzites. We have previously reported that a typical ZTC obtained by using FUA zeolite has an opengraphene framework, which is like the cross-linked
buckybowls shown in Fig. 3 (denoted as Model-I), rather than a closed tubular framework [8]. Model-I was
proposed as one of the possible structures, which meetmany experimental characterization results. However,the crystalline Model-I structure cannot perfectly

34

Figure 3. A geometric structure model for ZTC [Model-I]. Reprinted with permission [10]. Copyright 2018 Elsevier.

reflect the actual material, which contains amorphous
structures. Thus, we proposed recently a new model denoted as Model-II, constructed by molecular dynamics(MD) simulation to include randomized irregularity/defects [10]. This short review expounds our recent reporton the analysis of carbon polygons (pentagons, hexagons, heptagons, and octagons) included in the ZTC
framework, which was elucidated by comparing a pair
distribution function, g(r), of experiment with the onesof the aforementioned two models [10].

Figure 1. The structure of the Mackay crystal.

2. Experimental
ZTC was prepared by using the FAU zeolite as a template [8]. To discuss the presence of carbon polygons, ahigh-resolution g(r) was obtained by the neutron total
scattering instrument, NOVA (BL21), at Material and Life
Science Facility of J-PARC. The structure factor, S(Q), wasobtained from a measured diffraction profile after data
correction [11], including background, self-attenuation,
number of incident neutrons, solid angle of detectors,
multiple scattering, and incoherent scattering crosssections. To obtain g(r), S(Q) was Fourier transformed in
the Q range of 0.2–55.0 Å–1.

Figure 2. The structure of (a) FAU zeolite and (b) its nanochannel morphology. Reprinted with permission [10].
Copyright 2018 Elsevier.

3. Construction of Model-II
As shown in Fig. 4a, Model-II was constructed in
the FAU zeolite framework (2×2×2 supercell with dimensions Lx = 48.14 Å, Ly = 48.14 Å, and Lz = 48.14 Å) byquench molecular dynamics simulation with the reaction state summation potential [12]. The details can befound in our previous publication [10]. A part of the resulting structure is cut out and shown in Fig. 4b. Someof the representative framework units corresponding to
one zeolite supercage are shown in Fig. 4c-k.

MLF Annual Report 2017

Research and Development Highlights

Figure 4. (a) The initial state of the calculation for the construction of Model-II. Carbon atoms are distributed inzeolite nanochannels. (b) A part of Model-II corresponding to Fig. 2b. Representative nine framework
units are enlarged in (c-k). Carbon polygons, except hexagons, are indicated by the polygon numbers.
Reprinted with permission [10]. Copyright 2018 Elsevier.

4. Carbon polygons
From the analogy of imaginary structures like
Mackay crystals or carbon Schwarzites [6, 7], the presence of carbon heptagons and octagons is expected
to realize a continuous open framework. On the other
hand, carbon pentagons basically make a framework
closed like C60, though the Model-I realizes a continuous open framework only by carbon pentagons andhexagons. Thus, the ratio of carbon polygons in the ZTC
framework is an interesting issue. Fig. 5a shows g(r) of
ZTC, compared with those of the two models. As references, the experimental data of graphite and C60 are
also shown. In Fig. 5a, the distances to the 1st, 2nd, 3rd,
4th, and 5th neighboring carbon atoms (d1st, d2nd, d3rd,
d4th, and d5th) in ZTC are denoted. Figs. 5b-e show d2nd
on the four types of carbon structures. In graphite hexagons (Fig. 5b), d2nd is 2.46 Å, while d2nd in C60 pentagons
is 2.33 Å (Fig. 5c). Pentagons in Model-I (Fig. 5d) also
have a short d2nd (2.25–2.30 Å), and the difference fromd2nd of hexagons is 0.16–0.21 Å. On the other hand, d2ndof carbon heptagons is 2.48–2.50 Å (Fig. 5e), and thedifference from d2nd of carbon hexagons is only 0.02–
0.04 Å. Carbon octagons and larger polygons have very
close d2nd values to that of hexagons and thus, they cannot be distinguished each other in g(r).
In Model-I, about 19% of carbon atoms are involvedin carbon pentagons, while 81% are in hexagons. Thus,
Model-I shows a peak corresponding to pentagons at
2.28 Å. Model-II contains carbon pentagons, hexagons,
heptagons, and octagons, with ratios approximately
3%, 63%, 23%, and 11%, respectively, if further larger

polygons are not considered. While the amount of thepentagons is too small to show an apparent peak, aheptagon shows a shoulder at 2.49 Å. In an actual

Figure 5. (a) Pair distribution function, g(r). Experiment: ZTC,
C60, and graphite. Calculation: Model-I and Model-II.
Peaks corresponding to the 1st-5th nearest neighboring carbon atoms in ZTC are denoted. The peak
positions of carbon pentagons (red font) and heptagons (green font) are described. Negative peaks
are indicated by black arrows, and d4th of C60 andModel-I is indicated by purple arrows. (b-e) Structure models of (b) graphite, (c) C60, (d) Model I, and(e) Model II. The values of d2nd [Å] are described forcarbon pentagon (red), hexagon (blue), and heptagon (green). Reprinted with permission [10]. Copyright 2018 Elsevier.

35

Research and Development Highlights

MLF Annual Report 2017

experiment, however, the peak broadening is inevitable. Nevertheless, C60 barely shows a broad shoulder at
2.33 Å, corresponding to carbon pentagons, by the presence of significant amount of carbon pentagons (37.5%)
and the high-resolution neutron diffraction measurement. The presence of pentagons appears also at d4th.
In C60, d1st, d2nd, and d3rd peaks corresponding to C–C distances inside carbon hexagons are the same as those ofgraphite. But, d4th, involving two neighboring hexagon/
pentagon rings, is noticeably shorter than that of graphite because of a positively curved framework induced bycarbon pentagons. The d4th position of Model-I is almost
the same as that of C60 because Model-I includes carbon
pentagons and has a positively curved framework. Thus,
carbon pentagons can be distinguished from hexagons,
if their amount is large enough in the present experiment. On the other hand, it is still difficult to distinguishcarbon heptagons and larger polygons in the present
resolution of the experiment.
ZTC does not show a peak/shoulder at 2.28–2.30 Å,and its d4th is almost the same as that of graphite, indicating that the ZTC framework rarely contains carbon pentagons. Note that negative peaks at 1.08–1.11 Å in ZTC
and two models are derived from negative correlation
between C and H atoms. Apart from the amount of H,
the overall ZTC g(r) related to the C–C correlation agrees
well with that of Model-II rather than Model-I. Thus,
Model-II represents very well the internal graphene microstructure of ZTC, and the results suggest an interesting possibility, i.e., the presence of significant amount ofcarbon heptagons and octagons in ZTC. The framework
topology of zeolite nanochannels, in which graphene
growth is developed, is analogous to those of Mackay
crystals and carbon Schwarzites, and it is hypothesizedthat such a geometrical restriction induces the inclusionof carbon heptagons and octagons rather than carbon
pentagons in a hexagon-based sp2 network.
5. Summary
The types of carbon polygons included in the ZTC
framework are analyzed by comparing a pair distribution function, g(r), obtained by experiment with theones of the two structure models. It is suggested that
the ZTC framework contains a diverse range of carbon
polygons such as hexagons, heptagons and octagons,
while the number of the pentagons is small. Such

distribution of carbon polygons demonstrates interesting similarities between the real three-dimensionalgraphene-based framework and the imaginary ones
like Mackay crystals and carbon Schwarzites.
Acknowledgements
The neutron scattering experiment was approved by the Neutron Scattering Program Advisory
Committee of IMSS, KEK (Proposal No. 2014S06). This
work was supported by a Grant-in-Aid for Scientific
Research (A), 17H01042 (H.N.); Dynamic Alliance forOpen Innovation Bridging Human, Environment andMaterials; and the Network Joint Research Center for
Materials and Devices.
References[1] H. W. Kroto, J. R. Heath, S. C. O'Brien, R. F. Curl and R.
E. Smalley, Nature, 318, 162 (1985).
[2] S. Iijima and T. Ichihashi, Nature, 363, 603 (1993).
[3] K. Hata, D. N. Futaba, K. Mizuno, T. Namai, M. Yumura
and S. Iijima, Science, 306, 1362-1364 (2004).
[4] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang,
Y. Zhang, S. V. Dubonos, I. V. Grigorieva and A. A.
Firsov, Science, 306, 666-669 (2004).
[5] A. K. Geim and K. S. Novoselov, Nat. Mater., 6, 183191 (2007).
[6] A. L. Mackay and H. Terrones, Nature, 352, 762(1991).
[7] T. Lenosky, X. Gonze, M. Teter and V. Elser, Nature,355, 333-335 (1992).
[8] H. Nishihara, Q.-H. Yang, P.-X. Hou, M. Unno, S.
Yamauchi, R. Saito, J. I. Paredes, A. Martinez-Alonso,
J. M. D. Tascon, Y. Sato, M. Terauchi and T. Kyotani,
Carbon, 47, 1220-1230 (2009).
[9] E. Braun, Y. Lee, S. M. Moosavi, S. Barthel, R. Mercado,
I. A. Baburin, D. M. Proserpio and B. Smit, Proc. Natl.
Acad. Sci. USA, DIO: 10.1073/pnas.1805062115.
[10] H. Nishihara, H. Fujimoto, H. Itoi, K. Nomura, H.
Tanaka, M. T. Miyahara, P. A. Bonnaud, R. Miura, A.
Suzuki, N. Miyamoto, N. Hatakeyama, A. Miyamoto,K. Ikeda, T. Otomo and T. Kyotani, Carbon, 129, 854862 (2018).
[11] T. Egami and S. Billinge, Underneath the Bragg Peaks-Structural Analysis of Complex Materials, Elsevier,
2012.
[12] Y. F. Shi, J. Chem. Phys., 128, 234707 (2008).

H. Nishihara1, H. Tanaka2, M. T. Miyahara2, K. Ikeda3, T. Otomo3, and T. Kyotani1
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University; 2Department of Chemical Engineering, Kyoto University;
3
Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK)1

36

MLF Annual Report 2017

Research and Development Highlights

Linking Spin-Fluctuations in Ba0.75K0.25Fe2As2 to Electron
Correlations
1. Introduction
Since the discovery of high-temperature superconductivity in iron-based superconductors (FeSC) in2008 [1], many studies have been performed to elucidate their electronic and magnetic properties. Earlier
studies have suggested that FeSCs are weakly correlatedmaterials [2], in sharp contrast to cuprate superconductors, in which Mott physics is more fundamentally tied
to superconductivity. However, increasing evidence
suggests that electron correlations in FeSCs are muchstronger than previously thought [3, 4]. The role of electron correlations is therefore the most interesting, yet
not well understood, aspect of the physics of FeSCs.
Here, we use inelastic neutron scattering (INS) to
study the effect of electron correlations on spin dynamics in hole-doped FeSCs Ba0.75K0.25Fe2As2. By combining
angle-resolved photoemission spectroscopy (ARPES)
measurements and first-principles calculations, weshow that the measured spin excitations are heavily
renormalized due to the correlated Fe-3d bands withenhanced effective electron masses. These results highlight the strongly correlated nature of FeSCs that should
be considered for a realistic treatment of the spin dynamics. In addition, the consistency between the results of the two momentum-resolved spectroscopic
methods, INS and ARPES, demonstrates a quantitative

(a)

(b)

E = 3±1 meV30

2

E = 60±5 meV
1.4

(e)
1.2

1

K (r.l.u.)

K (r.l.u.)

2. Results and discussion
INS measurements of Ba0.75K0.25Fe2As2 were performed using BL01 4SEASONS installed at J-PARC.
Figures 1 (a)-(d) compare the two-dimensional constantenergy maps of spin excitations in the (H, K) scattering plane for various energy transfers. At low energies
around E = 60 meV, spin excitations peak strongly at Q
= (1, 0), which corresponds to the nesting vector between hole and electron FSs. As the energy increases,
spin excitations form transversely elongated ellipses
that lead to splitting into two branches. At even higher
energies, these excitations broaden rapidly and form
broad circular shapes centered at the zone boundary Q= (1, 1). These dispersive features are also confirmed by
the constant energy cuts along the (1, 0) → (1, 1) highsymmetry direction in Fig. 1 (e), where a single commensurate peak centered at Q = (1, 0) at low energies (E< 60 meV) splits into a pair of two peaks with increasingenergy, and eventually moves close to the zone boundary Q = (1, 1) at E ∼ 200 meV.

2

1

0

200

0

-1

-1

-2

0
-2

-1

0

1

-2
-2

2

-1

H (r.l.u.)
(c)

0

1

2

0

150

H (r.l.u.)

E = 120±10 meV

(d)
1

2

E = 170±10 meV
0.5

2

1

100

1

K (r.l.u.)

K (r.l.u.)link between the magnetic response and the underlying electronic structure of FeSCs. This opens up new
possibilities for using INS as a momentum-resolved
spectroscopy for determining the correlated electronic
structure [5].

0

-1

50
0

-1

0
-2
-2

-1

0

H (r.l.u.)

1

2

0

-2
-2

-1

0

H (r.l.u.)

1

2

0

0
-1

0

1

(1, K ) (r.l.u.)

Figure 1. (a)-(d) Constant-energy maps of Ba0.75K0.25Fe2As2 in the (H, K) plane at energy transfers of E = 3 ± 1 meV, E = 60 ± 5 meV, E =120 ± 5 meV, E = 170 ± 10 meV, respectively. (e) Energy-band dispersion of spin excitations along the (1,K) high-symmetry
direction (see Ref [5]).

37Research and Development Highlights

MLF Annual Report 2017

the energy scale of the excitations. Along the (1, 0) →(1, 1) direction, the theoretical spin excitation peak extends approximately to ~ 600 meV, which is larger by afactor of ~ 3 than the experimental data.
This overestimation of the spin excitation energy
in our RPA analysis has important implications for theelectronic state of FeSCs. As it can be seen in Eq. (2), theelectronic band structure εmk determines the momentum- and energy-dependent structure of the dynamical spin susceptibility. The discrepancy between theexperimental and theoretical spin excitations, therefore, suggests that the actual electronic structure of
Ba0.75K0.25Fe2As2 deviates from the DFT-derived model. In
principle, DFT provides a good starting point for modeling the electronic structure of the weakly correlated
regime. However, when electron correlations become
sizable, the low-energy bands near the Fermi levelare heavily renormalized, which results in a substantial effective mass (m*) enhancement [or equivalently,
bandwidth (W) narrowing] relative to DFT calculations.
Spectroscopic probes, such as ARPES, can provide direct information about the real single-particle spectraof the correlated materials, which cannot be accurately
captured by DFT.
To gain more insight into the experimental electronic structure, we performed ARPES measurements
on crystals from the same batch as that used for INS
measurements. Figure 2 (c) shows the spectral image of
Ba0.75K0.25Fe2As2 along the high-symmetry Z-X direction
overlaid with DFT bands. The high-intensity region at
the X point corresponds to the bottom of the dxz/yz electron band. From the ARPES data, one can notice that

To understand the INS data, we provide a firstprinciples analysis of the spin excitation spectrum of
FeSCs on the basis of the itinerant picture. As a first step,
we construct an effective five-orbital model based on
density-functional theory (DFT) calculations (see Fig. 2(a)). Then, by considering Hubbard-type interactions(i.e., the intra-orbital Coulomb repulsion U, interorbital
Coulomb repulsion U’, Hund’s coupling J, and pair hopping J’) on top of the five-orbital model, we obtain the
dynamical spin susceptibility χs(q, E) within the randomphase approximation (RPA) as(1)
Here, S is the corresponding interaction vertex matrixand χ0(q, E) is the irreducible susceptibility given as(2)
where f (ε), εmk , and U1,n(k) are, respectively, the Fermi
distribution function, energy dispersion, and elementsof the unitary matrices from the orbital to the band basis. Figure 2 (b) shows a contour plot of the calculated
χs(q, E) along the high-symmetry directions. The spin
excitations are markedly different in the two directions (1,0) → (1,1) and (1, 0) → (0, 0). This is consistent
with the transversely elongated spin excitations seenin Fig. 1 (c). However, while our RPA calculation reproduces the spin-wave-like dispersive feature along thehigh-symmetry directions, it apparently overestimates(a)3

DFT bandfive-orbital model

(c)

(b)

(d)

600

200
6.48

Z
Z

2

27

X
X

0
150

-1

Energy (meV)

0

400
-0.05

E-E F (eV)Energy (meV)

Energy (eV)

1

-0.10

200
High

-0.15
-2

-3
Γ (0,0)100

X ( π,0)Z ( π,π)Γ (0,0)

0

0
(0,0)

(1,0)

(1,1)

(0,0)

DFT bandrenormalizedband
m*/mDFT ~ 3

50

Low

0

0

-0.20
0

0.5

1.0

(0,0)

(1,0)

(1,1)

(0,0)

Momentum (π/a)

Figure 2. (a) Electronic band structure of BaFe2As2 along high-symmetry directions. The black solid lines denote the DFT band structure, whereas the red dotted lines denote the effective five-orbital model. (b) Energy-band dispersion of RPA dynamical
spin susceptibility, χs(q, E), along high-symmetry directions. The RPA calculation was performed for the original DFT derived
band structure without mass renormalization (m*/mDFT = 1). (c) Comparison between ARPES and DFT band structures
along the Z-X direction. The black and red lines denote the original (m*/mDFT = 1) and the renormalized (m*/mDFT ~ 3) DFT
bands, respectively. The dxz/yz electron bands at the X point are denoted by the thick lines. (d) Energy-band dispersion of
RPA dynamical spin susceptibility, χs(q, E), along high-symmetry directions. To account for the ARPES-derived mass enhancement factor, the RPA calculation was performed for the renormalized (m*/mDFT ~ 3) DFT band structure (see ref [5]).

38MLF Annual Report 2017

the experimental dxz/yz bandwidth is much narrower
than the DFT-calculated one. As mentioned above, thisis a manifestation of strong electronic correlation. Theband renormalization factor (m*/mDFT ), which quantifies the strength of electron correlation, is estimated byscaling the DFT band to fit the dxz/yz band bottom at X.
This analysis yields m* /mDFT ∼ 3, which is surprisingly
close to the renormalization factor of the spin excitation bandwidth. Such consistency between the resultsof INS and ARPES has not been reported before.
Considering the strong sensitivity of the spin excitations to the underlying electronic structure, one can
expect that the Fe-3d bandwidth narrowing due toelectron correlations is directly reflected in the spin excitation energy scale. To confirm this, we re-evaluatedthe dynamical spin susceptibility under the scaling of
the electron band energy as εmk → εmk /z. (Here, z = m*/
mDFT is the ARPES-derived mass enhancement factor.)
As shown in Fig. 2 (d), this scaling reduced the spin excitation bandwidth to ∼ 1/ 3 of its original width, yielding
a broadly consistent description of the observed INS
data. The reasons for this consistency can easily be understood as follows. The dispersion of spin excitations isdefined by the resonance condition in Eq. (2), in which
the denominator of irreducible susceptibility becomeszero. If the electron band energy is renormalized as εmk→ εmk /z, correspondingly, a spin excitation peak energy,
defined as εnk+q → εmk, shows similar renormalization,much like the electron bands. This means that the concept of mass renormalization in the Fermi-liquid theory
can be extended to dynamical spin susceptibility.
Our results thus demonstrate that it is possible tomodel the spin excitations of FeSCs by incorporating
aspects of the low-energy quasiparticle renormalization that affect both single- and two-particle quantities.
In addition, the consistency of the mass renormalization factors determined by independent INS and ARPES
measurements highlights the potential capability of INS
for characterizing the strength of electron correlations.
The observed mass renormalization m/mDFT ∼ 3 is comparable to, or even larger than that of typical correlated
metals such as SrVO3 (m*/mDFT ∼ 2) [6] and Tl2Ba2CuO6+δ
(m*/mDFT ∼ 3) [7]. This means that FeSCs have stronger
electron correlations than previously expected, andResearch and Development Highlights

more importantly, such a correlated electronic state isa crucial aspect that must be taken into account for therealistic description of spin dynamics in these materials.
With recent advances in modern INS spectrometers at
spallation neutron sources, it is now becoming possible
to experimentally determine the complicated spin susceptibility arising from the correlated electronic band
structure, and in the future INS will allows us to discussboth electronic and magnetic structures on an equal
footing.
3. Summary and perspectives
Historically, the development of experimental
methods and instrumentation has greatly accelerated
scientific progress, and this is also true for neutron spectroscopies. In particular, the availability of high-energy
and high-flux neutrons at spallation neutron facilities
offers a unique opportunity to use INS as a complementary spectroscopic probe to ARPES for the study of electronic band structures in the sub-eV range. The present
work highlights the power and versatility of modern
neutron spectroscopy as a bulk-sensitive probe of theelectronic structure, by addressing some fundamental
issues of electron correlation effects in FeSCs.
To date, J-PARC has ramped the operational beam
power to 500 kW. The present beam power is not ashigh as expected, but when ramped up to its full-power capability of 1.0 MW, J-PARC will provide one of themost intense pulsed neutron beams in the world. The
availability of more intense neutron sources in the next
few years would further improve the potential of INS
as a versatile and practical spectroscopic technique toinvestigate both electronic and magnetic structures onan equal footing.
References[1] Y. Kamihara et al., J. Am. Chem. Soc. 130, 3296
(2008).
[2] W. L. Yang et al., Phys. Rev. B 80, 014508 (2009).
[3] Z. P. Yin et al., Nat. Mater.10, 932 (2011).
[4] M. Yi et al., npj Quantum Materials 2, 57 (2017).
[5] N. Murai et al., Phys. Rev. B 97, 241112(R) (2018).
[6] T. Yoshida et al., Phys. Rev. Lett. 95, 146404 (2005).
[7] P. M. C. Rourke et al., New J. Phys. 12, 105009 (2010).

N. Murai1, K. Suzuki2, S. Ideta3, M. Nakajima4, K. Tanaka3, H. Ikeda5, and R. Kajimoto1
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Research Organization of Science and Technology, Ritsumeikan
University; 3UVSOR Facility, Institute for Molecular Science; 4Department of Physics, Osaka University; 5Department of Physics, Ritsumeikan
University

139Research and Development Highlights

MLF Annual Report 2017

Tomonaga-Luttinger Liquid State in the Inequilateral
Diamond-Chain Compound K3Cu3AlO2(SO4)4
1. Introduction
Identifying spin liquid phases in the ground stateis one of the hot topics in the field of low-dimensional
quantum magnets. However, in most cases, experimental verification is difficult, because it is rare to have an
ideal compound with negligibly weak inter-chain interactions. The distorted diamond-chain system is such asystem. The ground state phase diagram of the distorted diamond-chain has been determined and it showsthat there are three phases, a ferrimagnetic phase, analternating tetramer-dimer phase, and an alternating
dimer-monomer phase that represents the special caseof a Tomonaga-Luttinger (TL) spin-liquid state [1, 2].
Azurite Cu3(CO3)2(OH)2 is considered to be one of thefirst experimental realizations of a spin-1/2 distorted diamond-chain system [3-6]. Therefore, a few theoreticalworks have also attempted to explain the unique magnetic properties of azurite, although none has yet beenable to fully account for the experimentally observed
behavior of this material [7, 8], due to the occurrence ofrelatively strong inter-chain interactions.
Recently, a highly one-dimensional (1D) inequilateral diamond-chain compound alumoklyuchevskite
K3Cu3AlO2(SO4)4 has been reported by some of the present authors [9].
The space group and structural parameters for thesynthesized material are determined from single crystal
XRD and synchrotron powder XRD [10]. Figure 1(a) and
Fig. 1(b) show that K3Cu3AlO2(SO4)4 contains magnetic
Cu2+ ions in an inequilateral diamond-chain arrangement along the a-axis direction. The nearest-neighbormagnetic couplings, Ji (i = 1 to 5), are the superexchangeinteractions through Cu-O-Cu bonds, see Fig. 1(c). In addition, the exchange interactions through the Cu-O-SO-Cu exchange paths are denoted by Jm, Jd, Jd′ in Fig. 1(c).
The magnetic susceptibility exhibits a double broad
peak at around 200 K and 50 K. By analyzing the magnetic susceptibility, an effective model for K3Cu3AlO2(SO4)4
has been proposed [11], where the dimer is formed by
one of the four sides in the diamond and the remaining
spins form a 1D Heisenberg chain, as shown in Fig. 1(d).
The model is different from that for the azurite.
Here we report our detailed studies ofK3Cu3AlO2(SO4)4 through muon spin rotation/relaxation (μSR) spectroscopy and inelastic neutron scattering (INS). These experimental results indicate that
K3Cu3AlO2(SO4)4 is an appropriate model material forthe investigation of the TL spin liquid state at low temperatures close to the ground state.
2. Experimental Details
Single phase polycrystalline K3Cu3AlO2(SO4)4 wassynthesized by solid-state reaction. The ZF and LF μSR
experiments were performed using the spin-polarized
pulsed surface-muon (μ+) beam at the D1 beamlineof the MLF of J-PARC. The INS experiments were performed on the HRC, installed at the BL12 beamline at
the MLF of the J-PARC. A 400 Hz Fermi chopper wasused to obtain a high neutron flux. A GM-type closed
cycle cryostat was used to achieve 100 K and 4 K. Theenergies of incident neutrons were Ei = 205.8 meV and
45.95 meV (second frame), which yielded energy resolutions of E = 5 and 1 meV at the elastic position.

Figure 1. (a) Crystal structure of K3Cu3AlO2(SO4)4 featuring a large inter-chain spacing. (b) The diamond chain of K3Cu3AlO2(SO4)4,
which consists of Cu2+ ions (grey spheres) along the a-axis with nearby oxygen (red spheres) and sulfur ions (yellow
spheres). (c) Effective spin model of K3Cu3AlO2(SO4)4 with the nearest-neighbor exchange couplings Ji (i = 1 to 5), and thenext nearest-neighbor exchange couplings of Jm, Jd, and Jd,. (d) Spin configuration of the ground state for K3Cu3AlO2(SO4)4.

40

MLF Annual Report 2017

3. μSR evidence for a quantum spin liquid state in
K3Cu3AlO2(SO4)4
Quantum spin fluctuations in K3Cu3AlO2(SO4)4 areinvestigated by using ZF and LF μSR measurements fora powder sample in the temperature range from 90 mK
to 300 K.
The ZF-μSR spectra are fitted by the stretched exponential functiona(t) = a1 exp[−(λt)β] + aBG,
where a1 is an intrinsic asymmetry, aBG is a constantbackground, λ is the muon spin relaxation rate, and β isthe stretching exponent. The spectra at representative
temperatures are presented in Fig. 2(a). The combined
effect of these multiple nuclear dipole fields leads to aphenomenologically described relaxation function of
the stretched exponential. The field distribution andthe stretching exponent at high temperatures are approximately given by ∆nuclear = λ /γμ = 0.6 G and β ≈ 2,
respectively, which are typical for a nuclear dipole field.
The ZF spectrum at the lowest temperature 90 mK decreases continuously without oscillations up to 20 μs(see Fig. 2(b)). If this ZF spectrum is due to static magnetism, the internal field should be approximately 1.1 G.
However, the relaxation is clearly observed, even in the
LF at 0.4 T (see Fig. 2(c)), which is evidence for the fluctuation of Cu2+ electron spins without static ordering
down to 90 mK.

Figure 2. (a) ZF-μSR spectra at representative temperatures.
The thick lines behind the data points are curves
fitted by using the stretched exponential function(see text). (b) ZF-μSR spectrum measured at 90 mK,
which decreases continuously without oscillations
up to 20 μs. (c) μSR spectra measured at 90 mK under ZF and representative longitudinal magnetic
fields.

Research and Development Highlights

4. Spinon continuum and spin-singlet dimer excitations in the inelastic neutron scattering spectra
The theoretical study predicted that a gaplesslow-energy spin excitation and gap excitation will beobserved by an INS experiment, because the spin dimer together with a nearly isolated 1D Heisenberg
spin chain characterizes the magnetic properties ofK3Cu3AlO2(SO4)4.
Figure 3(a) shows the magnetic scattering contribution at 4 K, which is obtained by subtracting thephonon contribution from the observed spectrum at
100 K. The strong flat signal is seen at approximately
10 meV, indicating that there is a van Hove singularityof spinon continuum edges at this energy. On the other
hand, especially in the 1D system, powder orientational
average obfuscates the INS intensity distribution anddisplaces considerably the Q position from the true
q1D position, where Q denotes the experimental wavenumber in powder experiment and q1D is defined as thewavenumber along 1 chain direction. Thus, we also use
a conversion method mitigating the powder average
effect for a one-dimensional system [12]. This methodenhances the vertically rising part of dispersion andcorrects the Q position to the corresponding q1D position on the basis of the differential with respect to Q.
The converted result is shown in Fig. 3(b). The spinon
continuum edges rise from the Brillouin zone centers inchain direction, q1D = π/a = 0.64 Å−1 and 3π/a = 1.91 Å−1.
In addition, the observed lower-energy boundary of
the continuum is consistent with the theoretical line forthe 1D spin-1/2 Heisenberg antiferromagnet given by(πJd/2) |sin(Qa)| [13], indicating that the velocity of spin
excitations of K3Cu3AlO2(SO4)4 is an appropriate for the
1D spin-1/2 Heisenberg antiferromagnet.
Figure 3(c) shows the data measured with Ei =205.8 meV. A signal is observed at around E = 40 meV
and Q = 1.0 Å−1. The signal due to magnetic excitations
is generally enhanced at low-Q values, whereas phonon
excitations are dominant at high-Q. Therefore, we consider that this signal comes from magnetic excitations.
The dynamical spin structure factor for the proposed model has been calculated by the dynamical
density-matrix renormalization group [12]. In order tocompare the calculated spectrum with the powder INS
spectra in Figs. 3(a) and 3(c), we simulate the powderaveraged INS spectrum, including the magnetic form
factor of Cu2+ , by using a conversion technique (seeEq. (2) of Ref. 13). Figure 3(d) shows the simulated
powder-averaged INS spectrum. The agreement with41

Research and Development Highlights

MLF Annual Report 2017

Figure 3. (a) INS spectra for K3Cu3AlO2(SO4)4. (a) Magnetic scattering contribution extracted the 100 K data from the 4 K data corrected for the phonon population factor (Ei = 45.95 meV). (b) Single-crystal-like data obtained by applying the conversion
method. The superimposed gray dashed lines indicate the lower and upper energy boundaries of the continuum given by(πJd/2)|sin(Qa)| and πJd|sin(Qa/2)| [13], respectively, where a is the lattice parameter in the chain direction. (c) Experimental
raw data measured at 4 K with incident neutron energy of 205.8meV. (d) Simulated powder-averaged INS spectrum.

experimental data in Figs. 3(a) and 3(c) is fairly good.
Therefore, we are confident that the proposed exchange interactions and the spin configuration shownin Fig. 1(c) are appropriate for this compound. In otherwords, the low-energy excitation is characterized by a
TL spin liquid.
5. Summary
Spin-1/2 inequilateral diamond-chain compound
K3Cu3AlO2(SO4)4 has been experimentally examined bymuon spin rotation/relaxation spectroscopy and inelastic neutron scattering. No three-dimensional longrange order is present down to 90 mK, K3Cu3AlO2(SO4)4
is regarded as a typical compound that exhibits a TL
spin liquid behavior at low temperatures close to theground state. By comparing the INS experimental datawith calculations for a theoretically proposed model,
we have confirmed that the compound is describedby a composite structure consisting of singlet dimers
and a one-dimensional Heisenberg chain, which is different from an alternating dimer-monomer model corresponding to azurite. K3Cu3AlO2(SO4)4 would further
contribute to the experimental efforts in uncovering

exotic properties of the TL spin liquid, such as spinon
spin currents and ballistic thermal conduction.
References[1] K. Okamoto, et. al., J. Phys.: Condens. Matter 11,
10485 (1999).
[2] K. Okamoto, et. al., J. Phys.: Condens. Matter 15,5979 (2003).
[3] H. Kikuchi, et. al., Phys. Rev. Lett. 94, 227201 (2005).
[4] K. C. Rule, et. al., Phys. Rev. Lett. 100, 117202 (2008).
[5] K. C. Rule, et. al., Phys. Rev. B 83, 104401 (2011).
[6] K. C. Rule, et. al., Phys. Rev. B 84, 184419 (2011).
[7] B. Gu, et. al., Phys. Rev. Lett. 97, 089701 (2006).
[8] H. Jeschke, et. al., Phys. Rev. Lett. 106, 217201(2011).
[9] M. Fujihala, et. al., J. Phys. Soc. Jpn. 84, 073702(2015).
[10] M. Fujihala, et. al., Sci. Rep. 7, 16785 (2017).
[11] K. Morita, et. al., Phys. Rev. B 95, 184412 (2017).
[12] K. Tomiyasu, et. al., Appl. Phys. Lett. 94,
092502 (2009).
[13] B. Lake, et. al., Nat. Mater. 4, 329–334 (2005).

M. Fujihala1, H. Koorikawa1, S. Mitsuda1, K. Morita2, T. Tohyama2, K. Tomiyasu3, A. Koda4,5, H. Okabe4,5, T. Yokoo4,6, S. Ibuka4,and S. Itoh4,61
Department of Physics, Faculty of Science, Tokyo University of Science; 2Department of Applied Physics, Faculty of Science, Tokyo Universityof Science; 3Department of Physics, Tohoku University; 4Institute of Materials Structure Science, KEK; 5Muon Science Section, Materials andLife Science Division, J-PARC Center; 6Neutron Science Section, Materials and Life Science Division, J-PARC Center42

MLF Annual Report 2017

Research and Development Highlights

Magnetic Excitations from Two-Dimensional
Interpenetrating Cu Framework in Ba2Cu3O4Cl2
1. Introduction
The elusive nature of high-temperature superconductivity continues to attract significant attention
from the scientific community. At the heart of the mostof these fascinating materials lies the copper-oxygen
building block. To understand the electronic correlations originating from such plaquettes, closely related
compounds, broadly referred to as cuprates, have received much attention. These materials are layered,possessing a square arrangement of Cu coordinated by
O ions with various atoms separating the layers. Doping
holes into the CuO2 planes have been shown to drive
many of these systems into complex phase space with
regions in which the superconducting state is stabilized.

Figure 1. Depiction of the magnetic structure in Ba2Cu3O4Cl2.
The blue and red circles represent CuA and CuB sites,
respectively. The blank circles denote intermediate
O atoms. The shaded blue and red outlines represent the magnetic unit cells when CuA and CuA-CuB
are magnetically ordered, respectively. The hopping terms between ions used in our modelling areconnected by colorized lines.

The planar crystal structure of Ba2Cu3O4Cl2 is somewhat peculiar, comprising of square lattice of Cu ionswith O ions in-between mediating the exchange interactions. However, in addition there are Cu in the middleof every other square. This forms two interpenetrating
Cu square lattices with an order of magnitude different
coupling strengths. This arrangement is between closely related Sr2CuO2Cl2 where no intermediate Cu ions arepresent and tetragonal CuO that possess Cu ions in the
middle of every square. In order to characterise thesecompounds, we have performed a series of neutron
scattering [1] and resonant x-ray experiments to map
out the magnetic dispersions [2]. Using an extended

one-band Hubbard model, we have been able to relate
successfully the fundamental electronic correlations toderive the magnetic spectra in each compound.
2. Experimental details
Inelastic time-of-flight (TOF) neutron scattering measurements were performed using spectrometers: HRC at
J-PARC, MAPS and MERLIN at ISIS. In the HRC measurements 5 crystals with a total mass of 4 g were coaligned.
A Fermi chopper operating at 300 Hz was employed forthe data presented herein. The MAPS and MERLIN measurements were carried out on 10 pieces of Ba2Cu3O4Cl2
with a combined mass of around 8 g. The Fermi chopper
was set to 550 Hz and 500 Hz for the MERLIN and MAPS
measurements, respectively. For all spectrometers, multirep mode was employed to obtain data at additional incident neutron energies Ei. The triple-axis spectrometer
IN20 was used for magnetic field studies with both horizontal and vertical focusing of the Si(111) monochromator and PG(002) analyzer. A sample of co-aligned crystals
totalling 8 g was mounted inside a 10 T vertical fieldmagnet with field along the c-axis. A fixed final neutronenergy of 14.7 meV was used for the measurements.
3. Inelastic neutron scattering results
Figure 2 shows the extracted magnon dispersion
in Ba2Cu3O4Cl2. Our measurements suggest that the interaction between CuA and CuB must be rather small as
we do not observe any magnetic zone folding or CuA
branch splitting that would be otherwise expected.
Strongly dispersive spin-waves emerge from the (0.5,0.5) point due to coupling between CuA spins as it
would be expected in the absence of CuB sublattice.
Tracking the CuA dispersion in energy transfer
shows a maximum of around 250 meV at (0.75, 0.25)
and close to 300 meV at (0.5, 0), see Fig. 2(a). The statistics of the data are poor above 300 meV and require
closer examination using RIXS to complement thisneutron scattering study [2]. A magnetic zone-boundary dispersion of at least 50 meV between (0.5, 0) and(0.75, 0.25) is found from our measurements. This effect has also been observed in closely related La2CuO4
and Sr2CuO2Cl2 compounds and explained in terms of
multi-spin exchange [3, 4]. To simulate the spin-wave
spectrum, we set the hopping parameters, shownin Fig. 1, between the CuA sites to be the same as the43Research and Development Highlights

MLF Annual Report 2017

closely related Sr2CuO2Cl2 compound. Examining theout-of-plane dispersion of the CuA modes and spingaps, we managed to constrain the exchange coupling
between CuA spins along c to be 0.025(1) meV and the
CuA-CuB sublattice coupling to be around JAB = −10 meV.
We found out that our model accounted well for the
CuA dispersion over the entire magnetic Brillouin zone.
Small differences, such as lower calculated spin-wave
velocity at the zone center may be accounted for by (i)taking higher-order hopping parameters or (ii) inclusion of Q-dependence of the renormalization Zc.
Now we turn to the low-energy dynamics of the
weakly-coupled CuB sublattice. The CuB spin-waves
emerge from (0.5, 0), and equivalent, positions in reciprocal space up to around 19 meV, as shown in Fig. 2(c).
The excitations are gapped by 3.8(2) meV. In Fig. 2(c)we observe spin-waves from CuB as well as steeply rising CuA excitations at (0.5, 0.5). A strong magnetic zone
boundary dispersion is found along (h, 0.25) which isshown in Fig. 2(a).

Figure 2. Dispersion along high-symmetry directions in the
2D Brillouin zone obtained at 6 K. (a) Extracted dispersion was obtained from TOF measurements using neutron incident energies in the 28–400 meVrange. The simulated spin-wave spectrum is shownfor different parameters of t’3 and JAB in units ofmeV. Other parameters were fixed to those shownin Table II and J⊥ = 0.025 meV. Data were collectedusing MERLIN, MAPS, HRC, and IN20 spectrometers.
Panels (b) and (c) show representative cuts throughthe measured spectrum obtained from the HRC
measurements. (b) shows rings from CuA latticehigh-energy modes centred at (0.5, 0.5) while in (c)we show the gapped CuA modes and low-energy
CuB dispersion.

44

The magnetic zone boundary in S = 1/2 squarelattice AFMs displays a number of intriguing quantum
effects. This is reflected on the spectrum in the following
ways: (i) the zone boundary at (π,0) is around 8% lower
than at (π/2,π/2); (ii) half of the single-magnon intensity
at (π/2,π/2) is missing; and (iii) a continuum of intensity
is found at (π/2,π/2). The first is reproduced by the inclusion of quantum fluctuations using series expansion
and quantum Monte Carlo methods for S = 1/2 squarelattice AFMs [5-7]. The zone-boundary dispersion canalso be modified by further neighbor interactions, as
found for the CuA sublattice in Ba2Cu3O4Cl2 and other related materials [3,4,8-10]. However, the latter (ii) and (iii)seem to be robust for all realizations of S = 1/2 squarelattice AFMs studied in sufficient detail thus far. One possible origin of this effect is spinon deconfinement [11],though it may also be a spin-wave interaction effect [12].
In this framework, for sufficiently large magnetic
fields, it may be possible to observe the confinementof ΔS = 1/2 spinons into ΔS = 1 spin waves. This is wellout of reach for systems such as La2CuO4 and Sr2CuO2Cl2that would require magnetic fields far in excess of whatis experimentally possible. To address this effect in
Ba2Cu3O4Cl2, we have performed TAS measurements using a 10 T magnet with field along the crystallographic
c axis. We observed what appeared to be a 5% sharpening of the mode at the zone boundary of the CuB sublattice at (1.25,0,0) — from a FWHM of 1.24(7) in zero
field to 1.18(5) meV at 10 T as shown in Fig. 3. However,no clear signs of a continuum could be detected in our
measurements.
In interpreting our results, we will first reflect on theseemingly missing continuum. Due to the phonon contribution, we would require polarized neutrons to conclusively exclude a continuum. However, the following
considerations apply if indeed the continuum is missing. If the continuum is already suppressed in zero field,
this would then explain why we also see no significant
change upon applying a magnetic field. The reductionin quantum fluctuations would also impact the size ofthe ordered moment. Treating the CuB sublattice as apurely nearest-neighbor coupled Heisenberg AFM withan Ising anisotropy of 0.026 would result in an orderedmoment of 0.73 μB, compared to the 0.6 μB for isotropic exchange coupling. However, our diffraction resultsthat found a CuB moment of 0.6(1) μB cannot distinguish reliably between the two scenarios. The potential absence of a continuum could provide a promising
direction for theoretical studies aiming to uncover thenature of quantum effects and we suggest both spinon

MLF Annual Report 2017

Figure 3. Magnetic field dependence of CuB sublattice. Constant wavevector measurements at high-symmetry
points on the magnetic zone boundary, at (1.25,0,0)and (1.25,0.25,0), are shown in (a) and (b), respectively. Error bars on points for base temperature in 0
and 10 T are smaller than the point size. A Gaussianline shape is fitted to the magnetic excitations in (a).

and interacting-spin-wave based theories should investigate the effect of adding anisotropy.
4. Conclusion
Using neutron diffraction and spectroscopy wehave characterized the static and dynamic magnetic
properties of Ba2Cu3O4Cl2. Magnetic excitations arefound to emerge from interpenetrating laminar sublattices of CuA and CuB spins each of which is arranged on asquare-lattice. Lower energy excitations between 3 and20 meV originate from the weakly coupled CuB spinsand closely resemble the Sr2Cu3O4Cl2 spectra [13]. In addition, we track the CuA-like excitations up to 300 meV,which have not been previously studied in this family

Research and Development Highlights

of materials. To characterize the spin dynamics, we employ a single-band Hubbard model from which wederive an effective spin Hamiltonian. A suitable parameterization of the magnetic spectrum is found using
linear spin-wave theory. Careful analysis of the CuA andCuB spin-gaps provides us with the out-of-plane coupling, the strength of the CuA and CuB coupling as wellas the exchange anisotropies. The interpenetrating CuB
sublattice is found to be only weakly coupled to the CuA
spins. Along the magnetic Brillouin zone boundary of
weakly-coupled CuB spins we find a significant dispersion that we argue is a quantum effect that is beyond
linear spin wave theory. On applying a magnetic field of
10 T we see a tiny magnon energy shift and sharpening.
However, the effects are smaller than expected, whichhints that anisotropy could be a useful parameter totune and better understand this quantum effect.
References[1] P. Babkevich et al., Phys. Rev. B 96, 014410 (2017).
[2] S. Fatale et al., submitted.
[3] R. Coldea et al., Phys. Rev. Lett. 86, 5377 (2001).
[4] M. Guarise et al., Phys. Rev. Lett. 105, 157006 (2010).
[5] R. P. Singh and M. P. Gelfand, Phys. Rev. B 52, R15695(1995).
[6] O. F. Syljuåsen and H. Rønnow, J. Phys.: Condens.
Matter 12, L405 (2000).
[7] P. Babkevich et al., Phys. Rev. Lett. 117, 237203(2016).
[8] P. Babkevich et al., Phys. Rev. B 82, 184425 (2010).
[9] B. D Piazza et al., Phys. Rev. B 85, 100508 (2012).
[10] S. Moser et al., Phys. Rev. B 92, 140404 (2015).
[11] B. D. Piazza et al., Nat. Phys. 11, 62 (2015).
[12] M. Powalski, G. S. Uhrig, and K. P. Schmidt, Phys.
Rev. Lett. 115, 207202 (2015).
[13] Y. J. Kim et al., Phys. Rev. B 64, 024435 (2001).

P. Babkevich1, N. E. Shaik1, D. Lançon1,2, A. Kikkawa3, M. Enderle2, R. A. Ewings4, H. C. Walker4, D. T. Adroja4,5, P. Manuel4, D. D.
Khalyavin4, Y. Taguchi3, Y. Tokura3,6, M. Soda7, T. Masuda7, and H. M. Rønnow1
1
Laboratory for Quantum Magnetism, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL); 2Institut Laue-Langevin;3
RIKEN Center for Emergent Matter Science (CEMS); 4ISIS facility, STFC Rutherford Appleton Laboratory; 5Highly Correlated Matter
Research Group, Physics Department, University of Johannesburg; 6Department of Applied Physics, University of Tokyo; 7Institute for Solid
State Physics, University of Tokyo

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Research and Development Highlights

MLF Annual Report 2017

Mono-Chiral Helimagnetism in CsCuCl3
1. Introduction
Chiral helimagnetic structures, which form only
one-handed screw magnetic structures, have attracted
attention due to their characteristic magnetic textures
such as Skyrmion lattices and chiral magnetic soliton
lattices [1, 2]. Therefore, it is important to investigate theinterplay between crystallographic and helimagnetic
chirality since the sense of the rotation of helimagnetic
structures strongly depends on the chiral crystal structures, which allow an anti-symmetric DzyaloshinskiiMoriya (DM) interaction [3, 4]. However, there are notmany experimental results due to the difficulty of synthesizing homo-chiral single crystals that have only
right-handed (RH) or left-handed (LH) crystal domains.
Helimagnetic CsCuCl3 has a chiral crystal structurewith chiral space groups of RH P6122 and LH P6522, as illustrated in Fig. 1. Unpolarized neutron diffraction studies showed helimagnetic ordering with the magnetic
propagation vector kmag = (1/3, 1/3, δ) (δ ∼ 0.09) below
10.5 K, suggesting a chiral screw structure with a periodof 210 Å [5]. However, the interplay between crystal andmagnetic chirality of CsCuCl3 cannot be investigatedbecause conventional crystal growth techniques produce racemic twinned crystals that have RH and LH domains in a sample. Here, we present a new technique togrow enantiopure single crystals and polarized neutron
diffraction studies, probing a strong correlation between crystal and magnetic chiralities, which governs
the nature of anti-symmetric DM interaction [6].

