MLF Annual Report 2015

Preface

PrefaceToshiji Kanaya

Division Head of Materials and Life Science Division, MLF
In this introduction, we will outline the J-PARC MLF activities in 2015. The user operation in 2015A started on April 19th, 2015,
with a beam power of 500 kW. However, after an incident with the target vessel on April 30th, the user program had to be halted.
To accommodate the experiments that were not conducted due to the incident, we decided to cancel the call for proposals forthe 2015B period. We investigated the cause in detail, and concluded that a part of the welded surface between two steel plates
was not completed properly during the fabrication process, which caused a crack and repetitive thermal stress during the operating period. We changed the welding method for the shroud of a spare target vessel, and replaced the target vessel with a
new one. On October 27th, the neutron production for the user program resumed with a 500-kW proton beam. However, the user
operation stopped on November 20th, due to an unexpected problem with the target vessel. It occurred inside the target shroud
and was different from what happened in April. We should note that the problems with the target did not cause any leakage ofradioactive materials.
After the trouble in November, the users insisted strongly that we resume the MLF operation, so we decided to use an alternative spare target with a mechanically robust structure but without a helium gas bubbling system that is needed for a stable
operation with a power above 300 kW. After replacing the target, on February 20th, we resumed the user operation with a beam
power of 200 kW. At the same time, the performance of the helium refrigerator of the cryogenic hydrogen circulation system forthe moderators deteriorated. Then, after a 3-week user operating period, we stopped the user operation for maintenance of therefrigerator.
We continue our efforts to improve the robustness of the target vessel by eliminating welds and/or bolts as much as possible.
On February 22nd, an international design review assessed the adequacy of the improvements in the design of the target vessel.
The operational efficiency in MLF finally reached 35.1% in 2015. The number of unique users was 628 (559 for neutron, 69
for muon), and the number of proposals for general use was 305 (268 for neutron, 37 for muon), about half of the numbers fora normal year because of the cancellation of the call for proposals in 2015B. The fraction of industrial use was 16.4% of the approved proposals.
In 2015, we conducted many activities in MLF, such as workshops and schools. From May 31st to June 3rd, the 7th workshop on
NEUtron WAVElength-dependent imaging (NEUWAVE7) was held in the Ibaraki Prefectural Culture Center in Mito. The 1st JapanKorean Joint Workshop on Polarized Neutron Reflectometry also took place at J-PARC on July 30th, 2015. From December 1st to 5th,
the joint school of the 7th AONSA Neutron School and the 3rd MLF School was held. The school included 41 young researchers andgraduate students from Japan, Korea, Australia, Indonesia, India, China, Taiwan, Malaysia, the United States, and Iran. Quantum
Beam Science Festa 2015, which included the 7th MLF Symposium and the 33rd PF Symposium, was held on March 15th and 16that Epochal Tsukuba.
The High Energy Accelerator Research Organization (KEK), the Japan Atomic Energy Agency (JAEA), and ANSTO signed anarrangement for cooperation in the field of neutron science at Manly, Sydney, on July 20th at the opening of the 2nd Asia-Oceania
Conference on Neutron Scattering. The 1st workshop for J-PARC/ANSTO MOU collaboration was held at J-PARC.
As for the Muon Science Facility (MUSE) in MLF, the Muon Section staff focused their efforts into reinvestigation of the beamline components and instruments to ensure the safety of the resuming operations of the D-, U-, and S-lines after the fire incident
in the MUSE. Finally, the MUSE was cleared for restarting the operation.
The superconducting solenoid coils (SSC) and their cooling system were partially damaged in the Great East Japan Earthquake
in 2011 and fixed to operate temporarily before the complete restoration. During the shutdown period in the summer of 2015,
the superconducting solenoid coils (SSC) on the D-line were replaced. Good news for MUSE in November 2015 were the successful delivery of the first surface muon beam to the S1 area at the end of new S-line and the generation of the first ultra-slow muonin the U-line.
We will do our best to ensure stable operations in J-PARC MLF and produce fruitful results in science and industry.

Preface

MLF Annual Report 2015

Preface

Hideaki Yokomizo

Director, CROSS-Tokai
Five years have passed since CROSS-Tokai commenced operations in support of the user program of
the Public Beamlines at Materials and Life Science Experimental Facility of J-PARC (J-PARC MLF). Pursuant
to the Provision of the “Act on the Promotion of Public Utilization of the Specific Advanced Large Research
Facilities”, under which CROSS was appointed a Registered Institution for Facilities Use Promotion, we havebeen fully 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 2015, CROSS-Tokai supported the user programs with seven fully-operational Public Beamlines: BL01
4SEASONS, BL02 DNA, BL11 PLANET, BL15 TAIKAN, BL17 SHARAKU, BL18 SENJU and BL22 RADEN. In this period,
we accomplished a 40-day 500 kW beam-power supply for user experiments. However, the user operations
were interrupted twice by cooling-water leakage from the neutron target vessel. The user operation was
resumed on February 20th using the spare target vessel. The beam-power had to be reduced to 200 kW,
though, because it had no protection from the pitting damage on the beam window.
Special programs to promote facility utilization, such as Trial Use and Elementary Strategy Initiative,
proceeded successfully in 2015. Trial Use is a program promoting the use of neutrons by first-time or novice
users from both the industrial and academic sectors. Elementary Strategy Initiative is an integrated strategic
research program of the Japanese Government that promotes the development of innovative materials
and alternative technologies in the research areas of permanent magnets, catalysis and batteries, andelectronic and structural materials. Complementary Use is a program that encourages and facilitates thecomplementary and collaborative use of pulsed neutrons (J-PARC MLF), synchrotron radiation (SPring-8) andsupercomputer (K computer).
I hope this Annual Report would serve as a useful information source for anyone wishing to know more
about the current 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 CROSS-Tokai, 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

Contents
PrefaceResearch and Development Highlights
Synthesis, Structure, and Pressure-Induced Polymerization of Li3Fe(CN)6 Accompaniedwith Enhanced Conductivity····································································································································································

2

Investigation of Microstructure by Energy-Resolved Neutron Imaging·························································································

5

Impurity Effects in the Microscopic Elastic Properties of Polycrystalline Mg-Zn-Y Alloys
with Sychronized Long-Period Stacking Order Phase·····················································································································

8

High-Temperature Neutron Diffraction Study on CaWO4-based Oxide Ion Conductor···························································· 10High Resolution Powder Neutron Diffraction Unravels Magnetic Structure and Phase Transition Mechanism
in MnO, CoO, and NiO················································································································································································· 13
Silver Photo-Diffusion into Amorphous Ge-Chalcogenide Films: in situ Neutron Reflectivity Measurement·················· 16
Operando Measurement of Solid Electrolyte Interphase Formation at Working Electrode of Li-ion Battery
by Time-slicing Neutron Reflectometry··············································································································································· 18
Unusual Dynamics of α-synuclein Amyloid Fibrils Detected by Quasielastic Neutron Scattering······································· 21
Uniaxial-Stress Control of Skyrmion Phase in MnSi································································································································ 23
Weyl Fermion in Spin Dynamics of SrRuO3················································································································································ 25
Characterization of Ferromagnetic Order in CePd2P2···························································································································· 27
Magnetic Excitations in Antiferromagnetic Alternating Spin-3/2 Chain Compounds RCrGeO5············································ 30
Coherent Spin-Wave Excitations in a Correlated Metallic Antiferromagnet·················································································· 32
Magnetoelectric Coupling in the Honeycomb Antiferromagnet Co4Nb2O9·················································································· 34
Spin Excitations in Hole-Overdoped Iron-Based Superconductivity······························································································· 36
Tetra-Ortho-Tetra Type Phase Transitions and Inhomogeneous Magnetism in Sr2VO4····························································· 38
Lattice Dynamics and Crystal Fields in the Rare Earth Pyrochlores R2Ti2O7 (R = Tb, Dy, Ho)···················································· 40
Neutron Diffraction up to 41.2 T- the New Record Established at the J-PARC NOBORU Beamline······································· 42
Measurement of Neutron Capture Cross Section of 99Tc······················································································································ 44
Measurement of Low-Energy Positive Muons from Metal Foil··········································································································· 46
Neutron Phase Imaging with Absorption Grating Fabricated by Imprinting Gd-Based Metallic Glass······························· 48

Neutron Source
Progress of the Neutron Source Section····················································································································································· 52
Failure Cause Investigations and Design Improvements of the Mercury Target Vessel···························································· 54
The Status of the Cryogenic Hydrogen System······································································································································· 57
Present Status of the Spare Moderator and the Reflector Fabrication···························································································· 59
Modification of the Integral Control System for Sustainable Upgrade of Instruments····························································· 61

Neutron Science
Neutron Science Section·················································································································································································· 64
BL01: 4D-Space Access Neutron Spectrometer 4SEASONS····················································································································· 67
BL02: Current Status of the Broadband Micro-eV Quasielastic and Inelastic Neutron Spectrometer DNA······················· 69
Current Status of IBARAKI Biological Crystal Diffractometer iBIX······································································································ 71
Current Status of Accurate Neutron-Nucleus Reaction Measurement Instruments, ANNRI (BL04)······································ 73
Present Status of BL05 (NOP)·········································································································································································· 75
BL06: Commissioning Status of VIllage of Neutron ResOnance Spin Echo Spectrometers (VIN ROSE)······························· 77
Current Status of the Super High Resolution Powder Diffractometer, SuperHRPD···································································· 79
Battery Studies on the Special Environment Neutron Powder Diffractometer using Operando Techniques··················· 81
BL10: NOBORU····································································································································································································· 83
Recent Developments in BL11 PLANET······················································································································································ 84
High Resolution Chopper Spectrometer at BL12···································································································································· 86
BL14 AMATERAS·································································································································································································· 88
Upgrading TAIKAN······························································································································································································ 90
Sample Changers for High-Throughput Measurement at the SOFIA Reflectometer································································· 91
BL17: Polarized Neutron Reflectometer SHARAKU using 2-D MWPC with Indivisual Readout System······························ 93
SENJU 2015············································································································································································································ 95
Engineering Sciences in TAKUMI··································································································································································· 97
The Current Status of the Versatile Neutron Diffractometer, iMATERIA·························································································· 99
Status of the High Intensity Total Diffractometer (BL21, NOVA)········································································································ 101
Current Status of the Energy-Resolved Neutron Imaging System “RADEN”·················································································· 102
Status of Polarized Neutron Spectrometer POLANO (BL23)·····························································································································104
Magnetic Devices and Environment for Polarization Experiments at POLANO··········································································· 106
Development of an in-situ Polarized 3He Neutron Spin Filter in POLANO······················································································ 109
Development of Choppers in POLANO······················································································································································· 111
Sample Environment at MLF··········································································································································································· 113
Progress of Data Analysis Software······························································································································································ 115
High-Pressure Operation of Two-Dimensional Gaseous Neutron Detector·················································································· 118
Accessible Length Scale of the In-Plane Structure in Polarized Neutron Off-Specular Scattering Measurement··········· 119

Muon Scinece
Status of J-PARC MUSE······················································································································································································ 122
Muon Target System - Renovation of a Scraper Unit······························································································································ 124
Development of a Kicker System and Safety Measures for the Septum Power Supply at D-Line········································· 126
The Status of U-Line··························································································································································································· 129
Commissioning of the Muon S-Line and the General Purpose µSR Spectrometer ARTEMIS·················································· 132
Present Status of the H-line············································································································································································· 134

MLF Safety
Research Safety···································································································································································································· 138

MLF Operations in 2015
Beam Operation Status at MLF······································································································································································· 142
Users at the MLF·································································································································································································· 143
MLF Proposals Summary – FY2015······························································································································································· 144
MLF Division Staff 2015····················································································································································································· 146
CROSS-Tokai Staff 2015····················································································································································································· 149
Proposals Review System, Committees and Meetings·························································································································· 151
Workshops, Conferences, Seminars and Schools in 2015···················································································································· 154
Award List·············································································································································································································· 157
MLF Publication 2015························································································································································································ 158
Editorial Board - MLF Annual Report 2015················································································································································· 165

Organization Chart

MLF Annual Report 2015

Organization Chart

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

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

President
CROSS Head Office

Accelerator Division

Research center for
Science and Society

Materials & Life Science Division

Director,
CROSS-Tokai

Neutron Source Sec on

Science Coordinators

Neutron Science Sec on

Safety Division

Neutron Instrumenta on
Sec onAdministra on Division

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

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

Users Office

The Role of CROSS‐Tokai
Under the terms of the legislation that supports the
Public Neutron Beam Facility, CROSS‐Tokai is entrustedwith specific responsibilities. In practical terms, the corefunctions of CROSSTokai 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 2015

J-PARC Map
CROSS – Tokai(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 Center

J-PARC Map

As of March 2016

1m

MLF Annual Report 2015

400ｍm

25 m

BL22 RADEN

Muon and Neutron Instruments

Research and Development
Highlights

Research and Development Highlights

MLF Annual Report 2015

Synthesis, Structure, and Pressure-Induced Polymerizationof Li3Fe(CN)6 Accompanied with Enhanced Conductivity
1. Introduction
Pressure-induced polymerization (PIP) of alkynes
and nitriles produces polymers with conjugated double
bonds, which is a novel method to synthesize electricalconductive materials [1]. Metal-carbon network can bebuilt using this method, with functional components,
like metallic cations, embedded in the conductive matrix. However, the required pressure for polymerizationof most metal cyanides and acetylides is usually tensof gigapascals [1b, 2, 3], which is too high for industrial
processes. Thus, it is important to investigate the mechanism of the PIP and find low-pressure reaction routes
leading to the formation of these promising materials.
A promising method is to use smaller cations todecrease the distance between the monomers. In thiswork, by using Li+, we successfully compressed the cyanide ions to react at around 1 GPa and polymerize irreversibly above 5 GPa. Our crystallographic investigationsuggests that the PIP of Li3Fe(CN)6 starts from the dimerization inside Fe(CN)63-. This reaction can be realized on
an industrial scale, and is a practical and potentiallyscalable synthetic approach to prepare carbon-based
functional conductors.
2. Experimental section
Li3Fe(CN)6 was synthesized by the reaction between
Ag3Fe(CN)6 and LiCl in aqueous solution. The yellow
product [Li3Fe(CN)6·2H2O] crystallized from the solution
was heated at ~130°C in a glovebox to obtain the anhydrous Li3Fe(CN)6. 7Li and deuterated water were usedin the synthesis of the sample for neutron experiments.
X-ray diffraction patterns of Li3Fe(CN)6 were collected ona lab X-ray diffractometer (XRD) with a Bragg-Brentano
geometry. Neutron diffraction patterns at ambient pressure were collected in a sealed vanadium can at beamline 3 (SNAP), Spallation Neutron Source, Oak Ridge
National Lab (ORNL), and beamline 11 (PLANET) [4],Material and Life Science Experimental Facility, Japan
Proton Accelerator Research Complex (J-PARC). In situ
high-pressure neutron diffraction data were collectedon the 6-axis press [5] at PLANET, J-PARC. The Raman
data were collected on a laboratory-made spectrometer equipped with a second-harmonic Nd:YAG laser(operating at 532 nm) in a backscattering geometry for
excitation and signal collection. In situ high-pressure
XRD data were collected at 16-ID-B at Advanced Photon
Source (APS), Argonne National Laboratory. In situ impedance spectroscopy was performed on an alternating current impedance spectroscopy system basedon Zahner analyzer IM6 at the Center for Nanophase
Materials Sciences, ORNL. The recovered polymerized Li3Fe(CN)6 was obtained by using the VX3 Paris−
Edinburgh (PE) cell with sintered diamond anvils at
SNAP [6], with precalibrated pressure. The samples areloaded in 2 mm quartz capillaries for the neutron total
scattering experiment at Nanoscale Ordered Materials
Diffractometer (NOMAD), SNS [7]. Data presented werereduced by the autoreduction program of NOMAD with
Qmax = 31.4 Å−1 and convoluted by Lorch function.
3. Determination of Crystal Structure
The crystal structures of Li3Fe(CN)6 were determined
ab initio by X-ray and neutron diffraction. The structural model of Li3Fe(CN)6 is shown in Fig. 1. Fe(CN)63- inFigure 1.	Crystal structure of Li3Fe(CN)6, viewed along (a) approximately [001] and (b) [100]. The brown octahedron stands forFe(CN)63-and the purple atom stands for Li+; C and N are omitted for clarity.