(a)2. Sample preparation
Our two-step crystal growth technique for inorganic chiral compounds makes it possible to obtaincentimeter-sized homo-chiral single crystals of CsCuCl3
with the desired handedness. First, millimeter-sized
seed crystals were synthesized by spontaneous crystallization with stirring. We succeeded in growing thehomo-chiral crystals when the solution was constantly
stirred in a beaker during the crystallization process [7].
Then, centimeter-sized homo-chiral crystals were obtained from the selected homo-chiral seed crystals. The
spontaneous crystallization started with only one seed
crystal in the saturated solution. The crystalline chiralityof the obtained crystals matched that of the seed crystals. The large homo-chiral crystals made it possible toperform polarized neutron diffraction.
3. Experiments
To determine the helimagnetic chirality of thehomo-chiral crystals of CsCuCl3, polarized neutron
diffraction experiments were performed on the BL15(TAIKAN) in the MLF in Japan, and on the instrument
POLI at the Maier-Leibnitz Zentrum (MLZ) in Germany. A
single-crystal spherical neutron polarimetry techniqueusing CRYOPAD was carried out at the POLI diffractometer operated in 2-axis mode. Neutron polarization andanalysis were achieved by 3He-spin filters in the incoming and scattered beams. The incomplete neutron polarization due to 3He-spin filters was corrected by using
a transmission monitor for the incoming beam and(b)

Figure 1. Crystal structures of (a) right-handed (space group: P6122) and (b) left-handed (space group: P6522) CsCuCl3.
The large, middle and small balls represent Cs, Cu and Cl ions, respectively. The arrows in a Cu chain shown in(a) and (b) represent right-handed and left-handed helimagnetic structures, respectively.

46

MLF Annual Report 2017

nuclear Bragg reflections for the scattered beam. The
neutron spin polarization is analyzed along i,f, where iand f represent the incoming and outgoing neutron polarization, respectively. Here, x is one of three orthogonal directions and is parallel to the scattering vector Q.
4. Results and discussion
The omega-scan profiles of the spin-flip channelsof the magnetic satellites are shown in Fig. 1. For the(1/3,1/3,6−δ) reflection in the RH crystal, shown in Fig. 2(a), we observed the magnetic satellite peak only when
the neutron polarization was along +x,−x. However, for

Research and Development Highlights

the (1/3,1/3,6+δ) reflection, shown in Fig. 2 (b), the peak
was observed only when the polarization was along−x,+x. The opposite behavior happened for the LH crystal, shown in Fig. 2 (c) and (d). These results indicatedthat the RH crystalline CsCuCl3 forms purely RH helimagnetic structure, and the LH crystal forms purely LH
helimagnetic structure.
Our experimental data revealed that the handedness of the magnetic helicity is coupled and directly
controlled by the crystallographic lattice chirality. The
results can be understood in terms of a DM interaction
strongly coupled to the lattice.

Figure 2. Omega-scan profiles of (a) $(1/3, 1/3, 6−δ) and (b) (1/3, 1/3, 6+δ) magnetic Bragg reflections for right-handed (P6122)
homo-chiral crystal and of (c) (1/3, 1/3, 6−δ) and (d) (1/3, 1/3, 6+δ) for left-handed (P6522) homo-chiral crystal. The filled
circles and open squares represent the measured intensities; the continuous lines are gaussian fits to the data.

References[1] S. Muhlbauer, B. Binz, F. Jonietz, C. Pfleiderer, A.
Rosch, A. Neubauer, R. Georgii, and P. Boni, Science
323, 915 (2009).
[2] Y. Togawa, T. Koyama, K. Takayanagi, S. Mori, Y.
Kousaka, J. Akimitsu, S. Nishihara, K. Inoue, A. S.
Ovchinnikov, and J. Kishine, Phys. Rev. Lett. 108,107202 (2012).
[3] I. Dzyaloshinsky, J. Phys. Chem. Solids 4, 241 (1958).
[4] T. Moriya, Phys. Rev. 120, 91 (1960).

[5] K. Adachi, N. Achiwa, and M. Mekata, J. Phys. Soc.
Jpn. 49, 545 (1980).
[6] Y. Kousaka, T. Koyama, K. Ohishi, K. Kakurai, V.
Hutanu, H. Ohsumi, T. Arima, A. Tokuda, M. Suzuki,
N. Kawamura, A. Nakao, T. Hanashima, J. Suzuki,
J. Campo, Y. Miyamoto, A. Sera, K. Inoue, and J.
Akimitsu, Phys. Rev. Materials 1, 071402 (2017).
[7] D. K. Kondepudi, R. J. Kaufman, and N. Singh,
Science 250, 975 (1990).

Y. Kousaka1,2, T. Koyama3, K. Ohishi4, K. Kakurai4, V. Hutanu5, J. Campo6, A. Sera3, K. Inoue2,3, and J. Akimitsu1,2
Research Institute for Interdisciplinary Science, Okayama University; 2Chirality Research Center, Hiroshima University; 3Graduate Schoolof Science, Hiroshima Univerisity; 4Neutron Science and Technology Center, CROSS; 5Institute of Crystallography, RWTH Aachen University
and Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ); 6Aragon Materials Science Institute (CSIC-Universityof Zaragoza)

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Polarized Neutron Reflectometry Probe of the Structural
and Magnetic Interfacial Inhomogeneity of Epitaxial
ε-Fe2O3/GaN Films
1. Introduction
Hybridization of semiconducting and magnetic
materials into a single heterostructure is believed toprovide opportunities for designing novel functional
spintronic devices. The iron oxides form a big familyof magnetic materials exhibiting a rich variety of outstanding physical properties. The metastable ε-Fe2O3
is known to be the most intriguing ferrimagnetic andmultiferroic iron oxide phase exhibiting a bunch of exciting physical properties both below and above room
temperature [1]. The feasibility of growing the exotic
ε-Fe2O3 phase along with three other iron oxide phases(Fe3O4, α-Fe2O3 and γ-Fe2O3) has been demonstrated [2].
Placing iron oxide film with controllable spontaneous
magnetization / polarization next to the active zone of
the GaN-based semiconductor devices is expected to
add magnetic related functionality to these devices andattract attention to their potential use in novel designsfor (opto-) electronic and spintronic applications.
2. Experimental
Polarized neutron reflectometry (PNR) experiments
were performed at the SHARAKU time-of-flight instrument (beamline BL17) at the MLF [4] and D17 (ILL,
France). The temperature and magnetic field at the
SHARAKU instrument were controlled by a 4-T horizontal field cryomagnet (Fig. 1). The polarization of the direct beam was measured by analyzer for each value ofthe magnetic field used in the experiment. The amplitudes of the PNR curves were corrected for polarization
efficiency. For quantitative discussions of the structure
and magnetic properties of the ε-Fe2O3 samples the
PNR data were fitted using the Parratt algorithm in the
GenX software package [5].
3. PNR analysis of the nuclear and magnetic profilesof the ε-Fe2O3/GaN heterostructure
PNR curves R(Qz) measured at temperatures 300 K
and 10 K are shown in Fig. 2a. The splitting of R+(Qz)and R−(Qz) reflectivity components is proportional to
the net magnetization of the film along the field direction. Because of the relatively small magnetic momentof the ε-Fe2O3 film, the splitting is hardly distinguishable at 300 K, but clearly observed after the sample
48

Figure 1. Horizontal 4 T cryomagnet installed at the SHARAKU
beamline, MLF.

was cooled to 10 K in magnetic field of 2 T. For neutronreflectometry, the buffer GaN layer with thickness of
3 μm is considered the bulk medium. Thus, PNR data
was fitted assuming the model consisted of GaN substrate, transition layer (interface) and ε-Fe2O3 layer. The
resultant models are summarized in the nuclear scattering length density (SLD) and magnetic SLD profiles(ρn(z) and ρm(z), respectively) shown in Fig. 2b. The minimum found by the fitting algorithm corresponds to themodel containing an interface layer with thickness of
37 ± 3 Å and roughness 24 ± 10 Å between iron oxide
and GaN. The obtained density of the ε-Fe2O3 layer isreduced by 5% and GaN density is reduced by 1.5%
compared to the literature values. The nuclear SLD of
the interface layer is reduced compared to the main
film of ε-Fe2O3 and close to the nominal value of ρn of
GaFeO3. The resultant magnetic ρm(z) profile obtained
at 10 K and 2 T is also shown in Fig. 2b. Interestingly, theMLF Annual Report 2017

interface layer appears to be magnetically degraded interms of the absolute magnetization and much softer
compared to the main ε-Fe2O3 layer.

Research and Development Highlights

This result and the observations obtained by thecomplementary techniques [3] suggest that gallium
substitutes iron in the interface region of the iron oxide layer leading to formation of GaFeO3 compound
isostructural to ε-Fe2O3. Formation of gallium ferrite isa probable scenario, which can explain both the magnetic degradation of the ε-Fe2O3/GaN interface region
and the magnetization loop shapes similar to those reported for ε-Fe2O3 layers grown on GaFeO3 buffer [6].
In the future, this issue can be further investigated byblocking Ga diffusion through introduction of a barrier layer, such as MgO or Al2O3 between GaN and ironoxide.
Acknowledgements
The neutron reflectivity measurements were performed on SHARAKU in J-PARC MLF under Project No.
2018A0199. We would like to thank N. Miyata, K. Akutsu,
Y. Kawamura (CROSS) for the technical support and K.
Kakurai (CROSS) for the fruitful discussion.

Figure 2. (a) PNR curves measured at 300 K (B = 50 and2000 mT) and at 10 K (B = 2000 mT). Symbols represent the experimental data while the solid lines arecalculated. The curves are shifted vertically for clarity. (b) Nuclear and magnetic SLD profiles deliveredby fitting routine. Magnetic SLD profile obtained at
10 K and applied field 2 T is shown.

References[1] Gich, M. et al., Advanced Materials, 26, 4645–4652(2014).
[2] Suturin, S. et al., Physical Review Materials 2, 073403(2018).
[3] Ukleev, V., et al., Scientific reports, 8,1, 8741 (2018).
[4] Nakajima, K., et al., Quantum Beam Science 1,3,9(2017).
[5] Bjö rck, M., Andersson, G., Journal of Applied
Crystallography 40, 1174–1178 (2007).
[6] Thai, T. M. N. et al., Journal of Applied Physics 120,
185304 (2016).

V. Ukleev1,2, S. Suturin3, T. Nakajima2, T. Arima2,4, T. Saerbeck5, and T. Hanashima6
Paul Scherrer Institut (Switzerland); 2RIKEN CEMS; 3Ioffe Institute (Russia); 4Department of Advanced Materials Science, University ofTokyo; 5Institut Laue-Langevin (France); 6Neutron Science and Technology Center, CROSS
1

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MLF Annual Report 2017

3D Polarimetric Neutron Tomography (3DPNT)
1. Introduction
The knowledge of the inner 3D distribution of magnetic field directions and strengths inside bulk material
cannot be obtained with conventional non-destructive
methods. At the Energy-Resolved Neutron Imaging
System BL22 beamline RADEN we have conducted thefirst proof-of-principle experiments that, in combination with newly developed reconstruction algorithms,
have allowed us for the first time to measure the 3D
magnetic field distribution of a current carrying solenoid with a technique capable of probing bulk material.

BL22 [1], where polarizing super-mirrors and spin-rotators were used to select the initial and final spin states
for polarization and analysis (see Fig. 1). The multiple
spin-rotators were all ramped to be in sync with thepulsed neutron beam, so that the full polarization matrix could be measured for all wavelengths. The sample– a current carrying solenoid – was placed on a rotation
stage and neutron intensity data with time-of-flight(ToF) information were recorded for 60 projection angles, each with 18 different combinations of directionsof spin polarization and analysis.

2. Underlying principle
Though electrically neutral, the neutron possesses
an intrinsic magnetic moment, caused by its spin. The
magnetic moment of the neutron will then precess inthe presence of an external magnetic field with the precession angle being proportional to the magnitude of
the magnetic field and the time spent by the neutron in
the field. 3D Polarimetric Neutron Tomography (3DPNT)
utilizes this effect by mapping an investigated magnetic field into the precession of the neutrons, which canbe calculated from measurements of polarization for
multiple initial spin orientations and projection angles.

4. Reconstruction techniqueAs the final neutron spin orientation depends
not only on the strength and direction of the magnetic field regions it traverses, but also on the orderby which these fields are passed through, standard filtered back-projection reconstruction methods cannot
be applied directly. However, under the assumption ofa relatively weak magnetic field linearized around B=0(weak enough to not cause phase-wrapping, which iswhen neutron spin precession is larger than π), the recorded data can be transformed to an axis-angle representation, and the x, y, and z components of B canbe reconstructed individually. The ToF information fromthe measurements was used to select the wavelength
range in which no phase-wrapping occurred.

3. Experimental set-up
Our experiments were performed at RADEN,

Detector

Analyser

Sampleπ /2 spin rotator
π /2 spin rotator
Polariser
π /2 spin rotator
π /2 spin rotatoryπ spin ﬂipperxz
Neutron Source

Figure 1. Schematics of the instrumental set-up. Super-mirror polarizers and analyzers, pulse-synced spin-rotators,
and a both time- and position-sensitive multi-channel plate detector was used.

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MLF Annual Report 2017

Research and Development Highlights

Figure 2. The reconstruction of a current carrying solenoid measured using 3DPNT. The three plotsshow the Bx, By, and Bz components of the magnetic field respectively.

5. Results
Figure 2 shows the reconstructed magnetic fieldfrom the current carrying solenoid measured with
3DPNT [2]. The main magnetic field, along the solenoid
axis, as well as the magnetic field components, where
the field wraps around the ends of the solenoid, areeasily seen. Moreover, the magnetic field from the wires
going to and from the solenoid was resolved as well.
The reconstructed results were furthermore confirmedby finite element Biot-Savart law calculations of themagnetic field from a solenoid of the same shape andsize, carrying the same current of 0.6 A.
6. Conclusion
Our work at RADEN has provided a solid proofof-principle showing the possibilities of 3DPNT as atechnique capable of revealing hitherto unattainable
information of 3D magnetic field distributions andelectric current flow. Such information can be of value
in a range of scientific and material design disciplines
such as the development of batteries and other energy

materials, superconductors, shape-memory alloys, andin other investigations of the interplay between structural and magnetic sample compositions.
7. Future plans
The technique presented here is limited to themeasurement of magnetic fields strong enough tocause resolvable spin precession while at the same time
weak enough to not cause spin precession beyond π.
To broaden the applicable range of 3DPNT, we are currently working on an iterative forward model optimization reconstruction algorithm taking full advantage of
the ToF information at RADEN in order to reconstructstronger magnetic fields. Furthermore, we have recently used the technique at RADEN to study the 3D electric
current flow in a battery model.
References[1] T. Shinohara et al., J. Phys.: Conf. Ser. 862, 012025(2017).
[2] M. Sales et al., Sci. Rep., 8, 2214 (2018).

M. Sales1, M. Strobl2, T. Shinohara3, A. Tremsin4, L. Theil Kuhn5, W. R. B. Lionheart6, N. M. Desai6, A. Bjorholm Dahl7, and S. Schmidt1
Department of Physics, Technical University of Denmark; 2Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, Switzerland;
3
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 4Space Sciences Laboratory, University of California at
Berkeley, Berkeley, USA; 5Department of Energy Conversion and Storage, Technical University of Denmark; 6School of Mathematics, The
University of Manchester, United Kingdom; 7Department of Applied Mathematics and Computer Science, Technical University of Denmark

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MLF Annual Report 2017

First Muon Acceleration Using a Radio-Frequency
Accelerator
1. Introduction
Muon acceleration using radio-frequency (RF) accelerator has been discussed due to its potential advantages. For example, in muon collider and neutrino
factory studies [1], it has been proposed that the largetransverse emittance of the muon beam could be
reduced through ionization energy loss and subsequent acceleration [2, 3]. In material and life sciences,
one promising application of muon acceleration is in
the construction of a transmission muon microscope.
Transmission muon microscopes will become possible,
if the muons can be cooled to the thermal temperature(ultraslow muon, USM) and subsequently re-accelerated [4]. Another application of USM acceleration is theprecise measurement of the muon anomalous magnetic moment aμ = (gμ − 2)/2 and the electric dipole moment (EDM) [5] (Fig. 1). Muon acceleration is essential
to realize these applications; however, it has not been
demonstrated.

SiliconTracker

3 GeV proton beam
( 333 uA)
Producon target(20 mm)Surface muon beam
(28 MeV/c)
Muonium Producon(300 K ~ 25 meVэ2.3 keV/c)

Super Precision Storage Magnet(3T, ~1ppm local precision)

Resonant Laser Ionizaon of Muonium (~106 +/s)Δ(g-2) = 0.1 ppm
ΔEDM = 10-21 e䞉cm

1Figure 1. Overview of the J-PARC muon g-2/EDM experiment.

In October 2017, we successfully demonstrated thefirst negative muonium ions (Mu−‘s) [6], which will bereported in this paper.
2. Experimental setup
The experiment was conducted using a radio-frequency quadrupole linac (RFQ) installed at the MUSE D2
area. Figure 2 shows the experimental setup. A pulsed
surface muon (μ+) beam was injected into an aluminum
degrader, and some portions form the Mu−‘s. The μ+energy was chosen to be 2.9 MeV to maximize the Mu−
emission yield on the basis of a separate experiment [7].
The Mu−‘s were extracted and accelerated to 5.6 keV by
an electrostatic lens. They were then injected into the
RFQ and accelerated to 89 keV. The accelerated Mu−‘swere detected by a micro-channel plate (MCP) detector after a diagnostic beamline. The diagnostic beamline consisted of a magnetic quadrupole pair (QM1 andQM2) and a bending magnet.
3. Results
Figure 3 shows the time of flight (TOF) spectrumwith and without the RF operation after event selections. With the RF operation, a clear peak was observed
at 830 ns. The TOF spectrum was confirmed with a seriesof simulations and it was consistent with the measurement within statistical error. The hatched histogram in
Fig. 3 represents the simulated TOF spectrum of the accelerated Mu−‘s. The number of simulation events was
normalized to the number of the incident muons in thedata.
From these experimental results, it was concluded
that the observed TOF peak was due to the Mu−'s accelerated by the RFQ to 89 keV.

Figure 2. Schematic drawing of the experimental setup [6].

52

Events/50 ns/4×1011 μ+ incident

MLF Annual Report 2017is expected to be installed in this beamline to obtaina muon rate of 106/s, the design intensity for the muon
g-2/EDM experiment.
The results presented in this article are the first step
toward making the low-emittance muon beam available as a powerful tool for application in material andlife sciences and fundamental physics research.

RF on

40

Research and Development Highlights

RF offsimulation

20

Figure 3. TOF spectra of the negative-charge configuration
with RF on (rec circle) and off (blue rectangle) [6].
A simulated TOF spectrum of the accelerated Mu−‘sis also plotted (green hatched).

Acknowledgements
This work was supported by JSPS KAKENHI Grant
Numbers JP25800164, JP15H03666, JP16H03987,
JP15H05742, JP16J07784, and JP18H03707. This experiment at the Materials and Life Science Experimental
Facility of the J-PARC was performed under user programs (Proposal No. 2017A0263).

4. Conclusion and outlook
In summary, muons have been accelerated by RF
acceleration for the first time. Slow Mu−‘s were generated through the electron capture process of the degraded μ+'s in the D2 area of J-PARC MUSE, and accelerated
with the RFQ up to 89 keV.
The intensity of the accelerated Mu− in this experiment was limited by the very low conversion efficiencyof μ+ to Mu−. With the construction of the new H line andassuming the design value of 1-MW beam power fromthe RCS, the intensity is expected to reach 2 × 10−2/s.
Finally, the laser-dissociation ultraslow muon source

References[1] M.A. Palmer, ICFA Beam Dynamics Newsletter, 55(ICFA, 2011).
[2] D. Neuffer, Part. Accel. 14, 75 (1983).
[3] P. Franchini, Proc. of 9 th International Particle
Accelerator Conference, Vancouver, BC, Canada, pp.
4766 – 4768.
[4] http://slowmuon.kek.jp/MuonMicroscopy_e.html[5] http://g-2.kek.jp/portal/index.html[6] S. Bae et al., Phys. Rev. Accel. Beams 21, 050101(2018).
[7] R. Kitamura et al., J. Phys. Conf. Ser. 85, 012055(2017).

0

500

1000

1500

2000

Time of flight [ns]M. Otani1,2, S. Bae3, H. Choi3, S. Choi3, Y. Fukao4,5, K. Futatsukawa1,2, K. Hasegawa6, T. Iijima7, H. Iinuma8, K. Ishida9, N. Kawamura10,11,
B. Kim3, R. Kitamura12, H. S. Ko3, Y. Kondo6, S. Li12, T. Mibe4,5, Y. Miyake10,11, T. Morishita6, Y. Nakazawa8, G. P. Razuvaev13, N. Saito14,
K. Shimomura10,11, Y. Sue7, E. Won15, and T. Yamazaki10,11
1
Accelerator Division, J-PARC Center; 2Accelerator Laboratory, KEK; 3Seoul National University; 4Particle and Nuclear Physics Division,
J-PARC Center; 5Institute of Particle and Nuclear Studies, KEK; 6Japan Atomic Energy Agency; 7Nagoya University; 8Ibaraki University;
9
Riken; 10Muon Science Section, Materials and Life Science Division, J-PARC Center; 11Institute of Materials Structure Science, KEK;
12University of Tokyo; 13Budker Institute of Nuclear Physics; 14J-PARC Center; 15Korea University

53

Research and Development Highlights

MLF Annual Report 2017

μSR Study of Sr2−xLaxIrO4 Synthesized by Mechanical
Alloying
1. Introduction
5d transition-metal oxides (TMOs) exhibit exotic
phenomena because their spin-orbit coupling (SOC) is
one order of magnitude larger than that of 3d TMOs.
Recently, Kim et al. proposed a spin-orbit Mott statewith a local Jeff = 1/2 in Sr2IrO4 [1]. Spin-orbital coupling
Mott insulator Sr2IrO4 (SIO) shares with cuprates several
distinctive features [2] that characterize high-temperature superconductors (HTSC). Due to the similar Mott
physics between cuprates and iridates, Sr2IrO4 is a goodcandidate for exploring unconventional HTSC by carrier
doping.
The physical properties of electron-doped Sr2IrO4
systems have been extensively studied in experimentsby several groups. The neutron scattering study insingle-crystalline samples of Sr2−xLaxIrO4 indicated thatthe long-range antiferromagnetic (AF) order was suppressed up to x = 0.08 and the short-range AF order persisted up to x = 0.12 due to the lack of a magnetic Bragg
peak [3]. However, it was mentioned that the detection
limit of magnetic scattering was 0.06 μB because ofhigh neutron absorption of Ir. Thus, it remains unclear
whether a short-range AF above x = 0.08 can be observed. Therefore, we have performed μSR experiments
in Sr1.9La0.1IrO4 to clarify the mentioned uncertainty.
2. Experiments
Polycrystalline samples of Sr1.9La0.1IrO4 were prepared by conventional solid-state reactions. A mixtureof SrCO3, La2O3, and IrO2 was ground and further mixedby planetary ball milling (Fritsch, P-7) at a rotation rateof 400 rpm for 3 h with 15 (5 mm-diameter) and 10(10 mm-diameter) ZrO2 balls. The resulting powders
were calcined in air at 1150°C for 15 min. To examine
the effects of mechanical milling on the morphology
of polycrystalline Sr2−xLaxIrO4 samples, we characterized these samples by SEM. Comparing the mechanicalalloying (MA) and non-MA samples, there were fewer
grains in the MA samples at the same scale length,
indicating that a post-MA reaction increased the sizeof the crystal grains and reduced the number of grainboundaries.
Zero-ﬁeld (ZF)- and longitudinal ﬁeld (LF)-μSR
experiments were performed using the Advanced
Research Targeted Experimental Muon Instrument at
the S line (ARTEMIS) spectrometer [4] with a ﬂy-past
54

chamber at the Material and Life Science Experimental
Facility (MLF), J-PARC, Tokai, Japan.
3. Results and discussion
Figure 1(a) shows selected ZF-μSR time spectra ofSr1.9La0.1IrO4 in the temperature range 3.4–300 K. Nonoscillatory signals are present, indicating the absenceof a long-range-magnetic order even below TN (~180 K),
which was also determined by magnetic susceptibility
measurements. The oscillations are not completely absent, but the spectral damping becomes faster with decreasing temperature and the spectrum at 3.4 K showsa shallow “dip” that signals freezing of ﬂuctuating random local ﬁelds, where the line shape is close to thatof a quasi-static spin-glass state. The time evolution of
the spectra above 14 K can be ﬁtted by the following
function:(1)
AZF(t) = Asexp(−λt)β + Abg
Here, As and Abg are the positron decay asymmetries (amplitudes) of the sample (As = 0.2048) andbackground (Abg = 0.0293, mainly from a silver plate)components, respectively; λ is the relaxation rate; andβ is the stretching exponent.
Figure 1(b) shows the temperature dependencesof λ and β. A three-step decrease appears in β as thetemperature decreases. As evidenced in the lower
panel of Fig. 1(b), β begins to decrease from approximately 300 K, suggesting the development of shortrange spin correlations between the intralayer Ir ions.
Subsequently, a gradual decrease of β from 0.8 to 0.6
appears around 180 K, corresponding to TN. Because
this behavior has often been observed in frustrated
antiferromagnets, the magnetic state below TN was
determined as a short-range AF order coexisting withspin ﬂuctuation that is detectable within the muontime scale. This situation can also be explained as a
Grifﬁths phase, in which short-range AF clusters occur
and grow upon cooling in the paramagnetic phase.
Spin autocorrelation functions in the Grifﬁths phasecan be described by a stretched exponential of the form
exp(−λt)β with β = 0.5 [5], which is also consistent with
our ﬁtting results. As the temperature decreases further(to below 50 K), β reaches around 1/3, a typical value in
dilute spin-glass systems.
To distinguish the low-temperature spin-glass state
more clearly, we performed LF-μSR measurements on

MLF Annual Report 2017

Sr1.9La0.1IrO4. As the LF increases, the persisting asymmetry is enhanced under restoration of the initial muonpolarization; usually, this is called decoupling effect.
The decoupling behavior in Fig. 1(c) clearly indicatesthat most of the Ir electronic spins are static in this state.
Before discussing the Ir moment size, we should
determine where the implanted muon is located in
Sr1.9La0.1IrO4. The previous μSR study [6] indicated that
there were two main types of muon sites in Sr2IrO4; onenear the apical oxygen, the other near the in-plane oxygen. However, the implanted muons do not occupy
these sites equally: more than 90% of the muons are located in the apical oxygen site of Sr2IrO4. We thus assume
that all implanted muons occupy the apical oxygen sitein Sr1.9La0.1IrO4 (as in Sr2IrO4), because both crystal structures (x = 0 and x = 0.1) are nearly unchanged. We now
estimate the Ir moment size of Sr1.9La0.1IrO4. In Sr2IrO4,
the moment size of the Jeff = 1/2 pseudospin is reduced
to ~0.4 μB, as conﬁrmed by previous μSR, RIXS, and neutron diffraction measurements. On the other hand, theeffective Ir moment size of Sr1.9La0.1IrO4 |μIr| was determined as 0.0452(3) μB. This value is about one-tenth ofthat of Sr2IrO4 (0.4 μB), so the decrease of the Ir moment
is attributed to the effects of electron doping by La substitution. This work has been published in PRB [7].

Research and Development Highlights

4. Future Plans
We summarized the magnetic phase diagram of
Sr2−xLaxIrO4 determined by μSR and magnetic susceptibility measurements (Fig. 2). Although we have clariﬁed
the short-range magnetic order in Sr1.9La0.1IrO4, it is still
not clear how the long-range order changes to a shortrange order with electron doping in the Sr214 system.
To clarify the magnetic phase diagram in the Sr214
system, we will perform μSR experiments in electrondoped Sr2−xLaxIrO4 [x = 0.05 (TN ~208 K), x = 0.075 (TN~198 K), and x = 0.13 (TN ~114 K)] in a future work.

Figure 2. Magnetic phase diagram of Sr2−xLaxIrO4 deteminedby magnetic susceptibility and μSR measurements.
Inset shows the magnetic susceptibility data (x =0.1) under a zero-field cooling process

Figure 1. (a) Temperature dependence of ZF-μSR time spectra for Sr1.9La0.1IrO4. (b) Temperature dependence ofthe λ and β. (c) LF-μSR time spectra

References[1] B. J. Kim et al., PRL. 101, 076402 (2008).
[2] K. Terashima et al., PRB 96, 041106(R) (2017).
[3] C. Chen et al., PRB 92, 075125 (2015).
[4] K. M. Kojima et al., J. Phys. Conf. Ser. 551, 012063(2014).
[5] A. J. Bray, PRL. 59, 586 (1987).
[6] M. Miyazaki et al., PRB 91, 155113 (2015).
[7] K. Horigane et al., PRB 97, 064425 (2018).

K. Horigane1, M. Fujii2, H. Okabe3,4, K. Kobayashi1,2, R. Horie1, H. Ishii5, Y. F. Liao5, Y. Kubozono1 A. Koda3,4, R. Kadono3,4, and J. Akimitsu1
Research Institute for Interdisciplinary Science, Okayama University; 2Graduate School of Natural Science and Technology, Okayama
University; 3Muon Science Section, Materials and Life Science Division, J-PARC Center; 4Institute of Materials Structure Science, KEK;
5National Synchrotron Radiation Research Center

1

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Research and Development Highlights

MLF Annual Report 2017

Development of Ferromagnetic Fluctuations in Heavily
Overdoped (Bi,Pb)2Sr2CuO6+δ Copper Oxides
1. Introduction
It is well known in the hole-doped high-Tc superconducting cuprates that the superconductivity
emerges through hole doping into the parent antiferromagnetic (AF) Mott insulator, suggesting that the superconductivity is mediated by AF spin fluctuations in
the underdoped and optimally doped regimes. In theoverdoped regime where the superconducting (SC)transition temperature Tc is depressed with hole doping, inelastic neutron-scattering [1] and muon spin
relaxation (μSR) [2] experiments have revealed theweakening of the low-energy AF spin fluctuations withhole doping. A recent resonant inelastic x-ray scattering experiment, on the other hand, has revealed thathigh-energy AF fluctuations persist to the non-SC heavily overdoped regime [3]. This suggests that the suppression of superconductivity in the heavily overdoped
regime might not be related to AF fluctuations.
Formerly, Sonier et al. have observed from zerofield (ZF) μSR measurements in the non-SC heavily
overdoped La2−xSrxCuO4 single crystals that the relaxation rate of muon spins λ is enhanced at very low temperatures below 0.9 K [4]. Considering the ab-planeelectrical-resistivity ρab and magnetization results, they
have proposed the formation of a three-dimensional
ferromagnetic (FM) order of itinerant electrons in the
non-SC heavily overdoped regime. This seems to be achallenge to the common understanding that a simple
Fermi-liquid-like ground state without magnetism is realized in the non-SC heavily overdoped cuprates. The
FM fluctuations might suppress the superconductivity
in the heavily overdoped regime owing to the competition between AF and FM fluctuations [5]. Since the FMorder appears at very low temperatures, however, its
details, including the universality of this phenomenon
in high-Tc cuprates, have not yet been investigated.
In order to investigate possible FM fluctuations, wehave performed measurements of ρab, magnetization,
specific heat, μSR in heavily overdoped (Bi,Pb)2Sr2CuO6+δ
(Bi-2201) cuprates [6]. Single crystals of Bi-2201 weregrown by the floating-zone technique. The hole concentration per Cu p was determined by the empiricalequation and the thermoelectric power. ZF- and longitudinal-field μSR measurements were performed at
J-PARC/MLF and the RIKEN-RAL Muon Facility in the UK.

56

2. Results and discussion
The static magnetization curve of heavily overdoped Bi-2201 have revealed that, while the magnetization curves are linear in the magnetic field above
20 K, it becomes nonlinear and tends to be saturated
in high magnetic-field regions below 20 K. Considering
no hysteresis in the magnetization curve down to 0.5 K,
the saturated magnetization in high magnetic fields at
low temperatures is probably a precursor phenomenonof the FM transition at a lower temperature.
For dynamic behaviors of spins, Fig. 1 shows thetemperature dependence of λ of Bi-2201. It was foundthat λ increases with decreasing temperature below 200 K and the increase becomes larger with hole
doping. These results suggest that spin fluctuations,probably FM fluctuations, are developed at high temperatures and are enhanced with hole doping in heavily
overdoped Bi-2201.
The temperature dependence of ρab in Bi-2201 haveexhibited a T 4/3 behavior over a wide temperature range
in the heavily overdoped regime. Figure 2 shows the pdependence of the exponent n obtained by expressing ρab in the normal state as ρab = ρ0 + ATn, where ρ0 is
the temperature-independent term and A is the temperature coefficient. It was found that n ∼ 1 near the
optimally doped regime and that n increases with overdoping and converges to 4/3 in the heavily overdoped
regime, which is incompatible with the nonmagnetic(Bi,Pb)2Sr2CuO6+δ
p = 0.274
p = 0.264
p = 0.236

Figure 1. Temperature dependence of the relaxation rate ofmuon spins λ of (Bi,Pb)2Sr2CuO6+δ. The solid lines areincluded to guide the reader’s eye.

MLF Annual Report 2017

Research and Development Highlights

RW

RW

n

f uctuationflFerromagnetic fluctuation

Antifer
Antiferromagnetic
f romagnetic
ffluctuation
fluctuation

Exponent n

Antiferf romagnetic order
Antiferromagnetic(Bi,Pb)2Sr2CuO6+δ

n = 4/3
2D FM
ffluctuationfluc

Superconductivity

Figure 2. Schematic phase diagram of (Bi,Pb)2Sr2CuO6+δ. The open circles represent the Wilson ratio RW.
The closed circles, triangles, squares and diamonds represent the exponent n of ρab = ρ0 + ATn.
The dashed lines are included to guide the reader’s eye.

Fermi-liquid-like T 2 behavior. According to the SCR
theory, the T 4/3 behavior of ρab is characteristic of metals
with two-dimensional FM fluctuations due to itinerant
electrons. The specific heat of Bi-2201 has also exhibited the behavioral characteristics of metals with twodimensional FM fluctuations.
To obtain further insights into the FM fluctuations,
we have estimated the Wilson ratio RW relating to spin
fluctuations from the static magnetic susceptibility andthe electronic specific-heat coefficient. As shown in
Fig. 2, surprisingly, RW increases with hole doping in theheavily overdoped regime of p > 0.23, suggesting theenhancement of spin fluctuations.
The proposed new phase diagram of Bi-2201 isshown in Fig. 2. As characterized by the increase in RW
and the saturation of n around 4/3, the region of the FM
fluctuations is shown in the heavily overdoped regime.
It was found that the magnetic ground state changes
from the AF to FM one with hole doping. The FM fluctuations exist even in the SC heavily overdoped regime,
implying the interference between FM fluctuations andthe electron paring mediated by AF fluctuations andresulting in the decrease in Tc with hole doping in theheavily overdoped regime.
The origin of the FM fluctuations has not been clarified yet. A possible candidate is the metallic ferromagnetism due to enhanced spin fluctuations as observedin RW, the large density of states at the Fermi level suggested from angle-resolved photoemission spectroscopy [7] etc. and the good Fermi-surface nesting with thenesting vector of q ∼ 0 suggested from the theoretical
calculation [8].
3. Conclusion
FM fluctuations exist in heavily overdoped Bi-2201,
suggesting the universal feature of the hole-doped cuprates. The magnetic ground state changes from the AF
to FM one with hole doping. Moreover, the FM fluctuations are possibly related to the suppression of superconductivity in the heavily overdoped regime. The specificrelationship between the FM fluctuations and superconductivity in cuprates should be clarified in the future.
References[1] S. Wakimoto et al., Phys. Rev. Lett. 92, 217004 (2004).
[2] Risdiana et al., Phys. Rev. B 77, 054516 (2008).
[3] M. P. M. Dean et al., Nat. Mater. 12, 1019 (2013).
[4] J. E. Sonier et al., PNAS 107, 17131 (2010).
[5] A. Kopp et al., PNAS 104, 6123 (2007).
[6] K. Kurashima et al., Phys. Rev. Lett. 121, 057002(2018).
[7] M. Hashimoto et al., Phys. Rev. B 77, 094516 (2008).
[8] D. Ogura and K. Kuroki, Phys. Rev. B 92, 144511(2015).

T. Adachi1, K. Kurashima2, I. Watanabe3, M. Miyazaki4, A. Koda5, R. Kadono5, and Y. Koike2
Department of Engineering and Applied Sciences, Sophia University; 2Department of Applied Physics, Tohoku University; 3Meson Science
Laboratory, RIKEN Nishina center; 4Graduate School of Engineering, Muroran Institute of Technology; 5Muon Science Section, Materials andLife Science Division, J-PARC Center and Institute of Materials Structure Science, KEK

1

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Neutron SourceNeutron Source

MLF Annual Report 2017

Progress of the Neutron Source Section
Fiscal year 2017 set in motion a new challenge toachieve a high-power operation by using a re-designed
target vessel. The aim of the target operation was to establish a stable neutron production with a beam powerfrom 300 to 500 kW. In the first half of the fiscal year,
target vessel #2, which does not have a gas micro-bubbles injection system, operated at 150 kW continuously
from the previous fiscal year until June 2017. The operation was calm and stable, without any serious problems.
In the summer shutdown period, target vessel #2
was replaced with a brand-new re-designed one. The
proton beam window was also replaced with a newone. Details of the observation of damages induced ontarget #2 and the proton beam window replacement
are described elsewhere in this activity report.
1. Mercury target operations with a re-designed
target vessel
Figure 1 shows a photograph of the re-designed
target vessel. It is the eighth target vessel in the fabrication order. To ensure more reliable structural integrityof the target vessel #8, a new fabrication method wasintroduced. The welding, previously used for coupling
between the inner mercury vessel and the outer water
shroud, was replaced by a monolithic structure in theforward part where high thermal stress is induced. In
the rear part, the structure of the water shroud has also
been improved by adopting a monolithic structure.
Furthermore, all welding lines were inspected carefully
with RT (Radiographic Test). In the end, target vessel #8
was delivered to the MLF on September 17, 2017.

For target vessel #8, the following measures weretaken to mitigate pitting damage at the beam window
portion: 1) gas-micro-bubbles injection and 2) highspeed mercury flow in a narrow channel formed witha double-walled window structure. These concepts are
depicted in Fig. 2. In 2015, pitting damage with a depthof 25 μm was observed on the outer wall of target vessel #5, which has the same narrow channel structure
as target #8, after an accumulated proton irradiationof 670 MWh with an average beam power of 407 kW.
Therefore, it is quite important to investigate the damage on target vessel #8 for estimating its life time.
The neutron production operation using target #8
resumed with a power of 300 kW. During the operating
period, we measured the temperature rise at the heatload of the target vessel and the effectiveness of the gas
micro-bubbles injection on mitigation: the maximum
temperature on the mercury with a proton beam injection was lower than the allowable value, as expected.
As shown in Fig. 3, the displacement velocity at an
upper position of the mercury vessel was reduced byabout 1/3 with gas micro-bubbles injection. From theuser operation in January, therefore, the proton beam
power was increased to 400 kW. The target operations
at 400 kW continued stably until the end of March 2018.

Figure 2. Horizontal cross-sectional view of target vessel #8.

Displacement velocity [m/s]

0.6
0.5

w/o micro-bubbles

0.4
0.3
0.2
0.1
0

with micro-bubbles
0

100

200

300

400

500

600

Beam power [kW]Figure 1. Photo of re-designed target vessel #8 with schematics
of structures in the forward and the rear part (lower).

60

Figure 3. Displacement velocity at an upper position of target
vessel #8 at the time of injecting the proton beam.

MLF Annual Report 2017

Then, from April, the beam power was ramped up to
500 kW. The total accumulated power on target #8 willreach 1800 MWh at the end of the operation.
2. Efforts to improve the target design
The fabrication of target vessel #9, which has thesame structure as the one designed for target #8, hadalso been continued by the same vendor. It has been
completed about half a year after the fabrication of target vessel #8. On the other hand, we have been designing a different type of target vessel. Its coupling-freestructure between the inner mercury and the surrounding outer water shroud will remove the structuralcause of generating high heat load on the target. The
coupling-free structure uses the same design concept
as the one applied for the mercury target at the SNS
of Oak Ridge National Laboratory. However, the size ofthe target vessel at J-PARC is bigger than that of SNS.
Realizing a 3-mm gap with a deformation of less than
1 mm between the mercury target and the surrounding water shroud was the key issue in both design andfabrication.
Our structural analyses confirmed that the specifications satisfied the requirement to enhance the rigidity of the water shroud by changing the cooling channel
structure and the thicknesses of the inner and outershroud plates. The resultant thicknesses of the inner

Neutron Source

and outer water shrouds are 3.5 mm and 3.5 mm with
8.5 mm in the rear part, respectively. Furthermore, wehave reduced the volume of water manifold and added
a cooling channel there to decrease the temperature
difference, the source of thermal stress, between the
beam dump and the end plate at the rear of the target
vessel. Figure 4 shows a schematic of the coupling-free
type target vessel. The fabrication of the coupling-free
type target vessel is under way.
3. New storage building for used target vessels
At the Materials and Life Science Experimental
Facility (MLF), the capacity of the storage room for theused mercury vessels is limited. Therefore, a new storage building, named RAM (Radio Activated Materials
building), has been under construction near MLF in the
J-PARC site for the last four years. It was completed on
December 26, 2017. Figure 5 shows a photo of the RAM
building.
Furthermore, we have designed a shipping container and a shielding container to transfer the used
target vessel from MLF to the RAM building. The shielding container was designed to meet the regulation thatthe dose rate on the surface must be less than 2 mSv/h.
The structural integrity of the shipping container issufficient to endure the impact of a drop from a 1.6 m
height when the shielding container is in it.

Figure 4. Vertical cross-sectional view of the coupling-free
type target vessel.

Figure 5. Photo of the RAM building.

H. Takada
Neutron Source Section, Materials and Life Science Division, J-PARC Center61

Neutron Source

MLF Annual Report 2017

Progress of the Target Beam Window Cutting
1. Introduction
In the mercury target for the J-PARC neutron source,
cavitation damage caused by the proton beam-inducedpressure waves degrades the structural integrity of thetarget vessel. The cavitation damage is likely to increase
with the proton beam power and operating time. Since
the thickness of the beam entrance portion of the target vessel is only 3 mm, the cavitation damage is a crucial factor to determine the lifetime of the target vessel
and the necessary restriction on ramping-up the proton beam power. To reduce the cavitation damage inthe mercury target, we have applied a technology of
injecting gas microbubbles with radii less than 100 μm
into mercury to suppress the pressure waves from target No. 3 (in fabrication order) operated from October
2012 [1]. In addition, from target No. 5 (operated from
October 2014), the beam window was changed to a double-walled structure to suppress the growth of cavitation
bubbles caused by high-speed flow and narrow gap [2].
The effect of these cavitation damage mitigation
technologies had been investigated by inspecting theinterior surface of the beam window portion after cutting out a specimen with an annular cutter. The specimen will be used to measure its mechanical properties
in a post-irradiation examination.
Since the used target vessel No. 2 after operating up to 1048 MWh, was highly activated to 350 Sv/hat contact after 2 months cooling by the proton andneutron irradiation, cutting and inspection processes
should be performed by full-remote handling.
The target vessel has a multi-walled structure consisting of outer and inner water shroud and mercury
vessel. We cut the beam window from three used target
vessels but faced the following difficulties: in 2014, themercury vessel specimen fell inside the vessel for target No. 3 and the cutter’s blade was broken by overheat
because of dry-cutting for target No. 5 in 2015. For the
cutting of target No. 2, therefore, we improved the cutting conditions through careful cold cutting tests andsuccessfully cut out a specimen from the beam window
portion without any troubles.
2. Cold cutting tests
Figure 1 shows a photograph of the cutting machine used for the cutting. It consists of a drill machinewith an annular cutter, in which the outer/inner diameters of the cutter are 55/50 mm, a wireless system
control unit, and a battery with a power convertor. The
62

cutting was performed with fixing the target vessel tothe target trolley as for the beam operation. The horizontal access is aiming to prevent a spill of the activatedmercury and cooling water from the cut portion [3].
Prior to the actual cutting, we carried out cold cutting tests using a mock-up cutting machine to optimize
the rotation speed, the feed rate of the forward motion
and the frequency of feed of the cutter by changing
them parametrically. Table 1 shows the parameters ofcold cutting tests. During cutting in the past, the heatgenerated by the friction between the cutter and thebeam window degraded significantly the cutter’s blade.
Therefore, a thermography was used to measure thetemperature of the lateral surface of the annular cutter
and a beam window mock-up of the cutting portion.
Under dry conditions, without using any lubricant,the cutting tests failed within all cutting parameters.
As a remedy, we used a water-base lubricant to dissipate the heat. Figure 2 shows a typical example of thetemperature distribution of the cutting portion and thetime histories of the peak temperature in the square of
the temperature distribution. It can be seen that thepeak temperature is clearly reduced by splaying lubricant. As a result, we were able to cut out the specimensmoothly by adopting lubricant, regardless of the cutting conditions.