2

MLF Annual Report 2015

Li3Fe(CN)6 forms close-packed layers arranged approximately perpendicularly to one another. Li+ are locatedmainly between the Fe(CN)63- layers and are too small
to completely separate Fe(CN)63-. The nearest N-N distance between neighbored Fe(CN)63- in Li3Fe(CN)6 isaround 3.2 Å, approximately the sum of van der Waals
radii of nitrogen atom (3.1 Å) [8]. This indicates that in
Li3Fe(CN)6 the N atoms of the neighboring Fe(CN)63- arealmost touching each other directly. This short distance
between Fe(CN)63- groups will facilitate significantly theinter group addition reactions.
4. Structural Transition under High Pressure
The crystal structure of Li3Fe(CN)6 under externalpressure was studied by in situ neutron diffraction, andthe structure model is shown in Fig. 2. The Fe(CN)63complex anions are severely distorted, while theirstacking remains nearly unchanged. This suggests that
the Fe-C-N and the C-Fe-C connections are the easiest
to be distorted against the electrostatic repulsion between Fe(CN)63-. The distortion may promote reaction
between the neighboring cyanide ions that coordinate
to the same Fe3+, as reported in our previous K3Fe(CN)6
paper [9].
To study the phase transitions above 1 GPa, an insitu synchrotron XRD experiment was performed withneon as the pressure medium. During the experiment,
three phase transitions have been found at around 1,
5, and 10 GPa. The features of the XRD patterns were
almost the same through these transitions, whichsuggests the crystal structure was not reconstructed,
and the transitions were most likely induced by local
reactions.

Research and Development Highlights

5. Reaction between Cyanides
The phase transitions are attributed to the reaction
between cyanide anions, which can be identified by
Raman spectroscopy. The intensity of the CN stretching mode, ν(CN), decreases above 1 GPa and remains
unchanged up to 5 GPa, above which it disappears inthe background. These two phase transitions are consistent with the transitions uncovered by diffraction
experiments. The weakening of the ν(CN) peak above
1 GPa may be attributed to the reaction between two
CN groups that coordinate to the same Fe(III), as suggested in the neutron diffraction results.
Strong evidence supporting the reaction between
CN- comes from neutron PDF analysis. G(r) patterns of
Li3Fe(CN)6 recovered from high pressure are shown in
Fig. 3. The peak at 1.1 Å corresponds to the C-N triple
bond (Fig. 3a). Its intensity decreases above 5 GPa withincreasing pressure up to above 10 GPa. A shoulder inthe range 1.3−1.5 Å rises simultaneously, which corresponds to the formation of conjugated C=N bonds.
Conjugated C=N bonds are also evidenced by the peakrising at around 2.4 Å. This is the distance between theatom and its next nearest neighbors in the sp2-conjugated chain with bond angles α = 120° (Fig. 3b). Thisevidence clearly verifies that the cyanide anions reactwith each other and the reaction is partially irreversible.
The conductivity of Li3Fe(CN)6 was enhanced by
3 fold when external pressure was applied. This is~10
caused mainly by the approaching and bonding between the cyanide anions. The conductivity reaches alocal maximum at around 5 GPa, which is attributed tothe beginning of the second phase transition.

Figure 2.	Crystal structure of Li3Fe(CN)6 at 0.8 GPa, viewed along (a) approximately [001] and (b) [100]. Brown, black, blue, and purple
atoms represent Fe, C, N, and Li, respectively.

3

Research and Development Highlights

MLF Annual Report 2015

Figure 3.	Neutron PDF patterns [G(r)] of Li3Fe(CN)6 recovered from high pressure. PDF plots with (a) r = 0.9−1.7 Å and (b) r = 1.9−2.9 Å
are shown.

6. conclusion
In conclusion, we designed and synthesized anhydrous Li3Fe(CN)6, determined its crystal structure using neutron diffraction techniques, and investigatedits PIP and phase behavior under external pressure up
to ~20 GPa. The crystal structure of Li3Fe(CN)6 under
external pressure was determined. Fe(CN)63- is highly
distorted and two of the cyano groups coordinatingon the same Fe(III) cation are expected to get bonded
to each other. The PIP of the cyano groups is irreversible when they are compressed to above 5 GPa and isbelieved to be responsible for the enhancement of the
conductivity.
Adapted with permission from ref 10. Copyright2015 American Chemical Society.
References[1] (a) Aoki, K.; Kakudate, Y.; et al., Synth. Met. 1989, 28,
D91-D98.
(b) Li, Y. L.; Luo, W.; et al., Natl. Acad. Sci. U. S.A. 2013,110, 9289-9294.

[2] Nylen, J.; Konar, S.; et al., J. Chem. Phys. 2012, 137,
No. 224507.
[3] (a) Kulkarni, A.; Doll, K.; et al., J. Phys. Chem.B 2010,
114, 15573-15581.
(b) Heckathorn, J. W.; Kruger, M. B.; et al., Phys. Rev.
B: Condens. Matter Mater. Phys. 1999,60, 979-983.
(c) Chen, X. Q.; Fu, C. L.; Franchini, C. J. Phys.:Condens.
Matter 2010, 22, No. 292201.
[4] Hattori, T.; Sano-Furukawa, A.; et al., Nucl. Instrum.
Methods Phys. Res., Sect.A 2015, 780, 55-67.
[5] Sano-Furukawa, A.; Hattori, T.; et al., Rev. Sci.
Instrum. 2014,85, No. 113905.
[6] Klotz, S.; Hamel, G.; Frelat, J. High Pressure Res.
2004, 24, 219-223.
[7] Neuefeind, J.; Feygenson, M.; et al., K. Nucl. Instrum.
Methods Phys. Res., Sect. B 2012, 287, 68-75.
[8] Bondi, A. J. Phys. Chem. 1964, 68, 441-451.
[9] Li, K.; Zheng, H.; et al., J. Phys. Chem. C 2015,119,22351-22356.
[10] Li, K.; Zheng, H.; et al., Inorg. Chem. 2015, 54,
11276-11282.

K. Li1,2, H. Zheng1,2, T. Hattori3, A. Sano-Furukawa3, C. A. Tulk4, J. Molaison4, M. Feygenson4, I. N. Ivanov5, W. Yang1,6, H. Mao1,2,
and J. Huang1
1Center for High Pressure Science and Technology Advanced Research; 2Geophysical Laboratory, Carnegie Institution of Washington; 3Japan
Proton Accelerator Research Complex Center, Japan Atomic Energy Agency; 4Spallation Neutron Source and 5Center for Nanophase Materials
Sciences, Oak Ridge National Laboratory; 6HPSynC, Geophysical Laboratory, Carnegie Institution of Washington

4MLF Annual Report 2015

Research and Development Highlights

Investigation of Microstructure by Energy-Resolved
Neutron Imaging
1. Introduction
Recent developments of high resolution energyresolved neutron imaging, enabled by the brightpulsed neutron beamlines (e.g. Noboru and Raden at
J-PARC, IMAT at ISIS, FP5 at Los Alamos, VENUS andODIN to be built at SNS and ESS, respectively) and fastneutron counting detectors (e.g. MCP/Timepix devices [1, 2]) provide unique opportunity to study microstructure within relatively thick metal samples in cases
where they cannot be studied by conventional X-ray
diffraction techniques. Indeed, cutting metal samples
to thin slices, which is required for X-ray studies dueto the opacity of metals, often affects the microstructure of the sample (e.g. releases residual strains [3, 4]).
Neutrons can still interrogate thick metal samples. Theenergy-resolved imaging, a complementary method
to neutron diffraction (which is a well-establishedtechnique nowadays), accomplishes this task by providing the entire map of some microstructure parameters with spatial resolution of ~100 µm, all from one
measurement. The deficiency of transmission imaging
should be pointed out here: only the integral characteristics through the sample thickness are obtained bythis technique. However, in some cases that averaged
information is sufficient, as demonstrated by the studies of weld cross sections and other samples reported
previously [5-8].
2. Experimental setup
There are several methods of energy-resolved neutron imaging currently available, with energy resolution
provided by some type of energy selection technique(e.g. velocity selector or double crystal monochromator used at continuous sources) or by neutron time offlight technique (TOF) by either chopping the beam bychoppers or by taking advantage of the pulsed natureof spallation neutron sources. The energy resolution
DE/E of velocity selectors and crystal monochromators
are typically on the scale of 15% and 3%, respectively,
and multiple measurements, scanning through various energies, are required. The time of flight method
has been demonstrated to reach energy resolution
better than ~0.1% at spallation sources, enabling various unique studies, where all energies are measured
at the same time, in one experiment. The challenge ofenergy-resolved imaging with the TOF technique lies in

the requirement to detect both position and time forevery registered neutron with fluxes exceeding now
107 n/cm2/s. Such high fluxes are necessary for highresolution imaging studies, where multiple transmission spectra are measured within areas as small as 55
× 55 µm2 [1, 2, 6-9], with as many as >250000 spectra
measured at the same time.
Various neutron detection technologies were developed for energy-resolved neutron imaging over the
past decade, each having its advantages and disadvantages (e.g. large active area, but low count rate capability, and vice versa). Unfortunately, there is no one
device yet, which can meet all the requirements andcompromises are always necessary in conducting eachexperiment.
In this study, a detector with Microchannel Plates
and Timepix readout [1, 2] was installed at the Noboru(BL10) beamline facility in the direct beam at ~14 mfrom the neutron source. That detector allows for simultaneous acquisition of spectra in each 55 × 55 µm2
pixel within the area of 28 × 28 mm2 with time resolution as high as ~20 ns for epithermal neutrons and~0.5 µs for thermal and cold neutrons. Neutron transmission spectra in a wide range of energies, spanningfrom ~30 keV to 1 meV, can be acquired by such a detector, allowing studies of crystallographic properties
through Bragg scattering analysis in the thermal andcold ranges of energies, simultaneously with imagingof elemental composition and temperature throughneutron resonance absorption, as demonstrated previously [6, 9, 10]. No T0 chopper was used in our experiments. The detector was synchronized with the T0
pulse from the source, measuring the time of arrival foreach detected neutron relative to that trigger. Multiple
acquisition shutters, separated by readout gaps of~320 µs, were acquired for each neutron pulse in orderto prevent event saturation in a single frame. This readout deadtime resulted in the presence of small gaps
seen in the measured transmission spectra shown in
Fig. 1.
In this report, only the measurement of microstructure within polycrystalline metal samples is described
and the studies of microstructure within single crystal
materials and mapping of elemental composition andtemperature will be reported later elsewhere.
5Research and Development Highlights

MLF Annual Report 2015

0.6

0.6
Al weld area
Al rolled plate
Steel

331

0.4

311
222

200
220

0.3
0.2
211

0.1
0

2

0.3
0.2

220
311

3

4

0.1

(a)

111
5

Wavelength (A)

6

111

200

Ni n1
Ni n2
Ni s.cNi s.c. 30 deg

0.4

200
110

1

311

0.5
Transmission

Transmission

0.5

0

010
111
2-20

1

2

1-10

111
200
3

(b)

200
4

5

6

Wavelength (A)Figure 1.	Neutron transmission spectra measured at BL10 for various polycrystalline metal samples, Fig. 1.a (~1 cm steel, ~10 cm Al
and ~0.5 cm nickel) as well as single-crystal Ni alloy, Fig. 1.b (~0.5 cm). Each spectrum is obtained for a ~5 x 5 mm2 area,
although transmission spectrum (much noisier, only due to limited acquisition time) was measured for each 55 x 55 µm2
pixel. The variation of transmission spectra between different areas of the same sample can be used for the reconstructionof microstructure parameters (e.g. residual strain as demonstrated in Fig. 2).

3. Results
The flight path length and trigger delay, required
for the conversion of neutron time of flight to energy,
were first calibrated with resonance absorption spectrum measured for an Indium-based alloy. Each image
and each spectrum measured for samples were normalized by the “open beam” spectrum and images, whichwere obtained with no samples present in the beam.
The acquisition time for the results reported here wason the scale of 1-2 hours.
The microstructure within relatively thick metal
samples can be studied due to the presence of a sharp
variation of neutron transmission at certain wavelengths, characteristic to a particular material, which isoften referred to as Bragg edges (similar to Bragg peaks
observed in the diffraction spectrum). The wavelengthand the shape of these Bragg edges can be used for thereconstruction of certain microstructure parameters:for example, the residual strain within the sample canbe reconstructed from the variation of wavelengthof a particular Bragg, measured at different areas ofthe sample (up to a limit of a 55-µm pixel, providing
sufficient statistics are acquired for the transmission
spectra within each pixel); some texture-related variations of the microstructure within the sample can bereconstructed from the variation of edge shape and thespectrum between the edges; quantification of the different phases within the sample can be obtained fromthe height of respective Bragg edges, etc. Ideally, a full
spectrum analysis, such as Rietveld refinement [11],should provide the most accurate and diverse information on the microstructure within the samples. However,the challenge of energy-resolved imaging is in the factthat such refinement has to be performed >105 times
in order to provide the maps of microstructure distribution across the sample, which is not implemented
6in the present study. Instead, a fitting to a single Bragg
edge is used here to recover the variation of residualstrain within a weld sample. The images acquired within a narrow range of neutron energies (around specific
Bragg edges) were employed in our study to visualize
some microstructure variations within weld samples.
Typical spectra, measured for steel and Al samples,
are shown in Fig. 1.a. A large difference in the measured spectra of the Al weld sample is observed for theareas within the weld (where friction stir welding produced material with small grains free of strong texture)
and within the adjacent rolled plate area, exhibiting astrong texture variation through the sample thickness.
Such transmission spectra are obtained in each pixelof our detector in one measurement, although the statistical variation of single pixel spectra is much larger
compared to the curves shown for a ~5 × 5 mm2 areain Fig. 1. That is why an accurate curve fitting for eachsmall area of the sample is very important for the analysis of our data. The spectra of Fig. 1 also demonstratethat residual strain and some other microstructure
parameters can be reconstructed for the assemblies,
where these materials overlap (e.g. as performed in reference [8]). Indeed, the fact that Bragg edges occur atdifferent wavelength allows analysis of certain parts of
the assembly separately from the surrounding material
if Bragg edges do not overlap in wavelengths.
A similar variation of transmission spectra due tothe presence of texture within Ni samples is observedin Fig. 1.b, especially between (200) and (111) edges.
This Figure also demonstrates the large difference intransmission spectra measured for a polycrystalline
material versus single crystal samples of the same material, where dips instead of edges are observed in the
spectra. These dips can be used for the quantification of
crystal orientation (single grain orientation in case theMLF Annual Report 2015

(a)

(b)

Research and Development Highlights(c)Figure 2.	(a) Full spectrum neutron transmission image of a weld between two steel plates with a different filler material. (b) Sameweld imaged at a narrow energy range around (110) Bragg edge. Heat affected zone in the welded plates is observedwith a higher contrast compared to a white spectrum image (a). (c) The map of the residual strain reconstructed from(110) Bragg edge measured within each pixel of our dataset. An accurate fitting of a 5-parameter analytic function allows
reconstruction of residual strain with sub-mm spatial resolution, across the entire sample measured in one experiment.
The color legend represents the strain values measured in microstrain.

grains are large enough [12]), crystal mosaicity [13] andpossibly strains within single crystal samples.
The residual strain within a steel weld sample,
reconstructed from the measured transmission, isshown in Fig. 2, together with two transmission images, revealing some microstructure variations formed
within the weld area. The location of the filler material
is clearly seen in these transmission images, since thefiller material in that weld had a different neutron attenuation coefficient due to changed composition. The
heat-affected zone is also clearly seen in these images.
However, in friction stir welds with the same materials
present everywhere in the sample, no contrast can beobserved in a white spectrum image [7], while energy
resolved imaging helps to visualize the bulk variationof microstructure within the welds and other samples,
which can be complementary to many other well established characterization techniques.
4. Future Plans
We plan to continue working on the neutron detection technology optimized specifically for highresolution energy-resolved imaging. Multiple detector
characteristics and the reconstruction of sample parameters can still be improved by optimization of existing detector hardware, firmware and data acquisitionand data analysis software. Some new event-encoding
electronics with event-driven Timepix3 readout may bevery useful for such experiments, as no readout gaps
will exist in the measured spectra. We also hope to increase the active area of the detector by tiling up larger
arrays of these chips.

References[1] A. S. Tremsin: Neutron News 23 35-38 (2012).
[2] A. S. Tremsin, J. V. Vallerga, J. B. McPhate, O. H. W.
Siegmund: Nucl, Instr. Meth., A787 20-25 (2015).
[3] J. Altenkirch, A. Steuwer, M. Peel, D.G. Richards, P. J.
Withers: Materials Science and Engineering, A488
16-24 (2008).
[4] J. Altenkirch, A. Steuwer, M. J. Peel, P. J. Withers:
Powder Diffraction Suppl. 24 S1 S31-S36 (2009).
[5] J. R. Santisteban, L. Edwards, M. E. Fizpatrick, A.
Steuwer, P. J. Withers: Appl. Phys., A74 S1433–
S1436 (2002).
[6] A. S. Tremsin, S. Ganguly, S. Meco, G. R. Pardal, T.
Shinohara, W. B. Feller: J. Appl. Crystallography, 491130-1140 (2016).
[7] A. S. Tremsin, W. Kockelmann, Shu-Yan Zhang, A.
M. Korsunsky, T. Shinohara, E. H. Lehmann: J. Phys.:Conference Series, 746 012040 (2016).
[8] A. S. Tremsin, T. Y. Yau, W. Kockelmann, “Nondestructive examination of loads in regular andself-locking Spiralock® threads through energyresolved neutron imaging”, in print, Strain, 2016.
[9] A. S. Tremsin, T. Shinohara, T. Kai, M. Ooi, T.
Kamiyama, Y. Kiyanagi, Y. Shiota, J. B. McPhate, J. V.
Vallerga, O. H. W. Siegmund, W. B. Feller: Nucl, Instr.
Meth., A746 47-58 (2014).
[10] A. S. Tremsin, W. Kockelmann, D. E. Pooley, W. B.
Feller: Nucl, Instr. Meth., A803 15-23 (2015).
[11] H. M. Rietveld, J. Appl. Cryst., 2 65 (1969).
[12] W. Ludwig, S. Schmidt, E. M. Lauridsen, HF Poulsen:
J. App. Crystal., 41 302-309 (2008).
[13] F. Malamud and J. R. Santisteban; J. Appl. Cryst., 49
348–365 (2016).

A. S. Tremsin1, S. Ganguly2, T. Shinohara3, and K. Oikawa3
University of California at Berkeley; 2Cranfield University; 3Japan Atomic Energy Agency

1

7Research and Development Highlights

MLF Annual Report 2015

Impurity Effects in the Microscopic Elastic Properties of
Polycrystalline Mg-Zn-Y Alloys with Sychronized LongPeriod Stacking Order Phase
1. Introduction
In recent years, novel Mg-based alloys containing
Zn and rare earth metal impurities have attracted muchattention owing to their potential for widespread applications as light-weighted structure materials [1]. In
contrast to pure Mg, the new Mg alloys exhibit nonflammable nature and high thermal stability.
To clarify the origin of these remarkable properties,
extensive studies on the microscopic structure of the
Mg alloys were performed using electron microscopeand diffraction techniques [2], and it was found that along period stacking ordered (LPSO) phase was formed.
According to an atomic-resolution Z-contrast imaging
of transmission electron microscope measurements [3]shown in Fig. 1, it was found that the Zn/Y impurities areenriched around the stacking faults as clusters. Egusa etal. [4] proposed a structural model of L12 clusters basedon an ab initio molecular dynamics simulation.
Inelastic scattering is a powerful tool to prove themicroscopic elastic properties in materials. We carriedout a complementary study of inelastic neutron and
X-ray scattering (INS and IXS) to clarify the impurity effects in the elastic properties on the excellent Mg LPSO
alloys [5].

Figure 1.	A TEM image of Mg86Zn6Y9 alloy with the LPSO
phase. Taken from [4].

2. Experimental procedure
The INS experiment was performed on the Mg97Zn1Y2
polycrystal using the HRC spectrometer [6], installed
at BL12/MLF/J-PARC. The incident neutron energy waschosen to be 200 meV, resulting in the energy resolution
8of about 6 meV. The Q resolution was set to be ±0.5 nm-1.
The measured Q-ω ranges were 1-11 nm-1 and ±40 meV,
respectively, mostly limited to a triangle region due tothe Q-ω relations of neutrons. The rod sample size was
29 mmf × 70 mm. A background measurement was carried out in the same experimental conditions, and an extremely low level of background was observed.
3. Results and discussion
The circles in Fig. 2 show the logarithmic plots of
the INS spectra of Mg97Zn1Y2 polycrystal at Q = 4.0, 6.0,
and 8.0 nm-1. The dashed curve indicates the resolution function of the present INS spectrometer. The
upward and downward arrows, and the bar indicate
longitudinal acoustic (LA), transverse acoustic (TA), andoptic modes assigned by the IXS data of pure Mg and
Mg97Zn1Y2 polycrystals.
The triangles exhibit the IXS spectrum at 7.9 nm-1
for comparison with the INS data at Q = 8.0 nm-1, which
was broadened to make the width of the quasielastic
peak coincide with the INS data. Distinct differences
can be clearly realized in the peak magnitudes between
the INS and IXS data. Namely, the LA mode, indicatedby the upward arrow, is quite small in the INS spectrum,
while it is very distinct even in the broadened IXS spectrum. On the other hand, the TA mode, indicated by the
downward arrow, exhibits a broad peak in the INS spectrum, while that is unclear in the broadened IXS spectrum. Also, the quasielastic peak in the INS spectrum ismuch smaller than that in the broadened IXS spectrum.
We will discuss further the contributions of the impurity atoms to the inelastic spectra. Table 1 shows theatomic numbers, Z, neutron coherent and incoherent
scattering lengths, bcoh, and binc, respectively, of the Mg,
Zn, and Y elements. The atomic form factors, f, for the
X-ray scattering rapidly decrease with an increasing Q.
However, the ratios of f values between the elements
are quite similar to the ratios of the Z values.
The binc values of all constituent elements are verysmall, compared with the bcoh values. Therefore, theINS spectra are dominated by the coherent scattering,and the contribution of the incoherent scattering is not
the reason for the difference between the INS and IXS
spectra.

MLF Annual Report 2015

Research and Development Highlights

scattering are 70-95%. The cross-sections are proportional to the squares of the f and bcoh values. As a result, the cross-sections of the impurities are more than
5 times larger in IXS than in INS. By comparing between
the IXS and INS spectra, it can be concluded that the LA
excitations are highly related to the motions of impurity
atoms, while the TA modes may concern more to thoseof host Mg atoms.
In addition, the magnitude of the quasielastic peaks
in INS is much smaller than those in IXS. The quasielastic
peaks in the Mg-LPSO alloys have originated from thescattering due to the stacking faults, and the impurity
atoms are enriched in the stacking fault regions. Thus,
the present experimental result is consistent with thesynchronized LPSO views in these Mg alloys.

Figure 2.	The circles show the INS spectra of Mg97Zn1Y2 polycrystal at Q = 4.0, 6.0, and 8.0 nm-1. The triangles exhibit the broadened IXS spectrum at 7.9 nm-1. The
upward and downward arrows, and bar indicate
LA, TA, and optic modes assigned by the IXS data ofpure Mg and Mg97Zn1Y2 polycrystals. Taken from [5].

Table 1. The Z, bcoh, and binc values of Mg, Zn, and Y elements.

Elements

Z

bcoh

binc

Mg

12

5.375

~0

Zn

30

5.680

~0

Y

39

7.75

1.1

As of the multiple scattering in the INS data, thetransmission of neutrons through the present sample isestimated to be about 75%, and most of the remaining
25% is coherent scattering. So, the multiple scattering
effect may not explain the large difference of the IXS
and INS spectra.
The remaining possible reason is the differenceof scattering cross-sections of X-rays and neutrons.
The f value of Mg is mostly 30-40% of those of impurities. On the other hand, the bcoh values for the neutron

4. Conclusion
The INS and IXS experiments are performed onpolycrystalline Mg97Zn1Y2 alloy with synchronized LPSO
phase to investigate the impurity effects in the microscopic elastic properties of the Mg LPSO alloy. By comparing with the INS data on the polycrystalline LPSO
alloy, the contributions of the impurities to these excitation modes are discussed using the differences in the
scattering cross-sections between neutrons and X-rays.
The LA mode and quasielastic peak are closely related
to the motions of impurity atoms, while the TA modes
may concern more to those of the host Mg atoms.
This work was supported by a Grant-in-Aid for
Scientific Research on Innovative Areas ‘Materials
Science on Synchronized LPSO structure’ (No. 26109716)
from the Japan Society for the Promotion of Science(JSPS). The INS experiments were performed at BL12 of
MLF in J-PARC (Proposal No. 2015A0059).
References[1] Y. Kawamura et al., Mater. Trans. 42, 1172 (2001).
[2] K. Hagihara et al., Acta Mater. 58, 6282 (2010).
[3] E. Abe et al., Philos. Mag. Lett. 91, 690 (2011).
[4] D. Egusa and E. Abe, Acta Mater. 60, 166 (2012).
[5] S. Hosokawa et al., J. Alloys Compd. 695, 426 (2017).
[6] S. Itoh et al., Nucl. Instrum. Met. Phys. Res. A 631, 90(2011).

S. Hosokawa1, M. Yamasaki2,3, Y. Kawamura2,3, K. Yosida4, Y. Kawakita5, and S. Itoh6
Department of Physics, Kumamoto University; 2Magnesium Research Center, Kumamoto University; 3Department of Materials Science,
Kumamoto University; 4Department of Chemistry, Fukuoka University; 5J-PARK Center, JAEA; 6Neutron Science Division, KEK

1

9

Research and Development Highlights

MLF Annual Report 2015

High-Temperature Neutron Diffraction Study on
CaWO4-based Oxide Ion Conductor

Figure 1.	Schematic view of Ca0.9K0.2WO3.9 with scheelite-type
structure. Part of Ca site is substituted by K.

10

Temperature, t / °C
1000
100

700

500

10–1

Conductivity, σ / Scm–1

1. Introduction
Oxide ion conductors have attracted significant
interest for application in electrolytes of gas sensors,
oxygen pumps or solid oxide fuel cells (SOFC). Several
distinct structured oxides have been intensively studied, e.g. fluorite, perovskite, pyrochlore or apatite, while
relatively fewer reports have been published aboutscheelite-type (Fig. 1) structured oxide ion conductors.
When lead ions in PbWO4 with scheelite-type structure
are partly substituted by lanthanum ions to form oxide
ion interstitials as Pb1-xLaxWO4+x/2, high oxide ion conduction occurs at elevated temperatures [1]. We havestudied on this compounds in terms of electrochemicaland structural point of view [1-3]. On the other hand,
CaWO4, which as a mineral is called “scheelite”, does notexhibit such an oxide ion conduction enhancement
due to the lanthanum substitution.
Recently, we revealed that alkaline ion substituted solid solutions of Ca1-xAxWO4-x/2 (A = K, Rb, Cs) also
exhibit high oxide ion conduction at high temperatures [4]. In this system, the created oxide ion vacancies
are supposed to contribute to the oxide ion diffusion
and oxide ion conduction mechanism and should be
similar to that of the PbWO4-based system with oxide
ion interstitials at high-temperatures. Nevertheless,some ambiguity in the conduction property still remains, i.e. CaWO4-based oxide ion conductors exhibita bend in slope of the Arrhenius plot around 500°C(Fig. 2), without showing thermal anomalies, and they
still have a little higher activation energy than the Lasubstituted PbWO4.

10–2
10–3
10–4
10–5
10–6

0.8

1.0

1.2

1.4

T –1 / kK–1

Figure 2.	Arrhenius plots of conductivity for Ca0.9A0.1WO3.95(A = K (r), Rb (£), Cs (s)).