Drill machine(Sugino-machine, SSV5-2610)
Power: 1.6 kW
Forward force: 7760 N

Annular cutter withquick change tool(Miyanaga, 278P-55(S))
Outer diameter: 55 mm
Saw thickness: 2 mm

Control equipment
PLC (Wireless LAN)
Battery 48 V , 85Ah
200V Converter

Machine Size: 2.1×0.7×1.5 m

Figure 1. Photograph of the cutting machine.

Table 1. Parameters for optimizing cutting condition.

Rotation speed of cutter [rpm]250, 400

Feed rate [mm/s]

0.1 [mm] for 0.1 [s],0.1 [mm] for 3.0 [s]Feed frequency [Hz]0.111, 0.167, 0.250

MLF Annual Report 2017

Beam window model

Peak temperature, °C

200
Cutter stoppedby over load150

Dry cut
Cutter100
50

With lubricant

0
0

5

10

15

20

25

30

35

Cutting time, min
Figure 2. Time histories of surface temperature for cold cutting test.

3. Cutting of used target No. 2
For cutting out a specimen from an actual target ina hot cell at the MLF, we have employed a handy sprayer with a long hose to supply lubricant from outside of
the hot cell, as shown in Fig. 3. The actual cutting of theused target No. 2 was completed without any troubles.
The blades of the annular cutter after cutting did notchange visually.
After cleaning the specimen using an ultrasonicbath with water, the specimen surface was directly observed using a HD video camera. Then, the damages on
the specimen’s surface were traced on a silicone rubber
replica for detailed observation outside of the hot cell,because the highly-activated specimen cannot be removed from the hot cell.
Figure 4 shows the inferior surface of the mercury
vessel after cleaning. It can be seen that the cavitation
damages are distributed around the center and the
top and bottom sides of the specimen. Furthermore,
a localized deep pit is superimposed on the damage

Neutron Source

clusters. Although the details are not described in thisreport, the distribution of the cavitation damage cluster is well correlated with the saturation time of thenegative pressure period, which is obtained by the FEM
simulation [4, 5]. For target No. 2, we confirmed the correlation between the distribution of the negative pressure period and the cavitation damage clusters.
Figure 5 shows typical examples of the cavitation
damage on replicated surface for the damage cluster
and the localized deep pit obtained by a 3D laser scanner (Keyence, VR-3200). The measured depth of the localized deep pit was 234 μm. The homogenous erosion,accompanied with mass loss, can be calculated with
an empirical equation, Dmax = 8MDE = MDE+ d, where
Dmax, MDE, d are the maximum damage depth, themean depth of erosion, and the measured depth, respectively [6], the Dmax of target No. 2 was concluded to
be 268 μm since d = 234 μm. This result will be applied
to improve the cavitation damage mitigation technologies and ensure a stable operation at high power.

12.5 mm

D=50 mmTop

Damage clusters
A
Upstream

2.5 mmB
Localized pit

Target center

Downstream

BottomFigure 4. Cavitation damage on specimen cutout from theused target No. 2.

Spray nozzle
with long hose

Cutting machine

Target exchange truck

Handy sprayer

Figure 3. Cutting machine with remote sprayer tools for cutting of target No.2.

63

Neutron Source

MLF Annual Report 2017(A) d= 134 μm

1.2

50

(B) d= 234 μm

1.2

0
-50

0.8

0.8

0.4

0.4

-100
-150
-200

0

0

0.4

0.8
1.2
Distance, mm

1.6

0

0

0.4

0.8
1.2
Distance, mm

1.6

-250
[μm]

Figure 5. Depth contour of the replicated cavitation damage for (A) damage cluster and (B) localized deep pit.

References[1] H. Kogawa, et al., J. Nucl. Sci. Technol., 54 (2017)733-741.
[2] T. Naoe, et al., J. Nucl. Mater., 506 (2018) 35-42.

[3] H. Kinoshita, et al., Proceedings of ICANS-XX (2012).
[4] B. Riemer, et al., J. Nucl. Mater., 450 (2014) 183-191.
[5] T. Naoe, et al., J. Nucl. Mater., 450 (2014) 123-129.
[6] T. Naoe, et al., J. Nucl. Mater., 468 (2016) 313-320.

T. Naoe, H. Kinoshita, T. Wakui, H. Kogawa, M. Teshigawara, K. Haga, and H. Takada
Neutron Source Section, Materials and Life Science Division, J-PARC center64

MLF Annual Report 2017

Neutron Source

R&D of Electron Beam Welding on Moderator Vessel
Fabrication
1. Introduction
The fabrication of a spare moderator and reflector has completed in 2017 to be ready for replacement
scheduled around 2021, which is needed because thesestructural materials suffer accumulated irradiation
damage.
A Gold-Indium-Cadmium (Au-In-Cd) decoupler wasdeveloped to reduce dramatically the radioactivity of
the used components in comparison with the previous
Silver-Indium-Cadmium (Ag-In-Cd) decoupler without
sacrificing neutronic performance. The main issue wasan implementation of (Au-In-Cd) alloy as a decopuler[1] and its assembly by welding in the spare moderator and reflector fabrication. Tungsten inert gas (TIG)
welding was used previously to assemble the moderator-reflector, however, the TIG welding heat sometimes
had an impact on the bonding region of the Au-In-Cd
decoupler, causing cracks, exfoliation, deformation,etc., in the parts’ manufacturing process, including the
Au-In-Cd decoupler. In order to improve the welding
conditions, electron beam welding (EBW) was applied
specifically to manufacture these parts, including the
Au-In-Cd decoupler. Here, we report the R&D of EBW on
the moderator vessel fabrication.

Outer vessel
Decoupler
vessel

Au‐In‐Cdalloy

Decoupler
vessel

2. Welding of decoupler vessel in decoupled moderator
As shown in Fig. 1 (a), the decoupled moderator,
which is one of the three spare moderators, consists offour vessels. The third vessel (decoupler vessel) includes
Au-In-Cd alloy. The Au-In-Cd alloy was bonded to aluminum alloy, A5083, a structural material of the vessel,
added by the Hot Isostatic Pressing (HIP) technique.
This decoupler vessel was assembled previously
by TIG welding at the welding position, as shown in
Fig. 1 (b). However, the TIG welding heat sometimes affected the bonding region of the Au-In-Cd and A5083
alloys, causing cracks, exfoliation, deformation, etc.,
in the manufacturing process. We applied the EBW
technique to improve the welding conditions for assembling the decoupler vessel. We performed R&D
of EBW to obtain optimum EBW conditions, such as
beam shape, power, focus position, welding speed, etc.
Another issue that we found was that the welding did
not reach full penetration but only partial one, preventing the required design weld thickness. Because there
was a vacuum vessel inside the decoupler vessel, as
shown in Fig. 1 (b), that was likely to cause problems,such as electron beam penetration to the vacuum vessel, contact of the penetration bead, etc.

Au‐In‐Cdalloy
VacuumvesselWelding
position

VacuumvesselHydrogenvessel(a) Cutway view of decoupled moderator

Weldingline(b) Decoupler vessel and welding position in fabrication process

Figure 1. (a) Cutway view of decoupled moderator and, (b) Decoupler vessel and welding position in fabrication process.

65

Neutron Source

MLF Annual Report 2017

We show a typical X-ray CT scanning image for unoptimized EBW condition, as shown in Fig. 3 (a) above. Many
blowholes were observed at the focus position for theunoptimized one. We managed to reduce successfully
the blowholes for the optimized EBW case, as shown in
Fig. 3 (a), bottom. In the optimized case, we controlled
the electron beam power from 32 to 48 mA with elliptical deflection beam according to the welding thickness
and the focus position was 5 mm deep. Finally, we applied the obtained optimum condition to assemble anactual decoupler vessel, as shown in Fig. 3 (b).

Weldingline

Figure 2. EBW element test model.

3. R&D of EBW
We performed an EBW element test to obtain optimum EBW conditions by using partial mockup modelof the welding part, as shown in Fig. 2. We consideredsame thermal capacity as actual decoupler vessel inthe mockup model, because the escape of heat in thewelding area affected the EBW condition. An X-ray computed tomography (CT) scanning technique was also
applied to confirm the state inside the welded area.

Acknowledgments
We are grateful for the cooperation of Metal
Technology Co. Ltd in the fabrication of the sparemoderators and reflector. We also thank the Nippon
Advanced Technology Co., Ltd. staff for their help in the
preparation of the Au-In-Cd material.
Reference[1] M. Teshigawara, et al., Nuclear Materials and Energy,
14, 14–21 (2018).

Not optimized EBW condition
Direction of EBW

Many blowholes
5mm

Decoupler
vesselEBW

Optimized EBW condition
Power: 32‐48mA, Speed: 1m/min,
Focus: 5mm in depth, elliptical deflection
beam

Decoupler vessel
Vacuum vessel
Hydrogen vessel(a) X ray CT scanning image(b) Setting inside EBW chamber

Figure 3. (a) X ray CT scanning image and (b)Setting inside EBW chamber.

M. Teshigawara, M. Harada, and M. Ooi
Neutron Source Section, Materials and Life Science Division, J-PARC Center66

MLF Annual Report 2017

Neutron Source

Replacement of the Proton Beam Window
1. Introduction
Proton beam window (PBW) is installed at the endof the proton beam line to divide high vacuum in the
proton beam line of 10−6 Pa and the helium vessel, whichcontains a neutron target, moderator and reflector. As
shown in Fig. 1, the window body of the PBW has a cylindrical shape with pillow seal, installed at the end of ashielding plug with a length of 3.8 m and total weightof 10 tons. The pillow seal kept airtightness by adhering
the metal surface polished like a mirror surface with gaspressure. The window part of the PBW is made of twolayers of aluminum alloy plates and is cooled by cooling water flowing between the aluminum plates. Fromprevious evaluations of the irradiation damage of thealuminum alloy, lifetime of the PBW is supposed to be
2 years during a 1 MW operation [1]. The PBW is directly
exposed to the proton beam, and because of the influence of neutrons generated in the neutron target, the
PBW is highly activated. So, it is necessary to perform replacement work in the hot cell. Also, because the doseof the PBW is high, it is needed to move into the hot cellusing a shielding transfer cask.
The total amount of the beam irradiation of PBWunit No. 2 is 2510 MWh, which is 1/4 of the expected
lifetime. However, considering the effect of corrosionof the window caused by water leakage from the target
container that occurred in 2015, we decided to replace
it with PBW unit No. 3 in order to avoid breakage during
the beam operation.
2. Replacement work
At first, the radiation shields over the He vessel was
removed. Vinyl curing is applied on the floor surface

and green house is built to control the tritium vapor.
Local exhaust system and online tritium monitoring
system are applied in the green house. This time, inorder to prevent internal exposure of the worker, airline mask was worn during the manual removal of thepipes, which is shown in Fig. 2. The dose rate of theworking area above the shielding plug was 3 μSv/h at
maximum.
After removing the pipes, PBW unit No. 2 was
moved to the hot cell by the shielding cask (Fig. 3), thenstored in the drying room under the hot cell. Because
PBW unit No. 3 was attached on another shielding plug,
it was installed to the PBW position and the pipes andcables were connected.
Figure 4 shows the vacuum side of the PBWs, aswell as the multi-wire profile monitor for measuring theproton beam profile. In the upper photo in Fig. 4 is PBWunit No. 2, and in the lower one is unit No. 3. We can see

Figure 2. The utility pipes of the PBW were removed manually. The workers were equipped with airline masks
and anoraks, and worked in the greenhouse.

Figure 1. Overview of the PBW. PBW is placed before the neutron production target, its height is 3.8 m and the weightis 10 tons with the shielding plug. PBW is made with a circler pillow seal and aluminum beam window.

67

Neutron Source

MLF Annual Report 2017

the beam footprint on PBW unit No. 2 and the wire of
the profile monitor is winding. Such slackness would becaused by an error on the beam profile measurement,
so we are planning to adopt a mechanism to suppress
the wire slack in PBW unit No. 4.

Figure 3. PBW is stored in the shielding cask and moved tothe hot cell with a 130-t crane.

3. Dose and contamination of the PBWThere are some utility pipes for the PBW, such as cooling water pipes, middle exhaust vacuum pipes, He gas
pipes for the pillow seal and beam monitor cables. The
cooling water used in the PBW is a part of 6552 coolingwater system in MLF, which contains 5.5 × 104 Bq/cc oftritium in the water. Before the replacement of the PBW,
the cooling water was drained and dried with the vacuum method to reduce the tritium contamination andavoid internal exposure of the workers. Table 1 shows aresults of the contamination measurement in the pipes.
The tritium contamination of the water pipe is lower thanthat of the middle exhaust pipe of the He vessel side, it isassumed that the tritium come from the He vessel.
In order to measure the dose of the PBW, a dosimeter was installed at 50 cm from the extraction path of
PBW. A dose rate of 202 mSv/h was observed at a maximum when the proton beam window was moved overthe shield. After the PBW was stored in the shielding
cask, the dose on the surface of the shielding cask was
0.8 μSv/h at the same height of the PBW, and the highest point was 20 μSv/h at 3 m from the floor shield.
Table 1. Results of surface contamination measurement of
the water pipe and the vacuum pipe (middle exhaust) of PBW.
[Bq/cm2]

Position
Water pipe
Middle exhaust (He Vessel side)
Middle exhaust (Vacuum side)

β(γ)
0.6
---

Tritium
1.9
5.2
0.9

4. Future Plans
PBW unit No. 2 will be removed from the shielding
plug, then the window body will be stored in the storage container after cutting the piping part. Then PBWunit No. 4 will be installed to the shielding plug for the
next PBW replacement.
Figure 4. The vacuum side of PBW unit 2 (upper) and unit 3(lower). An irradiation mark is shown in unit 2 andthe wires of the profile monitors are distorted.

Reference[1] S. Meigo et. al., J. of Nuclear Materials. 450(2014) 141.

M. Ooi, S. Meigo, H. Kinoshita, and M. Teshigawara
Neutron Source Section, Materials and Life Science Division, J-PARC Center68

Neutron ScienceNeutron Science

MLF Annual Report 2017

Neutron Science Section
1. User program
After replacing the target with the older modelNo.2 in 2016 due to two target incidents of water leakage in 2015, we had to reduce beam power to around
150 kW. We operated this target safely until the summer shutdown in 2017. Then, we replaced the target
with the newly-designed target No.8 and operated itwith 300 kW until December and 400 kW from January,
while maintaining a high level of beam availability over90%.
For the general-proposal round for 2017A, 153 general proposals and 5 new user promotion proposals
were approved from 228 submissions. For 2017B, 167
general proposals and 5 new user promotion proposals were approved from 291 submissions. Additionally,a new type of proposal was introduced in 2017B, theGeneral Proposal (Long Term), also called Long Term
Proposal. This Long Term Proposal, valid for three
years, is called once a year, every B term. 8 Long Term
Proposals were approved from 24 submissions.
A new proposal category for non-proprietary uses
(free of charge) started at two pilot instruments, Super
HRPD and NOVA, at the end of 2017B, which is a mail-in
program called Fast Track Proposal. The users send theirsamples to MLF, and MLF staffs carry out experimentson the user’s behalf and send the data.
2. Instruments
The layout of the neutron instruments at MLF, as ofthe end of JFY 2017, is shown in Fig. 1.
POLANO (Polarized Neutron Spectrometer) at BL23
is in the commissioning phase. On-beam commissioning, such as commissioning on the data acquisition system, was ongoing. In November 2017, a MIEZE
part of the neutron spin-echo suit VIN ROSE (VIllage of
Neutron ResOnance Spin Echo spectrometers) at BL06
moved into a user program phase (Fig. 2). Another lineof VIN ROSE, the NRSE spin-echo line, was still undercommissioning.
A measurement of the neutron lifetime is on-goingon NOP (Neutron Optics and Fundamental Physics) at
BL05 to achieve an accuracy of 1 s. The neutron lifetime
is an important parameter for the big bang nucleosynthesis and the standard model for elementary particle
physics. The first preliminary result was obtained as
896 +13/−14 s by analyzing data accumulated in 2014
- 2016. The data taking is still ongoing to reduce theuncertainty.
70

Figure 1. Layout of the neutron instruments at MLF as of JFY
2017. BL23 was in the commissioning phase.

Figure 2. Users carrying out their experiment on a MIEZE
spin-echo beam line at VAN ROSE.

Multiple-wavelength neutron holography with thetime-of-flight technique was developed on NOBORU(NeutrOn Beamline for Observation and Research Use)at BL10 to provide information on local structures ofmaterials. By using a single crystal of Eu-doped CaF2, aclear three-dimensional atomic image around Eu3+ substituted for Ca2+ was obtained, revealing the local structure that allows it to maintain charge neutrality.
Since the increase of neutron flux is always an important issue for neutron instruments, the following
work was done in that field. On 4SEASONS (4D-Space
Access Neutron Spectrometer) at BL01, a part of theguide tube was improved and the neutron flux increased by 10 - 20%. On HRC (High Resolution Chopper
Spectrometer) at BL12, the incident beam collimator as

MLF Annual Report 2017

well as the Fermi chopper were optimized, and the intensity gain was obtained for low angle experiments,
such as neutron Brillouin scattering. On AMATERAS(Cold Neutron Disk Chopper Spectrometer) at BL14,
10 detectors were installed to extend the scattering
angles from 4.9° to 3.4° for low angles and from 111.0°
to 116.1° for high angles. On TAIKAN (Small and WideAngle Neutron Scattering Instrument) at BL15, for chromatic aberration compensation, three magnetic lenses
and two spin-flippers were utilized to control the focal
length dependent on the wavelength. On SOFIA (SoftInterface Analyzer) at BL16, high resolution and highcounting rate were achieved by the grazing incidence
configuration of GEM (gas electron multiplier).
3. International activities
The 9th AONSA School / the 2nd Neutron and Muon
School was held in November 16-20. Details about
the school can be found on the web (https://neutron.

Figure 3. Dr. Yamada and his student enjoying hands-on experiment at DNA at BL02.

Figure 4. Dr. Hattori lecturing about the instrumental aparatus to students at PLANET at BL11.

Neutron Sciencecross.or.jp/9thAONSAschool/index.html). 49 young researchers and graduate students from Korea, Australia,
Indonesia, India, China, Taiwan, Thailand, Malaysia, New
Zealand, Viet Nam, Nepal, United Kingdom, RussianFederation, as well as Japan, participated in the school.
The neutron science group contributed 10 neutron instruments for hands-on experiments and 43 of the 49
participants took part in neutron experiments (Fig. 3
and 4).
J-PARC Center and CROSS hosted the J-PARC
Workshop “Deuterated Materials Enhancing Neutron
Science for Structure Function Applications” on October
19 and 20, 2017. We invited Dr. T. A. Darwish and
D. Anthony from ANSTO, Australia, Dr. L. Anna from ESS,
Sweden, and Prof. H. Sajiki from the Gifu Pharmaceutical
University for plenary talks. 62 scientists paticipated in
the meeting. Neutron studies on material and life siences by utlizing deuteration technology were discussed.
4. Resultant outcomes
The research activities in neutron science at MLF
resulted in more than 160 articles, including 80 referredpapers. This number includes papers in influential journals such as Nature Materials, Nature Communications
and Scientific Reports.
The HRC beam line (BL12) group won theTechnology Prize of the Japanese Society for Neutron
Science for the development of the construction ofhigh-resolution chopper spectrometer and implementation of neutron Brillouin scattering measurement.
The prize for development technology of Sumimoto
Rubber Industries, Ltd. (Cooperation of SPring-8 / J-PARC/ K-computer and Advanced tire developments) wasawarded as Commendation for Science and Technology
by the Minister of Education, Culture, Sports, Scienceand Technology, Japan in 2017. The technology has
confirmed that 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. This group had won numerous awards.
Based on these results, Sumitomo Rubber Industries
decided to hire a fixed-term resident researcher, whoworks closely with J-PARC staffs; this initiative is called
J-PARC/Sumitomo Fellowship program. The first fellow
employed by this program was assigned in JFY 2017.

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

171

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MLF Annual Report 2017

BL01: 4D-Space Access Neutron Spectrometer 4SEASONS

2. Beam transport update
The moderator-to-sample distance of 4SEASONS
is 18 m, and a supermirror neutron guide is installedfrom 2.3 m to 15.8 m relative to the moderator. The
guide has a square cross-section and an ellipticallyconverging shape along the longitudinal direction
to maximize the neutron flux reaching at sample.
Unfortunately, however, we found that the observed
neutron intensity at the sample was about 60% of thedesigned value [1], probably because of low reflectivity or misalignment of the supermirrors. Then, in 2017,
we renewed the last 1.7-m section of the neutron
guide (Fig. 1(a)). The designed shape and critical angleof the supermirrors (m = 4) in this new section are thesame as those in the original design. In spite of theshort length of this section (only 13% of the total neutron guide tube and less than 10% of the total flightpath to sample), it contributes considerably to the neutron flux at the sample, because this section has thehighest critical angle of supermirrors and the steepest slope in the neutron guide. Figure 1 shows the intensity ratio before and after replacing the last sectionof the neutron guide. The intensity ratio depends onneutron energy and no intensity gain was observed atenergies higher than 500 meV where the supermirrors
become ineffective, but we observed 10-20% intensity
gain at < 100 meV. (Fig. 1(b)).

72

(a)

Neutron Energy (meV)

(b)
1.4

Intensity Ratio (after/before)

1. Introduction
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, 3]. In 2017, 19 shortterm proposals were approved for 4SEASONS: 16
General Use proposals, 2 Urgent Use proposals, and 1
New User Promotion proposal. Three types of full-year
proposals, 1 Element Strategy Initiative Use proposal,
2 Project Use proposals, and 1 Instrument Group Use
proposal, were approved as well. In addition, 4 reserved (short-term) proposals were given beamtimes.
Most of the proposals were submitted for the fields ofmagnetism and strongly correlated electron systems,
and a few proposals were for materials science or energy materials.

1000 500

200 100 50

20

10

5

2

1.2
1.0
0.8
0.6
0.4
0.2
0.0
103

104

Time-of-Flight (μsec)

Figure 1. (a) A vacuum jacket with supermirror neutron guideis being removed by the technical supporting staffs
of MLF. (b) Ratio of neutron scattering intensity froma vanadium sample measured using white neutron
beam before and after the replacement of the neutron guide.

3. Preparation of the superconducting magnet
Because many iron components surround thesample area, and turbomolecular vacuum pumps withmagnetic bearings are attached just below the sample
position, it is difficult for 4SEASONS to use high-fieldmagnets. We have been trying to mitigate the problem to make the MLF-SE vertical-field superconducting
magnets (the maximum magnetic field is 7 T) available
on this instrument. So far, we evaluated the stray fields
from the magnet by calculation and performed a test
operation below 1 T to validate the calculation [4, 5].
Because we found that the stray field on the turbomolecular pumps limits the available amplitudeof the magnetic field, we decided to relocate the turbomolecular pumps. However, bending the exhaust
path between the vacuum tank and the pumps would

MLF Annual Report 2017degrade the pumping speed. Then, in 2017, we relocated the turbomolecular pumps downward as far as possible from the vacuum tank but kept the exhaust pathstraight (Fig. 2(a)). More specifically, we inserted a 25cm long extension pipe between the pumps and the attachment flange on the tank. After the relocation of thepump, we performed a test operation of the magnet
with the MLF Sample Environment (SE) team, measured
the stray fields around the magnet and confirmed that(a)

Neutron Science

the Fermi chopper, which also operates with a magnetic bearing, ran without problems under the magnetic
field. From these tests, we concluded that the maximum available magnetic field on 4SEASONS was 3 T for
the time being, although this value may change by future investigation. We will perform a test experimentwith a real sample under magnetic fields in 2018, and if
it is successful, we will accept proposals to use the MLFSE magnet from the second half of 2018.

(b)

Figure 2. (a) Turbomolecular vacuum pumps below the vacuum tank of 4SEASONS. They have been relocated downward
along the dotted arrow. (b) MLF-SE 7-T vertical-field magnet installed on the 4SEASONS sample flange.

References[1] R. Kajimoto et al., J. Phys. Soc. Jpn. 80, SB025 (2011).
[2] H. Seto et al., Biochim. Biophys. Acta, Gen. Subj.
1861, 3651 (2017).
[3] K. Nakajima et al., Quantum Beam Sci. 1, 9 (2017).

[4] R. Kajimoto et al., J-PARC Annual Report 2015, Vol.
2: Materials and Life Science Experimental Facility,
pp. 67-68.
[5] R. Kajimoto et al., J. Phys.: Conf. Ser. 1021, 012030(2018).

R. Kajimoto1, M. Nakamura1, K. Kamazawa2, Y. Inamura1, K. Ikeuchi2, K. Iida2, M. Ishikado2, N. Murai1, T. Harada1, H. Kira2,
and R. Takahashi3
1
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Neutron Science and Technology Center, CROSS; 3Technology
Development Section, Materials and Life Science Division, J-PARC Center73

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MLF Annual Report 2017

Current Status of BL02 DNA in 2017
1. Introduction
DNA is a micro eV spectrometer designed to elucidate atomic and molecular dynamics, phonon andmagnon excitations in −500 to 1500 micro eV range.
A high energy resolution is achieved by a pulse shaping chopper with four slits (one 10 mm and three
30 mm slits) and Si111 back scattering analyzers. The
first device makes DNA flexible to tuning energy resolution and enables the observation of a full energy
range while keeping the energy resolution high. The
second one is back-coated with Gd neutron absorber,
which ensures an extra high signal-to-noise ratio of approximately 105. The accessible momentum transfer
range is from 0.08 to 1.86 Å−1 by using Si111 analyzer
mirrors [1-3].
In 2017, the number of publications using DNA
finally increased up to nine reviewed papers per year.
These publications cover a variety of topics ranging
from hard materials, such as spintronics material, Ionic
Liquid, and thermoelectrics, to soft materials such aspolystyrene thin films, clay, human hemoglobin andcardiac muscle. The results from the experiments described in those articles became possible due to thewide energy range and extra high signal to noise ratioof DNA.
2. User program in the periods 2017A and 2017B
Thirteen General Proposals (GP) including one New
User Promotion (NUP) proposal, and twelve GPs, including one NUP, were approved for 2017A and 2017B, respectively. The portion of the approved beamtime in
the total of the requested beamtime was 63% for 2017A
and 64% for 2017B. The competition rate was approximately 1.6 which was almost average among all neutron instruments. During 2017B, one Urgent Proposal
was conducted.
In addition, a General Proposal (Long Term) (hereafter LTP) Program, started in 2017B, calls every B term
for a three-year project with a long-term strategy. One
LTP project, which will continue till 2020A through aninterim evaluation, was adopted at BL02.
The joint school of AONSA Neutron School and the
2nd Neutron and Muon School was held in mid-November. We at DNA accepted four students from Indonesia
and Korea. They took part in a hands-on experiment on
molecular dynamics of water on Nafion at DNA.

74

3. Beamline activities
Beamline
We relocated diffraction counters to the highest
angle position to install Si 311 analyzer mirror bank.
The diffraction data of LaB6 powder was successfully
confirmed.
Six years have passed since the commissioning of
DNA and several pieces of equipment started to failbecause of aging. Fast chopper No.2 stopped due tocommunication error between the control unit and the
motor driver. Since the other chopper instrument withthe same system had a similar problem, we were able
to minimize the unexpected shut-down by replacing
the control unit. Also, periodic maintenance was carriedout for the slow choppers and the pumps for the fast
choppers.
Sample environment
Low-temperature measurements are indispensable when DNA’s fine energy resolution is used to study
low-energy excitations. In the summer of 2017, we conducted a cooling test for MLF Sample Environment
Team’s 3He cryostat and Dilution refrigerator with a
new 2 K cryostat (Fig. 1). We achieved the lowest temperature of 300 mK (3He) and 50 mK (Dilution), which
opens doors to low-temperature measurement for
general users.
We also performed feasibility measurements of theParis-Edinburgh cell. The result received from an ionicliquid (C4mimPF6) is shown in Fig. 2. Even though the

Figure 1. Photo of the commissioning work of MLF SE’s dilution refrigerator with a new 2 K cryostat, summer of2017.

MLF Annual Report 2017

Neutron Science

SoftwareQENSFit, the software for fitting of QENS profiles bysome fitting functions convoluted with an instrument
resolution function, has been updated. QENSFit is currently available for both MAC and Windows.

Figure 2. Feasibility test of the Paris-Edinburgh type pressure
cell for QENS measurement. The sample was anionic liquid C4mimPF6.

intensity is much weaker than that measured by theconventional cell due to the relatively narrow opening
angle, we observed a quasi-elastic broadening causedby translational motion. Another type of cell for relatively low-pressure condition has been developed toincrease the sample volume.
In DNA, the solution sample is usually sealed in an
Al cell. Chemical reaction between our standard and thesolution was found in a few cases due to a small amountof additive in the solution, which broke the Al cell. We
strongly requested that the users precheck the sample’s
stability with Al (A1070). Pair of cylindrical quartz innerfits to be inserted into the Al cell has been developed forsample possibly interacting with aluminum. Currently
we are working on the design of two thickness setups,
approximately 0.2 mmt and 0.5 mmt each.
Due to the high sensitivity of DNA, the sample position could affect the spectrum. We found elastic position shifts in the time-of-flight spectrum when werotated the non-straight sample stick. We have developed a system to evaluate the displacement of the sample stick by using line-lasers. In addition, we installed acabinet to keep several of sample sticks straight. Now
we are developing a new sample stick with high reproducibility of the sample position.

4. Future plans
The pulse-shaping chopper, one of the key instruments of DNA, will be upgraded in 2018. The current
chopper was designed with the maximum rotational
speed of 300 Hz; however, the highest speed is limited
to 225 Hz due to large vibrations. Mr. Wataru Kambara,
the chief engineer of MLF, developed successfully a new
fast chopper, which ensures stable rotation at 300 Hz.
The new device will improve the energy resolution by
30% with the new disk chopper.
Further, Si311 analyzer mirrors will be installed before the summer shutdown in 2019, which will extend
the momentum transfer range to 3.8 Å−1 with 12 microeV with 10 mm slit.
5. Others
DNA received Interim Evaluation of Neutron
Instrument. In MLF, the activity of each neutron instrument is evaluated every five years after opening to user
program. The evaluation report stated that DNA has aworld-class performance and the experimental support
from the DNA team is satisfactory. However, considering the low number of publications, the leadership of
the instrument group is expected to increase the volume of data analysis and expand the user community
with scientists from many parts of the world.
The DNA group won the JAEA President Award
2017 for the construction of the DNA instrument andthe outcomes from the pilot studies.
The access safety of the sample environment
equipment on the top flange through the hatch was
improved by redesigning the handrail and the ladder.
References[1] Kaoru SHIBATA et al., JPS Conference Proceedings, 8(2015), 036022.
[2] Kenji Nakajima et al., Quantum Beam Sci., 1 (2017), 9.
[3] Hideki Seto et al., Biochimica et Biophysica (BBA)
General Subjects 1861 (2017), 3651.

Y. Kawakita1, M. Matsuura2, T. Yamada2, T. Tominaga2, M. Kobayashi2, H. Nakagawa1,3, and K. Shibata1
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Neutron Science and Technology Center, CROSS; 3Materials
Sciences Research Center, JAEA

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MLF Annual Report 2017

Current Status and Future Plans of iBIX
1. Introduction
The single-crystal neutron diffractometer is a
powerful tool for obtaining the structure and magnetic information of various materials, including lightelements. The IBARAKI biological crystal diffractometer, called iBIX, was constructed to accomplish highthroughput single-crystal neutron structure analysis forbiological macromolecules and organic compounds invarious life processes [1]. A new photon-counting twodimensional detector system using a scintillator sheet
and wavelength-shifting fiber arrays for the X and Y
axes has been developed with the cooperation of JAEA
to achieve high measurement efficiency. In 2012, theinstallation of 30 detectors on the iBIX diffractometer
was completed [2]. By the end of 2012, iBIX became
available for user experiments on biological macromolecules, supported by the Frontier Research Center ofApplied Atomic Sciences, Ibaraki University. The final
specifications of the iBIX are shown in Table 1.
Table 1. Specifications of iBIX.

Moderator
CoupledWavelength of incident neutron 0.7 ~ 4.0 (1st frame)
4.0 ~ 8.0 (2nd frame)(Å)2)
Neutron intensity (n/s/mm
0.7 × 106(@1 MW)40
L1 (m)500
L2 (mm)Solid angle of detectors
19.5(% for 4π)
Detector covered region
15.5 ~ 168.5(deg.)
Detector size (mm2)
133 × 1332)
Detectors pixel size (mm0.52 × 0.52
No. of detectors
30

2. Current status
The first period of the installation contract of iBIX
for J-PARC, MLF expired in the end of 2017. The second
period of the iBIX operation started in the beginningof 2018. In 2017, J-PARC was operated at accelerator
power of 150 ~ 300 kW. The results from the experiments on the full data set of biological macromolecules
for neutron structure analysis by using iBIX were as follows. We were able to collect a full data set of biological macromolecules for neutron structure analysis witharound 2.0 Å resolution in about 14 days by using iBIX.
76

The average volume of the sample measured by iBIX
was 2.3 mm3 (max. size: 4.7 mm3, min. size: 0.67 mm3).
If the accelerator power reaches 1 MW, the total measurement time of the sample size will be reduced to
one third of the previously necessary time. One organic
compound and five biological macromolecules were
provided for the diffraction experiments using iBIX.
Some interesting scientific results were obtained fromthese investigations by applying neutron structure
analysis, which will be covered in several papers to be
published next year. We project that iBIX will become
one of the world’s best performing diffractometers under 1 MW operation.
We prepared a users’ manual and a distribution
package of the data reduction software “STARGazer”,
which will allow the iBIX users to perform personallydata reduction in their laboratory [3]. At the same time,
we also held a software workshop for iBIX users.
3. Development
We assumed that a full data set of a 2-mm3 protein
sample could be obtained by iBIX in about 2 to 4 days
under the 1 MW operation. The assumption impliedthat iBIX was capable of achieving the designed target
value. However, the sample size was still large and themeasurement time was still long, especially for the users. We would like to reduce the difficulties of sample
preparation as much as possible. In other words, it isnecessary to further improve the measurement efficiency of iBIX by developing the beam line instrument.
As a simple and effective way to improve the measurement efficiency, we carried out the installation of
the newly-added detectors. A maximum of 60 detectors can be installed on the support frame of the iBIX
diffractometer without any design changes. In 2017,
we stated to assemble the four newly-added detectors
by ourselves. These have already been installed on theiBIX diffractometer (Fig. 1). The measurement efficiency
with 34 detectors will become 1.13 times higher thanthat of the previous 30 detectors. Commissioning thewithout/with neutron beam has already finished. By using the four newly-added detectors, we could obtainthe TOF diffraction data with the same accuracy as thecurrent detectors. The new detectors will be available
for users experiments in FY 2018.
We also started to develop a new scintillator unit
with high sensitivity for the iBIX detector system. The
scintillator unit consists of two scintillator sheets andMLF Annual Report 2017

Figure 1. Current diffractometer of iBIX with new detectors.

wave-length sift fiber for X and Y axes. The scintillator
sheet of the previous detectors is B2O2 scintillator. The
new unit’s scintillator was changed to a 6LiF scintillator.
Also, we optimized the material of the wave-length siftfiber for the new scintillator. In order to improve the position accuracy, we developed a method of fixation between neighboring WLSF. The development aim for the
new scintillator unit is 1.2 ~ 1.4 times higher sensitivity
than the previous one. We managed to demonstrate
this increased sensitivity by performing neutron experiments on a test piece. Now, we will try to develop new
scintillator sheets of practical size, to be fabricated later
by a manufacturing company.

Neutron Science

4. Future plans
It was demonstrated that iBIX achieved all design
target values (max cell dimension, resolution, measurement efficiency etc.). iBIX will progress to the nextstage, which is to continue achieving better scientificresults that make a full use of the neutron diffraction
experiment. In the future, the accelerator power of
J-PARC will increase to about 1 MW. iBIX should beavailable regularly for full data-set measurement ofsamples with a volume of 1 mm3. In order to speed up
the better scientific results, we will continue to develop
the data reduction software and the beam line instruments to improve the measurement efficiency and theaccuracy of intensity data obtained from small samples.
Specifically, we plan to install full detectors, a maximumof 60, and increase the number of incident neutrons to
crystal samples.
References[1] I. Tanaka, K. Kusaka, T. Hosoya, N. Niimura, T. Ohhara,
K. Kurihara, T. Yamada, Y. Ohnishi, K. Tomoyori and T.
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.
[3] N. Yano, T. Yamada, T. Hosoya, T. Ohhara, I. Tanaka,
N. Niimura and K. Kusaka, Acta Cryst. D74 (2018)
1041–1052.

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; 2Neutron Science Section, Materials and Life Science
Division, J-PARC Center

1

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MLF Annual Report 2017

Current Status of Accurate Neutron-Nucleus
Reaction Measurement Instruments, ANNRI (BL04)
1. Introduction
Accurate data of neutron-capture cross sections areimportant in detailed engineering designs and safety
evaluations of innovative nuclear reactor systems.
Especially, nuclear data for minor actinides (MAs) andlong-lived fission products (LLFPs) are necessary forburn-up analyses of nuclear fuels, improving the design
and performance of advanced nuclear reactors and thenuclear transmutation [1]. However, accurate measurements of these cross sections are very difficult due tothe high radioactivity of the samples.
To satisfy these demands, a time-of flight experimental instrument named “Accurate Neutron-Nucleus
Reaction measurement Instrument (ANNRI)” hasbeen constructed by the collaboration of Hokkaido
University, Tokyo Institute of Technology, and Japan
Atomic Energy Agency. Measurements of neutroncapture cross sections of MAs, LLFPs and some stable
isotopes with high intensity pulsed neutrons began
in 2008 [2]. In recent years, a measurement system forneutron total cross section and a new data acquisition
system for the array of the Ge detectors have been developed. In this report, we provide an outline of the improvements in the ANNRI.
2. New method for total neutron cross-section
measurement
In order to measure the total neutron cross-section,
two Li-glass scintillators with different characteristics
were prepared. The scintillator of the detector was GS20 (6Li enrichment higher than 95%) manufactured bySaint Gobain with dimensions of 50 mm × 50 mm andthickness of 1 mm. Additionally, to determine the background, an enriched 7Li-glass detector was used. The
scintillator of the 7Li-glass detector was GS-30 (7Li enrichment higher than 99.99%) manufactured by Saint
Gobain with the same size and chemical component of
the 6Li-glass scintillator. The set-up of the detectors isshown in Fig. 1. The 6Li-glass scintillation detector is installed at flight length of 28.7 m. The 7Li-glass detector
was set on the upstream side of the 6Li-glass detector.
The signals from the photomultipliers (HAMAMATSU:
H7195) were analyzed using CAEN V1720 (12 bit
250 MHz) module with digital pulse processing software, DPP-CI. The module recorded a pulse height anda time of flight in “event-by-event” mode.
78

Figure 1. The photo and the schematic view of the Li-glass
detectors for the total-neutron cross section measurement.

Figure 2. Typical PH spectra of the 6Li detector and the 7Li detector [3].

Typical pulse height spectra are shown in Fig. 2.
The spectra are results of a 957 MBq 241Am sample measurement with the 6Li-glass and 7Li-glass scintillation
detectors. Using this new method, neutron total crosssections of 241Am were reported in 2018 [3].
3. New data acquisition system
A new data acquisition system (DAQ system) in
ANNRI was developed. The growing beam power of
MLF in recent years allows the beam line users to obtain high quantity experimental data yields. By 2016,
the beam current had increased by more than 25 times,
compared to 2008.To match the strong beam power of
MLF, a new DAQ system for the array of the Ge detectors
in ANNRI is developed [4].
To digitize the detector signals, CAEN V1724 [5](14 bit 100 MHz) module with a digital pulse processing

MLF Annual Report 2017

software, DPP-PHA has been introduced. A pulse height
and a TOF were recorded in “event-by-event” mode withthe module. Optical link connections are used for datatransfer from the ADC boards to the PC using a CAEN
A3818 PCI express board. The maximum data transfer rate is about 80 MB/s. Trigger signals issued from
J-PARC were distributed to the DAQ in order to measuretime-of-flight events.
The CAEN v1724 ADC works with fixed dead-timefor each signal even, if the signal is not treated as a valid
event (defined as “not invalid”). If the signal is treatedas invalid (defined as “double pulses were detectedbut could not distinguish the pulse height information

Neutron Sciencefrom each other”), only the time-stamp information isrecorded. In order to estimate the count rate efficiency
by the constant dead-time analysis method, we can use
this time-stamp information as a starting point of theconstant dead-time. In this case, the probabilities of thedead-time appearance are proportional to the real signal rates.
A test of the new DAQ system was performed using standard γ-ray sources and the ANNRI beam line.
Figure 3 shows the counting efficiency. It depicts the Ge
detector with different shaping time settings. Typically,
the system works with 50 kcps for the Ge system.

Figure 3. The counting efficiency of the DAQ system with different shaping time. The solid line represents
the 3 μs shaping time setting. The dashed line shows the 1 μs case.

References[1] M. Salvatore, R. Jacqmin, “Uncertainty And Target
Accuracy Assessment for Innovative Systems using Recent Covariance Data Evaluations.” WPEC-26,
OECD NEA, (2008).
[2] H. Harada, et. al., J.Korean Phys. Soc. 59, (2011) 1547.
[3] K. Terada, et. al., Journal of Nuclear Science andTechnology, (2018), https://doi.org/10.1080/00223

131.2018.1485519[4] T. Nakao, K. Terada, et. al., In Proceedings of theInternational Conference on Nuclear Data for
Science and Technology (ND2016); 2016 September
11-16; Bruges, Belgium. EPJ Web of Conferences
2017;146:03021.
[5] http://www.caen.it/

A. Kimura
Nuclear Data Center, Nuclear Science and Engineering Center, JAEA

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MLF Annual Report 2017

Status of Fundamental Physics Beamline BL05 (NOP)2017
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, the so-called Polarized,
Unpolarized, and Low-Divergence branches, used indifferent experiments in a parallel way [1-2].
A neutron lifetime measurement was being carriedout at 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 by measuring neutron scattering with rare gases. The beamline isused also for R&D of optical elements and detectors [3].
2. Measurement of the Neutron Lifetime
A neutron decays into a proton, an electron, and an
antineutrino. The decay lifetime is an important parameter for the unitarity of the CKM matrix and also for theprimordial 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 a pulsed beam isongoing at BL05 (NOP). The lifetime is measured as aratio 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 havebeen collected for about four weeks by the TPC in 2016.

By analyzing the data, we obtained our first preliminary
result of the neutron lifetime as
τn = 896 ± 10 (stat.) +14−10 (sys.) [4].
3. Search for an Unknown Intermediate Force withRare Gas Scattering
Since then, many experiments have been performed
to measure the deviation from the inverse-square law of
Newtonian gravity down to tens of micrometers. We areprobing the short-range force in the nanometer scaleby 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 the masses of m and M can be described as−r/λV(r) = −GN mM
r (1 + αe )(1)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 equation (1) increase the forward angular distribution in neutron-scattering outgas
contamination in the noble gas samples for long timemeasurements. Two noble gases, He and Xe, were successfully measured in 2017. The results from the analysis by comparing the two gases were consistent withzero additional new forces [5].

915

Neutron lifetime [sec]

910

Pre

lim

905

ina

ry

900
895

8.4 sec (4σ)

890
885
880
875
1990

1995

2000

2005
2010
Publication year

2015

2020

Figure 1. The neutron lifetime measurements in the 2017
PDG [1], the storage methods are denoted as blue
squares, the proton counting is shown as closed
red circles. The J-PARC preliminary result is shown
as a red open circle [3].

80Figure 2. An exclusion line (red) in the α-λ plane resulting
from the recent data acquired on BL05 [5].

MLF Annual Report 2017

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.

Neutron Science[3] K. Mishima et al., Fundamental physics activities
with pulsed neutron at J-PARC (BL05). Proceedingsof International Conference on Neutron Optics(NOP2017) JPS Conference Proceedings, Vol. 22(2018) 11033. (arXiv:1712.06351, 2017)[4] K. Mishima et al., FUPA2018, in Nagoya, Japan.
[5] Haddock et al., Phys. Rev. D 97, 062002 (2018).

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

81Neutron Science

MLF Annual Report 2017

BL06: Commissioning Status of VIllage of Neutron
ResOnance Spin Echo Spectrometers (VIN ROSE)
1. Introduction
Neutron spin echo (NSE) is a variety of neutron
spectrometry for high-resolution inelastic and quasielastic neutron scattering methods [1]. Since the energy resolution of the energy transfer measurement is
not limited by the energy spectrum of the incoming
neutrons in the NSE technique, a moderately (10-15%
FWHM) monochromatic neutron beam is acceptable. In
addition, the intermediate scattering function can be directly derived by NSE, so that the method is suitable forstudying slow relaxation dynamics in condensed matter, and high-intensity and high-energy-resolution NSE
spectrometers have been developed and realized [2].
Since 2011, Kyoto University and The High Energy
Accelerator Research Organization (KEK) have been
jointly constructing Beam Line 6 (BL06), consisting of
two types of NSE spectrometers with neutron resonance spin flippers (RSFs), that is, a neutron resonancespin echo (NRSE) instrument and a modulated intensity by zero effort (MIEZE) instrument, at Materials andLife Science Experimental Facility (MLF), Japan Proton
Accelerator Research Complex (J-PARC) [3]. NRSE uses
RSFs, which can replace large magnetic precession

fields with low-guide fields, therefore downsizing andadjacence of the spectrometers become possible [4].
In this report, the status of the MIEZE and NRSE
spectrometers at BL06 in FY2017 is summarized.