We have previously measured the neutron diffraction experiment on the La-substituted PbWO4 atroom temperature [2] and also at high-temperature in
2015A0096. In the present study, we have carried out
the neutron diffraction experiment on the K-substituted
CaWO4 at high temperatures to clarify the structuralvariation with the temperature, as well as the differencein conduction properties with the PbWO4-based system.
2. Experimental
2.1 Sample preparation
Ca1-xKxWO4-x/2 (x = 0.2) were prepared by the conventional solid state reaction method, started with thestoichiometric mixture of CaCO3, K2CO3 and H2WO4. The
calcining and sintering temperatures were selected as
800°C and 1000°C, respectively. The crystalline phasesof the obtained samples were confirmed by powder
X-ray diffraction (Rigaku, Ultima IV) with CuKα radiation(40 kV, 40 mA).
2.2 High-temperature neutron diffraction
About 5.5 g of the Ca0.9K0.2WO3.9 sample pellets
were put into a quartz tube with 0.5 mm in thickness
to prevent the reaction, which was then installed intoa vanadium cell. TOF neutron diffraction experiments
are conducted using SHRPD in J-PARC with high-temperature furnace equipment. At first, the sample washeated up to 800°C, then the diffracted neutron data

MLF Annual Report 2015

were collected at 800, 600, 400, 200 and 36°C in thecooling order. The diffraction patterns were obtainedby detracting the contribution of the quartz tube aswell as the vanadium cell and furnace.
The Rietveld refinements were made using
Z-Rietveld assuming I41/a symmetry. Ca(K) and W ionswere placed on 4b and 4a sites, respectively and the O
ion was on 16f with the nominal occupancy (g = 0.9875).
3. Results and discussion
Figure 3 shows the measured and the Rietveld refined neutron diffraction patterns of Ca0.9K0.2WO3.9 at
800°C, where fairly good agreement was attained with
Rwp = 8.39%. Even at 800°C, no apparent symmetry
changes from the room temperature phase were found.
Figure 4 shows the temperature variation of lattice parameters. Both a and c gradually grew with the temperature and no inflection was observed as the bend in
Arrhenius plot in Fig. 2.

Intensity

30
20

Research and Development Highlights

The interatomic distance W-O, as represented inFig. 5(a), showed rapid decrease with temperature below 500°C, while it thereafter gradually increased athigh temperatures. Two types of O-W-O bond angles
in WO4 tetrahedra are also represented in Fig. 5(b) and(c). Angle ϕA, facing the center of the fluorite-related
structure part, at first increased with temperature up
to 600°C and then started to decrease. On the contrary,ϕB opening toward the side of the unit cell showed the
opposite behavior. Namely, in the lower temperature
region, the WO4 tetrahedra development flattened with
the increasing temperature. On the other hand, at ahigh temperature, they evolved along the c-axis when
the oxide ion conduction became evident.
Accordingly, it can be seen that the average oxide
ion positions are closely related to the oxide ion conduction. Unlike Pb1-xLaxWO4+x/2 system with oxide ioninterstitials, the nuclear density of (regular) oxide ion
estimated using Z-MEM code elongates toward the caxis. Such a difference might be due to the existence ofinterstitials or the electronegativity difference between
Pb (La) and Ca (K). Further consideration, including theBond Valence model, should be made to clarify the

10

1.795

1.0

1.5

2.0

2.5

3.0

3.5

d / AngstromdW–O / Å0

Figure 3.	The Rietveld refined TOF neutron diffraction patternsof Ca0.9K0.2WO3.9 based on measures taken at 800°C.

1.790

1.785
113.9

φA / degree

a/Å

5.30
5.28
5.26

113.8
113.7

φΑ

113.6

5.24

φΒ

107.5

φB / degree

11.6

c/Å

11.5
11.4
11.3

dW–O
107.4

107.3

0

200

400
600
Temperature, t / °C

800

Figure 4.	The Rietveld refined TOF neutron diffraction patterns of Ca0.9K0.2WO3.9 based on the measures taken
at 800°C.

0

200

400

600

800

Temperature, t / °C

Figure 5.	Temperature dependence of interatomic distancedW-O, and bond angles фA and фB in WO4 tetrahedra
obtained by the Rietveld refinements.

11Research and Development Highlights

MLF Annual Report 2015

precise oxide ion conduction mechanism in the scheelite-type structured oxide ion conductors. Moreover, we
are also planning to perform a high-temperature neutron diffraction experiment on Pb1-xLa2x/3WO4, which
does not possess the interstitials essentially, eventhough the PbWO4-based system.
4. Conclusions
We have investigated the high-temperature structure of the CaWO4-based oxide ion conductor withoxide ion vacancy by means of TOF-neutron diffraction. Accurate determination of the oxide ion position
revealed that the temperature variation of the oxide
ion position is altered at the high-oxide ion conduction region. The conduction mechanism is supposed tobe different from the PbWO4-based system with oxide
ion interstitials from the oxide ion position and MEM
estimation.
References[1] T. Esaka, T. Minaai, H. Iwahara, Denki Kagaku, 59343-344 (1991).
[2] S. Takai, S. Touda, K. Oikawa, K. Mori, S. Torii, T.
Kamiyama, T. Esaka, Solid State Ionics, 148 123-133(2002).
[3] S. Takai, T. Nakanishi, K. Oikawa, S. Torii, A.
Hoshikawa, T. Kamiyama, T. Esaka, Solid State Ionics,
170 297-304 (2004).
[4] S. Takai, Y. Morishita, Y. Kondo, T. Yao, T. Yabutsuka, T.
Esaka, J. Ceram. Soc. Jpn, 124 819-822 (2016).

S. Takai1, S. Kaji1, T. Yabutsuka1, S. Lee2, P. Miao2, S. Torii2, T. Kamiyama2, and T. Yao3,4
Graduate School of Energy Science, Kyoto University; 2Institute of Materials Structure Science, KEK; 3National Institute of Technology,
Kagawa College; 4Institute of Advanced Energy Science, Kyoto University

1

12

MLF Annual Report 2015

Research and Development Highlights

High-Resolution Powder Neutron Diffraction Unravels
Magnetic Structure and Phase Transition Mechanism in
MnO, CoO, and NiO
1. Introduction
C. G. Shull and his co-worker had carried out thefirst neutron diffraction for magnetic materials, i.e.
transition metal monoxides MnO, FeO, CoO, and NiO in
the Oak Ridge National Laboratory [1, 2]. They proved
experimentally the antiferromagnetic spin alignment,
which was proposed theoretically by Néel. Their pioneering works open new frontiers in the neutron science; and develop the way to answer on the questions‘where atoms are’ and ‘what atoms do’.
Because of this history, many textbooks of neutron
scattering and condensed matter physics introduce
neutron diffraction and antiferromagnetism using transition metal monoxides. For the general researcher incondensed matter physics and material science, this situation creates the misunderstanding that no issues remain in the study of crystal and magnetic structures oftransition metal monoxides. Actually, the details of thecrystal and magnetic structure have been discussed formore than half a century in complex situations, where
the magnetic transition induces structural phase transition and ferroelastic domains simultaneously [3, 4]. For
instance, each group of researchers has reported different scattered values for the CoO spin directions [4].
There is no information on the precise MnO and NiO
spin direction inside the R-3m hexagonal plane. In addition, the renormalization group theory, based on thereported crystal and magnetic structure that expects all
TMOs to show discontinuous phase transition, is inconsistent with the CoO and NiO experimental results.
2. Experiments
We obtained commercial powder samples MnO
99%, CoO 99.99%, and NiO 99.999% from Sigma Aldrich.
Time-of-flight neutron powder diffraction was carriedout in the super-high-resolution powder diffractometer(SuperHRPD, BL08 in MLF) with top-loading CCR and
Vanadium furnace option [5, 6]. Narrowing the selected
detector area allowed us to obtain higher-resolution diffraction data, while it decreased the diffraction intensity.
To observe tiny monoclinic distortion in CoO, we selected the middle-part area of the backscattering bank. We
employed the Z-Rietveld [7, 8] and Fullprof program [9]to analyze the crystal and magnetic structure using thetotal area of the backscattering bank. We also did grouptheoretical analysis to construct the group-subgroupfamily tree and study the phase transition mechanism.
3. Results and discussions
All MnO, CoO, and NiO are simple NaCl structures inparamagnetic phase. The spin parallel and anti-parallel
spatial distribution gives rise to distinguished bondstrength and length, the so-called ‘exchangestriction’.
On the other hand, the spin direction must be compatible with the crystal symmetry. For instance, spin
direction, which is perpendicular to the 3-fold crystal
symmetry, is not allowed by the 3-fold crystal symmetry. Therefore, this spin direction induces additional
structural distortion, the so-called ‘magnetostriction’.
The well-known rhombohedral structure model of MnO
and NiO couldn’t satisfy the comparability between the
3-fold crystal symmetry and the spin direction, which isperpendicular to the 3-fold axis [3, 4].
Regarding exchangestriction and magnetostriction,
we made a group-subgroup family tree that represents
the transformation of crystal and magnetic structurein the cubic, rhombohedral, and monoclinic structurewith their related physical interaction, as shown in Fig. 1.
Exchangestriction and magnetostriction break the
4-fold and 3-fold symmetry respectively that induces
common C2/m crystal structure and magnetic propagation vector km = (0 1 0.5). In principle, there are only two
Γ1+ = (0, my, 0) and Γ2+ = (mx, 0, mz) spin directions. The
Γ1+ spin direction induces normal strain with respect tothe mirror plane, while this spin direction is still inside
the spin easy-plane given by dipolar magnetic anisotropy energy. On the other hand, the Γ2+ spin direction induces shear strain, which is parallel to the mirror plane,
while the spin direction can deviate from the spin easyplane given by dipolar magnetic anisotropy. If the orbital
moment is quenched, the dipolar magnetic anisotropy
with normal strain selects Γ1+ spin direction. If the orbital
moment is unquenched, the spin-orbit-lattice coupling
can compensate for the increasing of dipolar magnetic
anisotropy energy and select Γ2+ spin direction. By simple comparison, all MnO, CoO, and NiO are described bycommon C2/m with km = (0 1 0.5). The difference comes
only from the Γ1+ and Γ2+ spin directions.
13Research and Development Highlights

MLF Annual Report 2015

Figure 1.	Group-subgroup family tree under exchangestriction and magnetostriction [4]. Spin spatial distribution and spin direction
reduce the crystal structure from cubic to rhombohedral, and finally to a monoclinic structure. We derived atomic position,
lattice constant, magnetic propagation vector, spin direction in each cubic, rhombohedral, and monoclinic structure byfollowing the physical mechanism.

For CoO, we confirmed successfully a very tiny
monoclinic peak splitting about 0.00025 Å, as shownin Fig. 2 [4]. It is consistent with the previous high-resolution synchrotron x-ray diffraction [10]. And then, we
determined unambiguously the Γ2+ magnetic structurewith precise spin directions. On the other hand, for
MnO and NiO, the well-known rhombohedral distortion is clearly detectable. However, the further monoclinic distortions are too small to be detectable evenwith the world’s best high-resolution diffractometerin existence. Fortunately, with our group-subgroupmodel and earlier experiments of references, we could
assign Γ1+ and Γ2+ magnetic structure to MnO and NiO,
respectively [3, 4].
We converted from the temperature dependenceof the magnetic moment M and monoclinic angle β
to order parameter vector diagram β - Mn as shownin Fig. 3. The initial monoclinic angle β0 is a paramagnetic phase. The increase of the ordered magnetic moment induces deviation in the monoclinic angle from
β0. The order parameter vector diagram shows two different cases by Γ1+ and Γ2+ spin directions. The orbital
quenched case of MnO and orbital unquenched caseof CoO and NiO choose the Γ1+ and Γ2+ spin directions,14

linear-quadratic ~βM2 and linear-cubic ~βM3 magnetoelastic couplings, and discontinuous and continuous
phase transitions, respectively.

Figure 2.	SuperHRPD observed successfully tiny monoclinic
distortions [4]. The peaks position difference isabout 0.00025 Å between d040 and d-404. So far, sucha small distortion has been considered practicallynegligible. However, any finite small distortion can
induce a different symmetry of order parameter. In
other words, it can affect the coupling type of orderparameters and the mechanism of phase transition.

MLF Annual Report 2015

Research and Development Highlights

describe the magnetic moment in condensed matterphysics [4]. Further theoretical studies and other experimental examples will be necessary to expand ourknowledge.

Figure 3.	Order-parameter vector diagram in MnO, CoO andNiO [4]. β0 is paramagnetic phase whereas β = β0
± Δβ is antiferromagnetic phase. The Mn d orbital
angular momentum is quenched, while Co and Ni
ones are unquenched case. The orbital quenchedcase and unquenched case prefer Γ1+ and Γ2+ spin
directions, respectively. Different Γ1+ and Γ2+ spin directions cause normal and shear strain, linear-quadratic ~βM2 and linear-cubic ~βM3 magnetoelastic
coupling, discontinuous and continuous phasetransition, respectively.

Traditionally, we used the time-reversal symmetry
breaking to describe magnetic structure and phasetransition. For the Landau theory of second-ordermagnetic phase transition, L. Landau expanded freeenergy in the polynomials of magnetic moments thatmust be invariant by time-reversal symmetry [11]. The
charge density or crystal distortion are invariant while
the magnetic moment, considered charge current fromthe classical viewpoint, is reversed by the time-reversal
symmetry operation. So far, we expect that the evenpower polynomials in magnetic moment will couples
with structural distortions. However, CoO and NiOshow experimentally linear-cubic magnetoelastic coupling forbidden by time-reversal symmetry. It seems
that monoclinic distortion and magnetic moment aresame irreducible representation which is not allowedby time-reversal symmetry. These experimental results provide the answer to the fundamental question
whether time-reversal symmetry is suitable or not to

4. Conclusion
We elucidated the long-standing problems of themagnetic structure and phase transition mechanism
for MnO, CoO, and NiO. Breaking the time-reversal symmetry couldn’t explain the linear-cubic magnetoelastic coupling and continuous phase transition in CoO
and NiO. These experimental results pose the generalquestion what symmetry can be used to describe themagnetic moment in condensed matter physics. Our
study shows that any tiny structural distortion and spin
directions must not be ignored from a strict symmetricviewpoint. Currently, the SuperHRPD beamline displays
the performance of the best high-resolution neutron
powder diffractometer in the world. Just as a micrometer can see details inaccessible to bare eyes, it can investigate new physical phenomena or mechanisms, which
we couldn’t see before by using conventional resolution of the neutron diffractometer.
References[1] C. G. Shull and J. S. Smart, Phys. Rev. 76, 1256
(1949).
[2] C. G. Shull et al., Phys. Rev. 83, 333 (1951).
[3] S. Lee et al., JPS Conf. Proc. 8, 034007 (2015).
[4] S. Lee et al., Phys. Rev. B 93, 064429 (2016).
[5] S. Torii et al., J. Phys. Soc. Jpn. 80, SB020 (2011).
[6] S. Torii et al., J. Phys.: Conf. Ser. 502, 012052 (2014).
[7] R. Oishi et al., Nucl. Instr. Meth. Phys. Res. A 600, 94(2009).
[8] R. Oishi-Tomiyasu et al., J. Appl. Cryst. 45, 299(2012).
[9] J. Rodriguez-Carvajal, Phys. B Condens. Matter 192,
55 (1993).
[10] W. Jauch et al., Phys. Rev. B 64, 052102 (2001).
[11] L. Landau, Zh. Eksp. Teor. Fiz. 7, 19 (1937).

S. Lee1, Y. Ishikawa1, P. Miao1,2, S. Torii1,3, T. Ishigaki4, and T. Kamiyama1,2,3
Institute of Materials Structure Science, KEK; 2Sokendai (The Graduate University for Advanced Studies); 3J-PARC center, KEK; 4Frontier
Research Center for Applied Atomic Science, Ibaraki University

115

Research and Development Highlights

MLF Annual Report 2015

Silver Photo-Diffusion into Amorphous Ge-Chalcogenide
Films: in situ Neutron Reflectivity Measurement

2. Experimental
The neutron reflectivity measurement was carriedout on SHARAKU (BL17) at the MLF [6]. In the measurement, the proton beam power was 300 kW. White lightfrom a 300 W xenon lamp (MAX-303, ASAHI Spectra,Co., Ltd.) was used as an excitation light source. The experimental setup is shown in Figure 1 [6]. Neutron data

were acquired using an event recording system, and arbitrarily time-sliced spectra were obtained from the fullrecorded data set.
3. Results and Discussion
Figure 2 shows the time evolution of the neutronreflectivity of Ge33S67 2000 Å/ Ag 500 Å/ Si substrate film
under light exposure of Xe lamp and Figure 3 shows
the time evolution of the scattering length density(SLD) profile, which is the result of the model fitting. As
shown in Fig. 3, the Ag layer became thinner during thelight exposure time and disappeared in about 17 min.
The SLD of the Ch layer increased (1.9 -> 2.2) with theexposure time, but remained uniform over the layer.
This means that the Ag ions spread over the layer, once
they enter the Ch layer, as illustrated in Fig. 4. It seems
that there is no potential barrier inside the Ch layer, but
a potential barrier exists only at the Ag/ a-Ch interface.
Such immediate diffusion is probably due to the ionconductive nature of the Ch host under the light exposure. After successive light exposure for more than
27 min, the neutron reflectivity in the total reflection

100
10–1
10–2
10–3

Before10–4

exposure time
0-1min

10–5

Reflectivity

1. Introduction
Interestingly, silver diffuses into amorphous chalcogenide (a-Ch) such as a-As2S3 and GeSe2 when lightilluminates Ag/ a-Ch double-layer film. This phenomenon is referred to as silver photo-diffusion, or, photo-doping [1, 2]. This effect has been used in several
applications such as photo-lithography, the fabricationof relief images in optical elements and non-volatilememory devices [3]. This diffusion is unique, showing
step-like silver-concentration changes in the depth direction with ‘a diffusion front’ and it was believed thatthe diffusion front progressed following the successive
light exposure. Such diffusion model was built up fromprevious works, mainly by using Rutherford backscattering spectroscopy by ex situ way. However, the in situ
measurement was difficult because the strong He ion
beams induce silver diffusion. The use of strong X-ray
beams also induces silver diffusion and the selection ofproper probe beams has been a crucial subject to perform an in situ measurement, which should provide a
correct answer to the kinetics. Recently, we performed
an in situ neutron reflectivity measurement of Ag/GeCh films and revealed their diversified kinetics [4-8].
Here we report the result of the neutron reflectivity
measurement of Ge33S67/ Ag/ Si substrate film [7, 8].

10–6

1-2

10–7

2-4
6-8

–8

10

8-10

10–9
10

10-12

–10

12-14

10–11

14-16

10–12

18-20

10–13

20-22

10–14
10

24-26

–15

26-28

10–16

28-30

10–17
0.010

0.020

0.030

0.040

Q (Å–1)Figure 1. Experimental setup.

16

Figure 2.	Time evolution of the neutron reflectivity of Ge33S67
2000 Å/ Ag 500 Å/ Si.

MLF Annual Report 2015

Research and Development Highlights

Ag
3

Before
Ge33S672

exposure time
0-1 min1

1-2

SLD (× 10–6 Å–2)

0

2-4

0

6-8

0

8-10

0

10-12

0

Figure 5.	Optical microscope image of the surface after thelight exposure.

12-14

0

14-16

0
0
0
0

500 1000 1500 2000 2500
d (Å)

Figure 3. Time evolution of the SLD profile.

Figure 4.	Schematic illustration of the diffusive nature of Ag
ions under light exposure.

region rapidly decreased and the fringes in the neutron reflectivity profile disappeared. Figure 5 shows the
optical microscope image of the surface after the light
exposure, suggesting macroscopic height-variations of
the surface similar to mountains and valleys. We inferthat a giant volume change or a change in the surface

tension on the Si substrate was induced by the continuous light exposure and the change caused the macroscopic height-variations of the surface. In summary, theexperimental result provided a profound insight into
the photo-structural properties and functionalities of
the Ge33S67/Ag/ Si film in terms of the ionic conductivity
and self-organization under light exposure.
The neutron reflectivity measurements were performed on SHARAKU in J-PARC MLF under Project No.
2013B0159. We would like to thank N. Miyata, K. Akutsu,
T. Ito, and S. Kasai (CROSS) for the technical support on
the neutron reflectivity instrument and M. Ailavajhala
for the sample preparation.
References[1] M. T. Kostyshin, E. V. Mikhailovskaya, and P. F.
Romanenko, Sov. Phys. (Solid State) 8, 451 (1966).
[2] A. V. Kolobov and S. R. Elliott, Adv. Phys. 40, 625(1991).
[3] M. Mitkova and M. N. Kozicki, J. Non-Cryst. Solids
299-302, 1023 (2002).
[4] Y. Sakaguchi et al., Can. J. Phys. 92, 654 (2014).
[5] Y. Sakaguchi et al., J. Phys. Conf. Ser. 619, 012046(2015).
[6] Y. Sakaguchi et al., JPS Conf. Proc. 8, 031023 (2015).
[7] Y. Sakaguchi et al., Phys. Status Solidi A 213(7),1894-1903 (2016).
[8] Y. Sakaguchi et al., J. Appl. Phys. 120, 055103 (2016).

Y. Sakaguchi1, H. Asaoka2, Y. Uozumi2, Y. Kawakita3, T. Hanashima1, D. Yamazaki4, K. Soyama4, and M. Mitkova5
Neutron Science and Technology Center, CROSS-Tokai; 2Advanced Science Research Center, JAEA; 3Neutron Science Section, Materials andLife Science Division, J-PARC Center; 4Neutron Instrumentation Section, Materials and Life Science Division, J-PARC Center; 5Department
of Electrical and Computer Engineering, Boise State University

1

17Research and Development Highlights

MLF Annual Report 2015

Operando Measurement of Solid Electrolyte Interphase
Formation at Working Electrode of Li-ion Battery by
Time-slicing Neutron Reflectometry
1. Introduction
In order to improve the safety and durability of thepresent lithium ion batteries (LIBs), we definitely needto understand the nature of a solid-electrolyte interphase (SEI) that is formed at the boundary between
negative electrode material and electrolyte in LIBs [1].
Neutron reflectometry (NR) was employed for direct observation of the electrode/electrolyte interface of a LIB
because neutrons can penetrate through the electrodeand provide interference that reflects the interfacial
structure [2-4]. The neutron scattering length density
ρ, can be evaluated in the depth range between a few
nanometers and a few hundred nanometers. Since ρ isrelated to the elemental composition and the density
at the interface. Therefore, NR can be used to detect not
only the SEI formation, but also the intercalation of Li+ions with an in situ method. Based on the operando NR
of a model electrode with the SOFIA reflectometer in
J-PARC/MLF [5, 6], we observed successfully for the firsttime the SEI growth process and the intercalation of Li+ions at an electrode during the charge reaction [7].
2. Experimental
Figure 1 shows a schematic of the electrochemical cell used for the present work. A carbon/titanium

multilayer thin film on a 3-mm thick silicon substratewith an area of 30 × 30 mm was used as a model electrode and soaked with an electrolyte (see reference [7]for details). The electrochemical cell was mounted on
the sample stage of the SOFIA reflectometer. The electrochemical potential at the carbon electrode, E, wascontrolled by an electrochemical analyzer with a scanrate of 1.0 mV/s in the potential range from 2.9 to 2.0 V(vs. Li/Li+) and at 0.2 mV/s from 2.0 to 0.05 V during the
NR measurement. The neutrons were introduced fromthe substrate side and the reflected neutrons wereacquired every 5 minutes with an incident angle θ of
0.4° to obtain the reflectivity profile as a function of the
momentum transfer normal to the basal plane Qz; Qz =(4πsinθ)/λ, by taking into account the wavelength ofneutrons, λ, -based on the time-of-flight method.
3. Results and discussion
Figure 2 shows the reflectivity profiles as a functionof E during the charge reaction. In contrast to the lackof change in the profile from the open circuit voltage(OCV; ca. 2.9 V) to 1.5 V, even with a decrease in E, theperiod and critical value of Qz at the total reflection began to change at 1.5 V and the change was more pronounced at 0.6 V. This change was consistent with the

Figure 1.	Schematic illustration of the electrochemical cell and cross-section of the model battery system for the in situ NR measurements [7].

18MLF Annual Report 2015

Research and Development Highlights

Figure 2. NR profiles as a function of E during the charging reaction obtained by the operando measurement [7].

voltammogram of the carbon electrode during the insitu NR experiment: no characteristic reaction occurredfrom OCV to 1.5 V (phase I), decomposition of the electrolyte and/or organic solvent occurred for the SEI
formation from 1.5 V to 0.6 V (phase II), and the intercalation of Li ions occurred from 0.6 V to 0.05 V (phase III).
Figure 3 shows the dependence of ρC, ρI, dC, and dI
obtained by the least-squares fitting based on a leastsquares fitting with the Parratt formalism [8, 9]. Here, dindicates the thickness of a layer, and subscripts C and
I indicate the carbon electrode and interfacial layer, respectively. The fitting result indicated the presence ofan interfacial layer, even at the OCV, with dI = 17.0 ±1.7 nm and ρI = (2.50 ± 0.20) × 10-4 nm-2. As a hydroxyl
layer was detected by an ex situ X-ray Photoelectron
Spectroscopy analysis on the surface of the carbon
electrode after immersion in the electrolyte withoutcharging, the interfacial layer is presumably attributed
to an adsorption layer formed upon contact with theelectrolyte before the SEI formation.
Furthermore, the values of dI and ρI changed witha decrease in E, which indicated that an SEI started toform at the interface due to a decomposition reaction.
According to the trend of dI, the SEI gradually thickened
with the charge reaction during phases I and II, andthe rate of thickening was enhanced during phase III.
On the other hand, ρI remained almost constant during phases I and II, while increasing during phase III up
to (3.26 ± 0.72) × 10-4 nm-2 at E = 0.05 V. ρ indicates thecomposition of the SEI; therefore, these results imply
a change of the product by the charge reaction. The
SEI formed in this system is reported to consist of thefollowing components: polyvinylene carbonate (ρ =2.84 × 10−4 nm−2), Li2CO3 (3.48 × 10−4 nm−2), lithium alkyl
carbonate (2.75 × 10−4 nm−2), polyethylene oxide (PEO;
8.22 × 10−5 nm−2), LiPF6 (2.21 × 10−4 nm−2), and LiF (2.30 ×
10−4 nm−2). Therefore, the change in ρ implies a changeof the product by the charge reaction, and Li2CO3, having the highest ρ value, is a strong candidate productthat contributes to the increase in ρI during phase III.
Next, we focused on the intercalation of the Li+ ions
into the electrode during the charge reaction; dC was
69.1 ± 0.3 nm at OCV, remained almost constant during phases I and II, and then increased monotonicallyup to 84.1 ± 0.8 nm at E = 0.05 V during phase III. Thechange in dC is consistent with the volumetric change
induced by the Li+ intercalation into carbon, because
the c-axis length of the Li+-intercalated carbon is larger
than that of carbon. On the other hand, Li has a negative coherent scattering length; therefore, the decreasein ρC also indicates intercalation. In fact, ρC at OCV, (6.46± 0.02) × 10-4 nm-2, remained constant during phase I,
and decreased monotonically down to (4.50 ± 0.27) ×
10-4 nm-2 at E = 0.05 V during phases II and III. It should
be noted here that the number of Li ions intercalated
into the carbon electrode with one-electron transfer
reaction during the charge reaction can be evaluatedbased on the changes in dC and ρC. This means that the
charge used for Li+ intercalation can be evaluated by
NR, the one and that used for SEI formation can be extracted by comparing with the total charge evaluatedby voltammogram. This is a novel information only operando NR can provide, which is valuable for understanding the process of SEI formation during the charging.
19Research and Development Highlights

MLF Annual Report 2015

Figure 3.	Evolution of the interfacial structure at the carbon electrode during electrochemical reaction: (a) thickness and (b) scattering length density of the electrode and interfacial layer as a function of E [7].

4. Conclusion
We have succeeded in the first operando measurement of SEI formation at the working electrode of a LIB
using a combination of time-slicing NR. The results obtained clearly show the formation of a SEI layer at the
carbon electrode and the intercalation of Li ions into
the electrode. This method has the potential to be used
to determine the chemical composition of an SEI andto evaluate the absolute amounts of charge used in
the SEI formation and Li intercalation during an electrochemical reaction. We believe the operando NR
technique opens a door to shed light on the “live” composition/decomposition process of SEIs under operation and deepens our understanding of the formation
mechanism and its relationship with the performanceof LIBs, which will lead to further improvement of thepresent LIBs and the development of advanced nextgeneration batteries.

Acknowledgements
JS was partially supported by a Kakenhi Grant-in-Aid(No. 23108003) from the Ministry of Education, Culture,
Sports, Science, and Technology (MEXT) of Japan.
References[1] M. Gauthier et al., J. Phys. Chem. Lett. 2015, 6,4653-4672.
[2] J. E. Owejan et al., Chem. Mater., 2012, 24, 2133-2140.
[3] J. F. Browning et al., ACS Appl. Mater. Interfaces, 2014,
6, 18569-18576.
[4] M. Hirayama et al., Electrochem. Comm., 2010, 78,
413-415.
[5] N. L. Yamada et al., Eur. Phys. J. Plus, 2011, 126, 1-13.
[6] K. Mitamura et al., Polym. J., 2013, 45, 100-108.
[7] H. Kawaura et al., ACS Appl. Mater. Interfaces 2016, 8,
9540-9544.
[8] L. G. Parratt, Phys. Rev., 1954, 95, 359-369.
[9] A. Nelson, J. Appl. Cryst. 2006, 39, 273-276.

H. Kawaura1, M. Harada1, Y. Kondo1, H. Kondo1, Y. Suganuma1, N. Takahashi1, J. Sugiyama1, Y. Seno1, and N. L. Yamada2
Toyota Central Research & Development Laboratories, Inc.; 2Institute of Materials Structure Science, High Energy Accelerator Research
Organization
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Research and Development Highlights

Unusual Dynamics of α-synuclein Amyloid Fibrils
Detected by Quasielastic Neutron Scattering
1. Introduction
α-synuclein (αSyn) is a protein consisting of 140
amino acid residues, which is abundant in the presynaptic nerve terminals in the brain. Although its precise
function is unknown, it is implicated in the pathogenesisof the Parkinson’s disease (PD), a progressive neurodegenerative disorder. Filamentous aggregates of αSyn areoften found to be a major component of the protein deposits in the brain of patients with PD. These aggregates(amyloid fibrils) and/or the intermediate structures toward the mature fibrils of αSyn are thought to be related
to the pathogenesis of PD. Elucidating the mechanismof the fibril formation of αSyn is thus important for understanding the mechanism of the pathogenesis of PD.
The formation of amyloid fibrils generally involves
partial unfolding of the proteins and the subsequent
growth of the protofilaments and the mature fibrils.
The involvement of the partial unfolding implies thatthe dynamics of the proteins plays an important rolein the process of the fibril formation. Investigating theprotein dynamics during the fibril formation is therefore important for elucidating the mechanism of thisprocess. The purified αSyn from bacterial expression ismonomeric but intrinsically disordered in solution andforms amyloid fibrils under various conditions. As a firststep toward elucidating the mechanism of the fibril formation of αSyn, we investigated the dynamic behaviorof the purified αSyn in the monomeric state and the fibril state. For this purpose, we employed quasielastic
neutron scattering.