(a)

(b)

2. Commissioning status at BL06 in FY2017
Time-of-flight neutron spectroscopy and MIEZE(TOF-MIEZE) is a novel approach. We have verified quantitatively fundamental characteristics of TOF-MIEZE [5].
In the 2017B proposal round, the user program has been
partially started. In addition, we modified the arrangement of RSFs, that is, 4 RSFs were arranged sequentiallywith π/2-, π-, π-, π/2-flip conditions, as shown in Fig. 1.
In this setup, the MIEZE-time-beating signal with frequency of 800 kHz can be observed by operating with
400 kHz frequency for the first π-flipper and 800 kHz
for the second π-flipper. Figure 2 shows the observed
800 kHz TOF-MIEZE signal and the corresponding power spectrum obtained by Fourier transformation.
At the NRSE spectrometer, the two-dimensional ellipsoidal neutron-focusing supermirrors with 3Qc, wherex Qc means that the critical angle is x times larger, weredeveloped in close collaboration with the RIKEN center for

Figure 1. (a) Experimental setup of TOF-MIEZE measurement with effective 800 kHz. (b) Corresponding energy diagram.

(a)

(b)

Figure 2. (a) 800 kHz MIEZE signal observed by the setup shown in Fig. 1. (b) Corresponding power spectrum obtained by Fouriertransformation.

82

MLF Annual Report 2017(a)

Neutron Science

(c)

(b)

Figure 3. (a) Picture of 900 mm-length metallic two-dimensional elliptic supermirror with 3Qc. (b) Experimental setup of the NRSE
spectrometer. (c) Focusing beam profile with a pair of the mirrors where the pinhole (ф = 1 mm) to detector length is 5 m.

advanced photonics [6]. The optical design is 1250 mm
semi-major axis and 65.4 mm semi-minor axis with
900 mm length as shown in Fig. 3 (a). The ellipsoidal supermirrors are essential for NRSE with high-energy resolution, which were installed before and after the sample
position symmetrically to correct the path difference, seeFig. 3 (b). In Fig. 3 (c), the focusing beam profile is shown,which clearly shows the required characteristics of themirrors can be achieved. The beam was restricted by aninitial pinhole with 1 mm φ, and passed the first focusing
mirror, then focused at the sample position (the center πflipper in this case) and refocused again by the second mirror at the detecting position, where the length between
the pinhole to the detector was 5 m. By using this system,
we tested the NRSE. RSFs were operated with 50 kHz forthe π/2-flippers and the π-flipper and 100 kHz for RSF1 ~RSF4, so that the effective frequency became 150 kHz inthis case. The repetition rate of the pulsed neutron was
tuned to 25/3 Hz by using a band chopper for observation of the neutron wavelength band. Figure 4 shows theobserved neutron spin echo signal as a function of the position of RSF4 with 0.05 mm steps, where the wavelengthband is from 0.7 nm to 1.6 nm and the intensity is normalized by the mean intensity. This observation is an important step in developing the NRSE spectrometer.
3. Summary
This was a brief report about the current status of
BL06 VIN ROSE. In FY2017, the public use with the MIEZE
spectrometer has been started partially, and 800 kHz
TOF-MIEZE signal was observed. At the NRSE spectrometer, the first NRSE signal was observed with ellipsoidal

Figure 4. Time-of-flight neutron spin echo signal as a function of the position of RSF4.

neutron-focusing supermirrors, which was a technicalhurdle for the development of NRSE with high-energy
resolution. Based on these successful achievements, wewill work intensely on the commissioning in FY2018.
References[1] F. Mezei ed., Neutron Spin Echo, Lecture Notes inPhysics, (Springer, Berlin) 128 (1982).
[2] D. Richter, M. Monkenbusch, A. Arbe, J. Colmenero,Adv. Polym. Sci. 174, (2005) 1-221.
[3] M. Hino, T. Oda, M. Kitaguch, N. L. Yamada, H.
Sagehashi, Y. Kawabata, H. Seto, Physics Procedia 42,(2013) 136.
[4] R. Gähler and R. Golub, J. Phys. France, 49, (1988)
1195-1202.
[5] T. Oda, M. Hino, H. Endo, N. L. Yamada, Y. Kawabata,H. Seto, J. Phys. Soc. Conf. Proc. in press.
[6] T. Hosobata, M. Hino, H. Yoshinaga, T. Kawai, H.
Endo, Y. Yamagata, N. L. Yamada, S. Takeda, J. Phys.
Soc. Conf. Proc. in press.

H. Endo1,2, M. Hino3, T. Oda3, N. L. Yamada1,2, H. Seto1,2, and Y. Kawabata3
Neutron Science Division, Institute of Materials Structure Science, KEK; 2Neutron Science Section, Materials and Life Science Division,
J-PARC Center; 3Institute for Integrated Radiation and Nuclear Science, Kyoto University

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MLF Annual Report 2017

Commissioning of a New 4K Cryostat at S-HRPD

2. Offline test
We installed a new 4 K GM cryostat with coolingpower of 1.5 W at 4.2 K. We can control the temperature
with a 100-W heater installed on the top of the coldhead. The cryostat has two jackets, one is the outer
vacuum chamber (OVC), the other is the inner Al tube
(φ124 mm) for the radiation shield. The incident neutron beam passes two vanadium windows (with thickness of 100 μm) at the front and back of OVC.
First, we did an offline operation check withoutsample holder. Because the cooling power was sufficiently strong, it was possible to go from room temperature (RT) to 4 k in about 90 minutes. On the other hand,when we measured NPD for samples with an enclosed
V-Ni 6-mm sample holder with helium gas at 1 atm, aproblem with the temperature emerged. Whereas themonitor displayed a temperature of 3 K, we could notobserve magnetic peak of one sample with TN = 5 K.
When the cold-head temperature was changed from20 K to 50 K, the Bragg peaks were gradually shifted84

in 6 hours; it took at least 6 hours to reach a thermal
equilibrium of the real sample temperature. There are
two possible explanations: i) the thermal conduction
from cold-head to sample is too weak, and ii) the position and temperature of the radiation shield are notsuitable.
Next, we tried to check the real sample temperature in an offline test. The V-Ni sample holder containing helium gas was mounted to the cold-head. The cell
was checked by helium gas detector and there was noleakage. The cryostat has two temperature sensors, one(sensor A) is at the center of the cold-head, the other(sensor B) is on the tip of cold-head. We moved sensor
B to the bottom of the sample holder to record the real
sample temperature. In this setting, large differences
between the temperatures of sensor A and sensor B
were observed; although sensor A showed 3 K as thelowest temperature, sensor B showed 19 K (Fig. 1). Thenthe holder was heated up to RT while keeping the temperature of sensor A at several points. Whereas the response of sensor A was quick, the response of sensor
B was very slow. In addition, at above 200 K, the temperature of sensor B was lower than that of sensor A.
We concluded that the major cause for the sample temperature problem was weak thermal conductivity of the
V-Ni sample cell. To stabilize a temperature of sample
position, copper stick imitating a sample cell was used.
There was almost no difference between the temperatures of the two sensors and the temperature responseof sensor B was good.

300

Temperature (K)

1. Introduction
S-HRPD (BL-08), installed at MLF, J-PARC, is a neutron powder diffractometer with the highest resolution
in the world (Δd/d ∼ 0.03%) [1]. It is very useful for highresolution experiments, for example, investigation of
structural transition together with very small distortion,and structure analysis of low-symmetry material whose
profile contains many overlapped Bragg peaks on diffractometers with conventional resolution. Although
the resolution of the neutron powder diffraction (NPD)
is inferior to that of the synchrotron XRD, NPD has advantages over XRD for some samples (e.g. material containing adjacent elements, and one containing light andheavy elements) and sample environment. Especially,
NPD can demonstrate diffraction experiment at low
temperature.
A new GM cryostat, with a better performance
than the old one, was installed on S-HRPD in the endof FY2016. We performed commissioning of the cryostat and found several problems. The fatal problem waswith the sample temperature. We were not able to control the real sample temperature by sample heater inreasonable time. Offline tests revealed the cause of thetemperature problem, which we solved by using an additional large vanadium holder and confirmed that it
performed NPD of magnetic transitions using 2014S05’s
beam time. The details are covered below.

200

100

sensor A
sensor B
0

0

20

40

Time (hour)
Figure 1. Temperature log of the offline test.

60

MLF Annual Report 2017

3. Online test
To realize good thermal coupling, we prepared additional 10-mm vanadium holder, the layout is shownin Fig. 2. The V-Ni 6-mm holder was enclosed in the 10mm cell together with helium gas. Because it was impossible to check the real sample temperature using atemperature sensor, we performed diffraction measurement as an online test. We used as a reference sampleof the temperature points, a powder sample of the geometrical frustrated compound Co2(OD)3Br [2]. Its crystal
structure was hexagonal (R-3m) and had a tetrahedral
arrangement of S = 3/2 Co2+ ions. There were two magnetic transitions at TN1 = 6.2 K, TN2 = 4.8 K. Each magnetictransition TN1 and TN2 was related to a magnetic peak indexed k1 = (1/2 0 1/2) and k2 = (0 0 3/2), respectively, thus,
we could check two temperature points. Figure 3 shows
NPD profiles at 10 K and 3 K. We performed Rietveld
analysis to refine the crystal and magnetic structures

Neutron Science

using Z-Rietveld program [3]. The results showed a good
agreement with the reference for both crystal and magnetic structures. The temperature dependence of theintegrated intensity of two kinds of magnetic peaks areshown in Fig. 4. Both transition temperatures could be
reproduced in this experiment. We also checked the response of the sample temperature during the heatingprocess. The temperature (sensor A) was set up to 10 K,
20 K, 40 K, 100 K, 150 K, 200 K and 250 K with 3 hours’
measurement at each temperature point. Before thismeasurement, sensor B was put back to the original position. Table 1 shows the elapsed time from the momentof setting a new temperature point to the start of thenext measurement, when the temperature of sensor B
is stable. The time-sliced data sets with 5 minutes’ interval are shown in Fig. 5. Only the first 5 minutes’ profileshows a slight peak shift, so it is enough to wait for about
additional 5 minutes after stabilizing the temperature.

Table 1. The elapsed time of the temperature increasing process.

Figure 2. The sample setting for the online test.

Intensity (a. u.)

40start T (K)set T (K)elapsed time (min.)

10

20

4.2

20

40

4.2

40

100

9.7

100

150

12.5

150

200

14.1

200

250

15.8

T = 10 K

observed
calculatedobs.-calc.
nuclear peak

30
20
10
0

Intensity (a. u.)

40

T=3K

observed
calculatedobs.-calc.
nuclear peakmag1 peakmag2 peak

30
20
10
0
0.5

1.0

1.5×105

t.o.f. ( μ sec.)
Figure 3. The NPD profile of back scatter bank and Rietveld refinement result on Co2(OD)3Br at (up) 10 K and (down) 3 K.

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MLF Annual Report 2017170-175 min.
@200 K
0-5 min.
5-10 min.
10-15 min.
15-20 min.
170-175 min.

600
6

400
4
200
2

20

Intensity (arb. unit)(1/2 0 1/2)

Integ. Int. (arb. unit)

Integrated Intensity (arb. unit)

8×103

10

(0 1 5/2)

0
2

3

4

5

6

7

8

0

Temperature (K)

0
1.105

1.110

1.115×105

TOF (micro sec.)

Figure 4. The temperature dependence of integrated intensity of two magnetic peaks. The (1/2 0 1/2) and the(0 1 5/2) reflection is related to k1 = (1/2 0 1/2) andk2 = (0 0 3/2) order, respectively.

Figure 5. The peak profiles of (2 0 4) reflection on Co2(OD)3Br.
The profiles were collected at 250 K, except for the
purple line (200 k).

4. Summary
We did commissioning of a new 4 K GM cryostat and improved the accuracy and response of thesample temperature. We provided the cryostat to user
programs and several user groups used it. An ongoingproblem is that it takes a long time to change a sample.
When the sample temperature reaches RT after cooling,
the most part of the cryostat is still cold, so we need to
wait for several hours to open the OVC. The backgroundsignal is high because of scattering from the OVC and

the inner Al tube. We will solve these problems in the
future.
References[1] S. Torii et. al., J. Phys. Soc. Jpn. SB020 SB020-1-4(2011).
[2] M. Hagihala et. al., Phys. Rev. B 82 214424 (2010).
[3] R. Oishi-Tomiyasu et. al., J. Appl. Crystallogr. 45 a299308 (2012).

M. Hagihala1,2, S. Lee2, S. Torii1,2, and T. Kamiyama1,2
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Institute of Materials Structure Science, KEK

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Neutron Science

Current Status of Special Environment Powder
Diffractometer, SPICA
1. Introduction
The battery is a key technology in society because
the consumer and business electronic devices, like mobile phones, laptop computers and even an electric vehicles (EV) work only with batteries as energy sources.
Currently, the lithium-ion battery (LIB) is the best system
to store large energy density. An all-solid-state battery,which has more powerful output performance, is also
being developed for commercial usage as the next battery system. And some other advanced battery systems,
like metal-air and fluoride ones, have been proposed
and are in the process of research. However, it will takea long time before they are ready for practical use.
Neutron operando measurements to observe directly inside a battery and detect key issues to improve its
performance in operative conditions are important for
current and future studies. BL09, SPICA is the only beamline in the world, solely dedicated to battery study. The
operando measurements have already been performed
and some results were reported [1, 2]. For the next step in
improving the operando measurements, a limited spacevolume measurement is being developed. To define
space as a gauge, volume, width, height, and depth arenecessary. The sizes of the width and height are definedby the size of the beam slits in front of a sample. They cannot limit the depth along the incident-beam direction.

If only 90 banks are used for the limited space volume
measurements, a radial collimator is very effective to define the gauge volume in the time of flight (TOF) diffraction technique. In this development, we tried to apply
3D-printing technique to create the radial collimator.
2. Development of the Radial Collimator as space
definitory
The radial collimator has many neutron-absorberblades in cylindrical locus, to define the gauge volume.
It is suitable equipment to limit the sight-view of depth
along an incident beam direction, especially in the TOF
diffraction technique at 90° banks. Figure 1 shows anillustration of the limited space volume technique in
the TOF diffraction measurements. An incident neutron
beam passes through four quadrant-multi slits in frontof a sample. The slits, made by sintered B4C plates withthickness of 10 mm, define the width and the height ofthe beam. The depth along an incident beam direction
is limited by a radial collimator.
Three different radial collimators with 2, 5, and
10 mm sight-view sizes, respectively, were developed
on SPICA. A basic design of a radial collimator was reviewed by Dr. Torii, Dr. Moriai and S. Harjo [3-5]. The radial collimators for BL09 were designed in 2014 on basisof their reports in 2014 [6].

Figure 1. The illustration of the limited space volume measurements in the time-of-flight technique.
The radial collimator is the key device to define the depth of the sample to measure.

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MLF Annual Report 2017

SPICA uses rough course collimators to reduce theair-scattering level in front of all detector-banks, except
the back-scattering ones. It is possible to install the newradial collimators in two different locations, between
the vacuum sample chamber and the detector-banks orin the chamber. In the 2014 design, we considered thelocation between the chamber and the detector-banks.
However, the experimental conditions may require removal of the collimators. But in the 2014 design, it was
not easy to remove them because they were confined
to a limited space due to overhung upper-detectorbanks. Therefore, the new ones were redesigned to beplaced in the sample chamber.
The basic parameters of the new ones are show inTable 1. The blades of the collimators are located between 200 to 400 mm from the center of the sample
position. The gap between each of the blades was calculated based on the previously reviewed papers [36]. These radial collimators were designed to cover anangle from 60° to 120°. Figure 2(a) shows the design
picture of the 10-mm one. The basic shapes of radialcollimators in this development are the same as seen in
Fig. 2. The 2, 5, and 10 mm sight-view collimations wereobtained from the different slit gaps. The narrow slitsize was consistent with the narrow sight-view. A pair ofthese collimators was installed at a 90° angle position.
Figure 2(b) shows the real collimators created by the
3D-printer, AGILISTA-3100 (KEYENCE corporation), whichwere placed at the Mechanical Engineering Center in theHigh Energy Accelerator Research Organization (KEK).
The price for this collimator was less than one fourth of(a)Table 1. The basic parameters of the radial collimators on
SPICA.

Distance of blades
from the sample center (mm)200
to the ends of collimators (mm)400
Gap between each blade
Depth
Near side
Far side
2 mm
0.90
1.80
5 mm
2.25
4.50
10 mm
4.50
9.00

the price for a manufactured radial collimator. The benefits from 3D-printing are 1) short time to create, 2) create
easily a complicated structure component and 3) low
weight. This 3D-printer creates an object from organic
polymer. The weight of the developing collimator (oneset of one side) is approximately 10 kg, which is amazingly low. The blade was formed by organic polymer
materials. The hydrogen in the organic polymer becamea neutron absorber. Therefore, it was not necessary tocoat them with an extra neutron absorber.
4. Performance of the 3D-printed radial collimator
The 3D-printed radial collimators were installed on
BL09 with 5-axis goniometer. Neutron diffraction data
were taken when a tandem of two different metals withdiameter of 10 mm shifted each sample position from+ 25 mm to − 25 mm with 1 mm steps along the neutron beam direction. The collected diffraction data withthe 5-mm radial collimator is shown in Fig. 3.

(b)Figure 2. The illustration of the radial collimators in this development. (a) The 3D-design picture of 10 mm radialcollimators. 90° banks have a 3 detector-bank (upper, middle and lower) at both the left and right sides.
(b) Photograph of the 3D-printed radial collimators.

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Figure 3. The neutron diffraction data, non-collimated and collimated by the 5 mm radial collimators in this development.

Figure 3 indicates that the radial collimator worked
successfully. In non-collimated conditions, the diffraction peaks from the tandem of two different metals appeared in all sample positions. On the other hand, thediffraction peaks from these metals were only observed
when these metals passed through the collimatedsight-vision area by the radial collimators. These results indicated a depth resolution of 4 mm against the
5 mm in the designed resolution. However, both metals having same diameter were observed in different
path-length, 9 and 13 mm, as shown in the Fig.3. These
differences might come from geometrical misalignment of the collimator. The sample position and height
were correct. However, the collimator was located at aslightly higher level than the sample position. To understand what happened, we will repeat the experimentwith a correct geometry condition.

Acknowledgements
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] S. Taminato, et. al., Scientific Reports, 6, Article#
28843 (2016).
[2] S. Shiotani, et. al., Journal of Power Sources, 325,
404–409 (2016).
[3] S. Torii, et. al., JAEA-Technology, 2005-004.
[4] S. Torii, et. al., Physica B, 385-386, 1287–1289 (2006).
[5] S. Harjo, et. al., JAEA-Technology, 2008-004.
[6] N. Suzuki, et. al., JPS Conf. 8, Article# 03010 (2015).

M. Yonemura1,2,3, Y. Ishikawa4, H. Kawamata5, M. Yamanaka5, and T. Kamiyama1,2,3
1

Institute of Materials Structure Science, KEK; 2Sokendai (The Graduate University for Advanced Studies); 3Neutron Science Section,
Materials and Life Science Division, J-PARC Center; 4Neutron Science and Technology Center, CROSS; 5Mechanical Engineering
Center, KEK

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MLF Annual Report 2017

BL10: NOBORU
1. Introduction
In FY 2017, twenty general-use proposals and threeproject-use proposals, in addition to the postponed
three proposals from FY 2016B, were carried out at
NOBORU. The user program was not disrupted by any
technical problems with the instruments.
This year, we did not add any beamline device. The
proton beam power was not increased because of theacceptance limitation of the mercury target, so thedependence of the neutron beam intensity on proton
beam intensity was not examined. Instead, we carriedout the other neutronic performance test describedhere in Section 2.
We also carried out the continuing test of the2012 model lithium-6 time analyzer neutron detector(LiTA12) system [1] at NOBORU. Its purpose is to provide
high efficiency at epi-cadmium cut-off energies and ahigh counting rate with a reasonable spatial resolution.
The result of the maximum counting rate estimated in2017 is reported in Section 3.
2. Dependence of neutron beam intensity on the
proton beam profile and the injection position
Neutron intensity depends on the profile and position of the proton beam injected into the mercury
target. Therefore, we measured the neutron intensities
during changes of the proton beam profile and position(Fig. 1).
The experiment was conducted at NOBORU witha monitor-type He-3 detector (Efficiency: 10−3) locatedat 13.0 m from the moderator. A rotary collimator with‘tiny’ size aperture (3.2 × 3.2 mm2) and a duct collimatorwith small size aperture (20 × 20 mm2) were adopted. A
disk chopper was used to suppress the frame overlap
neutrons. In the measurement, the proton beam conditions were changed as follows:
Vertical proton beam position:y = –4, –2, 0, 2, and 4 mm.
Proton beam profile:
Flat distribution (with octupole magnet) and
Gaussian distribution (without octupole magnet).
The results are shown in Fig. 2. The neutron intensities were integrated between 1 meV and 20 meV. As thevertical position of the proton beam rises, the neutron
intensity increases. As shown in Fig. 1, the reason wasthat the decoupled moderator providing neutrons to
NOBORU was located above the target. On the other
hand, the flat profile of the proton beam provided a
90

Figure 1. Vertical relation of proton beam, target and moderators.

Figure 2. Relative neutron intensity integrated between
1 meV and 20 meV during the change of the proton vertical position and the proton beam profile.

higher neutron intensity than the gaussian profile. The
possible reason for it was that the flat distribution of
protons provides a smaller proton beam loss than thegaussian distribution of protons. These results havebeen presented at the 2018 Fall Meeting of the Atomic
Energy Society of Japan.
3. Maximum counting rate of LiTA12 system
A 6Li-glass scintillator (GS20) of 1 mm in thickness
with a multi-anode photo multiplier tube (Hamamatsu
Photonics K.K.: H9500 series, detection area 49 × 49 mm2)
was set at the 13.4 m position of NOBORU. The proton
beam power was 150 kW. The spatial resolution of thissystem using the center-of-gravity calculation was estimated to be 0.7 mm for the energy at 4.9 eV as reported
last year [2]. The maximum counting rate was estimatedby measuring neutron spectra with varying neutron intensity by the rotary collimator and a filter device [3].

MLF Annual Report 2017

Neutron Science

Figure 3. Neutron counting rates as a function of neutron
flight time for different neutron intensities controlled by selection of ‘tiny’ or ‘small’ through-apertures in the rotary collimator and through various
thicknesses of the lead (Pb) filters.

Figure 4. Neutron intensity as a function of the thicknessof the lead (Pb) or bismuth (Bi) filters with ‘tiny’ or‘small’ rotary collimator apertures. The values areintegrated between 0.5 eV and 1 keV. The dashedlines for the ‘tiny’ cases are fitted ones, the solid lines
for the ‘small’ are an eye-guide.

The rotary collimator has a revolver equipped with four
through-apertures in a 400-mm long stainless-steel cylinder. Apertures designated ‘small’ and ‘tiny’ with crosssections of 10 × 10 and 3.2 × 3.2 mm2, respectively, wereused. The neutron intensities increased roughly tenfold
by changing the aperture from ‘tiny’ to ‘small’ expectedfrom the ratio of cross sections of them. The filter device
has four linear stages with two filters each. A cadmium
filter (thickness 2 mm) was used for all measurements.
The thicknesses of lead (Pb) or bismuth (Bi) used in themeasurements with the ‘tiny’ or ‘small’ apertures were 0,25, 50 and 75 mm.
Neutron counting rates as a function of time-offlight were measured in various neutron intensity conditions to find the maximum counting rate. Figure 3
shows those measured with the ‘tiny’ aperture and Pb
filters of 0, 25, 50 and 75 mm in thickness, and with the‘small’ aperture and 50-mm thick Pb filter. The rangeof flight time in the figure corresponds to the neutronenergy range between 1 keV and 0.5 eV. The shapes ofthese spectra were almost the same, indicating thatthose measurements were performed without counting loss. Some deteriorations in the spectra were recognized in the ‘small’ aperture cases without filter, withthe 25-mm thick Pb and Bi filters, and with the 50-mm
thick Bi one. The highest counting rate of 8 Mcps wasrecorded by the ‘small’ aperture with the 50-mm thickPb filter [4].
Figure 4 shows the neutron intensities integrated
between 0.5 eV and 1 keV as a function of the filter
thickness. In the near future, we plan to increase theneutron intensities 6.67 times by increasing the proton
beam power from 150 kW to 1 MW. The values in Fig. 4
were normalized so that the value of the ‘small’ aperture with the 50-mm thick Pb filter was 6.67 to project
the availability of the LiTA12 system at the higher beam
power. At a proton beam power of 1 MW, the LiTA12
system is expected to be available with intensity conditions with relative values below 1.0. In the case of
500 kW, the limit is 2.0. It indicates that the ‘tiny’ aperture with the 50-mm thick Pb filter is recommended formeasurements at epi-cadmium cut-off energies in the
future 1 MW operation.
References[1] S. Satoh, Development of a 2012 model for the 6Litime analyzer detector system, Phys. Procedia 60,
363 (2014).
[2] MLF Annual report 2016, 98 (2016).
[3] M. Harada, et al., JPS Conf. Proc. 1, 014015 (2014).
[4] T. Kai, et al., Physica B, to be published (Proceedingsof ICNS2017).

M. Harada1 and T. Kai2
Neutron Source Section Materials and Life Science Division, J-PARC Center; 2Neutron Science Section Materials and Life Science Division,
J-PARC Center
1

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MLF Annual Report 2017

BL11: Development of High-P Experiments Using a
Paris-Edinburgh Cell
1. Introduction
Since the start of the beamline operation at 2013,
accessible pressure and temperature range have been
extended by developing high-pressure devices, such asa six-axis press and diamond anvil cells [1,2]. Now we canroutinely collect diffraction data up to about 18 GPa [3].
However, the users’ demands are still expanding. To satisfy them, we tackled the following challenges this year:
a. Extend the maximum pressure limit by using a ParisEdinburgh (P-E) cell equipped with smaller top anvils.
b. Increase the data quality by avoiding freezing ofpressure-transmitting medium (PTM) using a heating system.
c. Correlate the pressure change with neutron dataacquisition.
Here, we will introduce these results in detail.
2. Extension of the maximum pressure limit with useof smaller top anvils for a P-E cell
In principle, pressure is equal to the force divided by
the area which the force is applied to. Therefore, higher
pressure is generated by applying the force to a smallerarea. So far at PLANET, anvils whose top are 4 mm or
6 mm in diameter have been normally applied in theexperiments using a P-E cell, which makes possible thestructure analysis at pressures up to 18 GPa [3]. To extend this pressure limit, we tested the pressure generation and data acquisition using anvils whose tops are
3 mm and 2.5 mm in diameter.
Figure 1 shows the diffraction patterns of a mixtureof NaCl and MgO compressed with a PTM of the methanol/ethanol mixture. Thanks to the narrow beam collimation, clean diffraction patterns were obtained up
to about 30 GPa. The generated pressures were calculated from the lattice parameters of the sample basedon the previously reported equation of state [4, 5].
Figure 2 shows pressure generation curves obtained inthis study (purple and green), together with those forthe anvils with a larger top size. Results showed that the
maximum pressure has been extended to 30 GPa without degrading the quality of the diffraction pattern.
Comparison of the pressure generation curve among
the different top anvils revealed that the pressure generation efficiency was proportional to the inverse areaof the top of the double toroid anvils (described as DT
in Fig. 2). Based on this relationship, it is expected that
92

Figure 1. Diffraction patterns of a mixture of NaCl and MgOtaken with 2.5 mm-top sintered diamond anvils.

Figure 2. Pressure generation curves for different anvil tops
(WC ST: single toroidal tungsten carbide anvils, SD
DT: double toroidal sintered diamond anvils).

100 GPa can be generated by applying load of 50 ton
with 1-mm-top anvils in future.
3. Increase of the data quality by avoiding the freezingof pressure-transmitting medium using a heating
systemNormally, in the experiments using P-E cell, thesample is compressed with liquid PTM to avoid broadening of the diffraction peaks due to the collision of
crystal grains, which makes the precise structure determination difficult. For this reason, liquid that has highfreezing pressure is preferable as PTM, and a mixture of
deuterated methanol and ethanol (ME) in volume ratioof 4:1 is normally used. This PTM works well at pressures
below 10 GPa, but at higher pressures it freezes, and hydrostatic condition is no more present. We actually encountered this situation when extending the maximum

MLF Annual Report 2017pressure range above 10 GPa. Heating of the PTM could
efficiently overcome this problem. Previously reportedpressure dependence of melting temperatures of ME
mixture suggests that the freezing pressure point canbe extended to 17 GPa by heating it to 100°C [6]. For
this purpose, we built a sample heating system for a
P-E cell. Figure 3 shows the system configuration andthe enlarged view of the anvil parts. The system consists of wire heaters (Watlow,130 W), DC power supplies(Takasago Den-netsu, ZX-400MAN) and PID controllers.
Each heater is attached to an upper or lower anvil via
an adapter. To transfer the heat effectively, each anvil ispress fitted into the adapter via a tapered ring. The temperature of the anvil is monitored with a K-type thermocouple attached to the anvil and is PID controlledindividually. By using this system, the PTM (and thesample) can be heated to 100°C.
To illustrate the effectiveness of heating, the pressure dependence of the 220-diffraction peak of MgO taken with and without heating are shown in Fig. 4. Without
heating (upper left in Fig. 4), the peak becomes broader
above 10 GPa. On the other hand, the peak with heatingshows no marked broadening even above 10 GPa (upper right in Fig. 4). To show the difference more quantitatively, the pressure dependence of the FWHM is shownin Fig. 4. Contrary to the significant increase of FWHM
above 10 GPa in the case without heating, the FWHM remains almost unchanged in the case with heating.

Figure 3. Configuration of the heating system and the enlarged view of the anvil parts.

Neutron Science

Figure 4. Pressure dependence of the profile of MgO 220
peaks (upper) and the FWHM (lower) with andwithout heating.

4. Correlation of pressure change with neutron dataacquisition
Usually in the experiments using a P-E cell, the diffraction data at high pressures are collected in the following sequences:
1. Compress the sample to the desired load.
2. Move back the sample position to the center of goniometer to compensate sample drift by compression.
3. Collect the diffraction data.
The typical exposure time is from 3 h to 12 h, thus users
had to come the beamline each time to execute the above
process manually. It’s often time consuming and exhausting. If the amount of drift is known in advance, these procedures can be done automatically by correlating pressurechange with data acquisition. To make it possible, we have
implemented pressure change commands in our software “Experimental Scheduler”, which uses batch control.
Thanks to this development, now a series of high-pressure
data are collected once the users plan the experiments.
References[1] T. Hattori, et al., MLF Annual Report 2013, 93.
[2] T. Hattori, et al., MLF Annual Report 2016, 99.
[3] T. Hattori, et al., MLF Annual Report 2014, 93.
[4] J. M. Brown, J. Appl. Phys., 86, 5801 (1999).
[5] I. Jackson, Geophys. J. Int., 134. 291 (1998).
[6] S. Klotz et al., High Press. Res., 29, 649 (2009).

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

1

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MLF Annual Report 2017

Status of High Resolution Chopper Spectrometer, HRC,
in FY2017

2. Instrumentation in FY2017
NBS is inelastic neutron scattering near to the forward direction. This technique is effective for observing coherent excitations in non-single-crystal samples,such as ferromagnetic spin waves in powder samples.
After the recent success of NBS [1], the neutron intensities for NBS experiments were increased by the doubled array of PSDs, the less deformed slit package of theFemi chopper and the longer incident beam collimator [2]. On HRC, one of the two Fermi choppers, which
are the high-intensity chopper and the high-resolution
chopper, can be selected to optimize every experiment.
The performance of the high intensity chopper has
been well established by the recent instrumentation. To
improve the performance of the NBS experiment, theparameters of the slit package of the high-resolution
chopper, which are the slit width and the slit curvature,
were optimized so that the intensity at Ei = 100 meV canbe doubled with unchanged energy resolution to reach
ΔE/Ei = 2%. Also, the long collimator was replaced by
one with better transmission. As shown in Fig. 1, theneutron flux greatly increased. Moreover, the best energy resolution was achieved to be 1% something with areasonable neutron flux by rotating the chopper faster.
Realizing inelastic neutron scattering experiments
under external fields is another important issue on HRC.
We performed inelastic neutron scattering experiments
94

under high pressures. A standard sample can contains
a cylindrical pressure cell with a sample crystal cooledwith a 1 K refrigerator. We confirmed a pressure-induced
phase transition and successfully observed magnetic excitations at 1.4 GPa in CsFeCl3 [3, 4], as shown in Fig. 2.
Magnetic field is also one of external fields, underwhich inelastic neutron scattering experiments are tobe performed on HRC. The superconducting magnet
was repaired due to vacuum leak. According to the20
Intensity (arb. units)

1. Introduction
The High Resolution Chopper Spectrometer (HRC)
is being operated at BL12 to study dynamics in condensed matters with high resolutions using relatively
high energy neutrons. A research project using HRC isbeing conducted to observe wide range of correlated
electron systems. In FY2014, we entered the second
phase of our project , where we will improve the performance of HRC in the following points: (1) detector
system at low angles for high energy experiments,(2) Fermi choppers for higher resolution and lower
background, (3) sample environments, (4) completionof installing detectors at high angles, and (5) computational environment for easy operation of experiments. In this phase, using these instrumentations, weare improving the neutron Brillouin scattering (NBS)
experiments and realizing inelastic neutron scatteringexperiments under external fields.

current setup
initial setup

La0.8Sr0.MnO3–1
Q = 0.225 Å
T = 250 K

10

0
–10

–5

0
E (meV)

5

10

Figure 1. NBS spectra for ferromagnetic spin waves in
La0.8Sr0.2MnO3 in the current improved set-up andin the initial set-up when the NBS experiment wasstarted on HRC for the first time. The experiments
were performed with Ei = 100 meV and ΔE/Ei = 2%.

Figure 2. A preliminary result of inelastic neutron scatteringfrom CsFeCl3 at P = 1.4 GPa and T = 0.6 K. The scattering intensities related to the ordering wave vector (1/3, −2/3, 0) can be seen.

MLF Annual Report 2017

manufacturer, the vacuum leak may have been caused
by a deformation due to applying magnetic fields on
HRC, which contains a large amount of iron materials.
The manufacturer evaluated the maximum magnetic
field to be 5 T under the HRC environment. Based on
this report, we plan to perform experiments using thismagnet in the next fiscal year.
At the secondary flight path L2 = 4 m on HRC, 256
pieces of position sensitive detectors (PSDs) with 2.8 m
long, 3/4 inch diameter and 1.8 MPa of 3He gas pressure
are mounted at the scattering angles from 3° to 62° andfrom −13° to −31°. Some PSDs showed inhomogeneous
positional dependence of neutron intensities due todistorted central wires, some PSDs did not work due
to broken wires, and therefore, 26 pieces of these defective PSDs were located randomly in the scattering
angles. Several PSDs could be repaired because of funding and several new PSDs were provided by the manufacturer, so the number of defective PSDs was reduced
to 10. The PSDs were reconfigured so that good PSDs
can be located continuously by moving the defective
PSDs to the side of the detector bank from −13° to −31°.
For the Fermi chopper control system, the control
algorithm was improved to realize a good phase control performance and the power of the uninterruptible
power supply was increased to ensure safe slowdownof the rotation of the chopper in case of power failure.
We experienced some breakdowns. Since thecryopump for the vacuum scattering chamber, theturbo molecular pump for the Femi chopper, and the1 K refrigerator failed, they were repaired. The flexible
tubes for helium gas circulation in the GM refrigerator
for the sample cooling were twisted and broken, causing leak of helium gas. This problem was also fixed.
The cooling water of the T0 chopper installed on
BL04, that is the same type as those installed on BL09,
BL12, BL21 and BL23, leaked at the coupler. The couplers

Neutron Science

were tightened too much and electrical erosion occurred by the difference of the ionization tendencies ofthe brass coupler of the water hose and the stainlesssteel coupler of the body of the T0 chopper. Then the
coupler was damaged. All brass couplers were changed
to ones made of stainless steel and the torques of tightening were properly controlled for the T0 choppers installed on BL09, BL12, BL21 and BL23.
3. Scientific results
The following scientific results were obtained fromthe S-type project on HRC. Pressure-induced quantum
phase transition was detected, and magnetic excitations
were observed under the pressure in a quantum antiferromagnet CsFeCl3 [3, 4]. The Stoner excitations wereobserved in metallic antiferromagnets γ-FexMn1−x [5,6]. Crystalline electric fields (CEF) as well as low energy coherent excitations were observed in breathing
pyrochlore antiferromagnet Ba3Yb2Zn5O11 [7]. The CEF
level scheme of the non-centrosymmetric CePtSi3 wasdetermined [8]. The magnetic and thermodynamic
properties of the charge and spin ordering in the highly hole-doped layered cobalt oxide La2−xSrxCoO4 were
investigated [9].
References[1] S. Itoh et al., J. Phys. Soc. Jpn. 82 (2013) 043001.
[2] S. Itoh et al., MLF Annual Report 2016, p.101.
[3] S. Hayashida, Doctoral Thesis, The University ofTokyo (2018).
[4] S. Hayashida et al., Phys. Rev. B 97 (2018) 140405(R).
[5] S. Ibuka et al., Phys. Rev. B 95 (2017) 224406.
[6] S. Itoh et al., Physica B, in press.
[7] T. Haku et al., J. Phys.: Conf. Series 828 (2017) 012018.
[8] D. Ueta et al., Physica B 536 (2018) 21.
[9] M. Yoshida et al., Physica B 536 (2018) 338.

S. Itoh1,2, T. Yokoo1,2, T. Masuda3, H. Yoshizawa3, T. Hawai1,2, M. Yoshida3, S. Asai3, D. Kawana3, R. Sugiura3, T. Asami3, and Y. Ihata4
Institute of Materials Structure Science, KEK; 2Neutron Science Section, J-PARC Center; 3The Institute for Solid State Physics, The Universityof Tokyo; 4Technology Development Section, J-PARC Center

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MLF Annual Report 2017

BL14 AMATERAS
1. Introduction
FY2017 was the ninth year of operation of
AMATERAS [1, 2], a cold-neutron disk-chopper spectrometer. We continued the user program out-reach activities. As it happened the previous year, this fiscal year
we encountered again some mechanical problems withthe equipment of AMATERAS. There were changes inthe staff of AMATERAS. From this fiscal year, we accepted a post-doctoral fellow from a company, Sumitomo
Rubber Industries, Ltd., Dr. Tatsuya Kikuchi, by using the“Industrial Post-Doctoral Fellow” program, which waslaunched by MLF to promote further industrial users'
activity.
2. User program, international activities & out-comes
The number of general proposals submitted forthe 2017A and 2017B periods was 23 (accepted: 10, reserved: 13) and 28 (accepted: 8, reserved: 20), respectively. Among the proposals, the studies on magnetism
dominated and the number of proposals, related toenergy materials increased. As a result, in FY2017, 24
general proposals (including two urgent proposals)
and three JAEA project proposals were carried out on
AMATERAS.
In the second Neutron and Muon School held in
November, five foreign students took part in a handson experiment at AMATERAS (Fig. 1). The students carried out inelastic neutron scattering measurement for
single crystal of one-dimensional antiferromagnetic
compound. They learned how to measure and analyze
the collective spin dynamics using the time-of-flightchopper spectrometer. The students reported their results at the presentation session held on the last day ofthe school and won the second prize of the presentation awards.
In 2017, 10 refereed papers covering the woks at
AMATERAS were published. Furthermore, two mastertheses, based on experiments at AMATERAS, were completed. The research topics included frustrated magnets, 4f electron systems, perovskite solar cells, andpolymer membranes.
3. Instrumental activities
AMATERAS has three sets of fast-disk choppers,
whose maximum frequency is 300 Hz in conventionaluse. In 2016, we limited the maximum frequency of oneof them, called CH03, to 275 Hz because of anomalous
vibration. In JFY2017, its maximum frequency was restored to 300 Hz after replacing a disk.
We also encountered several problems with the
cryopump, which is involved in the pumping system of
the vacuum scattering chamber. Although they were
fixed within JFY2016, we faced yet another problem
with it: a heater warming up the cold heads was broken.
In conventional operation, we warm up the system toroom temperature (RT) using the heater to vent the scattering chamber before introducing air into the chamber.
However, due to this problem, we were forced to warmthem up by letting helium gas into this huge scatteringchamber instead of using the heater and to introduce air
before the system is warmed up to RT to save time. The repair of the heater and refurbishment of some parts werecompleted during the summer shutdown , and the system recovered before restarting the beam operation. As
these problems were detected in two consecutive years,
we plan to replace it with a new cryopump in near future.

Figure 1. Students participated in the second Neutron and Muon School and staff members of AMATERAS.

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Neutron Science

Figure 2. (a) The oscillating radial collimator of the superconducting magnet. Inelastic neutron scattering spectrum taken at
experiments using the superconducting magnet (b) without and (c) with the collimator. Inelastic signal observed
around 2 meV in (c) is a real magnetic signal which can hardly be detected in (b).

Since 2008, the number of detectors installed to
AMATERAS was only 60% (266) of the final specified capacity (448). In JFY2017, 10 additional detectors were
installed: four detectors were installed to the low-angle
side, while six to the high-angle side.
Recently, the number of users’ proposals that require non-standard sample environment (SE), such as adilution refrigerator and superconducting magnet, had
gradually increased. As an oscillating radial collimator(ORC) of the superconducting magnet (Fig. 2 a) managed by the SE team has just been ready for inelastic
neutron scattering (INS) measurements, we carried out
commissioning on this magnet with the ORC. This ORC
was quite effective for the INS experiment. The background, mainly due to the thick Al walls of the magnet,
registered in the previous commissioning without the

ORC, was drastically reduced, and a magnetic excitation
spectrum was clearly observed (see Fig. 2 b and c). After
this commissioning, a general users’ experiment undermagnetic field was performed in the 2017B period.
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, Y. Inamura1, and D. Wakai3
Neutron Science Section, Materials and Life Science Division, J-PARC center; 2Chemical Analysis Center, Research & Development HQ,
Sumitomo Rubber Industries, Ltd.; 3Nippon Advanced Technology Co., Ltd.

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MLF Annual Report 2017

Upgrading TAIKAN
1. Introduction
The small and wide angle neutron scattering instrument TAIKAN (BL15) has been developed and upgradedat J-PARC to analyze precisely and efficiently the microstructures or hierarchical structures of substances invarious scientific fields with a 1 MW spallation neutron
source [1]. In FY2017, it was upgraded further to perform high-q measurement, also, the mid-term evaluation of TAIKAN was carried out.
2. Upgrading for high-q measurement
The detector system of TAIKAN is composed of 5detector banks: small-, middle-, high-, ultra-small-angle, and backward detector banks. On the high-angle
detector bank, 96 3He PSD tubes were additionally installed. The measurement efficiency of the high-angle
detector bank increased about twofold. The number of
3He tubes then increased to 768, 592, 200, and 48 forthe small-, middle-, high-angle, and backward detector banks, respectively. The installation ratios of the3
He tubes became 84, 82, 36, and 60% for the small-,middle-, high-angle, and backward detector banks, respectively. Figure 1 shows a photo of the high-angle
detector bank after installing the 3He tubes.

3. Mid-term evaluation
The mid-term evaluation of TAIKAN was carried out
on December 18, 2017. In the evaluation committee, we
introduced the history of conceptual study of TAIKAN
with a community of neutron science, the past performance of the instrument group members, and the technical progress of neutron optics and detector applicable
to TAIKAN. After the introduction, we explained the aimof the development of TAIKAN, the configuration andcomponents of TAIKAN, and the performance of TAIKAN(such as performance of T0 and disk choppers, neutron
flux at the sample position, background, q range, beamfocusing for extension of the q range, q resolution, measuring time, etc.), number and field of application, results obtained with TAIKAN, and future prospects.
The committee evaluated TAIKAN as follows:a. TAIKAN has been developed as a high level of small
and wide angle neutron scattering instrument,
which can perform precise and efficient measurement in a wide q range.
b. Many research outcomes are expected in the next
five years, focusing on the following two points:
b-1. Promoting academic researches using wide-q
measuring capabilities
b-2. Research achievements in usual small-angle
scattering studiesc. The instrument group members are expected tolead research projects and joint researches withpower users and produce academic results, which
can only be obtained with TAIKAN.
4. Future prospects
The improvement of the measurement efficiency
by the installation of high-angle detectors makes precise measurement in a high-q range easier. We, the instrument group members, will do our best to meet the
expectations of the evaluation committee and conduct
researches with the cooperation of users.

Figure 1. High-angle detector bank.