Neutron scattering provides a unique tool to directly measure the dynamics of proteins at ps-to-ns timescales and ångstrom length scales. In particular, incoherent quasielastic neutron scattering (QENS) provides
information on the average motion of (the hydrogenatoms within) the entire protein. Here, we carried out
the QENS experiments of the solution samples of αSynin the monomeric and fibril states, and compared the
dynamic properties of αSyn in these states [1]. It was
found that αSyn in the fibril state shows unusual dynamic behavior.
2. Materials and methods
The solution sample of αSyn was prepared by purifying human wild-type αSyn, expressed in E. coli. The solution, containing 9.5 mg/ml αSyn, was prepared in D2O.
This sample represents the monomeric state. Fibrils of
αSyn were prepared by incubating the solution sample
in D2O at 37°C under constant shaking. The sample representing the fibril state was prepared by pelleting thisfibril solution. The pellets contained 46 mg/ml of theαSyn fibrils. The QENS experiments on these samples
were carried out using the near-backscattering spectrometer, BL02 (DNA), at MLF/J-PARC. The measurements
were done at several temperature points between 280 K
and 300 K, at the energy resolution of 12 µeV.
3. Results
Figure 1 shows examples of the QENS spectra arising from αSyn in the monomeric and fibril states. The

Figure 1.	Examples of quasielastic neutron scattering spectra, S(Q,ω). The spectra of αSyn in (a) the monomeric state and (b) the
fibril state, at Q = 1.225 Å-1 and at 280 K, are shown along with the results of the fits using Eq. 1. In the upper panels, open
squares denote the data, thick solid lines in blue denote the total fits, solid lines in green and red denote Lglobal(Q,ω) and
Llocal(Q,ω), respectively, thin solid lines in blue show the background, and dashed lines in black show the resolution functions. The lower panels show the residuals of the fits.

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MLF Annual Report 2015

Figure 2.	Dapp of αSyn in the monomeric (■) and the fibril (■)
states evaluated from the QENS spectra. The translational diffusion coefficients of αSyn in the monomeric state determined from the dynamic lightscattering (■) are also shown.

Figure 3.	Radii of the confined spheres of αSyn in the monomeric (■) and the fibril (■) states, evaluated from the
EISF curves.

spectra, S(Q,ω), can be fit with equation,
S(Q,ω) = {A0(Q)δ(ω) + (1 - A0(Q))Llocal(Q,ω)}⊗ Lglobal(Q,ω) ⊗ RF(Q) + BG. (1)Here, Q is the momentum transfer, ℏω is the energy
transfer, A0(Q) is the elastic incoherent structure factor(EISF) that characterizes geometry of atomic motions,
Llocal(Q,ω) and Lglobal(Q,ω) are the Lorentzian functions
that characterize the local motions within the protein
and the global motions of the entire protein, respectively, and ⊗ denotes the convolution operation. By fitting the spectra with this phenomenological equation,
the global motions and local motions can be separated.
The Q-dependence of the width of Lglobal(Q,ω) provides information on the diffusive motions of the entire
molecules. Figure 2 shows the apparent diffusion coefficients (Dapp) of αSyn in the monomeric and fibril statesobtained from the analysis of these widths. It is shown
clearly that diffusive global motions are observed in
the monomeric state but largely suppressed in the fibril state. Note that Dapp has significant differences withthe translational diffusion coefficients evaluated fromdynamic light scattering, suggesting that Dapp obtained
from QENS contains contributions from rotational diffusion and segmental motions within the protein.
The Q-dependence of the width of Llocal(Q,ω) provides information on the rates of the local atomic motions within the protein. The residence times were foundto be larger in the fibril state than in the monomericstate, indicating that the rates of the atomic motions
within the protein are faster in the monomeric statethan in the fibril state.
Information on the geometry of these local
atomic motions can be obtained by analysis of the
EISF curves. Figure 3 shows the radius of the confined
sphere, in which the atoms undergo diffusive motions.
Surprisingly, this radius was found to be larger in the fibril state than in the monomeric state. This is contrary to
the expectation that aggregation reduces the motionsof the molecules in the aggregates. This indicates thatthe amplitudes of the local motions are larger in the fibril state than in the monomeric state. This is interpreted to mean that a significant solvent space exists within
the fibrils, which is attributable to the αSyn molecules
within the fibrils having a distribution of conformations.
The larger amplitudes of the local motions in the fibril
state imply that the degree of the conformational freedom is larger in the fibril state than in the monomericstate, i.e., the fibril state is entropically favorable. This
then implies that the fibril formation is entropically driven. The implication here is that once a potential barrieris overcome, the fibril formation proceeds naturally. The
rate-limiting step of the fibril formation would then be
the kinetics involved to overcome the potential barrier.
Reference[1] S. Fujiwara et al., PLOS ONE, 11 e015447 (2016).

S. Fujiwara1, K. Araki2, T. Matsuo1, H. Yagi3, T. Yamada4, K. Shibata5 and H. Mochizuki2
Quantum Beam Sci. Res. Dir., Natl. Inst. Quantum and Radiological Sci. Tech.; 2Grad. School of Medicine, Osaka Univ.; 3Tottori Univ.;
4Neutron R&D Division, CROSS-Tokai; 5Neutron Science Section, Materials and Life Science Division, J-PARC Center

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Research and Development Highlights

Uniaxial-Stress Control of Skyrmion Phase in MnSi
1. Introduction
Magnetic skyrmions are spin-swirling topologicalobjects discovered in a long-wavelength helimagnet
MnSi [1]. Figure 1(a) shows a schematic illustration of
the spin arrangements in a magnetic skyrmion. Due tothe two-dimensional soliton-like spin texture, the skyrmions acquire particle nature. Recent experimental
studies have demonstrated that these magnetic particles can be created, deleted and transferred througha variety of external stimuli, for example, by flowing(spin-polarized) electric current [2, 3] or applying laser
pulses [4]. Therefore, the skyrmions are expected tobe applied in new spintronic and/or information storage devices, in which each skyrmion particle acts as acountable information carrier.
The magnetic skyrmions often form a two-dimensional triangular lattice in a plane perpendicular
to the applied magnetic field, as shown in Fig. 1(b).
Interestingly, recent ultrasound measurements on MnSi
by Nii et al. revealed that the formation of the skyrmion
lattice (SkL) is accompanied by anisotropic changes inelastic constants [5]. This suggests in turn that the SkL
phase can be controlled by an application of anisotropic stress, which will be another methodology for manipulating skyrmions. Therefore, in the present study,
we investigated the uniaxial-stress effects on the SkL
phase in MnSi through small-angle neutron scattering

Figure 1.	Schematic drawings of (a) single skyrmion, (b) triangular SkL and (c) conical magnetic order. (takenfrom Ref. [6] and modified to fit the present report.)(SANS) measurements using single-crystal samples at
the TAIKAN instrument (BL15) in MLF of J-PARC.
2.	Preliminary magnetic susceptibility measurements under uniaxial stress
Prior to the SANS measurements, we performed
AC magnetic susceptibility measurements under uniaxial stress in order to reveal how the magnetic phase
diagram changes with the applied uniaxial stress.
Figure 2(a) and 2(c) show contour mapping of the realpart of the AC magnetic susceptibility on the H-T magnetic phase diagrams under zero uniaxial stress. Notethat the difference in the color scale is due to different
directions of the AC-magnetic fields; in Fig. 2(a) and2(c), the AC fields were parallel and perpendicular to theDC magnetic field, respectively. In addition, the criticalfields were also different because of the demagnetization effect arising from a difference in the shapes of thesamples. Figure 2(b) and 2(d) show the magnetic phase
diagram under uniaxial stress of 200 MPa applied parallel and perpendicular to the DC magnetic field, revealing that the parallel and perpendicular stresses squeeze
and enlarge the SkL phase, respectively.

Figure 2.	Contour maps of the real part of the AC magnetic
susceptibility on the H-T magnetic phase diagrams.
For (a) and (b), the AC and DC magnetic fields anduniaxial stress were parallel to each other. For (c)and (d), the uniaxial stress and the AC magnetic
field were applied perpendicular to the DC magnetic field. (taken from Ref. [6], and modified to fit
the present report.)

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MLF Annual Report 2015

3. SANS measurements under uniaxial stress
To observe directly the uniaxial stress effects on
the SkL phase, we performed SANS measurements under tunable uniaxial stresses. We prepared a bespoke
uniaxial-stress insert, and loaded it into a vertical-field
cryomagnet of MLF (see Ref. 6 for details). In Fig. 3(a),we schematically show the experimental setup. The
uniaxial stress was applied along the qz (vertical) direrction, which is parallel to the external DC magnetic field
applied by a superconducting magnet. At 27.7 K and
0.19 T, the system was in the SkL phase under zero uniaxial stress. The triangular lattice of the skyrmions produces six magnetic Bragg spots on the qx-qy plane, andtherefore we observed two of them on the scattering

plane (qy-qz plane), as shown in Fig. 3(b). We increased
the uniaxial stress without changing the temperatureand the magnetic field, and measured the stress dependence of the SANS pattern. As a result, we foundthat the two magnetic reflections corresponding to the
SkL phase disappeared with the stress’ increase, andinstead, two magnetic reflections appeared along theqz direction, as shown in Fig. 3(b). These reflections are
attributed to the conical magnetic order with magnetic
modulation wave vector parallel to the magnetic field(see Fig. 1(c)). This demonstrates that the application ofuniaxial stress indeed induces the phase transition fromthe SkL phase to the conical phase. Here, we emphasizethat the critical stress of this transition is about 30 MPa,
from which the mechanical energy to erase single skyrmion is roughly estimated to be 5 × 10-20 J. This value
is significantly smaller than the energy cost for electriccurrent-induced skyrmion creation, 2.25 × 10-17 J, calculated in Ref. 7. This suggests that the application ofuniaxial-stress can be another useful tool to manipulate
skyrmions in magnetic materials.
Acknowledgements
We thank Y. Yamauchi and the members of the sample environment team in MLF of J-PARC for their technical support in the SANS measurements.

Figure 3.	(a) A schematic showing the relationships among
the incident neutron beam, the scattering plane,
and the Bragg spots of the skyrmion and conical phases. (b) Typical SANS patterns measured at
27.7 K and 0.19 T with increasing uniaxial stress.
(c) Uniaxial stress dependence of the intensities ofthe magnetic reflections of the skyrmion and conical orders. (taken from Ref. [6], and modified to fit
the present report.)

References[1] S. Muhlbauer et al., Science 323, 915-919 (2009).
[2] F. Jonietz et al., Science 330, 1648-1651 (2010), X. Z.
Yu et al., Nat. Commun. 3, 988 (2012).
[3] N. Romming et al., Science 341, 636 (2013).
[4] M. Finazzi et al., Phys. Rev. Lett. 110, 177205 (2013).
[5] Y. Nii et al., Phys. Rev. Lett. 113, 267203 (2014).
[6] Y. Nii, T. Nakajima et al., Nat. Commun. 6, 8539
(2015).
[7] W. Koshibae et al., Jpn. J. Appl. Phys. 54, 053001(2015).

T. Nakajima1, Y. Nii1,*, A. Kikkawa1, Y. Yamasaki1,2, K. Ohishi3, J. Suzuki3, Y. Taguchi1, Y. Iwasa1,2, Y. Tokura1,2, and T. Arima1,4
RIKEN Center for Emergent Matter Science (CEMS); 2Department of Applied Physics and Quantum-Phase Electronics Center (QPEC),
University of Tokyo; 3Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS);
4Department of Advanced Materials Science, University of Tokyo*Present address: Department of Basic Science, University of Tokyo

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Research and Development Highlights

Weyl Fermion in Spin Dynamics of SrRuO3

2. Neutron Brillouin scattering experimentBecause a large single crystal necessary for inelastic neutron scattering has not been synthesized
for SrRuO3, we performed neutron Brillouin scattering(NBS) experiments on HRC by using a polycrystalline
sample [3]. NBS is the inelastic neutron scattering close
to the forward direction. For observing ferromagnetic
spin waves using a polycrystalline sample, the scattering intensity appears near (000) only and rapidly drops
with increasing Q by the powder average. We can access the space near (000) using low-angle detectors
and high-energy neutrons with high resolutions byapproaching the kinematical constraint of the neutron
scattering. HRC [4, 5], which has detectors at low angles
down to 0.6°, provides such an opportunity for the present study.
Figure 1 shows the observed inelastic neutron scattering spectra with the background subtracted. Welldefined spin waves were observed at T < TC, and it was
confirmed that the inelastic neutron spectrum changes
to that of the critical scattering at T = TC. The observed
peak positions of spin waves were well fitted to the dispersion relation of the ferromagnetic spin waves, E(Q)= DQ2 + Eg. We determined the temperature (T) dependence of the stiffness constant D and the spin wave gap
Eg, as shown in Fig. 2 (a) and (b).
T=4K

T=115K

20

20

10

10

0

0

-10

Intensity (arb. units)

1. Introduction
SrRuO3 is a rare material exhibiting a ferromagnetictransition among 4d electron systems: it transitions toa ferromagnetic state at TC = 165 K, takes a nearly-cubic
perovskite type crystal structure, and shows a goodelectric conductivity at low temperatures. Normally,
cubic ferromagnets, such as Fe, Ni, and so on, show
very small magnetic anisotropy, and therefore, theirspin wave gap is negligibly small. On the other hand,
SrRuO3 shows a large magnetic anisotropy and a finite
spin wave gap is observed in it. Also, SrRuO3 shows thatan anomalous Hall resistivity is not proportional to themagnetization [1].
In ferromagnets, the repulsive Coulomb interaction between electrons results in an exchange splitting
between bands with up- and down-spins, which produces spontaneous magnetization. The band crossing
between an up-spin band and a different band withthe opposite spin occurs due to the spin-orbit interaction, when the band overlaps of both spin components
are finite. In this case, the effective Hamiltonian is described by H = v(k-k0)σ with k, σ and v being the momentum, Pauli spin matrices, and velocity, respectively.
This is nothing but Weyl fermion and k0 is called Weyl
point. In the ferromagnetic phase of SrRuO3, a tightbinding model reveals that a number of Weyl points
are produced in the first Brillouin zone [2]. The Weyl
fermion produces the Berry phase, and the Berry curvature takes the form of the magnetic field of a monopole.
The anomalous Hall conductivity σxy is described by the
Berry curvature, and therefore, the fictitious magnetic
field of the monopole is the origin of the anomalous
Hall effect in SrRuO3 [1]. We tried to observe spin waves
in SrRuO3 in order to detect the fictitious magnetic field
as spin dynamics.

-5

0

5

10

-10

T=38K
20

20

10

10

0

0

-10

-5

0

5

T=86K

10

-10
40

20

0

5

10

-5

0

T=165K5

10–1

Q=0.2Å
–1
Q=0.25Å
–1
Q=0.3Å

20

10
0
-10

-5

T=147K0-50

5

10 -10E (meV)

-5

0

5

10

Figure 1.	Observed spectra as a function of E (energy transfer) at several Q values for selected T. Spectra areshifted by a constant to aid the eye. The verticalbars represent statistical errors. The solid lines are
curves fitted to the observed spectra, and the colored areas are magnetic components.

3. Results and summary
We found that D(T) is proportional to the magnetization M(T), which is a rather normal behavior. However,
Eg(T) was found to show a nonmonotonous T dependence, being well-fitted to the theoretical function Eg(T)= a(M(T)/M0)/[1+b(M(T)/M0)(sxy(T)/s0)], where M0 is themagnetization at zero temperature, s0 = e2/ha0 = 9.9 ×
102 W-1cm-1 with a0 = 3.9 Å (lattice constant of SrRuO3), aand b are adjustable parameters (solid line in Fig. 2(b)).
In this analysis, experimental data for M(T) and sxy(T)25Research and Development Highlights

MLF Annual Report 2015

were used: M(T) was determined by the T dependenceof the magnetic Bragg intensity at (100) (Fig. 2(c)), andσxy(T) was determined by the Hall effect measurement(Fig. 2(d)).
In the Hamiltonian of Weyl fermion H = v(k-k0)σ,one can relate the current operator ja linearly to the spin
operator σa (a = x, y, z) by replacing k with k+eA andtaking derivative of H with vector potential A. By using

3(a)

D / D0Eg (meV)

1

SrRuO3
M(T)/M0000.5
T / TC

1

2

1

0

1

(c)

(b)

Weyl fermion
Magnetization
0

bulk
film

σxy / σ0

(M / M0)2
0

-0.1
0.5
T / TC

1

0

(100)
0

0.5
T / TC

1

(d)
0

0.5
T / TC

1

Figure 2.	Stiffness constant D (a), spin wave gap Eg (b), intensity of magnetic Bragg scattering (c), and anomalous Hall conductivity σxy (d) in SrRuO3 as a functionof T/TC. The vertical bars represent experimental errors.

this relation and the Kubo formula (conductivity is expressed as a current-current correlation), the generalized susceptibility for the band-crossing contribution,
which is a spin-spin correlation, is proportional to σxy.
Therefore, the Berry phase can be observed by inelastic
neutron scattering through σxy.
Until this study was completed, Weyl fermions havebeen discussed in transport phenomena, in terms of
spintronics. However, we showed here for the first timethat the spin dynamics reflects directly Weyl fermions [3]. This result has revealed the novel connection
between the transport and dynamical magnetic properties through the enhanced spin-orbit coupling effect.
References[1] Z. Fang, N. Nagaosa, K. S. Takahashi, A. Asamitsu, R.
Mathieu, T. Ogasawara, H. Yamada, M. Kawasaki, Y.
Tokura, and K. Terakura, Science 302, 92 (2003).
[2] Y. Chen, D. L. Bergman, and A. A. Burkov, Phys. Rev.
B 88, 125110 (2013).
[3] S. Itoh, Y. Endoh, T. Yokoo, S. Ibuka, J.-G. Park, Y.
Kaneko, K. S. Takahashi, Y. Tokura, N. Nagaosa,Nature Communications 7, 11788 (2016).
[4] S. Itoh, T. Yokoo, S. Satoh, S. Yano, D. Kawano, J.
Suzuki, and T. J. Sato, Nucl. Instr. Meth. Phys. Res. A
631, 90 (2011).
[5] S. Itoh, Y. Endoh, T. Yokoo, D. Kawana, Y. Kaneko, Y.
Tokura, and M. Fujita, J. Phys. Soc. Jpn. 82, 043001(2013).

S. Itoh1,2, Y. Endoh1,3, T. Yokoo1,2, S. Ibuka1,2, J.-G. Park4,5, Y. Kaneko3, K. S. Takahashi3, Y. Tokura3,6, and N. Nagaosa3,6Institute of Materials Structure Science, KEK; 2Neutron Science Section, Materials and Life Science Division, J-PARC Center; 3RIKEN Center
for Emergent Matter Science; 4Institute for Basic Science; 5Seoul National University; 6Department of Applied Physics, The University of Tokyo

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Research and Development Highlights

Characterization of Ferromagnetic Order in CePd2P2
1. Introduction
A subject of significant interest in the f-electron
systems is the competition between the Kondo effectand magnetic ordering, which frequently result in theoccurrence of exotic quantum critical phenomena. In
this context, a number of Ce compounds were investigated to clarify how the antiferromagnetic ordering
competes with the Kondo effect, but a clear example offerromagnetic (FM) ordering in a Ce compound is difficult to find. This is in striking contrast to the case of
the uranium-based compounds, such as UGe2, URhGeand UCoGe [1]. In order to explore the essential featuresof the FM quantum critical behavior and related phenomena, it would be intriguing to search for a new FM
compound.
Recently, we found a new candidate for the Cebased FM compound CePd2P2 [2]. Although this material was prepared by Jeitschko et al. in 1983, at thattime, its detailed physical properties were not reported,
except for the crystal structure [3]. Only recently, twogroups independently examined the detailed magnetic
properties of CePd2P2, and established the FM orderingwith macroscopic measurements [4, 5]. Especially, Tran
et al. reported an anomalous critical behavior and discussed a possible competition between the ferromagnetism and the Kondo effect in CePd2P2 [5].
We would like to note that CePd2P2 possesses several interesting features: e.g. (i) a large Curie temperaturein spite of a large Ce-Ce distance, (ii) anomalous critical behavior, as reported in ref. [5], and more interestingly, (iii) it is a possible candidate for examining the FM
quantum critical phenomena in a Ce-based compound.
In the present study, we investigate the magnetic structure of CePd2P2 by neutron-scattering experiments, andexamine the FM transition through the DC magnetization measurements in further detail [6]. In addition, weinvestigate the crystalline electric field (CEF) effect on
the 4f electron in CePd2P2 by probing the inelastic neutron scattering spectra.
2. Results and Discussion
To begin with, we confirmed the ferromagnetic ordering in CePd2P2 by the neutron-scattering experiment.
Figure 1 exhibits neutron diffraction patterns measured
at 3 K in the magnetically ordered phase (filled-blue circles) and at 40 K in the paramagnetic phase (filled-red
circles). In order to extract magnetic signals, the intensity measured at 40 K was subtracted from that observed

Figure 1.	Neutron diffraction pattern at 3 and 40 K. The difference of the neutron-scattering intensity between
3 and 40 K is depicted with the open squares. The
numbers on the peaks are the Miller indices.

at 3 K, the residual intensity is depicted in Fig. 1 with
open-blue rectangles. In a low-Q region, no Bragg
peak was observed except for that at the fundamental
Bragg positions. From this difference pattern, it is obvious that the magnetically ordered phase of CePd2P2 isa simple ferromagnetic order. Furthermore, the lack ofa significant change of the intensity at the 002 position
clearly indicates that an ordered moment is parallel tothe c-axis. By analyzing the neutron scattering intensity
at the 101 position, the magnitude of the ordered moment has been evaluated as ~ 1.3(3) µB per Ce ion at 3 K.
A reduction in the ordered moment from the full moment (2.14 µB for J = 5/2) can be attributed to the CEF
and/or the Kondo effect, as discussed in ref. [5].
In Fig. 2(a), we show the isothermal magnetization
curves of CePd2P2 at 2 K. Here, the magnetization datalabeled as “no-oriented” (circles) and “oriented” (triangles) in Fig. 2(a) were measured with an as-grown powder sample and a magnetically aligned powder sample,
respectively. A clear hysteresis in the magnetization
curves is also indicative of the FM ordering in CePd2P2
at low temperatures. The saturation magnetization isevaluated to be about 1 µB and 0.8 µB per Ce ion fororiented and no-oriented powder sample, respectively. The value of the oriented sample is in a reasonable agreement with the evaluated ordered momentfrom the neutron-scattering experiment (~ 1.3 µB). The
slight discrepancy may be due to an imperfection of
the field orientation of the powder sample. In any case,27

Research and Development Highlights

MLF Annual Report 2015

Figure 2.	(a) Magnetic field dependence of the magnetization for CePd2 P2 measured at 2 K. (b) Reciprocal molar magnetic susceptibility of CePd2 P2 as a function of the temperature. Here χ0−1 indicated by “oriented” (triangles) were measured with thepowder sample, which was aligned in the magnetic field of 70 kOe at 345 K. The solid lines are results of a fit. The dash line
is a guide to the eye.

the difference between the oriented and non-oriented
powder sample is indicative of the magnetic anisotropy
in CePd2P2 in the FM ordering state.
Next, we examine the magnetic properties ina paramagnetic region. Figure 2(b) shows the temperature dependence of the reciprocal magnetic susceptibility χ0−1 of CePd2P2 for both “no-oriented” and“oriented” samples. As seen in Fig. 2(b), χ0−1 of the oriented sample is smaller than that of the non-oriented
sample. This difference in χ0−1 in a paramagnetic stateis also indicative of the magnetic anisotropy in CePd2P2
due to the CEF effect.
At high temperatures, χ0 of the oriented sample
shows Curie-Weiss behavior. From the result of a fit(red solid line), the effective magnetic moment andthe paramagnetic Curie-Weiss temperature of CePd2P2
are evaluated as µeff = 2.4(1) µB /Ce and Θp = +13(5) K,
respectively. The evaluated µeff is close to the free ion
moment (2.54 µB) and consistent with the reported
values [4, 5] within the experimental accuracy. On theother hand, Θp differs from their evaluated value (ΘpTran= −2 K [5]). This discrepancy in Θp can be attributed to amagnetic anisotropy owing to the CEF effect. In fact, asimilar negative value of Θp was also obtained for χ0−1 ofour non-oriented sample. In contrast to their interpretation in ref. [5], the positive Θp of our oriented sample isin reasonable agreement with the ferromagnetic transition temperature of TC ~ 28 K, and indicates strong FM
correlations between the magnetic moments of Ce ions.
Additionally, a deviation from the Curie-Weiss law at
28

low temperatures could be attributed to the CEF effectand/or the development of ferromagnetic correlations.
Our neutron-scattering data indicate that themagnetic moments are parallel to the c-axis, so thatthe magnetic easy axis of CePd2P2 can be considered
to be the c-axis. Considering the magnetic anisotropy
observed in the magnetization measurement, a uniaxial (Ising-like) FM ordering is likely to be realized in
CePd2P2.
Finally, we examine the inelastic neutron scattering spectra. Figure 3 shows the energy dependenceof the Q-integrated inelastic neutron scattering intensity of CePd2P2 (blue-closed rectangles) and LaPd2P2(red-open rectangles) measured at 3 K. To extract thecontribution of the CEF excitations, the latter spectra
is properly normalized and subtracted from that ofCePd2P2 as a background. The residual is shown withthe green-filled rectangles. In this Figure, one can observe a clear peak at around 35 meV, indicating the CEF
excitation. The LS ground state of J = 5/2 for 4f1 is lifted
into the G6, G71 and G72 doublets in the tetragonal CEF.
The observed single-peak excitation spectra indicatethat the excited two doublets have almost the same
eigen energy, or, alternatively, the linear combinationof G7 states is possibly negligible in CePd2P2 [7]. In order
to identify the CEF level scheme of CePd2P2, further experimental investigation is indispensable, in particulara magnetic measurement with a single-crystal sample
is important.

MLF Annual Report 2015

Intensity / arb. unit

0.01
Ce
La(normalized)
difference

0.008

Ei = 165.1 meV∆Q = 0-2.0 Å-1with Al cell

0.006
0.004
0.002
0

0

20

40

60

80

E / meVFigure 3.	Energy dependence of the Q-integrated inelastic
neutron scattering intensity of CePd2P2 (blue-closed
rectangles) and LaPd2P2 (red-open rectangles) measured at 3 K. These data are integrated in a low-Q
region [Q = 0 ~ 2 Å-1]. The green-filled rectangles
indicate the difference between those two sets ofdata. Here the data of LaPd2P2 is properly normalized and subtracted from the data of CePd2P2 as a
background. To evaluate the CEF excitation levels of
CePd2P2, we fitted the data with a Lorentzian curve,
shown with solid lines.

3. Conclusion
We have performed a neutron scattering experiment to investigate the magnetic ordering in CePd2P2
and confirmed that an FM order is realized below TC
in CePd2P2. The ordered moment was evaluated to be~ 1.3(3) µB per Ce ion at 3 K. The lack of a significant
change in the neutron-scattering intensity at the 002
position indicates that the ordered moment is parallelto the c-axis. In particular, no evidence of the change inthe magnetic structure was observed below TC within
the experimental accuracy.
In DC magnetization measurements with an asgrown powder sample and with a magnetically aligned
powder sample, a clear magnetic anisotropy was observed in CePd2P2 in both the FM and paramagnetic
phases. Considering the result of the neutron-scattering

Research and Development Highlights

experiment, the magnetic easy axis can be considered
to be the c-axis for CePd2P2. For the oriented sample,
the saturation moment at 2 K of CePd2P2 is about 1 µB
per Ce ion, and it is in reasonable agreement with theneutron-scattering data. From χ0−1 of the oriented sample, the effective magnetic moment and the paramagnetic Curie-Weiss temperature of CePd2P2 are evaluatedas µeff = 2.4(1) µB per Ce ion and Θp = +13(5) K, respectively. The positive value of Θp is in reasonable agreement with TC of CePd2P2 and clearly indicates strong FM
correlations between the magnetic moment of Ce ions.
A clear CEF excitation was observed at around35 meV in the inelastic neutron scattering. The observed single-peak excitation indicates that the exited
CEF states are almost quasi-quartet, or alternatively thelinear combination of G7 states is almost negligible for
CePd2P2.
References[1] As a review paper, e.g. D. Aoki, and J. Flouquet, J.
Phys. Soc. Jpn 83 (2014) 061011.
[2] Konishi S., Ikeda Y., Araki S., Kobayashi C. T. 2013presented at Japan Physical Society March meeting
27aPS33; Ikeda Y., Konishi S., Araki S., Kobayashi C.
T., Yoshizawa H. 2014 presented at Japan PhysicalSociety March meeting 28aPS27.
[3] Jeitschko W. and Hofmann K. W., J. Less-Common
Metals 95 (1983) 317.
[4] Shang T et al., J. Phys.: Condens. Matter 26 (2014)045601.
[5] Tran H. V. and Bukowski Z., J. Phys.: Condens. Matter
26 (2014) 255602.
[6] Y. Ikeda, H Yoshizawa, S Konishi, S Araki, T. C.
Kobayashi, T. Yokoo, and S. Ito J. Phys.: Conference
Series 592 (2015) 012013.
[7] Because the Curie-Weiss behavior was observed ataround 300 K, we expect that the energy scale ofthe second excited CEF state is at most as high as
at room temperature. Therefore, no CEF excitations
may be observed in a higher excitation range thanthose measured in this experiment.