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
Neutron Science and Technology Center, CROSS; 2Neutron Science Section, Materials and Life Science Division, J-PARC Center

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Neutron Science

0.1 mm Focusing Elliptic Mirror with Large Area for
Neutron Reflectometry at BL16
1. Introduction
Neutron reflectometry (NR) is very useful for investigations of structures of surfaces and buried interfaces
composed of soft materials. SOFIA is a horizontal-type
neutron reflectometer constructed at Beamline 16 (BL16)of the Materials and Life Science Experimental Facility(MLF) of the Japan Proton Accelerator Research Complex(J-PARC) [1, 2]. Due to the high-flux beam of J-PARC, lessthan one hour is needed for taking a full Q-range dataand only a few seconds for a limited Q-range data in thecase of a sample with 3 inches (76 mm) in diameter; eventhough the beam power is still one-third of the planned
value, 1 MW. However, several hours are still needed fora small sample such as 10 mm × 10 mm, which is a typical size of a sample for X-ray reflectometry.
For further upgrade of the SOFIA reflectometer, wehave been developing an elliptical focusing mirror toilluminate a sample with a neutron beam with a large
beam divergence. In the case of conventional double slit
collimation, the optimal beam divergence decreases according to the sample size. Hence, the focusing optics
with the mirror has an advantage on the beam flux especially for small samples. The planned specifications of the
focusing mirror and detector are a beam size of 0.1 mm
at a sample position with divergence of 2.5 mrad.
So far, we developed a prototype focusing supermirror capable of focusing neutrons with a width of
0.34 mm [3], and modified mirror with 0.17 mm in full
width at half maximum (FWHM) [4]. These mirrors work
well as focusing devices, however, the focusing size isinsufficient for our needs. Here, we discuss a new mirror
satisfying the specification of 0.1 mm focusing.
2. Manufacture
We employed an aluminum alloy as a base plate for thefocusing mirror. First, the base plate was machined with asingle diamond tool to produce a rough surface shape,in which the surface follows the central part of an ellipse
with a long axis of 4300 mm and a short axis of 430 mm.
Then, the plate was coated with nickel phosphorous byelectroless plating process and finished by an ultrahighprecision cutting (UPC) process. The surface was polished
before coating the super mirror to create a smooth surfaceof less than 1 nm in root mean square (RMS) roughness.
The super mirror with an m-value of 3 was deposited on
the substrate using an ion beam sputtering instrument at

the Kyoto University Research Reactor Institute [5]. Since
the mirror size, 550 mm in length and 60 mm in width,
was too large to coat the super mirror, the mirror was divided into two pieces and assembled into one unit after
the processes above were completed with the kinematic
coupling developed earlier [4].
3. Results
First, we checked the surface roughness of the super-mirror, which is sensitive to the reflectivity of neutrons. Figure 1(a) shows the surface roughness map
measured using white-light interferometer (NewView
7200, ZYGO). Remarkably, the RMS of the roughness
was only 0.105 nm in this field of view and the average of 10 different points on the mirror was 0.108 nm± 0.009 nm (standard deviation), that is, the roughness
was better than the commercially available Si substrates
over the whole mirror surface. Surprisingly, the neutronreflectivity at 20 different points with the area of 20 mm
× 25 mm was almost the same over the large area andmore than 80% below the critical angle as shown in
Fig. 1 (b), which is comparable with a neutron guidemirror. The low roughness was not the only reason forthis result; another contribution was the fabrication
process of the super-mirror, which focused on the homogeneity of the reflectivity, as well as the considerable
progress achieved compared with the former mirrors [4,5], which were inhomogeneous and had less reflectivity.
Next, we evaluated the distribution of the slope error. As the slope error is the difference of the incident
angle from the ideal value to reflect neutrons on a focal
point, the distribution is closely linked to the minimum
size of the focal image. Figure 2(a) shows the slope error
map on one segment of the mirror. Due to the propertyof the UPC process, the waviness arose with the spatial
frequency of a few millimeters. Even though the waviness was reduced in the polishing process, it could not
be completely removed and was still dominant on theslope error. To estimate the minimum size of the focal
image, the frequency distribution of the slope error
was estimated as shown in Fig. 2(b). The distribution
followed a Gaussian well and the FWHM was 24 μrad.
As the distance between the mirror and the focal point,that is, the sample position, is designed to be 2150 mm,
the minimum beam size is expected to be 50 μm to satisfy the specification value, 0.1 mm.
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MLF Annual Report 2017(a) Optical measurement(b) Neutron reflectivity
1.2

Homogeneous

Reflectivity

1.0
0.8
0.6
0.4
0.2
0.0

Position scan with thearea of 20 mm × 25 mm

0.2

0.4

0.6

0.8

−1

Qz [nm ]Better than Si substrate

Figure 1. Evaluation of surface roughness and neutron reflectivity of a mirror segment: (a) the surface roughness
map measured using white-light interferometer and (b) neutron reflectivity at 20 different points withan area of 20 mm × 25 mm.

(a) Slope error distribution in real space(b) Frequency distribution- FWHM in slope error was 24 μrad.
→ The beam size is expected to be 50 μm
at the focusing spot.

Figure 2. Evaluation of slope error of a mirror segment: (a) the slope error map and (b) frequency distribution of
the slope error.

Beam size at focal point [μm]500

Finally, we conducted the focusing measurementwith neutrons at BL16. Although the two segmentsof the focusing mirror were fixed with the kinematic
coupling developed before, the positions of focal images of the segments were not coincident at the focal
point because of the misalignment of the relative tilt.
Hence, this time, one segment in the upstream side wasremoved for the measurement. Figure 3 presents the
FWHM of the focal images evaluated with changing theslit aperture working as the virtual source. The beam
size at the focal point decrease with the source size, andthe minimum beam size in the experiment was 83 μm,
which satisfied the requested specification.

400

300

200

100

0

0

100

200

300

400

500

600

Source size [μm]Figure 3. Beam size at the focal point evaluated with changing the slit size working as the virtual source.

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MLF Annual Report 2017

4. Future Plans
Here, we reported on the improvement of the focusing mirror developed for the neutron reflectometer
SOFIA. The roughness of the new base-plate for the mirror was approximately 0.1 nm in RMS over the wholesurface, and a homogeneous super-mirror was fabricated on it. Owing to these developments, high andhomogeneous neutron reflectivity was achieved over
the whole surface of the mirror. Concerning the focusing capability, the figure errors of two segments composing the focusing mirror were low enough to realize
the focusing image smaller than 0.1 mm according tothe optical measurement. In fact, it was confirmed by
the neutron beam that one segment of the mirror was

Neutron Sciencecapable of focusing with a width of 83 μm in FWHM. On
the other hand, we still have a problem with aligningof the two segments into one mirror unit. We continue
our work to overcome the problem with the alignmentof the segments and install the focusing mirror to the
SOFIA reflectometer in near future.
References[1] N. L. Yamada et. al., Euro. Phys. J. Plus, 44 (2011) 9424.
[2] K. Mitamura et. al., Polymer J., 45 (2013) 100.
[3] S. Takeda et. al., Opt. Express, 24, (2016) 12478-12488.
[4] T. Hosobata et. al., Opt. Express, 25, (2017) 20012-20024.
[5] M. Hino et. al., Nucl. Instr. and Meth. A, 797 (2015)
265.

Norifumi L. Yamada1,2, Takuya Hosobata3, Masahiro Hino4, Koichiro Hori1,2, Fumiya Nemoto1,2, Toshihide Kawai3,
and Yutaka Yamagata3
1
Institute of Materials Structure Science, KEK; 2Neutron Science Section, Materials and Life Science Division, J-PARC Center; 3RIKEN Center
for Advanced Photonics, Wako, Japan; 4Kyoto University, Kumatori, Japan101

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MLF Annual Report 2017

BL17: Current Status of Polarized Neutron Reflectometer,
SHARAKU

2. Data reduction system for specular NR profile
measured by MWPCIn the NR experiment using MWPC, the NR profile
should be constructed considering the position data ofthe detected neutrons. This year, we developed a data
reduction system to achieve fast data acquisition withhigh q resolution.
The neutron beam has a finite divergence of anincident angle in the reflectometry measurement. The
increase in the beam divergence, Δθ (shown in Fig. 1a),increases the intensity of the reflection signal. However,the 0D detector detects the sum intensity at the reflection angle range from θ − Δθ/2 to θ + Δθ/2, resulting indecrease in the q resolution of the obtained NR profile.
On the other hand, the position sensitive detection by
MWPC can resolve the divergence of the reflected neutron beam. Figure 1b shows an intensity map of the reflected neutron from a 100-nm thin film of polystyrene
102

(a)

MWPC

Δθ
θ
(c)

(b)

35

TOF / ms

200
150

Y / px

1. Introduction
SHARAKU, installed at BL17 in Materials and Life
Science Experimental Facility (MLF), is a neutron reflectometer with vertical sample geometry used to investigate nanometric structures in thin film samples [1,2]. Since SHARAKU has a pair of a spin polarizer anda flipper for both of incident and reflected/scatteredneutrons, it can be employed to analyze the magnetic
structure of magnetic thin films [3, 4]. In SHARAKU, theneutron intensity reflected at the sample film has been
detected by a zero-dimensional (0D) 3He tube detector.
The low noise of the 0D detector allows a specular NR
measurement down to a reflectivity of 10−7; however,it cannot be used for an off-specular measurement.
Therefore, the installation of a two-dimensional position sensitive neutron detector was needed. Over thelast few years, the commissioning of a two-dimensional neutron detector, multi-wire proportional counter(MWPC), has been carried out and it is ready for use in
the specular and off-specular observation.
In this fiscal year, we developed a data reduction
environment for the NR measurement using the MWPC.
The data correction considering the position sensitive
information allows the efficient and reliable measurement of NR profiles. Moreover, a sample exchanging
system was developed for an automated measurementof a number of samples.

100
50
0

30
25
20
15

0

50

100

150

X / px

200

250

10

2.5

2.0

1.5

1.0

0.5

0.0

Reflection angle / degree

Figure 1. Illustration of reflection of a neutron beam at an incident incidence angle θ and a divergence Δθ (a),detected neutron intensity on the detector plane (b),and relation between the reflection angle and TOF (c).

on a silicon wafer at an incident angle of 1.2° with a divergence, Δθ/θ, of 0.20. In SHARAKU, a sample is mounted
vertically, therefore, the neutron beam is spread in the
X direction due to the large incident angle dispersion.
Figure 1c shows the reflection intensity dependent on
the reflection angle and the time-of-flight (TOF) of thereflected neutron. This indicates that the reflected TOF
profile is dependent on the reflection angle.
Figure 2 shows the NR profiles at a q-range of 0.2 –1.4 nm−1 obtained by the 0D detector and MWPC. The
black and blue curves show the data taken by the 0D
detector at beam divergence conditions of Δθ/θ = 0.06
and 0.20, respectively. This indicates that the increaseof the incident angle divergence results in the decreaseof the q resolution of the reflection profile. The structure in the sample film cannot be analyzed from the
NR spectrum with Δθ/θ = 0.20. On the other hand, theNR profile constructed from the MWPC data considering the reflection angle divergence due to the incident
beam (the red curve in Fig. 2) is in good agreement withthat obtained by the 0D detector, indicating similar q
resolution. The reflection intensity detected by MWPCwas 2-times higher than that by the 0D detector. This
indicates that the MWPC reduces the measurement
time without the q resolution of the reflection profile

MLF Annual Report 2017(a)

0D, Δθ/θ = 0.06
0D, Δθ/θ = 0.20
MWPC, Δθ/θ = 0.20

10–2

Neutron Science

Reflectivity

10–3

10–4

10–5

× 1/10

10–6

× 1/100

0.2

0.4

0.6

0.8

q / nm–1

1.0

1.2

(b)
1.4

Figure 2. NR profiles for a polystyrene thin film deposited ona silicon wafer observed by the 0D detector and
MWPC.

by using a strong incident neutron beam with a large
divergence. Moreover, the background signal can beevaluated from the neutron signal detected at the outside of the reflected beam. By the background subtraction, reflectivity of less than 10−7 can be observed.
3. Sample Changer
The increase of the neutron beam power of MLF reduces the measurement time. For example, a specular
NR profile for a polymer thin film deposited on a 2-inch
silicon wafer can be obtained in 30 – 60 min at an operating power of 500 kW. In BL17, a typical time to changea sample and to adjust the beam alignment is about
30 min, which is comparable to the measurement time.
Therefore, in order to reduce the total experiment time,
the time for the sample exchange must be shortened.
This year, the sample-exchanging and auto-alignment
systems were installed. Figure 3a shows a photographof the sample changer, which is a one-dimensionaltranslation stage with a stroke of 200 mm. With thissystem, the sample exchange and the beam alignment
process can be completed in about 10 min. A standard
sample holder for a 2-inch silicon wafer has a thicknessof 10 mm and can be stacked as shown in Fig. 3b. A sequential measurement of up to 16 samples can be carried out automatically.

Figure 3. Photographs of a 200-mm translation stage for asample exchange (a) and stackable sample holders
for a 2-inch silicon wafer (b).

4. Summary
We developed a data reduction system for the
NR measurement using MWPC and automatic sample
changing system, which enables fast data acquisition
with high q resolution and reduction of the time required for sample exchange, respectively. Their combined use would improve the measurement efficiency.
References[1] K. Akutsu, T. Niizeki, S. Nagayama, N. Miyata, M.
Sahara, A. Shimomura, M. Yoshii, and Y. Hasegawa,
J. Ceram. Soc. Jpn., 124, 172 (2016).
[2] Y. Sakaguchi, H. Asaoka, and M. Mitkova, J. Appl.
Phys., 122, 235105 (2017).
[3] K. Amemiya, M. Sakamaki, M. Mizusawa, and M.
Takeda, Phys. Rev. B, 89, 54404 (2014).
[4] V. Ukleev, S. Suturin, T. Nakajima, T. Arima, T.
Saerbeck, T. Hanashima, A. Sitnikova, D. Kirilenko,
N. Yakovlev, and N. Sokolov, Sci. Rep., 8, 8741 (2018).

H. Aoki1,2, K. Soyama1, D. Yamazaki1, N. Miyata3, K. Akutsu3, T. Hanashima3, S. Kasai3, and J. Suzuki3
Materials and Life Science Division, J-PARC Center; 2Institute of Materials Structure Science, KEK; 3Neutron Science and Technology Center,
CROSS

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MLF Annual Report 2017

Status of SENJU 2017
1. Introduction
SENJU is a TOF single-crystal neutron diffractometer designed for precise crystal and magnetic structure
analyses under multiple extreme environments, suchas 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 2017, we upgraded two important componentsof SENJU. One was the software for data processing,
STARGazer for SENJU, and the other was the DAQcomputer system of SENJU. In addition to the upgrade,
we also report on the purposes for which the instrument beam-time for SENJU was used.
2. Upgrade 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 FY2017, we upgraded some functions of
STARGazer for SENJU. The major areas of the upgradewere as follows:
1. Showing major candidates of true UB-matrix in
the UB-matrix finding process.
2. Goniometer-angle correction in the UB-matrix
refinement process.
The first one was developed to find the true cellparameters and UB-matrix more easily. Before the upgrade, STARGazer for SENJU showed only the most

likely candidate of the true UB-matrix in the “Find-Cell”
component. While upgrading, we modified the FindCell component to show several candidates of the true
UB-matrix.
The second one was developed to define only one
UB-matrix for all data-set of one sample. Although eachaxis of the goniometers for SENJU outputs their current
rotational angles, those angles were usually different
from the true angles (±10°). Consequently, we had todefine an UB-matrix when we changed the rotational
angle of goniometers. It means that we could not define a common UB-matrix for one data-set. During the
upgrade, we added to STARGazer for SENJU a new component to search the true goniometer angles of eachdiffraction data and define a common UB-matrix. For
example, when we measure diffraction data with threesettings of goniometer angles, an UB-matrix of one of
the three settings is defined as a standard UB-matrix.
For the other two settings, the goniometer angles areadjusted to make their UB-matrixes match the standard
UB-matrix. Finally, the standard UB-matrix becomes thecommon UB-matrix for the three settings.
3. Virtualization of the DAQ-computer system
The DAQ-computer system of SENJU, installed
in 2010, just before the Earthquake of March 2011,
was already “obsolete”. In 2017, we replaced the DAQcomputers of SENJU and built up a new “virtualized”
DAQ-computer system to improve the system’s redundancy. The DAQ-computer system of SENJU is composed of four DAQ control servers. In the replacement,each server is constructed in a virtual-PC software andall four virtual-PC systems operate on two physical servers (Fig. 1). After the virtualization, the neutron events
detected at the detectors are successfully stored in

Figure 1. Schematic image of the virtualization of the DAQ-computer system at SENJU.

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the storage system of SENJU and the data-processing
speed of the new system is almost the same as the one
before the replacement and sufficient for data processing in the 1 MW operation.
The major advantage of the virtualization is the
improvement of redundancy. In case of any computer
problem, we only need to copy the virtual-PC software,in which a DAQ control server is installed, to anothercomputer.
4. Use of the instrument beam-time
In 2017, the instrument beam-time was mainly used for measurements of standard samples, a

Neutron Science

vanadium-nickel alloy and a C12A7 single crystal, for
instrument calibration. The latter was for the oscillational radial collimator developed in 2016. 40 diffraction data of a C12A7 were measured with 0.5° intervalwith the collimator to clarify the intensity change of thesame Bragg peak by the collimator. The analysis of theobtained data is now in progress. In addition, we used
the instrument beam-time to compensate beam-timeof some general-use proposals lost due to usage problems of sample environment devices.
Reference[1] T. Ohhara et al., J. Appl. Cryst., 49 120 (2016).

T. Ohhara1, R. Kiyanagi1, A. Nakao2, K. Munakata2, T. Moyoshi2, K. Moriyama2, I. Tamura1, and K. Kaneko1
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Neutron Science and Technology Center, CROSS

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Status of TAKUMI, BL19
1. Introduction
TAKUMI, BL19 is an engineering diffractometer, atype of powder diffractometer installed as a pair of 90°
scattering detector bank, dedicated for engineering
materials.
There are three stress-loading instruments in
TAKUMI, BL19. The first one is a versatile type withtemperature range from nitrogen level to 1300 K, thesecond one is a compact type with temperature range
from room level to 1000 K, and the third one is a dedicated instrument for low temperature up to 6 K. These
instruments are used to study the deformation mechanism and mechanical properties of various kinds ofmetal and composite materials under normal deformation speed and temperature control. On the other hand,
there is demand to study the optimized manufacturing
process of metals, such as steel, under the conditionsof high-speed deformation and temperature control.
Therefore, over the last few years, we have worked on
the conceptual design of a new stress-loading instrument with high-speed deformation and temperature
control. Finally, we decided to adopt a high-frequency
heating system for temperature control.
In FY 2017, we introduced at BL19 high-frequency
heating type stress-loading equipment with coolinggas blowing function, which can perform high-speed
deformation, high-speed heating/cooling for high temperature stress-loading instrument of steel, etc.
2. Specification of the new stress-loading instrument
The new stress-loading instrument consists of astress load device and high-frequency heating system.
The main specifications of the instrument are shown
below.
(1) Stress-load device
1) Sample size
Tensile test:
Parallel part diameter 6 × 20 mm,
Approximately 80 mm
Compression test:
Diameter 6 × length 10 mm
Total length 20 mm
Deformation test method:
Horizontal uniaxial swing mechanism type
Deformation maximum load:
Tension 50 kN, Compression 50 kN
Deformation speed:

1060.01 mm/mim – 500 mm/min
Deformation mode:
Tension, Compression,
Tension/compression, Fatigue, CreepControl method:
Load control, Displacement control,
External extensometer control(2) High-frequency heating system
Heating rate:
20 K/s or more
Cooling rate:
30 K/s or more
Maximum temperature:
1570 K or higher
Thermal band (length):
20 mm or more
Isothermal holding time:
12 hours or more
Atmosphere:
Inert gas (Ar gas, nitrogen gas) atmosphere
3. Expected application
The new stress-loading instrument is fully fitted to
TAKUMI, because the horizontal uniaxial loading method was adopted in its design, as a result, it can be used
for standard simultaneous measurements in radial andaxial directions of neutron diffraction, which is necessary for understanding the mechanical behavior.
Expected proposals using the new stress-load instrument include, for example, elucidation of the dynamic ferrite transformation mechanism of low-carbon
steel at high temperature and evaluating thermal fatigue characteristics by thermal fatigue test (acceleratedtest) of materials used in thermal cycling environment.
Also, it can be used to observe the solidification process and phase separation of alloy under high-speed
cooling.
4. Future plans
Now, off-beam commissioning about the basic performance at the J-PARC research building is ongoing.
We plan to perform commissioning of the new stressloading instrument using neutron beams after passing
the instrument safety check by the MLF safety team in
FY 2018. And we would like to open it to general proposals as soon as possible.

MLF Annual Report 2017

Neutron Science

Figure 1. Schematic layout of the new stress-loading instrument.

K. Aizawa1, S. Harjo2, and T. Kawasaki2
Technology Development Section, Materials and Life Science Division, J-PARC Center; 2Neutron Science Section, Materials and Life Science
Division, J-PARC Center

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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, including chemical 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.
A diffractometer with super high resolution is not required to achieve those goals. The match of features
like intermediate resolution around Δd/d = 0.15%, highintensity 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 it has an incident flight path
(L1) of 26.5 m, with three wavelength selection diskchoppers and straight neutron guides with a total
length of 14.0 m. The instrumental parameters are listed in Table 1. There are four detector banks, including

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

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Table 1. Instrumental parameters of iMATERIA. L2 is the scattered flight path. The d-range (q-range) for eachbank is the maximum value for 2-measurement
mode.

L1
Guide length
Position of Disk choppers

High
Resolution
Bank
SpecialEnvironment
Bank
Low
Angle
Bank
Small
Angle
Bank

2θ
L2
d-range2θ
L2d-range2θ
L2d-range2θ
L2
q-range26.5 m
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

a low-angle and small-angle scattering detector bank.
The angular coverage of each detector bank is also
shown in Table 1. The rotation speeds for the disk-choppers 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 detector banksof 90-degree, low-angle and small-angle with gradually changing resolution. When the speed of the wavelength selection disk-choppers is reduced to 12.5 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 graduallychanging resolution with doubled measurement timecompared to the SF mode.
2. Current status
All of the four banks, high-resolution bank (BSbank), special environment bank (90-degree bank),
low-angle bank and small-angle bank, are operational. It takes about 5 minutes (in DF mode) to obtain a‘Rietveld-quality’ 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 theMLF Annual Report 2017

Figure 2. Rietveld refinement pattern for LiCoO2 at the highresolution bank of iMATERIA.

multi-bank analysis function of Z-Rietveld [2]. It takes
20 min in DF mode to collect the available Rietveld
data, due to the high neutron absorption cross section
for natural Li (σsNat = 70 barn).
3. Sample Environments
The automatic sample changer is the most important sample environment for high-throughput experiments. Our automatic sample changer [3] consists of a

Neutron Sciencesample 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. The in-operando experiment
system for LIB with a sample changer is available in cylindrical and coin types of batteries.
Recently, the rapid heating and cooling furnacewith automatic sample changer also became available
for texture measurement.
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, 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)
1. Introduction
Total scattering is a technique created to analyze
non-crystalline structure in materials with atomic Pair
Distribution Function (PDF). NOVA was designed toperform total scattering and is the most intense powder diffractometer with reasonable resolution (Δd/d ~0.5%) in J-PARC. It is easy to adapt NOVA to a very wide
range of fields: liquids, glass, local disordered crystalline, magnetic structure of long lattice constant and soon. The observation of the hydrogen position in materials is one of the most important scientific themes of
NOVA.
Sample temperature and gas pressure are controlled by various environments at NOVA (Table 1), but
a radiation shield or a vacuum chamber degrades thesignal-to-noise ratio and diminishes the statistical accuracy. Hence, a radial collimator was introduced to NOVA,
as an effective device to reduce the background signal.

Apparatus

Specification

Sample Changer

sample: 10 or 40 (RT)

Temperature controlled
Sample Changer

sample: 18

Top Load Cryostat

temp.: 5 ~ 700 K

PCT(hydrogen gas atm.)press.: max. 10 MPa H2/D2
temp.: 50 ~ 473 K

Vanadium Furnace

temp.: max. 1273 K

2 K cryostat (MLF SE)

temp.: 1.8 ~ 300 K

temp.: 20 ~ 750 K

2. Design of the radial collimator
NOVA covers a wide-Q range with detector banksfrom small-angle to high-angle and short wavelength
neutron (λ ~ 0.12 Å) for total scattering. However,there is no shielding material for a radial collimator tokeep the performance and decrease the background.
Additionally, it is difficult to install collimator blades
along the Debye-Scherrer rings in the small-angle or
high-angle direction. Therefore, as the first step of theradial collimator development, 50-μm-thick Cd coated
100-μm-thick Al plates were placed only around the 90°
bank at intervals of 2° (Fig. 1).

110

3. Performance of evaluation
The shielding effect of the radial collimator was
examined for the vanadium furnace environment at
NOVA. Figure 2 shows incident proton numbers normalized neutron counts scattered from vanadium foils
in the furnace without sample. The detected neutrons
are reduced by about an order due to the radial collimator. The shielding effect is not enough below 0.4 Å
because Cd indicates cut-off energy of 500 meV. The
neutron transmittance at 1 Å was evaluated for 4.7%,
which corresponds to shielding by 3 or 4 blades. It is
insufficient in case of scattering path of fewer blades.

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Neutron Counts

Table 1. Sample environmental equipment of NOVA.

Figure 1. Radial collimator installed at NOVA.

104
103
102
without radial collimatorwith radial collimator

101

2

4

6

8

Wavelength / ÅFigure 2. Scattering intensity from vanadium furnace.

MLF Annual Report 2017

S(Q)

2

1

VF with radial collimator
SC
0

20

40

60

Q / Å–1
Figure 3. S(Q) of SiO2 glass rod measured under vanadium
furnace (VF) with the radial collimator and sample
changer (SC) environments.

Structure factor, S(Q), of SiO2 glass rod was measured under the vanadium furnace with the radial collimator and sample changer environments, as shown in

Neutron ScienceFig. 3. Both S(Q) are valid and similar PDFs are derived,
even though there is a slight difference. However, theshielding effect of the radial collimator for a 2 K cryostat
is low compared to the vanadium furnace in the smallangle and high-angle direction, because the cryostat
has a vacuum chamber with a larger diameter and thescattering neutron passes through deficient shielding
blades. Though it is necessary to reinforce the shielding
ability, the basic performance of the radial collimator
was confirmed to be available for the experiments.
Acknowledgement
The authors would like to thank Mr. Kambara forhis helpful assistance in manufacturing the radial collimator. The operation and developments of NOVA were
performed under the S1-type program (2014S06) approved by the Neutron Scattering Program Advisory
Committee of IMSS, KEK.

K. Ikeda1,2, T. Otomo1,2,3, T. Honda1,2, H. Ohshita1,2, M. Tsunoda3, 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; 3Graduate
School of Science and Engineering, Ibaraki University

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Present Status of the Energy-Resolved Neutron Imaging
System RADEN
1. Introduction
The energy-resolved neutron imaging system“RADEN”, installed at beam line BL22 in the Materials
and Life Science Experimental Facility (MLF) of J-PARC,
is a dedicated instrument for wavelength/energydependent neutron imaging experiments with full
utilization of the short-pulsed neutron’s nature, suchas broad available neutron energy range and narrowpulse shape [1]. RADEN provides capabilities to conduct the following energy-resolved neutron imaging(ER-NI) techniques: Bragg-edge, neutron resonanceabsorption, and polarized pulsed neutron imaging. In
addition, neutron phase imaging based on a TalbotLau interferometer has recently been adapted to thewavelength dependence analysis for effective and precise determination of phase change [2]. In this report,
we will cover the current status of RADEN’s activities,
including technical developments and application
studies.
2. Improvement of neutron imaging detector
systems
Owing to continuing studies on improving theperformance of imaging detectors, the counting-type
detector system with fine time resolution, which isimportant for energy-resolved neutron imaging experiments, and good spatial resolution up to 100 μm,

similar to the conventional camera-type detector system, became available without sacrificing the neutron
beam intensity due to their limited count rate. Figure 1
shows neutron transmission images of a Gd test target [3] obtained by three different detector systems [4].
At RADEN, the nGEM detector was initially used due
to its stable performance, but now the μNID detector
is near completion, ready to provide five times higher
counting rate performance and 1/10 the spatial resolution of the nGEM detector. Moreover, to achieve amuch higher counting rate capacity, a new detector
system with the same micro-pattern readout plane as
the μNID is being developed. Its neutron conversion
medium (i.e., the material that converts incident neutrons into charged particles that can be detected) has
been changed from 3He gas to a solid, thin 10B layer(B-μNID). Because the alpha particle produced by theneutron-10B reaction travels a shorter distance thanthe particles released in the neutron-3He reaction, thenumber of hit channels per one neutron event is reduced. Consequently, a very high neutron count rate
capacity of over 20 Mcps could be obtained. Since currently the 10B conversion layer is very thin, its efficiency
is not high, but it can be improved by increasing the
thickness of the 10B layer relative to the incoming neutron beam direction.

Figure 1. Neutron transmission images of a Gd test target taken by three counting-type neutron imaging detectors:(a) nGEM detector, (b) μNID detector using 10B converter, and (c) normal μNID detector.

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Figure 2. (a) Photograph of the model electric transformer. The dashed square indicates the FoV. (b) Neutron radiograph ofthe transformer. (c) Polarization image for each element of the spin rotation matrix D [9] obtained at a wavelengthof 2.51 Å. The wavelength resolution (Δλ) is 0.043 Å [8].

3. Application studies of energy-resolved neutron
imaging
After RADEN started its user program in FY 2015, 63
proposals have been approved through FY 2017. Morethan half of the beam time for the user programs wasused for experiments using wavelength/energy analysis. Especially, new application studies of ER-NI, e.g.,
in-situ observation of liquid/solid interface and segregation of elements during the single-crystal growth
process [5] and applications of tomography techniques
to visualize the three-dimensional distribution of strain
in a steel sample in combination with Bragg-edge imaging [6] or of both magnetic field strength and direction in a solenoid coil with TOF polarimetric imaging [7],have been successfully carried out. Another remarkableachievement is the application of ER-NI to industrial objects. The leaked field from an electric transformer has
been observed by using the polarized neutron imaging
technique [8]. Figure 2 shows polarization imaging results of a small transformer with a direct current applied(c), together with a photograph of the small transformer sample (a) and a neutron radiograph (b). Apparently,
a change in polarization could be found in the polarization images around the top part of the transformer
core, where a gap in the wrapped electric steel sheet
is located, and in the primary winding. This change indicates leakage of magnetic fields from the wrapping

part and the primary coil. Moreover, spatial distributions of both strength and direction of the leakage field
could be evaluated by analyzing the oscillatory behavior which appeared in the wavelength dependent polarization at each point in the image.
4. Summary and future plans
Now, RADEN is under user operation and is being
continuously upgraded. The detector performance improves year after year, and we will continue the development in order to achieve finer spatial resolution andhigher count rate. Another ongoing project at RADEN
is the development of new imaging techniques utilizing wavelength/energy dependence, especially the
combination of ER-NI and computed tomography. In
the future, we will develop a general technique to visualize the three-dimensional distribution of strain,
magnetic field, elemental composition, and temperature. The application of ER-NI techniques has started
to spread widely in both scientific and industrial disciplines. In-situ or in-operando observation experiments
are expected to be very important subjects for RADEN,
because they can utilize the advantages of neutron imaging. We are going to improve the RADEN instrument
and prepare an easy-to-use environment to promotethese kinds of application studies.

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Acknowledgements
This work was partially supported by the JST ERATO
Momose Quantum Beam Phase Imaging Project and by
the 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] Y. Seki et al., J. Phys. Soc. Jpn. 86 044001 (2017).
[3] M. Segawa et al., JPS conference proceedings(accepted).
[4] J. D. Parker et al., JPS conference proceedings(accepted).
[5] A. S. Tremsin et al., Crystal Growth & Design 17 6372
(2017).
[6] J. N. Hendriks et al., Phys. Rev. Materials 1 053802(2017).
[7] M. Sales et al., Scientific Reports 8 2214 (2018).
[8] K. Hiroi et al., JPS conference proceedings(accepted).
[9] M. Th. Rekveldt: Z. Physik 259 391 (1973).

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

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Commissioning Started on New Spectrometer POLANO
1. Introduction
POLANO is a brand-new spectrometer being constructed in MLF with polarization analysis capability [14]. The polarization analysis technique in the field of
inelastic neutron scattering was formerly developed in
the end of the 1960s and in the early 1970s at reactorbased neutron sources. At that time, a new generationof high-flux neutron reactor became available and it
brought a resurgence of interest in polarization methods. The first new technique to appear was one-dimensional polarization analysis in 1969 [5]. After many yearsof the successful experiments in reactor-based polarization, the application of the polarization method
to accelerator-based neutron sources (time-of-flightmethod) was commenced [6]. The reactor-based andaccelerator-based neutron methods are in principle
similar but there are many big differences in terms oftechniques. POLANO was designed to realize the polarization analysis in inelastic neutron scattering up tohigher energy (100 meV) beyond the reactor-based
method.
The construction of POLANO was initiated in 2013.
Before that, we had many discussions about the project,designs, technical issues and numerous other items.
Also, the preliminary construction and R&D of the required devices began within a limited budget. In 2012,
we successfully obtained a large amount of funding
for the instruments, and the construction process was
accelerated after 2013. The major part of the construction of the instrument was completed by 2016, and radiation assessment was conducted. In 2017, POLANO

accepted the first neutron beam and started on-beamcommissioning as well as device tests.
2. Present status of POLANO
As mentioned above, we just accepted the firstneutron beam in June 2017. After the summer shutdown, we started running tests, electrical communication tests, operational tests, and so on.
Vacuum Chamber System
POLANO has a 20 m3 class vacuum chamber and vacuum system as other chopper type instruments. Figure 1
shows the vacuum chamber (right) and the evacuation
test results. Ten minutes after starting pumping by mechanical dry pumps, the vacuum of the tank reached theso-called crossover pressure where the cryo-pump canbe safely started (main gate valve opens). Once the main
valve opens, the vacuum immediately goes down to theorder of 10−3 Pa, at which point we can start cooling thesample down. This vacuum chamber is used for the following two reasons. First, to avoid air scattering in theneutron flight paths and second, for vacuum insulation
for sample environment devices such as cryostat, furnace, and magnet. For the above purposes, the vacuum
obtained in these tests is sufficiently low. When the main
valve is closed, the vacuum abruptly increases (at around3000 min in the plot of Fig. 1). This is simply because of
the gases coming out of many components inside thetank, such as B4C shielding liner, the analyzer mirror andits rotational system. This type of out-gas can be reduced
by repeating the evacuation process many times.

Figure 1. (left) Evacuation test of the POLANO vacuum chamber. Time evolution of the vacuum (pressure) in thechamber. The black line shows the result of the first trial, and the purple line is the second trial.
(right) POLANO vacuum chamber viewed from downstream.

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Detector Alignment
We adopted so-called PSD (position sensitive detector) system. PSDs are placed at the very end of thevacuum chamber detecting the scattered neutron withreasonable spatial resolution. POLANO detectors arecomposed of three layers of 60 cm PSDs as shown in
Fig. 2 on the right. The detector efficiencies of adopted
PSD conditions (SUS tube, 0.35 mm, 3/4" diameter, 3He
10 atm) can be calculated as shown in Fig. 2 left. Even
with 100 meV of the neutron energy, nearly 80% efficiency is expected, which is a reasonable performance.
The assembled PSDs were tuned with cadmium slit jigs.
In Fig. 3 left, perfectly aligned three slit patterns arepresented. Since 3He gas for the detectors is extremely
expensive, we purchased only a part of full detectors.
The black area of the upper and lower detector layer
represents blank space. Figure 3 right shows the actual
measurement of a vanadium sample translated to thereciprocal space Qb (transverse to the incoming beam
direction) and Qc (vertical direction). A clear Debye-ring
pattern originating from aluminum can be observed inaddition to the scattering from vanadium.
Other Devices
Much effort and time were also spent for the newly
installed chopper system. Four different types of choppers will be used in POLANO. Three types of choppers,
excluding the statistical chopper, were tested at thebeam line. It was confirmed that they worked properly
and performed according to expectations. Remote control and status logging of POLANO devices including
above choppers were successfully operated by newly
developed device controlling software YUI for POLANO.
The data visualization and analysis software HANA for
POLANO was also checked and Fig. 3 are the resultsfrom HANA.

Figure 2. (left) Calculated position sensitive detector (PSD) efficiencies as a function of incoming neutron energy.
The detector condition presented by the red line is adopted in POLANO.
(right) PSD arrangement on the large vacuum chamber wall. 60 cm effective length PSDs are layered tomake a 2-dimensional detector array.

Figure 3. (left) Detected neutrons by tuning of PSDs. 3 lines from cadmium slits can be observed.
(right) Reciprocally translated observed signal in Qb-Qc plane. Part of the ring patterns (arcs) are due to theisotropic diffractions from aluminum.

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3. Future plans
Still there are many things to take care of for theroutine operation of the beam line. We are specificallyfocusing on improvement of devices to realize onbeam experiments and user programs, such as sample
environment devices and data-acquisition, data-analysis software.
References[1] T. Yokoo et al., AIP conference proceedings 1969

Neutron Science

050001 (2018).
[2] H. Seto et al., Biochimica et Biophysica Acta 1861
3651 (2017).
[3] T. Yokoo et al., EPJ Web of Conferences 83 03018(2015).
[4] T. Yokoo et al., J. of Physics Conf. Series 502 012043(2014).
[5] R. Moon et al., Phys. Rev., 181 920 (1969).
[6] J. R. Stewart et al., J. Appl. Cryst. 42 69 (2009).

T. Yokoo1,2, Y. Ikeda3, N. Kaneko1,2, M. Ohkawara3, T. Ino1,2, S. Sugai1,2, S. Itoh1,2, and M. Fujita3
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Institute of Materials Structure Science, KEK; 3Institute forMaterial Research, Tohoku University

1

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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 a key component
for polarized neutron scattering in POLANO. Pressurized
3He gas is polarized in-situ by the spin-exchange optical pumping (SEOP) method [1] to keep the incident
neutron beam at a constant polarization. A compact
in-situ polarized 3He NSF, suitable for the limited spacein POLANO, was developed [2], and off-line tests are underway (Fig. 1).

reversing the spins of polarized 3He instead of flipping
the neutron spins. Unlike neutron spin flippers, the3He spins can be almost perfectly reversed by using
the technique called adiabatic fast passage or AFP [3].
In AFP, an oscillating magnetic field is applied perpendicular to the static magnetic field that holds the 3He
nuclear spins, and by sweeping the oscillating field frequency or the static field strength so that either passes
through the Larmor resonance of the 3He nuclei, the3He spins are instantaneously reversed. The AFP spin reversal causes little depolarization of 3He spins, but it canbe drastically reduced by modulating the strength ofthe oscillating field. In addition to the AFP spin reversal,
the 3He polarization can also be measured by using a
nuclear magnetic resonance (NMR) technique. The 3He
NSF for POLANO is equipped with such an AFP NMR
system that reverses the 3He spins and simultaneously
performs 3He polarization measurements (Fig. 2).
The frequency of the oscillating magnetic field is
swept linearly, while the strength (amplitude) is modulated by a trapezoidal function; the amplitude is increased in the beginning, kept constant around theLarmor resonance, and decreased to zero in the ending.
The increase and decrease rates of the oscillating field
amplitude, as well as the frequency sweep rate, are key

Figure 1. An in-situ polarized 3He NSF for POLANO in laboratory testing. The essential components are packed
in a laser shield box, 60 cm long, 60 cm wide, and25 cm high (the top shield plate is detached). A 3He
cell is placed inside the magnetically-shielded solenoid. A laser diode array (LDA) and optical components provide circularly-polarized light of up
to 70 W power for SEOP. The circularity and wavelength of the laser can be controlled remotely. The
3He cell transmission light is continuously monitored with a fiber coupled optical spectrum analyzer (OSA). A low-noise amplifier (LNA) is for the NMR
measurements of polarized 3He gas. The neutron
beam is shown as arrows.

2. AFP NMR system
In polarized neutron scattering, it is indispensable to reverse neutron spins to make the spin-up andspin-down measurements. It is often done by using aneutron spin flipper that may introduce a systematic
error unless otherwise the neutron spins are perfectly reversed. With a use of a 3He NSF, it can be done by
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Figure 2. A cosine theta coil (AFP drive coil) arranged inside
an aluminum oven generates an oscillating magnetic field perpendicular to the static magnetic
field. A small pick-up coil is placed under the 3He
cell for NMR measurements. Note that the 3He cell
diameter is 60 mm.

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parameters to minimize the 3He depolarization during
the AFP spin reversal. As for the NMR measurement, it
is important not to change the amplitude around theLarmor resonance frequency to distinguish the NMR
signal by the rotating 3He spins from the backgroundsignal caused by the oscillating field itself, since thesignal amplitude of the background is nearly constant,while that by the rotating 3He spins follows the squareroot of the Lorentzian function to the sweep frequency.
In the NMR measurements, the signal detection is
generally done with a lock-in-amplifier, but in the AFP

Neutron Science

NMR system for POLANO, it is performed in software ona PC with a USB oscilloscope, which has eliminated an
expensive lock-in-amplifier (Fig. 3). A simple algorithm
that detects NMR signals in real time has been developed. It has made the AFP NMR system compact, lowcost, and flexible.
The 3He depolarization by the AFP spin flip was determined to be less than 10−4 in one spin-flip, which ispractically negligible. It is also worth noting that the
3He spins are flipped in less than 0.1 seconds. The 3He
NSF will be installed in POLANO soon.

Figure 3. A schematic diagram of the AFP NMR system. A modulated oscillating current is generated,
amplified, and applied to a drive coil for AFP. The rotating 3He spin signal is sensed by a pickup coil, then amplified, and stored in a USB oscilloscope for the NMR detection on a PC.

References[1] T. R. Gentile, P. J. Nacher, B. Saam, and T. G. Walker,
Rev. Mod. Phys. 89, 045004 (2017).
[2] T. Ino, M. Ohkawara, K. Ohoyama, T. Yokoo, S. Itoh,Y. Nambu, H. Kira, H. Hayashida, K. Hiroi, K. Sakai, T.

Oku and K. Kakurai, J. Phys.: Conf. Ser. 862, 012011(2017).
[3] A. Abragam, The Principles of Nuclear Magnetism,
Oxford University Press (1961).

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

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MLF Annual Report 2017

Development of the Magnetic Field Environment
System for Polarized Neutron Experiments on POLANO
1. Introduction
Although the polarized neutron spectrometer,
POLANO, is under commissioning, we reached the firstmilestone, namely, standard unpolarized neutron experiments become available on BL23. The next goal isto realize polarization analysis experiments on BL23, sothat it is indispensable to develop neutron-polarization
devices, such as an in-situ polarized 3He neutron spin filter (SEOP), a magnetic field environment system (guidefield), and the analyzer. In this report, we present thestatus of the construction of the magnetic field environment system.
Figure 1 shows the configuration of the magnetic
field environment devices on POLANO. Here, the guidecoil, longitudinal-field guide magnet, fan-shaped guidemagnet and magnetic housing of the supermirror analyzer have been installed into the beam line, while the
SEOP-type spin filter and a Helmholtz coil are underconstruction. The completed Helmholtz coil consists ofa split-pair longitudinal field coil and three transverse
field coils. By tuning the current ratio, the magnetic
field direction can be controlled three dimensionally inthe range of ±50 Gauss at around the sample position.
Since the Helmholtz coil is installed into the vacuum
chamber, a cooling system is required to remove theJoule heat at the coil.

2. Design and Model Calculation of the Cooling
SystemWe examined the cooling efficiency of the watercooled flange prior to the construction of the system.
The left panel in Fig. 2 show results of the calculation of
the temperature profile. In this model, we assumed thatthe cooling water was kept at 25°C and the total heating of 327 Watts was generated at the coil as a standard
experimental condition. Furthermore, we inserted ahigher thermal conducting material (heat pipe) into thealuminum-A5052 columns to assist the efficient heattransfer from the coil to the cooling flange. In this case,the maximum temperature was estimated to rise up
to ~55°C at the bottom of the Helmholtz coil. Next, weinvestigated the earthquake-resistant strength of thecooling system. As a typical case, we calculated the distribution of the principal stress when the accelerationof 1/4 G was transversely applied to the cooling system,
which roughly corresponds to the seismic earthquake
intensity of 3~4. As seen in the right panel of Fig. 2, themaximum principle stress was estimated as ~5.5 MPaat the connection area of the aluminum columns. Thisvalue was sufficiently smaller than the mechanicalstrength of the main material of the cooling system (c.f.
yield strength of A5052 is 215 MPa). Based on the above
simulations, we then constructed the cooling system.

Figure 1. Configuration of the magnetic field environment system on POLANO.

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Figure 2. (Left) Simulations of the temperature profile of the cooling system. (Right) Calculation of the distributionof the principle stress for the case when the transverse acceleration of 1/4 G is applied.

3. Interlock and Monitoring System
We prepared the interlock and monitoring systems
for safe operation. These systems monitor the current
value of the Helmholtz coil, the temperature of the cooling system, and the flow rate of the water. When thesemonitoring values deviate from the limit, the interlock
system immediately shuts down the power sources ofthe Helmholtz coil.
4. Performance Test
We carried out a performance test by using theconstructed system. The left panel of Fig. 3 shows thetime evolution of the temperature on the Helmholtz
coil when the current of 10 A is applied to the threetransverse field coils. Meanwhile, the right panel ofFig. 3 displays the results for another case when the current of 8 A is applied to the split-pair longitudinal fieldcoil. As seen in these figures, the maximum temperature at a steady state is estimated to be 65 ~ 95°C, which
is substantially lower than the maximum safe operating
temperature of the coils.
5. Future
Now, we work on passing the safety review for themagnetic field environment system. The constructedsystem will be installed on POLANO soon after the safety examination is finished.

Figure 3. Time evolution of the temperature on the Helmholtz coil for (Left) 10 A on the three transverse field coils,and (Right) 8 A on the longitudinal field coil.

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

1

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MLF Annual Report 2017

Improvement of the Computing Environment System on
POLANO
1. Introduction
The polarized neutron spectrometer, POLANO, hasbeen designed with the ability to perform polarization
analysis capable of utilizing the advantages of a pulsedneutron beam [1]. In this report, we present the commissioning of the computing environment system on
POLANO.
2. Improvement of the computing environment
systemThe device diagram of POLANO is shown in Fig. 1:
here, grey-colored devices are under construction or
not implemented. As seen in this figure, the hardware
device for “unpolarized-neutron” experiments has
been almost completely installed. Indeed, we have carried out various test measurements with unpolarized
neutron beam and succeeded in observing magnetic
excitation spectra from CsVCl3 as a standard one-dimensional antiferromagnet [2].
To improve the computing environment system,
we customized the control program of the GiffordMcMahon type refrigerator installed on BL23. Due tothis update, users can carry out a standard low-temperature measurement from T = 4 K to room temperature.
In addition, we improved the usability of the log visualization program on BL23 (Fig. 2). After this update, thegraph-expansion (reduction) function and the exportfunction of log data are available.

Figure 2. Improved log visualization program on BL23. Due tothe update, the extension/reduction of the graph andthe export function of the log data were improved.

3. Maintenance and Debugging
For preserving the colossal amount of event data,
POLANO has two network-attached storage (NAS) servers of 30 TB with redundant arrays of inexpensive disks(RAID60). Unfortunately, unidentified warnings frequently occurred in the components of NAS. This hardware problem was solved by updating the firmware
and replacing the defective hard disks.
When neutrons are detected at the position-sensitive detectors, the electronic signals are converted into
event data (i.e. detected position and time). In the position calculation, we found an incorrect calculation process. Because of the incorrect calculation, the detected
neutron positions were distorted, as shown in the top
panel of Fig. 3. By modifying the calculation program,

Figure 1. Device diagram and computing environment system on POLANO. Grey-colored devices are underconstruction or not implemented. Bold-solid lines indicate the flow of data/signals.

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Figure 3. Debugging position calculation algorithm on the data visualization program HANA.

we were able to obtain a correct result, as seen in thebottom panel of Fig. 3.
4. Future plans
In the near future, we plan to install several core devices for “polarized-neutron” experiments, such as an insitu polarized 3He neutron spin filter (SEOP) device [3],a magnetic field environment system (a Helmholtz
coil and its control system) [4], and a special cryostat.
To operate such core devices, further development of
the control programs is needed. In addition, further improvement on the data analysis program is indispensable for polarization analysis experiments. In particular,
since it is difficult to install a wide-angle spin-flipper
system, we must devise an ingenious analysis method
to realize XYZ polarization analysis on POLANO. As afeasible analysis method, the Schärpf equations may be
useful [5].

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] T. Yokoo et al., presentation on WINS (2018); seealso the related document in this annual report.
[3] T. Ino et al., (private communication) see the related
document in this annual report.
[4] M. Ohkawara et al., see the related document in thisannual report.
[5] O. Schärpf and H. Capellmann, Phys. Stat. Sol. A
135, 359 (1993).

Y. Ikeda1, 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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MLF Annual Report 2017

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
thirteen members: seven from JAEA, four from CROSSand two from an outsourcing company, and is divided
into sub-teams of cryogenics and magnets, high temperature, high pressure, soft-matter, pulsed magnet,
light irradiation and 3He spin filter. The status and activities of the SE team in JFY 2017 are summarized inthis report.
2. Cryogenics and magnets
As of cryogenics and magnets, we have operated
a top-loading 4He cryostat, a bottom-loading 3He cryostat, a dilution refrigerator (DR) insert and a superconducting magnet. The number of users’ experiments we
supported increased significantly over the past year. In
JFY2017, the 3He cryostat was operated for eight experiments, the DR insert for four experiments and themagnet for eleven experiments, including instrument
proposals. The 4He cryostat, into which the DR insert canbe set, was used for seven experiments until January
2018. However, when preparing a users’ experiment inJanuary 2018, a serious leakage was found on this cryostat. Because the combination of the 4He cryostat and
DR insert is in high demand among users, we requested
that the manufacturer repair it and are preparing an alternative cryostat.
3. High temperature equipment
The high temperature sub-team has a niobium furnace for quasi-elastic neutron scattering and inelastic
neutron scattering measurements as the BL-common
SE equipment. The niobium furnace is used with a radial collimator, allowing the elimination of unwanted
background from the furnace. However, it is difficult toeliminate such background at the small-angle region
because the line-of-sight from the detector to the sample and that to the background source are very close
to each other in the small-angle region. Therefore, we
recently developed a furnace for small-angle neutron
scattering, which enables us to obtain small-angle
neutron scattering data with a very low backgroundlevel (Fig. 1). In JFY2017, we supported five users’ experiments at BLs14, 15 and 18 using these furnaces.

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

4. A pulsed magnet system
We have developed a prototype of a general-use
pulsed magnet system of 30 T at the maximum. The
pulsed magnet system consists of a solenoid coil, asample stick and a pulsed power supply. The pulse
width of the generated current is 2.65 msec at 50%of peak. Neutron scattering pulsed magnet experiments were carried out at NOBORU (BL10) in this fiscal
year. As samples, a triangular lattice antiferromagnetic
material and a heavy electron system superconducting material were employed. The main objective of
the pulsed magnet equipment is to demonstrate repetitive firing by automatic operation of the pulsed
power supply using control device in this experiment.
Figure 2 shows the screen of the touch panel on thecontrol box. In the automatic operation, the charged
voltage was set to 700 V, output peak current and thepeak magnetic field were 2.3 kA and 5.84 T, respectively. As a result, each shot was fired every 75 seconds(approximately 50 shots per 1 hour) and150 continuous automatic shots were successfully fired inapproximately 3 hours; the total was 2000 shots in approximately 2.5 days.

MLF Annual Report 2017

Figure 2. The touch panel on the control box.

5. Light irradiation
In JFY2017, we installed a new mercury lamp, which
provides strong ultra-violet illumination (Fig. 3). Also, aphotodetector was installed to “stamp” the time whena light shutter was open and closed, synchronized withthe data acquisition system at the MLF.

Neutron Science

6. 3He 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.
In 2017JFY, we started the assembly of a 3He gas filling station to fabricate hybrid cells with Rb and K.
A laser lab for laser pumping based on the SEOP
was prepared in the beam hall of MLF in 2016. However,the problem was that the relaxation time of the 3He
polarization was too short and the achieved polarization was not high enough for polarized neutron experiments. In 2017, therefore, we investigated the causes ofthe problem, and found out that the situation could be
improved drastically by setting a noise-cut transformer
in the electric power supply line, thus, we managed toobtain adequate 3He relaxation time and the necessary
polarization.
In 2017, we performed a demonstrative study ofpolarized-neutron single-crystal diffraction measurement at BL18 (SENJU). The sample was a single crystal
Fe. In the results, the expected flipping ratios of Bragg
peaks were not observed. To understand the results, wethought of the possibility that severe depolarizationof neutrons had occurred in the sample. To check theidea experimentally, we performed a depolarization
experiment of neutrons transmitted through the sample at BL10. Then it was found out that neutrons wereseverely depolarized in the sample, which was almost
magnetically saturated under an applied magnetic fieldof 4.2 kG. This result indicated the existence of somedomains whose magnetization is not oriented in the
direction of the applied magnetic field even in the fieldof 4.2 kG.

Figure 3. The mercury lamp.

T. Oku1, M. Watanabe1, R. Takahashi1, S. Ohira-Kawamura1,2, M. Ishikado4, K. Ohuchi4, Y. Yamauchi5, M. Nakamura5, 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; 4Neutron Science and Technology
Center, CROSS; 5Nippon Advanced Technology co.

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MLF Annual Report 2017

Development of a Remote Data Access Based on the
Cloud Environment
1. Introduction
The remote access environment for data retrieval,
download, and analysis plays an important role in the
research workflow after experiments in MLF. Such anenvironment allows the facility users to perform theanalysis smoothly and effectively in their home institution. However, building such an environment is quite
challenging because, in addition to adequate management of large and diverse experimental data acquiredby neutron instruments in the whole facility, it requires
secure, quick and easy data access via network from theoutside of the facility.
In recent years, we have been developing the remote access environment based on the public cloud.
Owing to the recent rapid progress and spread of
public clouds such as Amazon Web Service (AWS) andMicrosoft Azure, it is possible to develop effectively
more advanced systems and applications using various
services provided by public clouds.
This year, we completed two developments for the
remote data access using Amazon Web service (AWS).
One is a development of the data delivery function of
the MLF experimental database (MLF EXP-DB) [1]. The
MLF EXP-DB is the integrated system creating a metadata catalog for data management and access. The
other is a development of the general-purpose framework for a web-based analysis environment. In addition, to confirm the feasibility of this system, we haveconducted a performance test for load distribution.
This framework consists of two components, which area web interface, called “Nokiba” and processing backend, called “Shigure” [1]. Using this framework, facility
users can execute various types of analysis software according to the experiment, as well as perform analysis
through a browser.
2. Development of data delivery service
A new data delivery function of the MLF EXP-DB
utilizes the cloud service provided by the AWS. The
MLF EXP-DB centrally manages the experimental data
generated in neutron instruments by cataloging it as a
metadata catalog. The cataloged data files are stored
in the data repository of the facility. Since the MLF
EXP-DB is a web-based integrated system, the management operation can be performed using a web
browser.
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Figure 1. The schematic view of the data delivery service.

Figure 1 shows schematic overview of the data delivery using the new function. This function transfers
the data selected from the metadata catalog by the
instrument staff through the browser from the facility
data repository to the storage service AWS S3 [2] on demand. The access to the data preserved on the AWS S3
is controlled by the Identity and Access Management
service AWS IAM [3]. The facility user is issued an ID and
one-time password (OTP) to access the AWS S3. Data
download using a general-purpose FTP client tool ispossible. In addition, the data on the AWS S3 can bearchived for a long term and fast downloaded from a
distance by using other services and foreign regions of
the AWS.
3. Development and performance tests of the remote analysis environment
Since a large number of facility users will perform
data analysis on the remote analysis environment after the experiment, this environment should be able toprocess large amounts of analysis activities by simultaneous access. Therefore, we have constructed theremote access environment using our framework as ascalable clustered system on the cloud.
Using the Elastic Computing Cloud service AWS
EC2 service [4], we constructed the environment of
the analysis server × 10 (640 core) and developed theprogram execution environment as a cluster by Docker
swarm. For the analysis program, we converted event
data to histograms in parallel using UTSUSEMI [5, 6] developed in MLF. We performed the histogram processing in parallel using analysis software called UTSUSEMI,
developed in MLF. The AWS S3 service was used forMLF Annual Report 2017

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Figure 2. The configuration of the remote analysis environment for the performance test.

object storage. Originally, we were building a clusterwith Docker swarm standalone [7], but due to a change
in the number of Sessions, but the Docker service itself
crashed due to insufficient memory, so in Docker swarm
mode [8], to fix the number of sessions, we decided toovercome the memory shortage problem by limiting
the number of replicas.
In the performance tests, it was assumed thatanalysis processing of 6 sessions could be performed
simultaneously on each beam line, and the goal was toaccomplish simultaneous processing of 6 sessions × 23
beam lines = 138 sessions or more.
As a result, concurrent processing could be done in
up to about 200 sessions at the maximum, but memory
shortage occasionally occurred depending on the situation, so it was possible to finally carry out stable processing in up to 180 sessions.
According to the results of this experiment, a stable
operation was achieved with the configuration combining Docker swarm mode and standalone (Fig. 2). In
this configuration, swarm mode is for the Web service(entry point) and Agent. On the other hand, a clustercomposed of swarm standalone is assigned as a computing resource. Cloud resources used in this work wasprovided in the Demonstration Experiment of CloudUse conducted by National Institute of Informatics (NII)
Japan (FY2017).
4. Conclusion and future plans
In FY2018, as our first attempt to use the cloud, we
will make this service available to the instrument users of BL18 and we also plan to extend the service toother instruments in stages. In addition, we have developed the remote data analysis environment as theflexible clustered system on the cloud and conducted
the performance test. Based on the result of this test,
we plan to develop a more user-friendly web interface
in the future.
References[1] K. Sakasai et. al., Quantum Beam Sci. 2017, 1, 10.
[2] https://aws.amazon.com/s3/?nc1=h_ls[3] https://aws.amazon.com/iam/?nc1=h_ls[4] https://aws.amazon.com/ec2/?nc1=h_ls[5] Y. Inamura et. al., J. Phys. Soc. Jpn. 2013, 82,
SA031-1-SA-031-9.
[6] J. Suzuki et. al., Nuclear Inst. and Meth. Phys. Res.
2009, 600, 123.
[7] https://github.com/docker/swarm[8] https://docs.docker.com/engine/swarm

K. Moriyama and N. Okazaki
Neutron Science and Technology Center, CROSS127

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MLF Annual Report 2017“Live Data Reduction” Project
1. Introduction
Since the commissioning of the first neutron beamat MLF, we, the computing group, have successfully produced a lot of software for facility users to improve theefficiency of measurement and data analysis. On theother hand, there are some users’ requests left on thecomputing environment at MLF. One of the strong users’ demands is real-time data processing during a measurement. Because the measurement time becomesshorter with the increase of the neutron beam intensity,
users want to analyze and visualize their current data
while conducting their measurement to decide thenext measurement conditions.
To see the current data of measurements in theoriginal data acquisition system (DAQ) adapted at MLF,
we had to access directly the data files during DAQ
system writes. This access can potentially damage therecorded data. To reduce such risks, we have started a
new project, named “Live data reduction”, which treats
and visualizes current data with “Safety”, “Speed” and“Flexibility” in real time. This real-time processing method is used not only in the real-time analysis but also
for automated executions of the measurement schedule by cooperation with instrument control software.
In this report, we share the results of our work on thisproject, accomplished in FY2017.
2. Developments
MLF has adopted the event-recording method bymeans of DAQ middleware [1] for the data acquisition
system. The DAQ middleware gathers event-recorded
data (event data) produced by the electric module ofneutron detectors and devices installed in a beam line
instrument to store the data into the storage as a file.
We attempted before to implement real-time data processing by using differential events reading methods

as an online monitoring system [2]. Under this method,
the software reads the differential events in data files
updated by the DAQ system at regular intervals to execute some data processing steps using only differential
data. This method certainly reduces the access to data
files and the damage risk. However, the method was
not good enough because it still involved file access.
To achieve our targets for data processing with“Safety”, “Speed” and “Flexibility” in real-time, the system requires high throughput with safety and flexibility. Therefore, we’ve decided to adopt softwarearchitecture, based on “Publish – Subscribe” patternwith a message-oriented middleware, which is used inmany internet services. In this model, the data senders,called publishers, and data receivers, called subscribers, are connected loosely through a broker. Publishers
and subscribers do not communicate with each otherdirectly, which means that the publishers do not need
to wait for a reaction from subscribers and the latter do
not need to know the status of the publishers. In addition to this flexibility, this method has high scalability
to increase easily the number of both publishers andsubscribers by any request.
As a broker in our system, we chose the open source“Redis” [3], which is an in-memory database for fasterprocessing and has interfaces in various languages.
Next, we decided to treat events data produced from
DAQ directly as messages (data) sent by the publishers. This decision simplifies the structure of publishers’
activities and ensures the flexibility of subscribers. We,
therefore, started to develop publisher software as amodule working in the DAQ middleware. By using thismodule, we can introduce another data stream which isdifferent with a stream to write data into files, as shownin Fig. 1. This means that we are able to access the current data without the danger of data files’ destruction. In

Figure 1. The structure of the DAQ middleware and the live data reduction system.

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addition, it’s easy to install this publisher module into abeam line using the DAQ middleware. In FY2017, thesebase components had already passed the long-term
stability examination and were introduced in some actual beam lines. As subscribers, we are able to develop
software suitable for each beam line adopting our live
data reduction system using Python or C++. We show
some applications of our system in the next section.
3. Applications of the live data reduction
Here, we introduce some applications using the live
data reduction system.
The first example is the online beam monitor forthe 2-dimensional neutron detector installed in BL17
(Fig. 2). As the subscriber for a 2-dimensional detector,
a member of the beam line staffs wrote by himself somePython codes to get event data from the Redis server

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to count kicker events for the time normalization andto make histograms for plotting. These subscribers are
simple Python codes with several tens of lines and theirprocessing speed is fast enough to check the status of
the measurements.
The second example is the online visualization on
the web browser used at BL21. In this system, the subscriber was written in C++. The subscriber obtains event
data from the Redis server and then makes some histograms with ROOT [4]. To visualize those histograms on
the web browser as shown in Fig. 3, JSROOT are used.
Users can see the 2-dimensional profile of the incident
beam and the intensity map for each detector bank inthe middle of their measurement. This visualizations
system has already been working successfully. The next
step is to add the functions to execute some data reduction codes to calculate a structure factor S(Q).

Figure 2. Screen shots of the online monitoring software for the 2D detector (MWPC) in BL17 (Sharaku).

Figure 3. Screenshots of the online monitoring software in BL21 (NOVA).

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Figure 4. Screen shots of GUI and the plotter of the live data reduction on Utsusemi.

The last example is the attempt to add the subscriber function into Utsusemi software, which is a series of software to analyse and visualize the event datawith a graphical interface and is introduced in a lot ofbeam lines in MLF [5]. One of important functions of
Utsusemi is the flexible conversion from the event data
to the histogram format data filtered by the various
experimental conditions. Utsusemi is normally utilized
as offline analysis software, which means the codesin Utsusemi treat only static data files in a storage. On
the other hand, as mentioned before, we have already
implemented the differential events reading method
in Utsusemi. We, therefore, appended a subscribe function to this method instead of the function to read datafrom data files for the live data reduction. As a result,
Utsusemi receives the differential events from the Redis
server at regular intervals, and then converts the events
to histogram format to do the data reduction codes, forexample various data corrections, background subtraction, time normalization and so on. It should be notedthat all the offline data reduction codes can be used forthe live data reduction without code modification. Thismeans that the results of the live data reduction process match completely the ones derived from offline
data reduction. In other words, this method allows theusers to get the analyzed data immediately after theusers’ measurements are completed. This new function
in Utsusemi had been already demonstrated in the actual beam line with enough results. In near future, wewill make it available to users.
4. Summary and future plans
In this project, we produced successfully a basesystem for the live data reduction and introduced itin some actual beam lines. However, there are many
problems to be solved. One is the issue of the timing
for subscribing. In the current system, if the software
subscribes after publishing by the publishers, the data
stream before subscribing is lost. When we implement
the actual live data reduction system, we must develop
a system that will let the subscribers cooperate withpublishers in the DAQ system. We will continue ourwork to refine the system and make it more useful.
References[1] Y. Yasu et. al., J. Phys. Conf. Ser., 219, 022025 (2010).
[2] Y. Inamura, et. al., J. Phys. Conf. Ser., 1021, 12015(2018).
[3] https://redis.io[4] https://root.cern.ch[5] Y. Inamura, et. al., J. Phys. Soc. Jpn. 82, SA031-1(2013).

Y. Inamura1, S. Kasai2, H. Ohshita1,3, and Y. Yasu3
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Neutron Science and Technology Center, CROSS; 3Instituteof Materials Structure Science, KEK

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Bump Cathode Element for Two-Dimensional Neutron
Detector
1. Introduction
Neutron scattering experiments that measure neutron-induced signals near high-intensity direct beams
require two-dimensional neutron detectors that haveparticular features, such as a high counting rate, a good
spatial resolution, a high detection efficiency, and asuperior signal-to-noise (S/N) ratio. Gas-based twodimensional neutron detectors using a multiwire- andmicropattern-element are candidates for use in theseneutron-scattering experiments, and we have developed a gas-based position-sensitive neutron-detection
system that consists of a two-dimensional detector element and can read out an individual signal line [1]. Ina gaseous neutron detector for the neutron scatteringexperiment, a conversion gap, a reaction length between neutron and neutron converter, should be madeas small as possible, because the gap causes the parallax effect of incident neutrons. At the same time, thegas pressure should be increased to obtain a high-detection efficiency performance, though the increase of
the gas pressure causes the decrease of the output signal. To measure the decreased output signals, the gaseous amplification and/or charge collection efficiency
must be increased. In the present study, we developed
a dedicated two-dimensional detector element using
circular cathode bumps for charge collection and performed preliminary neutron irradiation experiments.
2. Bump cathode element
The developed element has triangularly arranged,
small-sized circular cathode bumps, which are linked
together in the x- and y-directions for the individual
signal line readout. The photograph and the magnified
schematic view of a developed bump cathode element
are shown in Fig. 1.
The developed bump cathode element consistedof a polyimide insulator and circular cathode bumps(pads) made from Cu on the insulator. A polyimide layer with a thickness of 0.025 mm was used as the substrate and the thickness of the bumps was 0.02 mm.
Two types of circular bumps, with diameters of 0.6 and0.65 mm, were triangularly arranged on the surfaceof the polyimide. The 0.65- and 0.6-mm bumps werelinked in lengthwise direction on the bottom of thesubstrate using 0.1 mm lines, and the crosswise direction on the surface of the substrate using 0.05 mm lines,

Figure 1. Entire and partially magnified photograph of a developed bump cathode element.

respectively. Both lines were arranged orthogonally. As
a result, the 0.65- and 0.6-mm bumps were used for detection of incident neutrons in the x- and y-directions,
respectively.
The sensitive area is 128 mm × 128 mm with apitch of 1 mm in both directions. For use in the detector system, the bump element was placed on the baseplate made from an alumina ceramic with thickness of
1.5 mm.
Irradiation experiments for the bump cathodeelement were performed using a neutron detection
system consisting of a pressure vessel, amplifier-shaperdiscriminator boards, optical signal transmission devices, position encoders with field-programmablegate arrays, and a data acquisition device. The element
was arranged on the base plate with anode wires in
the pressure vessel with a 20 mm conversion gap. Thebase plate had multichannel connectors (X: 128 ch, Y:
128 ch) for signal transmission from a detector element
to signal processing electronics mounted outside of
the pressure vessel. A schematic sectional view in thepressure vessel is shown in Fig. 2. Gold-plated tungsten
wires with diameter of 20 μm were used as anode wires,and a total of 128 wires were arranged with 1 mm pitch.
Gaseous amplification around each anode wire was
induced by the strong electric field between the electrodes. The conversion gap, distance from drift planeto anode wires, for nuclear reaction between neutronsand 3He is 20 mm, and the distance from the anodewires to the cathode bumps was 1.0 mm.

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Drift plane
20 mm
Anode wires
1 mm
Bump cathode element
Figure 2. Schematic sectional view in the pressure vessel.
Figure 3. Flat-field image under Cf-252 neutron irradiation.

500

400

Number of pixels

3. Experimental results
Preliminary neutron irradiation experiments were
performed using the developed bump cathode element with a fill gas of composition He/(15%)CF4
at 0.7 MPa. Neutron irradiation to the element was
performed by embedding a Cf-252 neutron source.
Figures 3 and 4 show the flat-field image measured by
the detector, which confirmed the spatial homogeneityof the detector element, and the histogram of the pixel
counts of the flat-field image, respectively. The histogram of all pixel counts was evaluated by a Gaussian
fit and showed good homogeneity. The average pixel
count was 134 with a standard deviation of σ = 13.5,
which corresponded to an average count fluctuationof 10.1%. The intrinsic spatial resolution can be calculated from the obtained flat-field image in our detector system [2]. The average intrinsic spatial resolution in
the sensitive region was 1.89 mm FWHM calculated bytaking into account the track lengths of the secondary
particles with He/(15%)CF4 at a pressure of 0.7 MPa.

300
Standatd deviation: 13.5

200
Average countfluctuation: 10.1

100
Average: 134

0

50

100

150

Figure 4. Histogram of the count distribution of the flat-field
image.

References[1] K. Toh et. al., Nuclear Inst. and Meth. Phys. Res.,
A726 (2013) 169.
[2] K. Toh et. al., J. Phys. Conf. Ser. 528 (2014) 012045.

K. Toh1, T. Nakamura1, K. Sakasai1, and H. Yamagishi2
Neutron Instrumentation Section, Materials and Life Science Division, J-PARC center; 2Nippon Advanced Technology

1

132

200

Counts/pixelMuon ScienceMuon Science

MLF Annual Report 2017

Status of J-PARC MUSE
1. D-line
The D-line, which is a superconducting decay/surface channel with a modest-acceptance (about 40 mSr)
pion injector, was originally constructed with a re-usedsuperconducting magnet, which had been used at KEKMSL for more than 30 years, having a cold bore (innerbore radius of ϕ12), and therefore beam windows at the
inlet and outlet.
Through the beam commissioning, we achieved abeam with much more narrowed momentum bite. The
beam has been realized by slit slicing of the laterally
dispersed beam after bending magnet of beam transport optics. In that condition, we used two slits for limiting the beam passing. In the first slit, located next toDQ6, the slit opening was laterally 30 mm and vertically
20 mm. Then, in the second slit, located next to Septum,
the slit opening was also laterally 30 mm and vertically
240 mm. (the full opening is 240 mm in the both slits).
As a result, the beam condition yields a minimum momentum bite, where Δp/p is 1.7% as σ of Gaussian function and the beam divergence is laterally 24 mm andvertically 60 mm within full width (6 σ) of 2D Gaussian,as shown in Fig. 1.

(a)

(b)

Figure 2. Beam collimator: (a) design (b) its picture patteimage obtained by profile monitor.

2. S-line
The S-line was open for users in FY2017. As of theend of 2017, 43 researchers from 25 research institutes
around the world, including 10 students and 5 researchers from overseas, have carried out 17 experiment proposals, as shown in Fig. 3. Thanks to the intense proton

Figure 1. Beam pattern image obtained by profile monitor.

At the D2 area, a beam collimator was designedwith conically tapered hole along the beam focusingenvelope: the 250-mm diameter at the beam port is focused up to 50-mm diameter at the beam extraction
port, as shown in Fig. 2(a) and (b). At the extraction
port, 50 μm-thick Kapton window is divided between
vacuum and air. The distance from the gate bulb to theextraction is 600 mm. The distance allows enough room
to place Ge detectors for measuring the muonic X-rays
emitted from the front side (beam upstream side) of thetarget.
134

Figure 3. Users from Toyota CRDL and KTH Sweden are preparing the sample mounted in a cryo-furnace.

MLF Annual Report 2017beam power of 400 kW, they were able to take muSR
measurements at a rate as high as 200 million events
per hour at the S1 area. Besides, the stable operationof the user program is enhancing the sample environments in order to meet various users’ demands. For example, the newly-installed cryo-furnace in the S1 area
made it possible to change seamlessly the sample temperature from 1.5 K to 500 K.
3. U-line
At the U-line, we conducted ultra-slow muon spinrotation experiments using a silver plate sample. In
February 2018, we observed for the first time rotation
spectrum using ultra-slow muon in U-line at J-PARC
MLF, as shown in Fig. 4. We will continue to perform
beam commissioning and upgrade of the apparatus of

Figure 4. The first ultra-slow muon rotation spectrum obtained in the silver plate with 20 G transverse fieldin J-PARC MLF.

Muon Science

the beamline components for further optimization of
the beam profile, confirmation of time resolution of theultra-slow muon beam, and deceleration test for thedepth profile experiment.
4. H-line
During the summer shutdown in 2017, we started
the construction of a new power sub-station (~5 MW)
designed to operate the H-line. The construction site is
located in the northeast side of the MLF. A new hatch
for electric transmission lines on the MLF wall was completed during the summer shutdown. Subsequently,
the building of the bedding of the sub-station wasstarted, as shown in Fig. 5, and the earth retaining work
was finished successfully during FY2017.

Figure 5. Current status of the construction of the electric
power sub-station.

Y. Miyake1,2, N. Kawamura1,2, K. Shimomura1,2 , P. Strasser1,2, A. Koda1,2, Y. Ikedo1,2, H. Fujimori1,2, S. Makimura1,2, Y. Kobayashi1,2,
J. Nakamura1,2, Y. Oishi1,2, T. Adachi1,2, K.M. Kojima1,2, T. Yamazaki1,2, S. Takeshita1,2 , M. Tampo1,2, W. Higemoto2,3, and T.U. Ito2,3
1
Institute of Materials Structure Science, KEK; 2Muon Science Section, Materials and Life Science Division, J-PARC Center; 3Advanced
Science Research Center, Japan Atomic Energy Agency (JAEA-ASRC)

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Present Status of the M2 Tunnel, the Central Part of MUSE
The muon production target and the front-end partof all muon beamlines, the D, U, S and H lines, are located in the proton beamline tunnel. The proton beamline from the muon target to the neutron target, named
M2 tunnel, is in a high radiation field due to the beamloss at the muon target, so all the devices there, i.e. thebeamline magnets, the vacuum components and soforth, were fabricated according to the design strategy [1], that was created with the effect of radiation inmind. The muon section is in charge of the operation of
all devices in the M2 tunnel shown in Fig. 1.

Figure 2. The cross-sectional view of the conceptual design
framework of a magnet placed in the M2 tunnel.

Figure 3. A typical simulated result of the distribution of theabsorbed dose in the M2 tunnel for a 1-MW 40-year
operation.
Figure 1. The horizontal (upper) and the vertical sectionalview (lower) of the M2 tunnel. The proton beamis transported from the left to the right side of theneutron target through it.

In the M2 tunnel, eight magnets were installed totransport the proton beam: six quadrupole magnets
and two pairs of horizontal and vertical steering magnets. All of them were fabricated under the design
framework shown in Fig. 2. The materials adopted inthese magnets were selected according to the simulated result of the absorbed dose shown in Fig. 3. Asof the insulator of the coil, there were two options: useof mineral insulation cable (MIC) or polyimide impregnated (PI) coil [2]. A MIC has a MgO insulation layer andan outer copper sheath in addition to a central conductor part. The radiation hardness of MgO is much higher
than that of an organic insulator like polyimide resin.
However, MgO is fragile, so the MgO layer must be surrounded by the copper sheath. Many MIC magnets
were adopted in J-PARC.
136

Due to the difference in the ampacity between a
MIC and a PI coil, different power supplier and cableto the magnet are used in each case. Their initial costs
were also different. Thus, either MIC or PI was carefully
selected according to the experience in KEK-PS. If theabsorbed dose around the coil was expected to exceed
400 MGy for a 1-MW 40-year operation, MIC was selected, as shown in Table 1. It was possible to adopt PI in themagnets of the upstream of the muon target, QM1 andQM2, and in most of the downstream, QN4 and XY23.
Just after the Great East Japan Earthquake in 2011,
while checking the soundness of the devices, unexpected high activation was accidentally found in most of thedownstream of the M2 tunnel around M23, which is the
profile monitor located just beside XY23. The dose fromthe residual activity was much higher than expected.
This was explained by beam loss higher than its design
value due to two reasons: (1) enlarging the beam profile to suppress the pitting damage on the wall of theneutron target vessel, and (2) an underestimation of theMLF Annual Report 2017

Table 1. The accumulated dose in some magnets for a 1-MW
40-year operation. They were averaged over the volume of each part, and the practical selection of either MIC or PI was done by referencing the detailed
distribution.

MGy/40y
QM2
QN2
X22
X23
SQ1
DQ1
DB1

yoke
0.1
21.3
202.5
4.4
75.8
271.1
0.4

coil
0.7
65.7
414.7
15.1
207.8
900.4
2.2

pole/duct insulator
10.1
PI
2574.9
MIC
349.3
MIC
19.5
PI
114.2
MIC
559.8
MIC
2.0
PI

small-angle scattering of protons by the muon target in
the simulation code. In response to this, an ad-hoc review meeting was called to discuss the possibility of theinsulation breakdown in the downstream PI magnets
and to plan appropriate countermeasures.
The beam loss around M23 was estimated to beabout 0.08 W/m, which was deduced from the observed dose rate of 70 mSv/h at a distance of 1 cm fromthe surface, applying the empirical formula [3,4]: D =3.4 × 10−4 P log10 ((T + t) ⁄ t), where D is the dose rate
at 40 cm, P is the beam loss rate in a unit of W/m, T =1 week and t = 4 hours are the operation and coolingtimes, respectively. Assuming that a loss rate of about
0.1 W/m is kept for 40 years (5000 hour op./year), theabsorbed dose will be below 1 MGy, applying the empirical proportionality of the absorbed dose; Da = 12 ×
10−3 P [3]. The estimated value is much lower than theallowable limit of PI, 400 MGy. This low loss rate wasachieved by introducing octupole magnets in the upstream of the M2 tunnel, by which the outer side of thebeam envelope is folded to the inner side. The octupole
magnets were introduced to reduce the heat generation in the outer edge of the neutron target vessel, butthey were also useful to suppress the beam loss in theM2 tunnel. The octupole magnets were put into use before May 2013, and by November 2015, the loss rate was
reduced to 0.02 W/m. The beam loss rate is determinedby the observed dose rate, and thus the loss rate involves the operation history. While the proton beam intensity increased from 300 kW in May 2013 to 500 kW in
November 2015, the loss was successfully suppressed

Muon Scienceand controlled. The beam loss is monitored by the loss
monitor, a wire chamber, mounted on M23. In addition,
dosimetry is regularly performed on the accelerator
maintenance day by inserting a budge through a gap
between magnets to the beamline level, 2.4 m downwards from the utility service floor of the M2 tunnel,
to measure the dose from the magnet body. The result
shown in Fig. 4 proves that the beam loss is well controlled. With the upcoming increase of the proton beam
intensity, the regular check becomes more important tokeep the beam loss low.

Figure 4. The result of the regular dosimetry for the devices
in the downstream of the M2 tunnel.

At present, the possibility of a serious problem in
a PI magnet and the necessity of replacement is quite
small. Thus, it is thought that the preparation of a standby PI magnet is not urgent. A standby MIC magnet was
fabricated in 2013JFY. This one can be replaced with
QN4, but not with QM1 and 2 due to the difference inthe power supplier. Also, a steering magnet does nothave any standby. In the future, a standby magnet
should be prepared sequentially.
References[1] N. Kawamura et al. 2009 Nucl. Inst. and Meth. A 600
114.
[2] K.H. Tanaka et al. 2008 IEEE Transactions on Applied
Superconductivity 18 244.
[3] CERN PS 87-3, “Kaon Factories seen from the CERN
PS”
[4] OHO 97, “ᅛᐃᦆኻࡢホ౯”N. Kawamura1,2, S. Meigo3, S. Makimura1,2, and S. Matoba1,2
Muon Science Section, Materials and Life Science Division, J-PARC Center; 2Institute of Materials Structure Science, KEK; 3Neutron Source
Section, Materials and Life Science Division, J-PARC Center
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Current Status of µSR Set Up at D1
At the D-line, muons are kicked out by using the magnetic kicker and delivered to the D1 and/or the D2 area.
Here we report the current status of the D1 area.
At the D1-area, a μSR spectrometer is installed as the
key instrument. Since high-momentum muons, up to
100 MeV/c, surface muons, and negatively charged muons
can be delivered at D1, it is possible to perform any type of
μSR measurement, except for ultra-slow μSR. For example,
μSR under high pressure can be carried out only at D1.

Recently, we have been developing a low backgroundsample holder for small sample in DR. An example is shownin Fig. 3. The holder is 10-mm pure silver and the muons,
which do not hit the sample holder, fly away.
“Minicryo” is a useful cryostat to cool down quickly to~4 K within an hour. In most of measurements, a “fly-pastchamber” is used to obtain a better S/N ratio. For example,
by using a thin-foil sample holder (Ag10-20 μm) and flypast chamber, 15-20% of asymmetry can be achieved in a
5 × 5 mm2 sample.
For high-temperature measurements, up to 800 K, an
infrared furnace is available.

Figure 1. μSR spectrometer at D1.

• Beam profile
Figure 2 shows one example of the profile of surface
muon beam at the sample position, which was measured
in the air. For most of the μSR, this beam tuning is used.

Figure 2. Example of the profile of the surface muon beam.

• Cryogenics and furnace
Temperature control is an important factor for μSR
measurements, so several kinds of refrigerators are available to maintain it. The lowest temperature (~80 mK), is obtained by using the top-loading dilution refrigerator. In our
top-loading DR, a sample can be changed by unloading or
loading just the sample holder. This feature is quite usefulfor the μSR experiment. Furthermore, the cooling systemof the DR is based on a pulse-tube type refrigerator andliquid Helium is not required at all to cool down the system.

Figure 3. Example of a low background DR holder (10 mm).

• Magnets
Magnetic fields of 3.8 kG and 120 G, respectively, canbe applied along the beam direction and perpendicularly
to it. A micro transverse coil (“μTC”), designed for the S1
spectrometer and able to apply up to 250 G, is also available for TF μSR measurement.
For precise zero-field measurements, an active zerofield correction system is being applied now. In this system,
the magnetic fields are monitored not at the sample position, but near the center of the spectrometer and a feedback system is used.
• Detector and DAQ“Iroha”, developed at MLF, is used as a slow control
system,. All μSR systems, including DAQ, can be controlled
through it. Auto run sequence is also available from Iroha.
“Kalliope” is now stably used for electron/positrondetectors.
The μSR system is still developing to obtain better beam and sample environment. Any contribution is
welcome.

W. Higemoto1,2,3 and A. Koda2,41
Advanced Science Research Center, Japan Atomic Energy Agency; 2Muon Science Section, Materials and Life Science Division, J-PARC
Center; 3Department of Physics, Tokyo Institute of Technology; 4Institute of Materials Structure Science, KEK

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MLF Annual Report 2017

Muon Science

Status of the D Line (D2 Area) Commissioning
During the summer shutdown period in FY2015, a
new solenoid was installed into an existing beam line.
This solenoid is a warm-bore type and requires no foils
for protection from thermal radiation. The inner radius of the coils was increased from 12 to 20 cm. Thus, adrastic improvement of the muon intensity is expected.
In FY2016, two new experimental tools were prepared
to determine this low-energy decay muon: a new typeof beam profile monitor and an automatic optimization
program for beam line components, such as magnetic
bends and quadrupoles (named FORTUNE).
In FY2017, the momentum narrowing was achievedby slit slicing a horizontally dispersed beam after passing through bending magnets of beam transport optics. For this purpose, we used two slits for limiting
beam passing. In the first slit, which is next to DQ6,
the final size of the slit opening was 240 mm horizontally and 240 mm vertically. Then, in the second slit,
located next to Septum, the slit opening was 30 mm
horizontally and 240 mm vertically (the full opening is
240 mm in both slits). As a result, the beam condition
yields that a minimum momentum bite, Δp/p is 1.7%
as σ of Gaussian function and beam divergence withlaterally 30 mm and vertically 60 mm within full width(6 σ) of 2D Gaussian, as shown in Fig. 1 at the D2 area.
The muon intensity that was obtained was more than
100 times larger than with the previous solenoid setup
at 5 MeV/c momentum (~120 keV in energy). Therefore,
the expected intensity of the negative muon is ~3 ×
103 muon/s @1 MW.
The success of beam transport with narrow momentum bites and beam divergence enabled us to install a new collimator with lead radiation shield withaluminum cover after the gate valve. The drawing andsnapshot are shown in Figs. 2 and 3. The collimator has
conically tapered shape along with the beam focusingenvelope. The diameter of an exit-hole is 50 mm, anda Kapton foil of 50-μm thickness separates vacuum
from the air. By using this apparatus, the distance of the
focusing point from the gate valve was decreased to
600 mm (200 mm shorter than in the previous setup).
Also, this distance provides the opportunity to place Ge
detectors for measuring muonic X-rays emitted fromthe upstream side of target.

After these developments, we constructed a new
muonic X-rays measurement chamber, which can be
filled with helium gas surrounding the sample without
evacuation. Therefore, now many new types of samples,such as archeological materials, art objects and so on
are coming into our research scope.

Figure 1. Beam profile at the D2 area focusing point.

Aluminum
80 mm

Lead
Figure 2. Drawing of the collimator.

Figure 3. Snapshot of the collimator.

M. Tampo1, K. Hamada1,2, S. Doiuchi1,2, S. Takeshita1,2, K. Shimomura1,2, and Y. Miyake1,2Institute of Materials Structure Science, KEK; 2Muon Science Section, Materials and Life Science Division, J-PARC Center

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MLF Annual Report 2017

Ultra-Slow Muon Beam Commissioning
We observed muon spin rotation spectrum fora silver plate sample, by using an ultra-slow muon
beam in J-PARC. In 2016, we confirmed for the firsttime the generation of an ultra-slow muon in J-PARC.
Since then, the beam commissioning of the ultra-slow
muon continued in order to obtain high intensity andsmall size ultra-slow muon beam. Figure 1 shows anultra-slow muon setup in the Material and Life Science
Experimental Facility (MLF), J-PARC. Ultra-slow muons
generated in the vicinity of the tungsten (W) target are
accelerated by electrostatic lenses and transported tothe μSR spectrometer using a series of electrostatic
quadrupole lenses, bends and a magnetic bend. The
generation method of ultra-slow muon is described indetail elsewhere [1].

was a silver plate with diameter of 20 mm and the transverse magnetic field was 20 Gauss. It took about threedays to accumulate one million events for the spectra.
At present, we continue to perform μSR experiments varying the incident energy of the ultra-slow
muon beam from 50 eV to 30 keV, using as a sample asilver layer with thickness of 50 nm on silicon dioxide,in order to confirm the validity of the ultra-slow muon
beam in J-PARC.

Figure 2. Progress of the event rate at the various focusing
points for a period of two years.

Figure 1. Ultra-slow muon setup in MLF, J-PARC. Multichannel plate detectors for counting the number ofultra-slow muons are placed at F3, F3’, F4A, F5A, F5B
and F6A. The μSR spectrometer can detect decayed
positrons from ultra-slow muons stopped in thesample.

The progress of the rate of ultra-slow muons atseveral focusing points for the period of two years, isshown in Fig. 2. The rate of the ultra-slow muon at F3
reached 73 μ+/s and the event rate of decayed positrons
from the ultra-slow muon was 42 /s in February 2018.
Figure 3 shows the first observed transverse field μSR
spectrum using a 30-keV ultra-slow muon. The sample

Figure 3. A μSR spectrum of the silver sample with 20-Gausstransverse field using an ultra-slow muon beam.

Reference[1] A. D. Pant et al., JPS Conf. Proc. 21 (2018) 011060.

T. Adachi1,2, A.D. Pant1,2, and Y. Ikedo1,2Muon Science Section, Materials and Life Science Division, J-PARC Center; 2Institute of Materials Structure Science, KEK

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Muon Science

Completion of ARTEMIS spectrometer at S1 experimental
area
1. Introduction
S1 experimental area, located in experimental hall
No. 1 of MLF, delivers the conventional 30 MeV/c momentum muon beam, called the surface muon. With
funds from the external budget of Element Strategy ofTokyo Institute of Technology, we have built a general-purpose spectrometer named ARTEMIS, (Advanced
Research Targeted Experimental Muon Instruments at
S-line) that has been described in the preceding MLF
annual reports and elsewhere [1-3]. The quality of thespectrometer generally depends not only on the physical design parameters and reliability, but also on theease of operations performed by the external users
who may not have knowledge about hardware. The
first goal of the spectrometer construction is to set up asystem, which can be operated by such users; ARTEMIS
has reached that level in fiscal year 2017.
Another factor to be considered in spectrometer
construction is the continuous increase of the beam
power. Starting in January 2018, the beam power
reached 400 kW, almost half of the design maximum
intensity of MLF. The corresponding count rate of positron events became over 400 Mevents/hour (if all theslits are wide open), yielding more than three positroncounts per channel per frame (400 Mevents/h = 400 M/1280/3600/25 events/ch/frame = 3.47 events/ch/frame) within the muon life time. The transient properties of the electronics have to be well-behaving tohandle this high rate without signal distortion.

As the accelerator power increases, the proton
beam tends to be double pulsed, separated by 600
nano seconds, in order to operate the machine without too much heat load or radiation damages. To avoid
the overlap of muons from the double pulse structure,
an electric kicker is installed in the S-line, so that thesecond muon pulse originating from the second proton pulse is kicked out of the beamline or sent to otherbranches of the beamline. In FY2017, the kicker system
was in operational to the user experiments, if required,because of the double pulse operation of the accelerator. The result of the operation is explained later in moredetail.
2. IROHA2 façades for ARTEMIS and D1
IROHA2, the framework system controlling all thesample environment devices and data acquisition (DAQ)
software, has a sequence server, which is the interface
between the experimentalist and the IROHA2 system
to run automatically a sequence of measurements. The
experimentalist chooses a façade (a preset procedure
to perform a certain function in Python script) from thelist on the IROHA sequence web browser to construct
the sequence of measurements. The original IROHA2
system developed by the MLF computer environment
team has very basic façades, such as starting/stopping DAQ or setting the target temperature and otherparameters on the standard temperature controller(Lakeshore 350) used in MLF.

Table 1. muon version of IROHA2 façades.
FaçadeSTARTSTOP
SET_Temperature
WAIT_Temperature
SET_HeaterRange
SET_PID
SET_Flow
SET_Magnet
SET_vectorH
SET_ZFFBSET_Rod
TITLE_x
DEFVAR_x

FunctionStart the run, wait for the preset statistics, and stop the run if achieved*.
Wait for the preset statistics and stop the run if achieved*.
Set the target temperatures and wait for the time and tolerance used in the WAIT_Temperature command.
Wait until the tolerance is satisfied for the preset wait time.
Set the heater range of Lakeshore 350 temperature controller.
Set the PID parameter of Lakeshore 350 temperature controller.
Set the helium flow rate controlled by MKS RP4000B.
Set the magnetic field at the sample position.
Set the magnetic field at the sample position in vector field mode.
Set on/off the active zero-field feedback system.
Set position and angle of the sample rod.
Set the field x of the run title.
Set the variable in x (=integer, float and string) format for looping.

* In the background, automatic histogram generation and database registration is performed.

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MLF Annual Report 2017

Before moving to the IROHA2 framework system,
which is the standard of MLF, the muon spin relaxation(μSR) spectrometers at MLF (ARTEMIS and D1 spectrometer) had been controlled by a LabVIEW macro(RODEM), which works as the autorun controller. For
this hand-made system, we developed a reporting system of accumulated statistics from DAQ and an automatic histogram generator from the list-mode data, as
well as a database registration system of run titles andexperimental conditions. In order to incorporate it withthe existing automated systems, we developed a seriesof muon extension of IROHA2 façades. In Table 1, I summarized the new commands in the IROHA2 sequence.
3. Experimental monitor and histogram viewer withuser login access control
Monitoring the ongoing experiments from public
internet outside of the facility is one of the key features,with which the user facilities must be equipped. The life
quality of the visiting experimentalists improves andthe supervision of the experiments by the collaborating
local staff becomes easier with the external monitoring system installed. At the same time, the protection of
the privacy of the experiment from the general public
has to be guaranteed. The solution is a user login to themonitoring website: the login id is distributed to eachexperimental number so that only the related experimental data may be visible. We completed the external monitoring system and histogram viewer with user
login access controls. The entire system (detector, DAQ,
monitoring system, automatic histogram converterand database registration system) has been used in thecourse of beam power increase and performed successfully up to the 400-kW operation.
4. Muon Kicker performance
The S-Line kicker is an electric beam kicker, consisting of bi-polar power supplies generating pulsed
high-voltage of ±54 kV by using MOS-FET to switch
charging/discharging of the high-voltage circuits. If theusers want to utilize both of the double-pulsed muon
beams, a switch yard magnet, which is a static component equipped with the S-Line kicker chamber, is used
to deliver the muon beam to the S1 area. Since resuming the beam operation in 2017 running the primary
proton beam power of 150 kW, the served beam wassingle-bunched. Therefore, the S-Line kicker was in astand-by state. However, the accelerator team decided
to operate in double-bunched mode for one week inMarch 2018 to reduce the radiation loss problem. It was
142

the first time to turn on the kicker in the user beamtime.
Unfortunately, the kicker failed after running for
only 3 days due to a malfunction of the high-voltage
circuit. The recovery from the failure was relatively easy,
because all the MOS-FET units are designed equivalentregardless of the polarity; the bipolar high-voltage,
which drives the kicker, is generated by connecting
the high-voltage taps of the pulsed transformers by
the MOS-FET of the same design. To recover from thefailure, only one of the high-voltage units was to be
replaced. Since we do not have the S2 area yet, we replaced the faulty unit for S1 with the one used in the S2area with opposite polarity of the high-voltage. Since
the power supply is placed in the beamline, we had to
wait for the maintenance day in order to remove theconcrete shields. The replacement of the power supplies was completed in one hour. Thus, the half-day
maintenance was enough to fix the failure.
Another issue, raised during the operational running of the kicker system, was the positron contamination. We found out that positrons have a kicked
trajectory with a much smaller angle than that for muons of the same momentum. Since most of the beamline components select momentum, the beamline istuned to the momentum p. The corresponding kinetic
energy E~p2/2m or velocity v~p/m becomes much larger for the positrons because of the 1/200 times lighter
mass. Since the electrostatic kicker is the device to kickthe particle traveling along the electrode during its
travel time, the kicking of positrons may be more difficult than that of muons. Although most of the positrons are discriminated by the Wien filter, the so-called
DC separator, remnant positrons with a momentum of
the beamline can reach the experimental area.
We have found that the prompt positrons are seenin the spectrum, even if the beam kicker is triggered,Figure1. Schematic drawing of the S-line electric kicker system. HV represents a high-voltage power supply.

MLF Annual Report 2017

suggesting that the beam profile of the positrons is
considerably spread at the inlet of the septum magnet. This may cause a serious problem when utilizing
the first muon pulse; the prompt positron of the second pulse may appear at around 600 ns after the muon
timing of the first pulse. Since we do not have the S2
area, the second muon pulse is currently used for the
S1 experiment, if the single-pulsed muon beam is required. However, we may need to improve the positroncontamination before we utilize the beam branch at
the other side, S2. We plan to increase the high voltage

Muon Scienceof the DC separator, in order to eliminate the positrons
more effectively.
References[1] MLF annual report 2014, p.136-137; 2015, p. 132133; 2016, p.143-144.
[2] K.M. Kojima, et al., JPS Conf. Proc., 21, 011062 (1–6),(2018).
[3] K. M. Kojima, et al., J. Phys: Conf. Ser., 551, 012063,(2014).

K.M. Kojima1,2, A. Koda1,2, M. Hiraishi1,2, H. Okabe1,2, S. Takeshita1,2, H. Lee1,2, P. Strasser1,2, Y. Irie1,2, and R. Kadono1,2
Muon Science Section, Materials and Life Science Division, J-PARC Center; 2Institute of Materials Structure Science, KEK

1143

Muon Science

MLF Annual Report 2017

H-Line Construction – Recent Progress
A new beam line, named H-line [1], is being constructed in the east #1 experimental hall of the MLF. The
H-line is planned to be used for various experiments,
which need high statistics, i.e. high-intensity beams andlong beamtime. These characteristics enable precise
measurements, such as muon g-2/EDM experiment [2]and high-precision measurement of the hyperfine
splitting of the ground state of muonium (MuSEUM
experiment [3]), and is also best suited for rare decay
search, like the DeeMe experiment [4], which searches
for charged lepton flavor violation (cLFV) using muonicatoms.
In order to deliver a high-intensity beam to experimental areas, the H-line has a large capture solenoid(HS1). It is located 600 mm from the muon production target and its acceptance is 108 mSr. Coils of HS1
are wound with radiation-resistant mineral insulation
cables (MIC) [5]. Because MIC is a normal conducting
wire, HS1 needs powerful electricity (~ 1 MW). Other
beamline components, such as bending magnets (HB1,
HB2), transportation solenoids (HS2, HS3), and focusing quadrupole triplet (HQ1-3) also have large aperturefor efficient muon transportation. Figure 1 is a layout

drawing of the H-line (1st phase).
The frontend apparatuses of the H-line (HS1, HB1,
HGV1) were installed during the summer shutdown in2012 and 2014. In 2016, all radiation shields until thefirst branch of the H-line, H1 area, were placed. A beam
blocker (HBB1) was also installed. With the beam blocker inserted, the dose rate inside the H1 area is expected
to be about 10 μSv/h, even when the beam is on.
The construction of a new electric power sub-station for the H-line is one of the most significant recent
advancements. The capacity of the electric sub-station
is about 5 MW, which is necessary to operate the H-line.
The construction site is located in the northeast side of
the MLF, as shown in Fig. 2.

Figure 2. Construction site of a new electric power sub-station. It is located outside the MLF building.

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

144

The construction started in FY2017 and still continues. During the summer shutdown in 2017, a new hatch
for electric transmission lines was completed on the
MLF wall. The size of the aperture is 2 m × 1 m . Figure 3
is its picture taken during its construction period. The
cabling work is scheduled after the electric sub-stationis completed.
After the hatch construction, we have started building the bedding of the electric sub-station. Earth retaining work was finished successfully in FY2017. Pictures
taken before and after the construction work in FY2017
are shown in Fig. 4.
The platform of the new electric sub-station will becompleted in 2018. In addition, the cabling work of thehigh-voltage lines is also scheduled for 2018.

MLF Annual Report 2017

Muon Science

Figure 3. Aperture for electric transmission lines. It is locatedabove the carry-in entrance of the east #1 experimental hall of the MLF.

Figure 4. Recent progress of the construction of the electric
power sub-station.

References[1] N. Kawamura, et al., J. Phys.: Conf. Ser. 408, 012072(2013).
[2] T. Mibe, et al., Chin. Phys. C 34, 745 (2010).
[3] K. Shimomura, AIP conf. proc. 1382, 245 (2011).

[4] H. Natori, et al., Nucl. Phys. B (Proc. Suppl.) 248-250,
52 (2014).
[5] H. Fujimori, et al., Nucl. Instrum. Methods Phys. Res.
Sect. A 600, 114 (2009).

T. Yamazaki1,2 and N. Kawamura1,2
Muon Science Section, Materials and Life Science Division, J-PARC Center; 2Muon Science Laboratory, High-Energy Accelerator Research
Organization (KEK-IMSS)

1

145

MLF Safety

MLF Safety

MLF Annual Report 2017

1. Radiation safety(Operation of the “Low-surface contamination area” at
the MLF Experimental halls)
The low-surface contamination area has been adopted
at the MLF Experimental halls from November 2016. The
purpose is to avoid surface-contamination problems
caused by a sample, an environmental atmosphere andso on, and to expand the flexibility of the experiments
conducted at MLF. Consequently, many experiments
using gaseous and liquid samples were conducted at
the MLF experimental halls. During the operation of the
low-surface contamination area, there was no criticalproblem. However, the monitor for take-out articles,
installed in 2016, sometimes had troubles due to damage of the light shielding sheets. One monitor for largesize take-out articles was additionally installed in order
to increase the usability for users. During the summer
maintenance period in 2017, a temporary classification change from the low-surface contamination area
to second class radiation-controlled area at the MLF
Experimental halls was carried out for the first time tomake the maintenance work on the instruments easier.
(Radiological License Upgrade)
The application for radiological license up-grades
in FY2017 was approved on February 26, 2018.
The following items were updated on February 26,
2018:(1) Addition of usage purposes of the radiation generator licensing
Materials science, neutrino experiment, elementary physics, particle physics and nuclear physics wereadded to the usage purpose.
(2) Addition of RAM building
The RAM building (Radio-Activated Materials building) has a storage area for radio-activated materials
produced by the radiation generator and supplements
the storage area in the MLF building. The storage area
for radio-activated materials in the RAM building has 5large underground pits and can be operated as a firstclass radiation-controlled area.
2. Chemical safety
As usual, routine chemical safety checks of userbrought chemical materials, such as specimen and reagents, were performed by the chemical-safety teamto evaluate their toxicity and the stability of their actual physical state-powder, solid, liquid or gas. After148

Number of chemical materials

Research Safety
8000

6000

4000

2000

0

2009 2010 2011 2012 2013 2014 2015 2016 2017

Year
Figure 1. Trend of chemical materials undergoing chemicalsafety check.

checking, the individual beamline staffs confirmed or
rejected the usability of the actual materials. As a result,the experiments were performed without serious troubles. Figure 1 shows a trend for the number of chemicalmaterials subjected to safety check. As of the form of thesample, solid was used most frequently, then powder,liquid, and gas. From the viewpoint of organic or in-organic matter, inorganic matter was used more frequently. In 2017, the total number of chemical materials to go
through chemical safety check was increased, and, asa result, 8045 chemical materials were brought to MLF,
which was a 25% increase compared with the last year.
3. Unattended operation of the cryo-furnace
When conducting high-temperature experiments,
the users have the obligation to monitor the status of
the furnace at the beamline. To reduce that workload,
the sample environment team and the instrument
safety team considered introducing an unattended
operation. As a result, the unattended operation of thehigh-temperature experiment was first applied to the
cryo-furnace, if the following conditions were met:
1) Passed safety check by the instrument safety team.
2) Maximum temperature is less than 800 K.
3) Heater output is less than 400 W.
4) Interlock system in case of temperature abnormality is available.
Heater stops automatically when the maximum
temperature is exceeded, without automatic return.
5) No fire spreading by the multiple holder into whichheater is placed.

MLF Annual Report 2017

MLF Safety

Table 1. List of unattended operation cryo-furnace.

Type
Top loading
Top loading
Top loading
Top loading
Bottom loading
Auto sample changer
Auto sample changer
Top loading
Top loading

Temperature range (K)4 ~ 600
15 ~ 680
10 ~ 800
5 ~ 550
4 ~ 600
4 ~ 800
20 ~ 500
5 ~ 500
5 ~ 700

6) Monitoring of the signal light of the alarm indication system in the monitoring room.
Table 1 show the list of cryo-furnace which isachieved unattended operation now.
4. Crane safety
Three cranes were used safely in experimental hall
No.1 and experimental hall No.2, which has an ex-tension building. These cranes are used mostly to change
the experimental setup during beam time and to perform summer maintenance by the technical staffs. They
were also used in construction works to install new devices after August. Figure 2 shows the statistics of thetotal crane usage in both experimental halls as a function of every month. The cranes were used 207 times intotal. The total use slightly decreased compared withthe last year.
The statistics for 2017 indicated high use in Octoberdue to the summer maintenance completion.
As usual, the crane safety team checked monthly
the mechanical sling, lifting sling, etc. and replaced theold ones with new ones when necessary. Furthermore,

Heater output (W)100, 150
50
100
100
70
150
75, 13075
240, 50

SensorRhodium ironplatinumK type thermocouple
platinum
Platinum, N type thermocouple
platinumplatinumplatinum
Platinum, silicona crane operator, who wants to use the cranes in theexperimental halls, needs to attend hands-on training
by the crane safety team staff before the actual operation. As a result, there were no serious troubles with thecrane operations.

25

Number of crane usage

BL
BL01
BL02
BL09
BL14
BL20
BL20
BL21
BL21
SE

in-house staff
constructor

20

15

10

5

0

4

5

6

7

8

9

10 11 12

1

2

3

Month
Figure 2. Trend of the total crane usage in one year.

M. Harada1, M. Ooi1, M. Sekijima1, K. Kawakami2, K. Aizawa2, A. Hori2, H. Tanaka2, W. Kambara2, M. Sawabe2, K. Suzuya3,
N. Kawamura4, Y. Sakaguchi5, R. Takahashi2, 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
and Life Science Division, J-PARC Center; 5Neutron Science and Technology Center, CROSS; 6Materials and Life Science Division

149

MLF Operations in 2017

MLF Operations in 2017

MLF Annual Report 2017

Beam Operation Status at MLF
In Japanese Fiscal Year (JFY) 2017, the beam operation at the MLF started on April 1, 2017, with a beam
power of 150 kW and ended on April 2, 2018. Table 1
shows the scheduled time and availability in JFY
2017. In the schedule, 2017A switched to 2017B on
November 16. Since Target #2, which was replaced in
the summer of 2016, did not have the helium bubbler
to mitigate cavitation erosion at the target vessel, thebeam power had to be lower than 200 kW. In JFY 2017,
the beam power had been maintained as low as 150 kW
from April 1 to the end of June. After the target was replaced by Target #8 with helium bubbler in the summerof 2017, the beam power was gradually increased from300 kW to 400 kW. The beam operation with a singlebunch beam continued up to 400-kW beam operation.
Due to the RF condition in the RCS, the beam is delivered to the target in two bunches with separation timeof about 600 ns for beam power larger than 500 kW,

which will start in the next fiscal year.
Since no significant failures occurred in JFY 2017,
the achieved average availability was as high as 92%. In
the past, a relatively long beam shutdown period was
required to complete the purification of the cryogenic
system for the neutron moderator. In the summer of
2016, the impurities in the loop of the cryogenic system
had been removed entirely; after that, the periodical
purification is not required. Thus, a long uninterrupted
work period of 4,179 h was attained in JFY 2017.
The beam operation was stopped on several
occasions due to minor failures described below.
Malfunctions related to the Personnel Protection
System (PPS) at BL04 occurred on May 15. The pumpor the helium bubbler in the mercury loop failed on
December 1. On January 16, the beam operation was
stopped due to flow decrease of the cooling water for
the LINAC.

Table 1. Run cycle, scheduled time and availability.

Run
74
75
76
77
78
2017A
2017B
Overall

DurationApr 1 – Apr 19
Apr 26 – Jun 29
Oct 2 – Nov 15
Nov 16 – Dec 23
Jan 10 – Apr 2
Apr 1 – Nov 15
Nov 16 – Apr 2

Scheduled time (h)
403
1224
504
765
1642
2131
2493
4538

Beam time (h)385.31135.1454.5
698.0
1506.51974.92287.64179.4

Availability (%)
95.6
92.7
90.2
91.2
91.8
92.7
91.8
92.1

Figure 1. Beam power trend (blue line) at the MLF and availability per day (red line).

152

MLF Annual Report 2017

MLF Operations in 2017

Users at the MLF
In fiscal year (FY) 2017, the initial beam power of
150 kW was increased to 300 kW after the summer
maintenance period, and again to 400 kW from January
2018. Due to the high beam power and stable operation throughout the year, the number of users grew tothe highest number to date. In particular, the numberof foreign users of the neutron and muon experimental
facilities in FY 2017 was almost twice that of FY 2016.
The trend for the number of users at the MLF since
the start of the operations in FY 2008 is summarized inTable 1 and Fig. 1.

Table 1. The number of domestic and foreign users by fiscal year.
FY2008Domestic
Users
NeutronMuon

FY2009Foreign
Users

Domestic
Users

12

303

107

18
18

0

38

Foreign
Users

Domestic
Users

Muon

113

476

13

59

FY2011

Foreign
Users

Domestic
Users

44

238

476

2

42

Foreign
Users

Domestic
Users

83

744

10

83

Domestic
Users

21

628

8

21

Foreign
Users

Domestic
Users

108

742

16

149

2

18
12
95
FY
Y2
2008
00
008

303

432

FY 2
01
10
2010

50

11

30

30

900

16
149

78
113

46
80

83
10

11

011
FY 2
2011

10

179

Muon (Foreigners)

628

50
61

185

Muon (Japanese)

50
50

108

185

750
600

59
83

450

711
744

399

238
FY 2
0 09
2009

46

Neutron (Foreigners)

2
21
21

449

Foreign
Users

13

38
14

399

927

99

42
44

80

ForeignUsers

FY2017852

10

2Domestic
Users

56

Neutron (Japanese)

8

FY2013Foreign
Users

708

23

FY201669

FY2012Foreign
Users

259

50

559

91
78

432

FY2015

824
711

14
40

FY2014

NeutronDomestic
Users

317

95

DomesticUsers

FY2010Foreign
Users

476

742

300
150

01
12
FY 201
2012

201
13
FY 2013F 20142014
FY

FY 20152015

FY
Y 2016
6

0
FY 2017

Figure 1. The number of domestic and foreign users by fiscal year.

153

MLF Operations in 2017

MLF Annual Report 2017

MLF Proposals Summary – FY2017
Table 1. Breakdown of Proposals Numbers for the 2017 Rounds.
2017A
Beamline

2017B

Full Year

Submitted Approved Submitted Approved

Instrument

GU

GU

GU

GU

Submitted
PU/S

IU

Approved
ES

PU/S

ES

BL01 4D-Space Access Neutron Spectrometer - 4SEASONS

18(0)

9(0)

19(1)

11(1)

0

1

1

0

1

1

BL02 Biomolecular Dynamics Spectrometer - DNA

16(1)

13(1)

18(1)

13(1)

0

1

0

0

1

0

(100−β)‡

8

1

6

0

0

0

0

0

0

0

(β)†

2

0

0

0

19

0

0

10

0

0

9

7

12

3

0

1

0

0

1

0

6

3

2

2

0

0

0

0

0

0

BL03 Ibaraki Biological Crystal Diffractometer - iBIX
BL04

Accurate Neutron-Nucleus Reaction Measurement
Instrument - ANNRI

BL05 Neutron Optics and Physics - NOP
BL06 Neutron Resonance Spin Echo Spectrometers - VIN ROSE

0

0

0

0

0

0

0

0

0

0

BL08 Super High Resolution Powder Diffractometer - S-HRPD

11

8

12

8(0)

0

0

0

0

0

0

BL09 Special Environment Neutron Power Diffractometer - SPICA

0

3

0

0

0

0

0

0

0

0

Neutron Beamline for Observation and Research Use NOBORU

11

6

8

7

0

1

0

0

1

0

BL11 High-Pressure Neutron Diffractometer - PLANET

8(0)

6(0)

15(0)

8

0

1

0

0

1

0

BL12 High Resolution Chopper Spectrometer - HRC

12

7

9

3

1

0

0

1

0

0

BL14 Cold-neutron Disk-chopper Spectrometer - AMATERAS

28

10

22

6

0

1

0

0

1

0

Small and Wide Angle Neutron Scattering Instrument BL15TAIKAN

18(2)

17(2)

26(0)

11(0)

0

3

1

0

3

1

19

9

7

7

0

0

0

0

0

0

BL17 Polarized Neutron Reflectometer - SHARAKU

9(1)

10(1)

20(1)

15(1)

0

1

1

0

1

1

Extreme Environment Single Crystal Neutron Diffractometer
BL18- SENJU

16(0)

11(0)

22(0)

5(0)

0

2

1

0

2

1

BL19 Engineering Diffractometer - TAKUMI

23

13

25

11(0)

0

1

2

0

1

2

13

6

19

4

0

0

0

0

0

0

BL10

BL16

BL20

High-Performance Neutron Reflectometer with a horizontal
Sample Geometry - SOFIA(100−β)‡Ibaraki Materials Design Diffractometer iMATERIA

†

(β)

44

24

20

20

18

0

0

18

0

0

BL21 High Intensity Total Diffractometer - NOVA

19

17

17

7

0

0

0

0

0

0

BL22 Energy Resolved Neutron Imaging System - RADEN

13(1)

11(1)

16(2)

8(2)

0

3

0

0

3

0

BL23 Polarization Analysis Neutron Spectrometer - POLANO

0

0

0

0

0

0

0

0

0

0

Muon Spectrometer for Materials and Life Science
Experiments - D1

15(1)

4(0)

15(1)

9(0)

0

1

0

0

1

0

D1
D2

Muon Spectrometer for Basic Science Experiments - D2

12(0)

7(0)

13(0)

9(0)

0

1

0

0

1

0

S1

General purpose μSR spectrometer - ARTEMIS

12(1)

9(1)

14(1)

9(1)

0

1

0

0

1

0

UA

Muon U

0

0

0

0

0

1

0

0

1

0

290

211

360

233

38

20

6

29

20

6

Total

GU : General Use
PU : Project Use or Ibaraki Pref. Project Use
IU : Instrument Group Use
ES : Element Strategy† : Ibaraki Pref. Exclusive Use Beamtime (β = 80% in FY2017)‡ : J-PARC Center General Use Beamtime (100−β = 20% in FY2017)( ) : Proposal Numbers under Neu User Promotion or P-type proposals (D1,D2) in GU

S : S-type Proposals

Table 2. Proposals Numbers of Long Term Proposal for the 2017 Rounds.
Application FY
2017

154

IU

1st Year

2nd Year

3rd year

Submitted

Approved

Submitted

Approved

Submitted

Approved

24

8

-

-

-

-

MLF Annual Report 2017

MLF Operations in 2017

800
700
278

142
Proposals

231

293

600

395

500

Not Approved

400

126

42
300

45

20
200
100

309

34
67

214

FY2008FY2009

460

507

469

422

255

Approved

321

353

FY2015FY20160
FY2010FY2011FY2012FY2013

FY2014FY2017

Proposal Round

Figure 1. MLF Proposal Numbers over Time.

JAEA
69
9%

KEK
42
6%

CROSS
28
4%

Universies (Japan)
Companies (Japan)
Universies (Japan)
354
48%

Foreign Organizaons
104
14%

Research Instutes (Japan)
Foreign Organizaons
JAEA
KEK

Research Instutes (Japan)
38
Companies (Japan)
5%
103
14%

CROSS

Figure 2. Origin of Submitted Proposals by affiliation - FY2017.

Q1
P9 30
P7 10 5%
44 2%
7%

P6
52
8%

Q2
51
8%
P5
157
25%

P1
128
21%
P3
83
14%

P2
64
10%

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 - FY2017.

155

MLF Operations in 2017

MLF Annual Report 2017

MLF Division Staff 2017
Toshiji Kanaya (Head)
Hideki Seto (Deputy Head)
Kazuhiko Soyama (Deputy Head)
Izumi Kuwahara

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

Tetsuya Kai *Kenji Sakai

Katsuhiro Haga (Sub-Leader)

Yoshinori Kikuchi

Masakazu Seki

Katsuhiro Aoyagi

Hidetaka Kinoshita *Mitsuaki Sekijima

Tomokazu Aso

Hiroyuki Kogawa

Motonori Takagi

Shinpei Fukuda

Shin-ichiro Meigo *Makoto Teshigawara

Wenhai Guan

Hideki Muto

Hiroyuki Uehara *Kouhei Hanano

Masakazu Nakamura

Eiichi Wakai

Masahide Harada

Takashi Naoe

Takashi Wakui

Shoichi Hasegawa *Norio Narui

Akihiko Watanabe

Miyuki Hoshino

Masaaki Nishikawa

Yoshinori Yanagida

Hidemitsu Hosokawa

Motoki Ooi

Shizuka Yoshinari

Masato Ida

Kenichi Oikawa *Neutron Science Section*: additional duties<JAEA>

156

Kenji Nakajima (Leader)

Hideaki Isozaki

Naoki Murai

Yukinobu Kawakita (Sub-Leader)

Tetsuya Kai

Hiroshi Nakagawa *Kazuya Aizawa *Ryoichi Kajimoto

Shoji Nakamura *Hiroyuki Aoki

Wataru Kambara *Mitsutaka Nakamura

Kazuhiro Aoyama

Kouji Kaneko *Takashi Ohhara

Hideo Harada *Chiho Katagiri

Mariko Ohtake

Masahide Harada *Seiko Kawamura

Kenichi Oikawa

Takeshi Harada

Takuro Kawasaki

Asami Sano

Stefanus Harjo

Tatsuya Kikuchi

Mariko Segawa *Takanori Hattori

Atsushi Kimura *Yoshichika Seki

Yuu Hirano *Ryoji Kiyanagi

Kaoru Shibata

Kousuke Hiroi

Maiko Kofu

Naoko Shimizu

Miho Igarashi

Kazuo Kurihara *Takenao Shinohara

Yasuhiro Inamura

Bing Li

Yuhua Su

Hirotaku Ishikawa

Satoshi Morooka *Hiroshi Suzuki *MLF Annual Report 2017

MLF Operations in 2017

Kentaro Suzuya

Itaru Tamura *Wakana Ueno

Shinichi Takata

Katsuaki Tomoyori *Masao Watanabe *Tarou Tamada *Yosuke Toh *Dai Yamazaki *Shinichi Ito (Sub-Leader)

Naokatsu Kaneko

Norifumi Yamada

Hideki Seto

Kenji Mishima

Testuya Yokoo

Hitoshi Endo

Fumiya Nemoto

Masao Yonemura

Takashi Honda

Hidetoshi Oshita

Masato Hagihara

Kazutaka Ikeda

Toshiya Otomo

Takafumi Hawai

Takashi Ino

Kaoru Taketani

Seiji Sugai

Takashi Kamiyama

Shuki Torii<KEK>Technology Development Section*: additional duties<JAEA>
Kazuya Aizawa (Leader)

Akihiro Hori

Kenji Sakai *Takayuki Oku (Sub-Leader)

Hiromichi Tanaka

Kaoru Sakasai *Takeshi Nakatani

Tomokazu Aso *Kentaro Suzuya *Masao Watanabe

Seiko Kawamura *Shinichi Takata *Chikako Doda

Masahide Harada *Motoyasu Adachi *Wu Gong

Yasuhiro Inamura *Tarou Tamada *Wataru Kambara

Tetsuya Kai *Satoru Fujiwara *Kazuhiro kawakami

Hiroyuki Kogawa *Yu Hirano *Masaki Sawabe

Mitsutaka Nakamura *Tatsuhito Matsuo *Shigekazu Inayoshi

Tatsuya Nakamura *Rumi Shimizu *Ryuta Takahashi

Motoki Ooi *Fumiaki Kono *Masataka Sakaguchi

Naritoshi Kawamura *Tomohiro Seya

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

Testuya Yokoo *<KEK>

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

Ryuji Maruyama

Noriaki Tsutsui

Noriko Amezawa

Tatsuya Nakamura

Dai Yamazaki

Masumi Ebine *Kentaro Toh

157

MLF Operations in 2017

MLF Annual Report 2017

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

Yasuo Kobayashi

Koichiro Shimomura

Naritoshi Kawamura (Sub-Leader)

Akihiro Koda

Patrick Strasser

Taihei Adachi

Kenji Kojima

Masato Tabe

Pant Amba Datt

Shunsuke Makimura

Soshi Takeshita

Hiroshi Fujimori

Shiro Matoba

Motonobu Tanpo

Koji Hamada

Yasuhiro Miyake

Shogo Doiuchi

Masatoshi Hiraishi

Junpei Nakamura

Tatsuhiko Tachibana

Hua LiYu Oishi

Takayuki Yamazaki

Yutaka Ikedo

Hirotaka Okabe<JAEA>
Wataru Higemoto *158

Takashi Ito *MLF Annual Report 2017

MLF Operations in 2017

CROSS Staff 2017
Director

Hideaki Yokomizo

Science Coordinators
Kazuhisa Kakurai

Makoto Hayashi

Mikio Kataoka

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)

Tsukasa Miyazaki *(Deputy Head)

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

Sayaka Suzuki

Hiroki Iwase

Yoshifumi Sakaguchi
Yukihiko Kawamura<BL01 Group><BL17 Group>

Hiroshi Kira

Kazuya Kamazawa (Leader)

Jun-ichi Suzuki *(Leader)Motoyuki Ishikado

Kazuhiko Ikeuchi

Noboru Miyata (Sub-Leader)

Nobuo Okazaki

Kazuki Iida

Kazuhiro Akutsu

Makoto Kobayashi

Takayasu Hanashima

Satoshi Kasai
Toshiaki Morikawa<BL02 Group>
Masato Matsuura (Leader)<BL18 Group>

Hideyuki Hiramatsu

Takeshi Yamada

Akiko Nakao (Leader)

Yutaka Ebara

Taiki Tominaga

Koji Munakata

Kentaro Moriyama

Taketo Moyoshi

Keiichi Ohuchi
Masae Sahara<BL11 Group>
Kenichi Funakoshi *(Leader)<BL22 Group>

Jun AbeHirotoshi Hayashida (Leader)

Shinichi Machida

Joseph Don Parker
Yoshihiro Matsumoto
Shuoyuan Zhang

Health and Safety Division
Yasuhiro Yamaguchi (Head)*: additional duties

Koji Kiriyama *Rei Ohuchi *159

MLF Operations in 2017

MLF Annual Report 2017

Utilization Promotion Division*: additional duties

Junichi Sato (Head)

Tazuko Mizusawa

Taeko Ishikawa

Tsukasa Miyazaki (Deputy Head)Toshiki Asai

Miho Kawato

Kenichi Funakoshi *(Deputy Head)

Atsuko Irie

Junko Ohta

Megumi Kawakami

Administration and Finance Division

160

Michihiko Murasawa (Head)

Rei Ohuchi

Yoshitaka Yasu

Mika Gunji

Takashi Hikita

Mutsumi Shiraishi

Sayaka Suzuki

MLF Annual Report 2017

MLF Operations in 2017

Proposals Review System, Committees and Meetings

Proposal Review System
The JAEA-KEK-CROSS Agreement of Cooperaon on the Promoon of Public Ulizaonof the Speciﬁc Neutron Beam Facilies at J-PARC (Enacted on 1 April 2011)
Director General
KEK

President
JAEA

Director
J-PARC

J-PARC
CenterPresident
CROSS

Director
CROSS

CollaboraonCommiee

Neutron Science and Technology Center(JAEA/KEK)

RegisteredInstuon(CROSS)All except Public Beamlines Public Beamlines Only

MLF Advisory
Board

Muon Instrument
Proposal Rev. Comm.

Muon Science
Proposal Rev. Comm.

Selecon
Commiee

Task Forces

All except Contract
Beamlines

Contract Beamlines
Only

All except Public
Beamlines

Public Beamlines Only

Neutron Instrument
Proposal Rev. Comm.

Contract Beamline
Evaluaon Comm.

Neutron Science
Proposal Rev. Comm.

Proposal
Evaluaon Comm.

Joint Meeng

Muon
Instrument
Proposals

Joint Meeng

Neutron Instrument
Proposals
Muon Program
Advisory Comm.

Muon Scienﬁc Proposals

Public Beamlines Only
All except Public Beamlines
JAEA Research
CROSS Development
Neutron Program
Proposal Advisory Proposal Evaluaon
Advisory
Commiee
PanelCommiee
Joint Meeng

Neutron Scienﬁc Proposals
UniﬁedAccess Point

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

161

MLF Operations in 2017

MLF Annual Report 2017

Takashi Kamiyama

High Energy Accelerator Research
Organization

Toshiya Otomo

High Energy Accelerator Research
Organization

Yasuhiro Miyake

High Energy Accelerator Research
Organization

Ryosuke KadonoHigh Energy Accelerator Research
Organization

Masatoshi Futakawa

Japan Atomic Energy Agency

Kazuya Aizawa

Japan Atomic Energy Agency

Masayasu Takeda

Japan Atomic Energy Agency

Kazuhiko Soyama

Japan Atomic Energy Agency

Kenji Nakajima

Japan Atomic Energy Agency

Yukinobu Kawakita

Japan Atomic Energy Agency

Jun-ichi Suzuki

Comprehensive Research
Organization for Science and Society

Selection Committee

Michihiro Furusaka

Hokkaido University

Jun Akimitsu

Okayama University

Toshio Yamaguchi

Fukuoka University

Taka-hisa Arima

The University of Tokyo

Yasuhiro Iye

Japan Society for Promotion of
Science

Yoshiaki Kiyanagi

Nagoya University
Naoki Kishimoto

Research Center for Strategic
Materials

Materials and Life Science Facility Advisory Board
Jun Akimitsu

Okayama University

Taka-hisa Arima

The University of Tokyo

Yoshiaki Kiyanagi

Nagoya University

Mitsuhiro Shibayama The University of Tokyo
Jun Sugiyama

Toyota Central R&D Labs., Inc.

Masaaki Sugiyama

Kyoto University

Masaki Takata

Tohoku University

Atsushi Takahara

Kyushu Universitu

Michihiro Furusaka

Hokkaido University

Toshio Yamaguchi

Fukuoka University

Hiroshi Amitsuka

Hokkaido University

Kenya Kubo

International Christian University

Toshiji Kanaya

High Energy Accelerator Research
Organization

Hideki Seto

High Energy Accelerator Research
Organization

Mitsuhiro Shibayama The University of Tokyo

162

Jun Sugiyama

Toyota Central R&D Labs., Inc.

Hiroyuki Kishimoto

Sumitomo Rubber Industries, LTD.

Masaaki Sugiyama

Kyoto University

Shinji Tsuneyuki

The University of Tokyo

Masaki Takata

Tohoku University

Atsushi Takahara

Kyushu University

MLF Annual Report 2017

MLF Operations in 2017

Neutron Advisory Committee (NAC)
NAC convened 26-27 February, 2018 at the J-PARC Research Building, TokaiGroup photo of NAC
Robert McGreevy (chair)

Neutron Advisory Committee (26-27 Feb. 2018)
Rutherford Appleton Laboratory

Bertrand Blau

Paul Scherrer Institut (PSI)

Mark Wendel

Oak Ridge National Laboratory

Yoshiaki Kiyanagi

Nagoya University

Christiane Alba-Simionesco

The Laboratoire Leon Brilloin (LLB) Sacley

Jamie Schulz

Australian Nuclear Science and Technology Organization (ANSTO)

Dimitri Argyriou

Ames Laboratory

Chang Hee Lee

Korea Atomic Energy Research InstituteMitsuhiro Shibayama

Institute for Solid State Physics, Tokyo University

Masaaki Sugiyama

Research Reactor Institute, Kyoto University

Muon Advisory Committee (MAC)
MAC convened 28 February – 1 March, 2018 at the KEK Tokai Campus, TokaiGroup photo of MAC

Muon Advisory Committee (28 Feb-1 Mar. 2018)

Francis Pratt (chair)

Rutherford Appleton Laboratory

Prokscha Thomas

The Paul Scherrer Institute

Andrew MacFarlane

The University of British Columbia

Klaus Jungmann

University of Groningen

Kenya Kubo

International Christian University

Toshiyuki Azuma

RIKEN Advanced Science InstituteYasuo Nozue

Osaka University

Jun Sugiyama

Toyota Centaral R & D Labs., Inc.

163

MLF Operations in 2017

MLF Annual Report 2017

Workshops, Conferences, Seminars and Schools in 2017
International Symposiums held by J-PARC MLF
and CROSSInternational Conference on Neutron Optics(NOP2017)
5-8 July 2017, Nara Kasugano International ForumIRAKA, Nara
International Conference on Neutron Scattering
2017 (ICNS2017)9-13 July 2017, Daejeon Convention Center, Daejeon,South Korea

Mini Symposium: The Cutting Edge of Protein
Dynamics Research
5 Sep. 2017, IBARAKI Quantum Beam Research Center,
Ibaraki
The 5th Workshop on Pulsed Neutron Imaging
26-27 Sep. 2017, Winc Aichi, Nagoya
User Group Meeting on MLF Spectrometers
DIRECTION 201716-17 Oct. 2017, IBARAKI Quantum Beam ResearchCenter, Ibaraki
Group photo of the User Group Meeting on MLF Spectrometers
DIRECTION 2017 (photo courtesy of CROSS)

Conferences held jointly by J-PARC MLF andCROSS2017 Meeting on J-PARC MLF Industrial Use
20-21 July 2017, Akihabara Convention Hall, Tokyo
Photo of the 2017 Meeting on J-PARC MLF
Industrial Use (photo courtesy of M. Hayashi)

The 20th CROSSroads Workshop“Hybrid Ribosomes – Toward New Cancer
Treatments”
28-29 Aug. 2017, IBARAKI Quantum Beam ResearchCenter and KEK Tokai Campus, Ibaraki

J-PARC Workshop: Deuterated Materials
Enhancing Neutron Science for Structure Function
Applications
19-20 Oct. 2017, IBARAKI Quantum Beam ResearchCenter, Ibaraki

Group photo of the J-PARC Workshop: Deuterated Materials
Enhancing Neutron Science for Structure Function
Applications (photo courtesy of J-PARC Center)2017 Z-Code Intermediate Level Training Course
2 Nov. 2017, LMJ Tokyo, Tokyo

Group photo of CROSSroads 20(photo courtesy of J-PARC Center)164

2nd Workshop on the Collaborative Use of Large
Research Institutions and the KEI Super Computer2017
10 Jan. 2018, IBARAKI Quantum Beam Research Center,
IbarakiMLF Annual Report 20172017 Z-Code Beginner Level Training Course
22-23 Feb. 2018, LMJ Tokyo, Tokyo

MLF Operations in 2017

Photo of the 4th Symposium on the Collaborative Use of Large
Research Institutions and the KEI Super Computer 2017
(photo courtesy of J-PARC Center)2017 Quantum Beam Science Festival (The 9th MLF
Symposium and The 35th PF Symposium)
2-4 Mar. 2018, Ibaraki Prefectural Culture Center, Mito
Group photo of the 2017 Quantum Beam Science Festival

2017 1st Workshop on Structural Biology
11 Sep. 2017, KENKYUSHA EIGO Center, Tokyo
2017 Workshop on Magnetic Materials
12 Oct. 2017, Essam Kanda Hall, Tokyo

Workshops held by KEK
Advanced Nano-Structure Analysis for SoftInterfaces using Neutron Reflectometry (BL16)
10 Sep. 2017, TKP, Tokyo
Fundamental Physics with Pulsed Cold Neutrons(BL05)
20 Oct. 2017, Nagoya University, Nagoya
Construction of the VIN ROSE (BL06)
6 Nov. 2017, KEK Tokai Campus, Ibaraki
High-Resolution Neutron Powder Diffraction
Method using SuperHRPD (BL08)
29 Nov. 2017, KEK Tsukuba Campus, Ibaraki
Analysis of Ordered/Disordered Structure in
Hydrides with a Total Scattering Technique (BL21)
19 Dec. 2017, KEK Tokai Campus, Ibaraki

2017 Workshop on Materials Science
20 Oct. 2017, FUKURACIA Yaesu, Tokyo
2017 1st Workshop on Residual Stress and Strain
26 Oct. 2017, KENKYUSHA EIGO Center, Tokyo
2017 Workshop on Non-destructive Visualization
and Analysis Methods
8 Nov. 2017, KENKYUSHA EIGO Center, Tokyo
Ibaraki Society for the Promotion of the Use of
Neutrons“2017 Meeting on Magnetic Materials”
20 Nov. 2017, Essam Kanda Hall, Tokyo
2017 Workshop on Metallographic Structure
24 Nov. 2017, Essam Kanda Hall, Tokyo
2017 Workshop on Soft Matter Neutron Scattering
27 Nov. 2017, Essam Kanda Hall, Tokyo
2017 Workshop on Neutron Science
28 Nov. 2017, Essam Kanda Hall, Tokyo

Workshops and Seminars held by CROSS andother organizations
4th Symposium on the Collaborative Use of Large
Research Institutions and the KEI Super Computer
2017
8 Sep. 2017, Akihabara UDX, Tokyo

2017 Workshop on Analytical Methods in Small
Angle Scattering
8 Dec. 2017, Essam Kanda Hall, Tokyo
2017 Workshop on Battery Materials
22 Jan. 2018, KENKYUSHA EIGO Center, Tokyo

165

MLF Operations in 2017

MLF Annual Report 20172017 Workshop on Surfaces and Interfaces
30 Jan. 2018, KENKYUSHA EIGO Center, Tokyo
2017 Workshop on Liquids and Amorphous
Materials
1 Mar. 2018, Ibaraki Prefectural Culture Center, Mito2017 2nd Workshop on Residual Stress and Strain
26 Mar. 2018, Essam Kanda Hall, Tokyo
2017 2nd Workshop on Structural Biology
29 Mar. 2018, KENKYUSHA EIGO Center, Tokyo

Schools in 2017
Hello Science from J-PARC: Looking at the World
with Neutrons
29 Sep. 2017, iVil, Tokai
The 9th AONSA Neutron School/The 2nd Neutron andMuon School
16-20 Nov. 2017, J-PARC Center and IBARAKI Quantum
Beam Research Center, IbarakindGroup photo of the 9thth AONSA Neutron School and the 2nd
Neutron and Muon School (photo courtesy of J-PARC Center)

Hello Science from J-PARC: Using Muons to Peer
into Things Big and Small
22 Dec. 2017, iVil, Tokai

166

MLF Annual Report 2017

MLF Operations in 2017

Award List
The University of Tokyo “Graduate School ofEngineering Dean Award”, “Shoji Tanaka Award(Physics Engineering Excellent Master ThesisAward)”, “President’s Award”
Versatile topological magnetic phases and emergent
transport phenomena in chiral magnets MnSi1−xGex
Y. Fujishiro (2018-03)

JAEA President Award 2017 [R & D Achievement
Prize]
Construction of DNA spectrometer and its leading
researches
K. Shibata, Y. Kawakita, H. Nakagawa, S. Kambara,
T. Yamada, M. Matsuura, and T. Tominaga (2017-11-06)

Quantum Beam Science Festa 2017 Student Award
Study on structure, hydration and stability of proteins insugar solution using WAXS and SANSS. Ajito (2018-03-03)

66th Symposium on Macromolecules Best posteraward
Dynamics of polyrotaxane glass by neutron quasielastic
scattering
M. Taniguchi (2017-10-02)

Koshiba Prize (High Energy Accelerator Science
Promotion Association)
Development and application of high multiplicity
positron detector Kalliope system
K. M. Kojima (2018-02-13)

IUMRS-ICAM 2017 Young Scientist Award GOLD
AWARD
Ion-Specific Hydration States and Interaction Potentials ofZwitterionic Poly(sulfobetain) Brushes
Y. Higaki (2017-08-30)

KEK Technical award
Transport and intensity measurement technique of
coherent Lyman alpha light realizing ultra-slow muon
generation
J. Nakamura (2017-12-26)

ACS Editor’s Choice
Effect of Charged Group Spacer Length in ZwitterionicSulfobetaines for Hydration State of Poly(sulfobetaine)
Brushes
Y. Higaki, Y. Inutsuka, T. Sakamaki, Y. Terayama,
A. Takenaka, K. Higaki, N. L. Yamada, Y. Ikemoto, and
A. Takahara (2017-07-25)

The 15th JSNS Technology Prize
Construction of High Resolution Chopper Spectrometer
HRC and implementation of Neutron Brillouin Scattering
MethodS. Ito, T. Yokoo, T. Masuda, H. Yoshizawa, Y. Endoh,
D. Kawana, R. Sugiura, T. Asami, M. Soda, S. Ibuka, andT. Hawai (2017-12-02)
The 17th JSNS Poster Prize
Dynamics of polyrotaxane glass by neutron quasielastic
scattering
M. Taniguchi (2017-12-02)
The 17th JSNS Poster Prize
Pressure-induced quantum phase transition in singlet
ground state magnet CsFeCl3
S. Hayashida, M. Hagihala, N. Kurita, H. Tanaka,
M. Matsumoto, Y. Uwatoko, S. Itoh, M. Soda, T. Hong,
O. Zaharko, and T. Masuda (2017-12-02)

Highlights of 2016 in Measurement Science andTechnology
Profile measurement of a bent neutron mirror using an
ultrahigh precision non-contact measurement systemwith an auto focus laser probe
S. Morita, J. Guo, N. L. Yamada, N. Torikai, S. Takeda,
M. Furusaka, and Y. Yamagata (2017-05-04)
Commendation for Science and Technology by the
Minister of Education, Culture, Sports, Science andTechnology, Japan in 2017
Cooperation of SPring-8 / J-PARC / K-computer andAdvanced tire developments
H. Kishimoto, T. Shiozawa, F. Kaneko, Y. Shinohara, and
Y. Masubuchi (2017-04)

167

MLF Operations in 2017

MLF Annual Report 2017

MLF Publication 2017
1

Y. Onuki, A. Hoshikawa, S. Nishino, S. Sato, and T. Ishigaki
Rietveld Texture Analysis for Metals Having Hexagonal Close-Packed
Phase by Using Time-of-Flight Neutron Diffraction at iMATERIAAdv. Eng. Mater. 20 1700227 (2017)2

P. Miao, X.H. Lin, A. Koda, S. Lee, Y. Ishikawa, S. Torii, M. Yonemura,
T. Mochiku, H. Sagayama, S. Itoh, K. Ikeda, T. Otomo, Y.X. Wang, R.
Kadono, and T. Kamiyama
Large Magnetovolume Effect Induced by Embedding Ferromagnetic
Clusters into Antiferromagnetic Matrix of Cobaltite Perovskite
Adv. Mater. 29 1605991 (2017)3

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
Inelastic and quasi-elastic neutron scattering spectrometers in
J-PARCBBA - General Subjects 1861 3651-3660 (2017)4

T. Matsuo, T. Tominaga, F. Kono, K. Shibata, and S. Fujiwara
Modulation of the picosecond dynamics of troponin by the
cardiomyopathy-causing mutation K247R of troponin T observedby quasielastic neutron scattering
BBA - Proteins and Proteomics 1865 1781-1789 (2017)5

M. Yoshimoto, R. Futamura, A. Hoshikawa, T. Ishigaki, T. Uchida,
and T. Iiyama
Unusually Stable Plastic Crystal Phase of CCl4 Confined in Graphitic
Slit-shaped Micropores from Neutron Diffraction
Chem. Lett. 46 923-925 (2017)

6

T. Yoshimura, Y. Nakatani, K. Matsuoka, K. Akutsu, and H. Iwase
Single-alkyl and multi-alkyl chain-containing amphiphilicoligomers with several sugar side chains: solution properties andnanostructural analysis of aggregates by SANS
Colloid Polym. Sci. 295 793-802 (2017)

13

A. Kimura, H. Harada, S. Nakamura, Y. Toh, M. Igashira, T.
Katabuchi, M. Mizumoto, and J. Hori
Neutron capture cross section measurements of 120Sn, 122Sn and
124Sn with the array of Ge spectrometer at the J-PARC/MLF/ANNRIEPJ Web Conf. 146 11031 (2017)14

T. Katabuchi, M. Mizumoto, M. Igashira, K. Terada, A. Kimura, S.
Nakamura, T. Nakao, O. Iwamoto, and N. Iwamoto
Measurement of the neutron capture cross section of 99Tc using
ANNRI at J-PARC
EPJ Web Conf. 146 11050 (2017)15

Y. Mizuguchi, Y. Hijikata, T. Abe, C. Moriyoshi, Y. Kuroiwa, Y. Goto,
A. Miura, S. Lee, S. Torii, T. Kamiyama, C.H. Lee, M. Ochi, and K.
Kuroki
Crystal structure, site selectivity, and electronic structure of layered
chalcogenide LaOBiPbS3
EPL 119 26002 (2017)16

Y. Ueno, M. Aoki, Y. Fukao, Y. Higashi, T. Higuchi, H. Iinuma, Y.
Ikedo, K. Ishida, T.U. Ito, M. Iwasaki, R. Kadono, O. Kamigaito,
S. Kanda, D. Kawall, N. Kawamura, A. Koda, K.M. Kojima, M.K.
Kubo, Y. Matsuda, T. Mibe, Y. Miyake, T. Mizutani, K. Nagamine, K.
Nishiyama, T. Ogitsu, R. Okubo, N. Saito, K. Sasaki, K. Shimomura, P.
Strasser, M. Sugano, M. Tajima, K.S. Tanaka, D. Tomono, H.A. Torii, E.
Torikai, A. Toyoda, K. Ueno, A. Yamamoto, and M. Yoshida
New precise measurement of muonium hyperfine structure interval
at J-PARC
Hyperfine Interactions 238 14 (2017)17

T. Hemmi, S. Harjo, H. Kajitani, T. Suwa, T. Saito, K. Aizawa, and K.
OsamuraEvaluation of Bending Strain in Nb3Sn Strands of CIC Conductor
Using Neutron Diffraction
IEEE Transactions on Applied Superconductivity 27 1-5 (2017)

7

T. Adachi, T. Kawamata, and Y. Koike
Novel electronic state and superconductivity in the electron-doped
high-Tc T’-superconductors
Condensed Matter. 2 23 (2017)
18

8

A.S. Tremsin, D. Perrodin, A.S. Losko, S.C. Vogel, T. Shinohara, K.
Oikawa, J.H. Peterson, C. Zhang, J.J. Derby, A.M. Zlokapa, G.A.
Bizarri, and E.D. Bourret
In-Situ observation of phase separation during growth of
Cs2LiLaBr6:Ce crystals using energy-resolved neutron imaging
Cryst. Growth Des. 17 6372-6381 (2017)

S.W. Park, H. Mizoguchi, H. Hiraka, K. Ikeda, T. Otomo, and H.
HosonoTransformation of the Chromium Coordination Environment in
LaCrAsO Induced by Hydride Doping: Formation of La2Cr2As2OyHx
Inorg. Chem. 56 13642-13645 (2017)

19

A. Watanabe, G. Kobayashi, N. Matsui, M. Yonemura, A. Kubota, K.
Suzuki, M. Hirayama, and R. Kanno
Ambient pressure synthesis and H-conductivity of LaSrLiH2O2
Electrochemistry 85 88-92 (2017)

S. Iimura, Y. Tomota, S. Matsuishi, R. Masuda, M. Seto, H. Hiraka, K.
Ikeda, T. Otomo, and H. Hosono
Ferrimagnetic Cage Framework in Ca12Fe10Si4O32Cl6
Inorg. Chem. 56 566-572 (2017)20

Y. Tomota, N. Sekido, S. Harjo, T. Kawasaki, and W. Gong
In situ observations of transformation behavior upon heating fora 1.5Mn-1.5Si-0.2C steel-comparison between neutron diffraction,
XRD, EBSD and dilatometry
ISIJ International 57 2237-2244 (2017)21

Y. Onuki䠈 S. Fujieda, S. Suzuki, and H. Fukutomi
Improvement of magnetostrictive properties of Fe-15mol%Ga alloy
by texture formation during high temperature uniaxial compression
deformation
ISIJ International 57 755-757 (2017)22

Y. Oba, S. Morooka, K. Ohishi, J. Suzuki, T. Tsuchiyama, and E.P.
Gilbert9

168

Measurement of the neutron capture resonances for platinum using
the Ge spectrometer and pulsed neutron beam at the J-PARC/MLF/
ANNRI
EPJ Web Conf. 146 11024 (2017)10

T. Nakao, K. Terada, A. Kimura, S. Nakamura, O. Iwamoto, H.
Harada, T. Katabuchi, M. Igashira, and J. Hori
Developments of a new data acquisition system at ANNRIEPJ Web Conf. 146 03021 (2017)11

H. Harada, O. Iwamoto, N. Iwamoto, A. Kimura, K. Terada, T.
Nakao, S. Nakamura, K. Mizuyama, and M. IgashiraResearch and development for accuracy improvement of neutron
nuclear data on minor actinides
EPJ Web Conf. 146 11001 (2017)12

K. Kino, H. Hasemi, A. Kimura, and Y. Kiyanagi

MLF Annual Report 2017

Characterization of microstructure using Bragg edge and energyresolved small-angle neutron scattering
ISSS-2017 151-154 (2017)
23

24

25

26

27

28

29

30

31

32

33

34

MLF Operations in 201735

T. Yamada, T. Takahashi, T. Tominaga, S. Takata, and H. Seto
Dynamical Behavior of Hydration Water Molecules between
Phospholipid Membranes
J. Phys. Chem. B 121 8322-8329 (2017)

H. Mizoguchi, S. Park, T. Honda, K. Ikeda, T. Otomo, and H. Hosono
Cubic Fluorite-Type CaH2 with a Small Bandgap
J. Am. Chem. Soc. 139 11317-11320 (2017)36

H. Sato, Y. Shiota, S. Morooka, Y. Todaka, N. Adachi, S. Sadamatsu,
K. Oikawa, M. Harada, S.H. Zhang, Y.H. Su, T. Kamiyama, M.
Ohnuma, M. Furusaka, T. Shinohara, and Y. Kiyanagi
Inverse pole figure mapping of bulk crystalline grains in apolycrystalline steel plate by pulsed neutron Bragg-dip transmission
imaging
J. Appl. Cryst. 50 1601-1610 (2017)

D.L. Price, O. Borodin, M.A. Gonzá lez, M. Kofu, K. Shibata, T.
Yamada, O. Yamamuro, and M.L. Saboungi
Relaxation in a Prototype Ionic Liquid: Influence of Water on the
Dynamics
J. Phys. Chem. Lett. 8 715-719 (2017)

37

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
Time-of-Flight Elastic and Inelastic Neutron Scattering Studies on
the Localized 4d Electron Layered Perovskite La5Mo4O16
J. Phys. Soc. Jpn. 86 064803 (2017)38

A. Esmaeili, T. Kamiyama, and R. Oishi-Tomiyasu
New functions and graphical user interface attached to powderindexing software CONOGRAPH
J. Appl. Cryst. 50 651 (2017)

K. Iida, M. Ishikado, Y. Nagai, H. Yoshida, A.D. Christianson, N.
Murai, K. Kawashima, Y. Yoshida, H. Eisaki, and A. Iyo
S p i n R e s o n a n ce i n t h e N e w- S t r u c t u r e -Ty p e I r o n - B a s e dSuperconductor CaKFe4As4
J. Phys. Soc. Jpn. 86 093703 (2017)39

M. Huang, Y. Toh, M. Ebihara, A. Kimura, and S. Nakamura
Development of a correction method for the time-of-flight prompt
gamma-ray analysis
J. Appl. Phys. 121 104901 (2017)

K. Tomiyasu, M. Sato, S. Koyama, T. Nojima, R. Kajimoto, S. Ji, and K.
Iwasa
Magnetic Properties of Electron-Doped LaCoO3
J. Phys. Soc. Jpn. 86 094706 (2017)40

T. Hayashi, K. Segawa, K. Sadakane, K. Fukao, and N.L. YamadaInterfacial interaction and glassy dynamics in stacked thin films ofpoly(methyl methacrylate)
J. Chem. Phys. 146 203305 (2017)

K. Kodama, K. Ikeda, S.-I. Shamoto, and T. Otomo
Alternative Equation on Magnetic Pair Distribution Function for
Quantitative Analysis
J. Phys. Soc. Jpn. 86 124708 (2017)41

Y. Doi, M. Wakeshima, K. Tezuka, Y. Shan, K. Ohoyama, S. Lee, S.
Torii, T. Kamiyama, and Y. Hinatsu
Crystal structures, magnetic properties, and DFT calculation of
B-site defected 12L-perovskites Ba2La2MW2O12 (M = Mn, Co, Ni, Zn)
J. Phys.: Condens. Matter 29 365802 (2017)42

S. Asano, K. Tsutsumi, K. Sato, and M. Fujita
Ce-substitution effects on the spin excitation spectra in
Pr1.4-xLa0.6CexCuO4+δ
J. Phys.: Conf. Ser. 807 52009 (2017)

43

K. Kamazawa and T. Moyhoshi
Possible low spin state of Fe ions in HoBaFe4O7
J. Phys.: Conf. Ser. 828 012012 (2017)

44

T. Haku, M. Soda, M. Sera, K. Kimura, J. Taylor, S. Itoh, T. Yokoo, Y.
Matsumoto, D. Yu, R.A. Mole, T. Takeuchi, S. Nakatsuji, Y. Kono, T.
Sakakibara, L.J. Chang, and T. Masuda
Neutron Scattering Study in Breathing Pyrochlore Antiferromagnet
Ba3Yb2Zn5O11
J. Phys.: Conf. Ser. 828 012018 (2017)45

K. Hiroi, T. Shinohara, H. Hayashida, J.D. Parker, K. Oikawa, M.
Harada, Y.H. Su, and T. Kai
Magnetic field imaging of a model electric motor using polarized
pulsed neutrons at J-PARC/MLF
J. Phys.: Conf. Ser. 862 012008 (2017)46

T. Ino, M. Ohkawara, K. Ohoyama, T. Yokoo, S. Itoh, Y. Nambu,
M. Fujita, H. Kira, H. Hayashida, K. Hiroi, K. Sakai, T. Oku, and K.
Kakurai
Development of a Polarized 3He Neutron Spin Filter for POLANO at
J-PARCJ. Phys.: Conf. Ser. 862 012011 (2017)

47

R. Maruyama, T. Bigault, A.R. Wildes, C.D. Dewhurst, T. Saerbeck, D.
Honecker, D. Yamazaki, K. Soyama, and P Courtois
Accessible length scale of the in-plane structure in polarized

Y. Oba, S. Morooka, K. Ohishi, J. Suzuki, S. Takata, N. Sato, R. Inoue,
T. Tsuchiyama, E.P. Gilbert, and M. Sugiyama
Energy-resolved small-angle neutron scattering from steel
J. Appl. Cryst. 50 334-339 (2017)

Y. Kawabata, B. Bradbur y, S. Kugizaki, K. Weigandt, Y.B.
Melnichenko, K. Sadakane, N.L. Yamada, H. Endo, M. Nagao, and H.
Seto
Effect of interlamellar interactions on shear induced multilamellar
vesicle formation
J. Chem. Phys. 147 034905 (2017)
Y. Onuki, A. Hoshikawa, S. Sato, T. Ishigaki, and T. Tomida
Quantitative phase fraction analysis of steel combined with texture
analysis using time-of-flight neutron diffraction
J. Mater. Sci. 52 11643-11658 (2017)
T. Matsukawa
Evaluation of Hydrogen-Bonding Distance in Organic Nonlinear
Optical Crystals for High-Output Terahertz-Wave Generation
J. Mol. Struc. 1134 835-839 (2017)
M. Hino, T. Oda, N.L. Yamada, H. Endo, H. Seto, M. Kitaguchi, M.
Harada, and Y. KawabataSupermirror neutron guide system for Neutron Resonance Spin Echo
spectrometers at a pulsed neutron source
J. Nucl. Sci. Technol. 54 1223-1232 (2017)
S. Maeda, Y. Kameda, Y. Amo, T. Usuki, K. Ikeda, T. Otomo, M.
Yanagisawa, S. Seki, N. Arai, H. Watanabe, and Y. Umebayashi
Local Structure of Li(+) in Concentrated Ethylene Carbonate
Solutions Studied by Low-Frequency Raman Scattering and Neutron
Diffraction with (6)Li/(7)Li Isotopic Substitution Methods
J. Phys. Chem. B 121 10979-10987 (2017)
T. Yamaguchi, K. Yoshida, T. Yamaguchi, Y. Kameda, K. Ikeda, and T.
Otomo
Analysis of Prepeak Structure of Concentrated Organic Lithium
Electrolyte by Means of Neutron Diffraction with Isotopic
Substitution and Molecular Dynamics Simulation
J. Phys. Chem. B 121 5355-5362 (2017)169

MLF Operations in 2017

MLF Annual Report 2017neutron off-specular and grazing-incidence small-angle scattering
measurements
J. Phys.: Conf. Ser. 862 012017 (2017)
48

49

60
T. Shinohara, K. Hiroi, Y.H. Su, T. Kai, T. Nakatani, K. Oikawa, M.
Segawa, H. Hayashida, J.D. Parker, Y. Matsumoto, S.Y. Zhang, and Y.
Kiyanagi
Polarization analysis for magnetic field imaging at RADEN in
J-PARC/MLF
J. Phys.: Conf. Ser. 862 012025 (2017)

S. Fujiwara, T. Chatake, T. Matsuo, F. Kono, T. Tominaga, K. Shibata,A. Sato-Tomita, and N. Shibayama
Ligation-Dependent Picosecond Dynamics in Human Hemoglobin
as Revealed by Quasielastic Neutron Scattering
Journal of Physical Chemistry B 121 8069-8077 (2017)61

S. Ibuka, T. Yokoo, S. Itoh, K. Kamazawa, M. Nakamura, and M.
ImaiSpin wave dispersion just above the magnetic order-order transitionin the metallic antiferromagnet Mn3Pt
J. Phys.: Conf. Ser. 868 012017 (2017)

F. Fujisaki, K. Mori, M. Yonemura, Y. Ishikawa, T. Kamiyama, T.
Otomo, E. Matsubara, and T. Fukunag
Mechanical synthesis and structural properties of the fast fluorideion conductor PbSnF4
Journal of Solid State Chemistry 253 287-293 (2017)62

Y. Sakai, J.Y. Yang, R. Yu, H. Hojo, I. Yamada, P Miao, S. Lee, S. Torii, T.
Kamiyama, M. Ležaić, G. Bihlmayer, M. Mizumaki, J. Komiyama, T.
Mizokawa, H. Yamamoto, T. Nishikubo, Y. Hattori, K. Oka, Y.Y. Yin,
J.H. Dai, W.M. Li, S. Ueda, A. Aimi, D. Mori, Y. Inaguma, Z.W. Hu, T.
Uozumi, C.Q. Jin, Y.W. Long, and M. Azuma
A Site and B Site Charge Orderings in an s−d Level Controlled
Perovskite Oxide PbCoO3
Journal of the American Chemical Society 139 4574-4581 (2017)63

Y. Seki, T. Shinohara, J.D. Parker, W. Yashiro, A. Momose, K. Kato, H.
Kato, M. Sadeghilaridjani, Y. Otake, and Y. Kiyanagi
Development of multi-colored neutron talbot–lau interferometerwith absorption grating fabricated by imprinting method of metallic
glasswith absorption grating fabricated by imprinting method of
metallic glass
Journal of the Physical Society of Japan 86 44001 (2017)

64

H. Tanoue, N.L. Yamada, K. Ito, and H. Yokoyama
Quantitative Analysis of Polymer Brush Formation Kinetics using
Quartz Crystal Microbalance: Viscoelasticity of Polymer Brush
Langmuir 33 5166-5172 (2017)

65

Y. Higaki, Y. Inutsuka, T. Sakamaki, Y. Terayama, A. Takenaka, K.
Higaki, N.L. Yamada, Y. Ikemoto, and A. Takahara
Effect of Charged Group Spacer Length on Hydration State in
Zwitterionic Poly (sulfobetaine) Brushes
Langmuir 33 8404-8412 (2017)50

M. Abe, H. Iba, K. Suzuki, H. Minamishima, M. Hirayama, K.
Tamura, J. Mizuki, T. Saito, Y. Ikuhara, and R. Kanno
Study on the deterioration mechanism of layered rock-salt
electrodes using epitaxial thin films – Li(Ni, Co, Mn)O2 and their Zr-O
surface modified electrodes
J. Power Sources 345 108-119 (2017)51

Y. Narita, Y. Takahashi, M. Harada, K. Oikawa, D. Kobayashi, K.
Hirose, H. Sato, S. Ikeda, T. Endoh, and H. Ohno
Fast neutron tolerance of the perpendicular-anisotropy CoFeB–MgO
magnetic tunnel junctions with junction diameters between 46 and64 nm
Japanese Journal of Applied Physics 56 0802B3 (2017)

52

S. Hosokawa, K. Kimura, M. Yamasaki, Y. Kawamura, K. Yoshida, M.
Inui, S. Tsutsui, A.Q.R. Baron, Y. Kawakita, and S. Itoh
Impurity effects in the microscopic elastic proper ties ofpolycrystalline Mg-Zn-Y alloys with a synchronized long-period
stacking ordered phase
Journal of Alloys and Compounds 695 426-432 (2017)53

Y. Sakaguchi, H. Asaoka, and M. Mitkova
Silver photodiffusion into Ge-rich amorphous germanium sulfide Neutron reflectivity study
Journal of Applied Physics 122 235105 (2017)54

T. Nyuui, G. Matsuba , S. Sato, K. Nagai, and A. Fujimori
Correlation between gas transport properties and the morphology/
dynamics of crystalline fluorinated copolymer membranes
Journal of Applied Polymer Science 135 45665 (2017)

66

K. Hori, N.L. Yamada, Y. Fujii, T. Masui, H. Kishimoto, and H. Seto
Structure and Mechanical Properties of Polybutadiene Thin Films
Bound to Surface-Modified Carbon Interface
Langmuir 33 8883-8890 (2017)55

K. Toh, T. Nakamura, K. Sakasai, and H. Yamagishi
Development of a bump cathode element for two-dimensional
neutron detection
Journal of Instrumentation 12 C12011 (2017)

67

H. Tanoue, M. Inutsuka, N.L. Yamada, K. Ito, and H. Yokoyama
Kinetics of Dynamic Polymer Brush Formation
Macromolecules 50 5549-5555 (2017)

68
56

T. Nakamura, K. Toh, N. Tsutsui, M. Ebine, A. Birumachi, and K.
Sakasai
Development of a position-sensitive scintillation neutron detector
for a new protein single-crystal diffractometer at J-PARC MLF
Journal of Instrumentation 12 C12025 (2017)

P.G. Xu, Y, Tomota, Y. Arakaki, S. Harjo, and H. Sueyoshi
Evaluation of austenite volume fraction in TRIP steel sheets using
neutron diffraction
Materials Characterization 127 104-110 (2017)

69

Y. Idemoto, T. Sekine, N. Ishida, and N. Kitamura
Change of local structures for 0.5Li2MnO3–0.5LiMn1/3Ni1/3Co1/3O2 in
first charge process of different rates
Journal of Materials Science 52 8630-8649 (2017)

N. Tsuchida, N. Nagahisa, and S. Harjo
Room-temperature creep tests under constant load on a TRIP-aided
multi-microstructure steel
Materials Science and Engineering: A 700 631-636 (2017)70

Y. Tomota, S. Sato, M. Uchida, P.G. Xu, S. Harjo, W. Gong, and T.
Kawasaki
Quantitative Evaluation of Texture and Dislocations during
Annealing after Hot Deformation in Austenitic Steel Using Neutron
Diffraction
Materials Science Forum 905 25-30 (2017)71

S. Harjo, T. Kawasaki, Y. Tomota, and W. Gong
Unusual Plastic Deformation Behavior in Lath Martensitic SteelContaining High Dislocation Density

57

170

cylindrical coupled hydrogen moderators
Journal of Nuclear Science and Technology 55 283-289 (2017)

58

S. Ohira-Kawamura, T. Oku, M. Watanabe, R. Takahashi, K.
Munakata, S. Takata, Y. Sakaguchi, M. Ishikado, K. Ohuchi, T.
Hattori, H. Kira, K. Sakai, T. Aso, Y. Yamauchi, and S. Isomae
Sample environment at the J-PARC MLF
Journal of Neutron Research 19 15-22 (2017)59

T. Kai, T. Kamiyama, F. Hiraga, M. Ooi, K. Hirota, and Y. Kiyanagi
Measurements of neutronic characteristics of rectangular andMLF Annual Report 2017

Materials Science Forum 905 46-51 (2017)
72

73

74

T. Ungár, S. Harjo, T. Kawasaki, Y. Tomota, G. Ribárik, and Z.M. Shi
Composite behavior of lath martensite steels induced by plasticstrain, a new paradigm for the elastic-plastic response of martensitic
steels
Metallurgical and Materials Transactions A 48 159-167 (2017)
S. Harjo, T. Kawasaki, Y. Tomota, W. Gong, K. Aizawa, G. Tichy, Z.M.
Shi, and T. Ungár
Work Hardening, Dislocation Structure, and Load Partitioning in
Lath Martensite Determined by In Situ Neutron Diffraction Line
Profile Analysis
Metallurgical and Materials Transactions A 48 4080-4092 (2017)
S. Ohisa, Y.J. Pu, N.L. Yamada, G. Matsuba, and J. Kido
Influence of solution- and thermal-annealing processes on the subnanometer-ordered organic–organic interface structure of organic
light-emitting devices
Nanoscale 9 25-30 (2017)

MLF Operations in 2017

Co2(OD)3Cl/Co2(OH)3Cl
Phys. Rev. B 95 024111 (2017)84

M. Matsuura, S. Kawamura, M. Fujita, R. Kajimoto, and K. Yamada
Development of spin-wave-like dispersive excitations below thepseudogap temperature in the high-temperature superconductor
La2-xSrxCuO4
Phys. Rev. B 95 024504 (2017)85

K. Kamazawa, M. Ishikado, S. Ohira-Kawamura, Y. Kawakita, K.
Kakurai, K. Nakajima, and M. SatoInteraction of spin-orbital-lattice degrees of freedom: Vibronic stateof the corner-sharing-tetrahedral frustrated spin system HoBaFe4O7
by dynamical Jahn-Teller effectPhys. Rev. B. 95 104413 (2017)86

P. Miao, X.H. Lin, S. Lee, Y. Ishikawa, S. Torii, M. Yonemura, T. Ueno,
N. Inami, K. Ono, Y.X. Wang, and T. Kamiyama
Hole-doping-induced melting of spin-state ordering in PrBaCo2O5.5+x
Phys. Rev. B 95 125123 (2017)75

M. Igarashi, T. Matsumoto, F. Yagihashi, H. Yamashita, T. Ohhara, T.
Hanashima, A. Nakao, T. Moyoshi, K. Sato, and S. Shimada
Non-aqueous selective synthesis of orthosilicic acid and its
oligomers
Nature Communications 8 140 (2017)87

H. Ishibashi, S. Shimono, K. Tomiyasu, S. Lee, S. Kawaguchi, H.
Iwane, H. Nakao, S. Torii, T. Kamiyama, and Y. Kubota
Small crystal distortion and long-range antiferro-orbital ordering inthe spinel oxide CoV2O4
Phys. Rev. B. 95 144424 (2017)76

R. Iizuka, T. Yagi, H. Gotou. T. Okuchi, T. Hattori, and A. SanoFurukawa
Hydrogenation of iron in the early stage of Earth's evolution
Nature Communications 8 14096 (2017)

88

S. Klotz, K. Komatsu, H. Kagi, K. Kunc, A. Sano-Furukawa, S.
Machida, and T. Hattori
Bulk moduli and equations of state of ice VII and ice VIII
Phys. Rev. B 95 174111 (2017)77

B. Li, Y. Kawakita, Y.C. Liu, M.C. Wang, M. Matsuura, K. Shibata, S.
Kawamura, T. Yamada, S.C. Lin, K. Nakajima, and S. Frank Liu
Polar rotor scattering as atomic-level origin of low mobility andthermal conductivity of perovskite CH3NH3PbI3Nature Communications 8 16086 (2017)89

K. Iwasa, Y. Otomo, K. Suyama, K. Tomiyasu, S. Ohira-Kawamura, K.
Nakajima, and J.M. Mignot
Crystalline-electric-field excitations and spin dynamics in Ce3Co4Sn13
semimetallic chiral-lattice phasePhys. Rev. B 95 195156 (2017)

78

S. Ito, N. Kurita, H. Tanaka, S. Ohira-Kawamura, K. Nakajima, S.
Itoh, K. Kuwahara, and K. Kakurai
Structure of the magnetic excitations in the spin-1/2 triangularlattice Heisenberg antiferromagnet Ba3CoSb2O9
Nature Communications 8 235 (2017)90

S. Ibuka, S. Itoh, T. Yokoo, and Y. Endoh
Damped spin-wave excitations in the itinerant antiferromagnet γ-Fe0.7Mn0.3
Phys. Rev. B. 95 224406 (2017)

91
79

S. Miyajima, H. Shishido, Y. Narukami, N. Yoshioka, A. Fujimaki, M.
Hidaka, K. Oikawa, M. Harada, T.i Oku, M. Arai, and T. Ishida
Neutron flux spectrum revealed by Nb-based current-biased kinetic
inductance detector with a 10B conversion layer
Nucl. Instrum. Meth. A, 842, 71-75 (2017)

P. Babkevich, N.E. Shaik, D. Lançon, A. Kikkawa, M. Enderle, R.A.
Ewings, H.C. Walker, D.T. Adroja, P. Manuel, D.D. Khalyavin, Y.
Taguchi, Y. Tokura, M. Soda, T. Masuda, and H.M. Rønnow
Magnetic excitations from two-dimensional interpenetrating Cu
framework in Ba2Cu3O4Cl2
Phys. Rev. B 96 014410 (2017)80

T. Hosobata, N.L. Yamada, M. Hino, Y. Yamagata, T. Kawai, H.
Yoshinaga, K. Hori, M. Takeda, S. Takeda, and S. Morita
Development of precision elliptic neutron-focusing supermirror
Opt. Express 25 20012-20024 (2017)92

M. Kofu, N. Hashimoto, H. Akiba, H. Kobayashi, H. Kitagawa, K.
Iida, M. Nakamura, and O. Yamamuro
Vibrational states of atomic hydrogen in bulk and nanocrystalline
palladium studied by neutron spectroscopy
Phys. Rev. B 96 054304 (2017)81

N. Naganawa, S. Awano, M. Hino, M. Hirose, K. Hirota, H.
Kawahara, M. Kitaguchi, K. Mishima, T. Nagae, H.M. Shimizu, S.
Tada, S. Tasaki, and A. Umemoto
Development of high spatial resolution cold/ultra- cold neutron
detector using fine-grained nuclear emulsion
Pcodeedings of Science PoS (KMI2017) 77 (2017)

93

C. Wang, D.W. Yu, X.Q. Liu, R.Y. Chen, X.Y. Du, B.Y. Hu, L.C. Wang, K.
Iida, K. Kamazawa, S. Wakimoto, J. Feng, N.L. Wang, and Y. Li
Observation of magnetoelastic effects in a quasi-one-dimensional
spiral magnet
Phys. Rev. B 96 085111 (2017)82

T.U. Ito, A. Koda, K. Shimomura, W. Higemoto, T. Matsuzaki, Y.
Kobayashi, and H. Kageyama
Excited configurations of hydrogen in the BaTiO3-xHx perovskite
lattice associated with hydrogen exchange and transport
Phys. Rev. B 95 020301(R) (2017)

94

K. Matsuura, H. Sagayama, A. Uehara, Y. Nii, R. Kajimoto, K.
Kamazawa, K. Ikeuchi, S. Ji, N. Abe, and T. Arima
Spin-Orbital Correlated Dynamics in the Spinel-Type Vanadium
Oxide MnV2O4
Phys. Rev. Lett. 119 017201 (2017)

83

X.L. Xu, D.D. Meng, X.G. Zheng, I. Yamauchi, I. Watanabe, and Q.X.
Guo
Critical slowing of quantum atomic deuterium/hydrogen withfeatures of multiferroicity in the geometrically frustrated system

95

T. Matsumoto, T. Ohhara, H. Sugimoto, S.M. Bennington, and S.
Ikeda
Quantum twin spectra in nanocrystalline silicon
Phys. Rev. Materials 1 051601 (2017)171

MLF Operations in 2017

MLF Annual Report 2017

J.N. Hendriks, A.W.T. Gregg, C.M. Wensrich, A.S. Tremsin, T.
Shinohara, M. Meylan, E.H. Kisi, V. Luzin, and O. Kirsten
Bragg-edge elastic strain tomography for in situ systems fromenergy-resolved neutron transmission imaging
Phys. Rev. Materials 1 053802 (2017)

107 D. Ito, Y. Saito, H. Sato, and T. Shinohara
Visualization of solidification process in lead-bismuth eutectic
Physics Procedia 88 58-63 (2017)

97

Y. Kousaka, T. Koyama, K. Ohishi, K. Kakurai, V. Hutanu, H.
Ohsumi, T. Arima, A. Tokuda, M. Suzuki, N. Kawamura, A. Nakao,
T. Hanashima, J. Suzuki, J. Campo, Y. Miyamoto, A. Sera, K. Inoue,and J. Akimitsu
Monochiral helimagnetism in homochiral crystals of CsCuCl3
Phys. Rev. Materials 1 071402 (2017)

108 T. Kanaya, M. Murakami, T. Maede, H. Ogawa, R. Inoue, K. Nishida,
G. Matsuba, N. Ohta, S. Takata, T. Tominaga, J. Suzuki, Y. Han, and T.
Kim
Role of molecular weight in shish-kebab formation during drawing
by small-angle neutron and X-ray scattering
Polymer J. 49 831-837 (2017)98

D.A. Pushin, D. Sarenac, D.S. Hussey, H. Miao, M. Arif, D.G. Cory,
M.G. Huber, D.L. Jacobson, J.M. LaManna, J.D. Parker, T. Shinohara,
W. Ueno, and H. Wen
Far-field interference of a neutron white beam and the applications
to noninvasive phase-contrast imaging
Physical Review A 95 043637 (2017)

109 Y. Sato on behalf of the E34 collaboration
Muon g-2/EDM experiment at J-PARC
PoS (INPC2016) 006 (2017)96

Y. Matsumoto, M. Segawa, T. Kai, T. Shinohara, T. Nakatani, K.
Oikawa, K. Hiroi, Y.H. Su, H. Hayashida, J.D. Parker, S. Zhang, and Y.
Kiyanagi
Recent progress of radiography and tomography at the energyresolved neutron imaging system RADEN
Physics Procedia 88 162-166 (2017)

110 H.M. Shimizu, W.M. Snow, V.P. Gudkov, J.D. Bowman, J. Curole, B.M.
Goodson, H. Harada, P. Hautle, M. Hino, K. Hirota, G. Ichikawa,T. Ino, S. Ishimoto, T. Iwata, A. Kimura, M. Kitaguchi, Y. Kiyanagi,
J. Koga, K. Mishima, Y. Miyachi, T. Momose, T. Morishima, K.
Nagamoto, A. Okada, T. Okudaira, S. Penttila, B. Plaster, K. Sakai, D.
Schaper, S. Takada, K. Taketani, X. Tong, A.S. Tremsin, Y. Yamagata,
T. Yamamoto, N. Yamanaka, M. Yokohashi, and T. Yoshioka
Discrete Symmetry Tests in Neutron-induced Compound States
PoS (INPC2016) INPC2016 187 (2017)

100 Y. Seki, T. Shinohara, W. Ueno, J.D. Parker, T. Samoto, W. Yashiro, A.
MomoseExperimental evaluation of neutron absorption grating fabricatedby oblique evaporation of gadolinium for phase imaging
Physics Procedia 88 217-223 (2017)

111 N. Oi, H.M. Shimizu, K. Hirota, M. Kitaguchi, C.C. Haddock, W.M.
Snow, T. Yoshioka, S. Matsumoto, K. Mishima, T. Ino, and T. Shima
Measurement of Neutron Scattering from Noble Gas to Search for
Short-range Unknown Force
PoS (INPC2016) INPC2016 188 (2017)

101 N. Naganawa, S. Awano, M. Hino, M. Hirose, K. Hirota, H.
Kawahara, M. Kitaguchi, K. Mishima, T. Nagae, H.M. Shimizu, S.
Tasaki, and A. Umemoto
A neutron detector with submicron spatial resolution using finegrained nuclear emulsion
Physics Procedia 88 224-230 (2017)

112 T. Okudaira, H.M. Shimizu, M. Kitaguchi, K. Hirota, S. Takada,T. Yamamoto, A. Okada, T. Yoshioka, T. Ino, K. Sakai, K. Asahi, T.
Momose, T. Iwata, M. Hino, T. Shima, and Y. Yamagata
Measurement of Angular Correlations in the (n,γ) Reaction for
T-violation Search
PoS (INPC2016) INPC2016 188 (2017)

102 H. Hayashida, K. Hiroi, T. Oku, H. Kira, K. Sakai, T. Shinohara, T. Kai,
J.D. Parker, Y. Matsumoto, S. Zhang, T. Ino, M. Ohkawara, and K.
Kakurai
Development of an in-situ SEOP 3He neutron spin filter for magnetic
imaging techniques
Physics Procedia 88 231-236 (2017)

113 T. Yamamoto, H.M. Shimizu, M. Kitaguchi, K. Hirota, T. Okudaira, S.
Takada, A. Okada, T. Yoshioka, T. Ino, K. Sakai, K. Asahi, T. Momose,
T. Iwata, M. Hino, T. Shima, and Y. Yamagata
Measurement of Angular Correlation of (n,gamma) Reaction with
Polarized Neutrons
PoS (KMI2017) KMI2017 049 (2017)

103 T. Kai, K. Hiroi, Y.H. Su, T. Shinohara, J.D. Parker, Y. Matsumoto, H.
Hayashida, M. Segawa, T. Nakatani, K. Oikawa, S. Zhang, and Y.
Kiyanagi
Reliability estimation of neutron resonance thermometry using
tantalum and tungsten
Physics Procedia 88 306-313 (2017)

114 N. Naganawa, S. Awano, M. Hino, M. Hirose, H. Kawahara, M.
Kitaguchi, K. Mishima, T. Nagae, H.M. Shimizu, S. Tada, S. Tasaki,
and A. Umemoto
Development of High Spatial Resolution Cold/Ultracold Neutron
Detector using Fine-grained Nuclear Emulsion
PoS (KMI2017) KMI2017 077 (2017)

104 K. Oikawa, Y.H. Su, Y. Tomota, T. Kawasaki, T. Shinohara, T. Kai, K.
Hiroi, S.Y. Zhang, J.D. Parker, H. Sato, and Y. Kiyanagi
A comparative study of the crystallite size and the dislocation
density of bent steel plates using Bragg-edge transmission imaging,
TOF neutron diffraction and EBSD
Physics Procedia 88 34-41 (2017)

115 S. Iimura, H. Okanishi, S. Matsuishi, H. Hiraka, T. Honda, K. Ikeda,
T.C. Hansen, T. Otomo, and H. Hosono
Large-moment antiferromagnetic order in overdoped high-Tc
154
superconductor SmFeAsO1-xDx
Proc. Natl. Acad. Sci. U. S. A. 114 E4354-E4359 (2017)99

105 Y.H. Su, K. Oikawa, T. Shinohara, T. Kai, K. Hiroi, S. Harjo, T.
Kawasaki, W. Gong, S.Y. Zhang, J.D. Parker, H. Hayashida, H. Sato, Y.
Kiyanagi, and Y. Tomota
Time-of-flight Neutron Transmission Imaging of Martensite
Transformation in Bent Plates of a Fe-25Ni-0.4C Alloy
Physics Procedia 88 42-49 (2017)
106 T. Kamiyama, K. Iwase, H. Sato, S. Harjo, T. Ito, S. Takata, and K.
AizawaMicrostructural Information Mapping of a Plastic-deformed α-ironPlate during Tensile Tests using Pulsed Neutron Transmission

172

Physics Procedia 88 50-57 (2017)

116 K. Hagiwara, T. Tanaka, P.K. Das, T. Yano, Y. Yamada, I. Ou, T. Mori,
T. Kayano, M.S. Reen, R. Dhir, Y. Koshio, M. Sakuda, A. Kimura, S.
Nakamura, N. Iwamoto, and H. Harada
Comparison of g production data from thermal neutron capture on
gadolinium with the Monte Carlo simulation
Proceedings of Science 294 KMI1017-035 (2017)
117 N. OI, H.M. Shimizu, K. Hirota, M. Kitaguchi, C.C. Haddock, W.M.
Snow, T. Yoshioka, S. Matsumoto, K. Mishima, T. Ino, and T. Shima
Measurement of neutron scattering from noble gas to search for ashort-range unknown force
Proceedings of the 26th International Nuclear Physics

MLF Annual Report 2017

Conference, 11-16 September, 2016, Adelaide, Australia,
Proceedings of Science KMI2017 050 (2017)
118 H. Natori, N. Teshima, M. Aoki, H. Nishiguchi, T.D. Nguyen, Y.
Takezaki, Y. Furuya, S. Ito, S. Mihara, D. Nagao, Y. Nakatsugawa, T.M.
Nguyen, Y. Seiya, K. Shimizu, and K. Yamamoto
A fast high-voltage switching multiwire proportional chamber
Prog. Theor. Exp. Phys. 2 023C01 (2017)

MLF Operations in 2017

Quasielastic Neutron Scattering Study of Microscopic Dynamics in
Polybutadiene Reinforced with an Unsaturated Carboxylate
Soft Matter 13 7862-7869 (2017)
130 V.K. Sharma, P. Mandal, S.K. Ghosh, T. Yamada, K. Shibata, S. Mitra,
and R. Mukhopadhyay
Effects of Ionic Liquids on the Nanoscopic Dynamics and Phase
Behaviour of a Phosphatidylcholine Membrane
Soft Matter 13 8969-8979 (2017)

119 W. Higemoto, R. Kadono, N. Kawamura, A. Koda, K.M. Kojima, S.
Makimura, S. Matoba, Y. Miyake, K. Shimomura, and P. Strasser
Materials and Life Science Experimental Facility at the Japan Proton
Accelerator Research Complex IV: The Muon Facility
Quantum Beam Sci. 1 11(1-24) (2017)

131 K. Mori, T. Kasai, K. Iwase, F. Fujisaki, Y. Onodera, and T. Fukunaga
Structural origin of massive improvement in Li-ion conductivity ontransition from (Li2S)5(GeS2)(P2S5) glass to Li10GeP2S12 crystal
Solid State Ionics 301 163-169 (2017)

120 M. Inutsuka, H. Tanoue, N.L. Yamada, K. Ito, and H. Yokoyama
Dynamic contact angle on a reconstructive polymer surface bysegregation
RSC Adv. 7 17202-17207 (2017)132 H. Shishido
Neutron detection using the superconducting Nb-based currentbiased kinetic inductance detector
Superconductor Science & Technology 30 094003 (2017)

121 H. Mamiya, Y. Oba, N. Terada, N. Watanabe, K. Hiroi, T. Shinohara,
and K. Oikawa
Magnetic Bragg dip and Bragg edge in neutron transmission spectraof typical spin superstructures
Scientific Reports 7 15516 (2017)

133 M.W. Hsu, Y.H. Tsai, Y. Chen, and K.S. Lin
Multifunctional nanocarrier combined with micro-RNA as a genetherapy tool
The 6th International Conference on Bio-based Polymers 269270 (2017)

122 A.S. Tremsin, J. Rakovan, T. Shinohara, W. Kockelmann, A.S. Losko,
and S.C. Vogel
Non- destructive sudy of bulk cr ystallinity and elemental
composition of natural gold single crystal samples by energyresolved neutron imaging
Scientific Reports 7 40759 (2017)

134 N.V. Mdlovu, T.W. Chang, Y.H. Tsai, Y. Chen, and K.S. Lin
Iron oxide-pluronic F127 polymer nanocomposites as carriers for
doxorubicin drug delivery system
The 6th International Conference on Bio-based Polymers 273274 (2017)

123 S. Takagi, Y. Iijima, T. Sato, H. Saitoh, K. Ikeda, T. Otomo, K. Miwa, T.
Ikeshoji, and S.I. Orimo
Formation of novel transition metal hydride complexes with
ninefold hydrogen coordination
Scientific Reports 7 44253 (2017)
124 S. Harjo, N. Tsuchida, J. Abe, and W. Gong
Martensite phase stress and the strengthening mechanism in TRIP
steel by neutron diffraction
Scientific Reports 7 15149 (2017)
125 M. Fujihala, H. Koorikawa, S. Mitsuda, K. Morita, T. Tohyama,
A. Koda, H. Okabe, K. Tomiyasu, S. Itoh, T. Yokoo, S. Ibuka, M.
Tadokoro, M. Itoh, H. Sagayama, R. Kumai, Y. Murakami, D.
Nakamura, and S. Takeyama
Possible Tomonaga-Luttinger spin liquid state in the spin-1/2
inequilateral diamond-chain compound K3Cu3AlO2(SO4)4
Scientific Reports 7 16785 (2017)
126 A. Cereser, M. Strobl, S.A. Hall, A. Steuwer, R. Kiyanagi, A.S.
Tremsin, E.B. Knudsen, T. Shinohara, P.K. Willendrup, A.B.S. Fanta,
S. Iyengar, P.M. Larsen, T. Hanashima, T. Moyoshi, P.M. Kadletz, P.
Krooß, T. Niendorf, M. Sales, W.W. Schmahl, and S. Schmidt
Time- of-Flight Three Dimensional Neutron Diffraction inTransmission Mode for Mapping Crystal Grain Structures
Scientific Reports 7 9561 (2017)
127 Y. Tomota, W. Gong, S Harjo, and T. Shinozaki
Reverse austenite transformation behavior in a tempered
martensite low-alloy steel studied using in situ neutron diffraction
Scripta Materialia 133 79-82 (2017)
128 Y.X. Wang, T. Ohnuki, Y. Tomota, S. Harjo, and T. Ohmura
Multi-scaled heterogeneous deformation behavior of pearlite steel
studied by in situ neutron diffraction
Scripta Materialia 140 45-49 (2017)
129 R. Mashita, R. Inoue, T. Tominaga, K. Shibata, H. Kishimoto, and T.
Kanaya173

Editorial Board

MLF Annual Report 2017

Editorial Board - MLF Annual Report 2017

Chief Editor

Yuhua Su

Yukinori Nagatani
Muon Science Section

Technology Development Section

Jun AbeTakashi Naoe

CROSS

Neutron Source Section

Akinori Hoshikawa

Kenichi Oikawa

Ibaraki University

Neutron Science Section

Kenji Mishima

Joseph Parker

Neutron Science Section

CROSS

Tazuko Mizusawa

Kaoru Sakasai

CROSS

Neutron Instrumentation Section

Yukiko Nagai
Technology Development Section

174

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

J-PARC ANNUAL REPORT 2017

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 18-04

J-PARC Center

Comprehensive Research Organization for Science and Society