Y. Ikeda1,*, H Yoshizawa1, S Konishi2, S Araki2, T. C. Kobayashi2, T. Yokoo3, and S. Ito3
Neutron Science Laboratory, The Institute for Solid State Physics, The University of Tokyo; 2Graduate School of Natural Science andTechnology, Okayama University; 3Neutron Science Division, Institute of Materials Structure Science, High Energy Accelerator Research
Organization*present address: Institute for Materials Research, Tohoku university

129Research and Development Highlights

MLF Annual Report 2015

Magnetic Excitations in Antiferromagnetic Alternating
Spin-3/2 Chain Compounds RCrGeO5
1. Introduction
We have studied the magnetism of the Cr3+ ions(spin 3/2) in RCrGeO5 (R = Y or rare earth). Figure 1
shows its crystal structure [1]. The Cr3+ spins are expected to form an alternating spin-3/2 chain. We define theexchange interaction parameters J1 and J2 in Cr-Cr pairs
with d1 and d2, respectively. The spin chains are separated from one another by GeO5 square pyramids andR3+ ions.
We performed inelastic neutron scattering (INS)measurements on RCrGeO5 (R = Y or 154Sm) powder using the High Resolution Chopper (HRC) spectrometer
at BL12 (Proposal Nos. 2012S01 and 2012B009). We
confirmed that the spin system of Cr3+ was an antiferromagnetic (AF) alternating spin-3/2 chain [2]. The twocompounds are the first spin-gap compounds with S ≥3/2 except for spin cluster systems. We evaluated J1 =16.0 and J2 = 2.3 meV for YCrGeO5 and J1 = 20.9 and J2 =1.1 meV for 154Sm CrGeO5.
The value of an exchange interaction is determined
mainly by the Cr-Cr distance because a direct exchangeinteraction is dominant. Table 1 shows d1 and d2 values. The J1 and J2 values in YCrGeO5 and 154Sm CrGeO5

are also written. The value of the exchange interaction
decreases with increasing the Cr-Cr distance. We performed INS measurements on RCrGeO5 (R = Ho, 166Er or
Nd) powder to investigate the Cr-Cr distance dependence on magnetism.
2. Experimental methods
Crystalline powder of RCrGeO5 was synthesized using a solid-state-reaction method at 1,523 K in air withintermediate grindings [1]. We performed INS measurements using the High Resolution Chopper (HRC)
spectrometer at BL12 (Proposal Nos. 2012B009 and2015A0016) [3-5].
3. Results and discussion
Figure 2 and 3 show the INS intensity I(Q,ω) mapsof RCrGeO5 powder. Here, Q and ω are the magnitudeof the scattering vector and the energy transfer, respectively. The energy of incident neutrons is Ei = 51.1 and46.1 meV for Figs. 2 and 3, respectively. The bindingsof Q and ω are 0.1 Å-1 and 0.25 meV, respectively. The
intensity is normalized to compare data in different proton numbers and sample weights.

Figure 1. 	A part of the RCrGeO5 structure showing two kindsof Cr-Cr distances in the chain of edge-sharing CrO6
octahedra, GeO5 square pyramids, and R atoms.
Table 1.	Values of d1, d2 and d2/d1 in RCrGeO5. We also show
the J1 and J2 values in YCrGeO5 and 154Sm CrGeO5.
Y
Er
Ho
Sm
Nd

30

d1 (Å)
2.811( 4)2.809(14)2.813(12)2.770( 4)2.781( 6)d2 (Å)
2.872( 4)2.873(14)2.875(12)2.952( 4)2.964( 6)

d2/d1
1.022
1.023
1.022
1.066
1.066

J1 (meV) J2 (meV)
16.0
2.3

20.9

1.1

Figure 2.	Maps of the neutron scattering intensity in theQ – ω plane. The energy of the incident neutrons
Ei is 51.1 meV. The right vertical key shows the INS
intensity in arbitrary units.

MLF Annual Report 2015

Figure 3.	Maps of the neutron scattering intensity in theQ – ω plane. The energy of the incident neutrons
Ei is 46.1 meV. The right vertical key shows the INS
intensity in arbitrary units.

We can see magnetic excitations at 8 ≤ ω ≤ 23 meVin YCrGeO5 and 18 ≤ ω ≤ 23 meV in 154SmCrGeO5. As suggested, the magnetic excitations can be explained by
the AF alternating spin-3/2 chain model.
We can see strong excitations at 10 ≤ ω ≤ 15 meV
in HoCrGeO5 and 9 ≤ ω ≤ 15 meV in 166ErCrGeO5. The excitations remain even at high Q. Probably, crystal-field
excitations of Ho and Er exist in the energy range. The
Q-dependence of the INS intensity around ω = 10 meV,
however, shows a maximum around Q = 1.3 Å-1 (notshown) in both the compounds. The Q-dependencecannot be explained by the crystal-field excitations. We
observed a maximum around Q = 1.3 Å-1 in YCrGeO5.
Therefore, the excitations at 10 ≤ ω ≤ 15 meV in
HoCrGeO5 and 9 ≤ ω ≤ 15 meV in 166ErCrGeO5 include
magnetic excitations of Cr. Weak excitations are seen
up to 24 and 25 meV in HoCrGeO5 and 166ErCrGeO5, respectively, at small Q. The d1 and d2 values are almost
the same in the three compounds. Probably, magnetic

Research and Development Highlights

excitations of Cr exist in almost the same energy range
in the three compounds.
We can see strong excitations at 20 ≤ ω ≤ 25 meVin NdCrGeO5. The excitations remain even at a highQ. Probably, crystal-field excitations of Nd exist in theenergy range. The Q-dependence of the INS intensity
around ω = 20 meV measured using neutrons with Ei= 207 meV shows a maximum around Q = 1.3 Å-1. In
addition, the d1 and d2 values in NdCrGeO5 are close to
those in SmCrGeO5. Therefore, magnetic excitations of
Cr must exist at 20 ≤ ω ≤ 25 meV.
4. Future Plans
We will evaluate the crystal-field excitations of Ho,
Er, and Nd and subtract them from the observed excitations to obtain magnetic excitations of Cr. We will obtain INS intensity maps along the spin chain in RCrGeO5(R = Ho, 166Er or Nd) using the conversion method [6]and evaluate the J1 and J2 values from comparison withthe calculated results as performed in [2].
References[1] R. V. Shpanchenko et. al., J. Solid State Chem. 181,
2433 (2008).
[2] M. Hase, et. al., Phys. Rev. B 90, 024416 (2014).
[3] S. Itoh, et. al., Nucl. Instr. Meth. Phys. Research A
631, 90 (2011).
[4] S. Yano, et. al., Nucl. Instr. Meth. Phys. Research A
654, 421 (2011).
[5] S. Itoh, et. al., Nucl. Instr. Meth. Phys. Research A
661, 58 (2012).
[6] K. Tomiyasu, et. al., Appl. Phys. Lett. 94, 092502(2009).

M. Hase1, S. Asai2, M. Soda2, T. Masuda2, D. Kawana2, T. Yokoo3, S. Itoh3, and M. Kohno1
National Institute for Materials Science (NIMS); 2The Institute for Solid State Physics (ISSP), The Univ. Tokyo; 3High Energy Accelerator
Research Organization (KEK)1

31

Research and Development Highlights

MLF Annual Report 2015

Coherent Spin-Wave Excitations in a Correlated Metallic
Antiferromagnet
1. Introduction
Topological materials have been a standout in thefield of quantum matter ever since the discovery of the
topological insulator [1]. However, their history reaches
back to Quantum Hall insulators (QHIs) are their futureseems ever more exciting with new systems surfacing
every day. Weyl semimetals are characterized by pairsof magnetic monopoles (skyrmions/anti-skyrmions) inmomentum space called Weyl nodes [2]. A distinguishing, but not necessarily unique, feature of WSMs is a surface “Fermi arc”—an incomplete line segment of filledstates which connects a pair of bulk Weyl nodes via the2D projection onto the surface. Such surface states havebeen observed by ARPES in a variety of materials following the initial discovery in the non-centrosymmetric
TaAs [3], and have been proposed to exist in Mn3Sn [4].
The anomalous Hall Effect observed in Mn3Sn at hightemperatures is may be explained if characterized as a
WSM, but definitive evidence awaits [5].
Weyl semimetals present a unique case where theorigin of the topological properties themselves is a particular pseudo-spin construction in k-space [6]. The potential for neutron scatter is paramount but relies onaccess to large ranges of momentum transfer, including the difficult to reach low-Q inelastic regime. The
High Resolution Chopper spectrometer (HRC) is aptly
designed to fill this tall order to separate the ordinary
scattering from the potentially anomalous.
2. Magnetic dispersion in Mn3Sn
We utilized a 200 meV incident energy conFiguration on the HRC at JPARC to map the full bandwidth ofdispersive magnetic modes in the metallic Mn3Sn. The
12 g sample used for this experiment was co-aligned
into a (3 cm)3 volume using the forward scattering xray Laue facilities available at ISSP (see Fig. 1), enabling
the use of the small angle detector bank typically used
for powder samples. With the multi-rep conFiguration
allowing 200 meV, 45 meV, and 19 meV the range of excitation energies covered in the first Brillouin zone wasimpressive.
The steep magnetic dispersion is clearly shown in
Fig. 2 for modes traveling along a (120)-type axis of thehexagonal plane. For an itinerant system, these excitations are surprisingly coherent. A complimentary viewof the hexagonal plane is shown Fig. 3. The presence of32rings at the finite energy transfer of 45 meV indicatesmodes propagating in all basal directions. The slightasymmetry of the spin-wave velocities seen here also
extends into the orthogonal direction. Past studies using a triple-axis spectrometer found the excitations
along the (00L) direction to be consistent with a linear spin-wave theory [7]. On the basis of our measurements, a localized magnetic component does seem tobe present for all independent crystal directions and anassessment of the degree to which this is captured by alinear model is underway.
Lastly, we made use of the small-angle scattering
capabilities of HRC to access the 1st Brillouin zone, where
the hexagonal symmetry of the magnetic scattering is
also discernable. While the wide angle scattering seems
the most reliable indicator of coherent excitations originating from magnetic moments with a relatively sharp
form factor, it is the low-angles that will be most sensitive to deviations from this conventional case. With
careful background subtraction and normalization toa vanadium standard, we hope this data can be used inconjunction with that from the other detector banks.

Figure 1.	Co-aligned sample of Mn3Sn (12 g). Alignment was
performed using the forward scattering X-ray Laueapparatus in the Masuda Lab at ISSP.

MLF Annual Report 2015

Research and Development Highlights

4. Future Plans
The extensive dataset on Mn3Sn gathered using
the HRC should be sufficient to establish an accurate
spin Hamiltonian. The first stage is to perform a global fit of a linear spin-wave theory consistent with themagnetic ground state. We will also combine the small
and wide angle scattering data by careful normalization in an effort to establish whether a localized modelis incomplete. If so, a follow-up experiment may well bewarranted.
Figure 2. Magnetic dispersion of Mn3Sn at 5 K.

Figure 3.	Dispersive rings for Mn3Sn shown in the hexagonalplane. The aspect ratio has been chosen to respect
the physical scattering angles.

References[1] M. Hasan and C. Kane, Rev. Mod. Phys. 82, 3045
(2010).
[2] X. Wan, A. M. Turner, A. Vishwanath, and S. Y.
Savrasov, Physical Review B 83, 205101 (2011).
[3] B. Q. Lv et al., Physical Review X, 5(3):031013, July
2015.
[4] H. Yang et al., https://arxiv.org/abs/1608.03404(preprint).
[5] S. Nakatsuji, N. Kiyohara, and T. Higo. Nature, Oct.
2015.
[6] M. Bjerngaard, B. Galilo, and A. Turner. Probing spinmomentum locking of Weyl nodes with neutron scattering. Bulletin of the American Physical Society,Mar. 2016.
[7] J. W. Cable, N. Wakabayashi, and P. Radhakrishna,
Physical Review B 48, 6159 (1993).

G. G. Marcus1, J. Kindervater1, M. Ikhlas1, N. Kiyohara1, M. Soda2,3, S. Nakatsuji2, T. Masuda2,3, and C. L. Broholm1
Institute for Quantum Matter, Department of Physics and Astronomy, Johns Hopkins University; 2Institute for Solid State Physics, Universityof Tokyo; 3Neutron Science Section, Materials and Life Science Division, J-PARC Center

1

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Research and Development Highlights

MLF Annual Report 2015

Magnetoelectric Coupling in the Honeycomb
Antiferromagnet Co4Nb2O9
1. Introduction
Co4Nb2O9 is one of the magnetoelectric multiferroics. This material belongs to the A4B2O9 (A = Co, Fe,
Mn, and B = Nb, Ta), which have been studied since
1960’s [1]. In Co4Nb2O9, the Co(1) and Co(2) honeycomb
layers alternately stack along the c-axis. Bertaut and coworkers analyzed its powder neutron diffraction patterns and reported that the Co2+ magnetic moments
are ordered in a antiferromagnetically parallel way
to the trigonal axis below TN = 27.4 K, resulting in themagnetic space group P-3’c’1 with identical magnetic
and crystallographic unit cells [1]. As a consequence,a linear ME effect is expected. In fact, the ME effect inpolycrystalline Co4Nb2O9 was first reported by Fischer
et al. [2] and reinvestigated recently by Fang et al. [3],which revealed a large magnetoelectric coupling. In
addition to the electric polarization induced by a magnetic field, they found out that Co4Nb2O9 also exhibits alarge modification in the magnetization by an electricfield in the antiferromagnetic phase.
Motivated by these facts, we performed an investigation using single crystals of Co4Nb2O9, necessary to
elucidate intriguing ME properties in this material [4].
2. Experimental details
Single crystals of Co4Nb2O9 were grown by the floating zone method. The crystallographic principal axes
were determined by using x-ray Laue photographs. The
magnetization was measured by using MPMS. The Lauephotograph and magnetization measurement were
performed at ISSP, University of Tokyo. The magnetic

structure was determined by neutron diffraction of asingle crystal (diameter of 0.5 cm and length ~1 cm)
using the time-of-flight neutron diffractometer BL18SENJU, installed at MLF, J-PARC. Intensities of 480 reflections (in condition I > 3σ) were collected at T = 10 K.
The crystal and magnetic structures with atomic coordination, scale factor, extinction, and volume fraction
parameters were refined using JANA 2006 [5] and visualized by VESTA [6].
3. Results
In the single-crystal neutron diffraction measurement, we observed an increase of 00l magnetic Braggreflections with l = 2n below TN as shown in Fig. 1, whichclearly indicates the ordering of the in-plane components of the Co2+ magnetic moments. It contradicts theearly magnetic structure analysis by Bertaut et al. [1].
According to a symmetry analysis, if the trigonal symmetry is retained, the magnetic moments should beparallel to the trigonal axis, which is not consistent withthe existence of 002 magnetic reflection and anisotropy in the magnetic susceptibility [4]. The magnetic
structure can be described as antiferromagnetic monoclinic or triclinic space group as C2/c’, C2’/c, or P-1’. We
obtained the best agreement between experimental
data and calculation for magnetic models, described bymonoclinic magnetic space groups C2/c’ with residual
factor R = 8.38% (wR = 15.72%), as shown in Fig. 2. In
this magnetic structure, the Co2+ magnetic moments
are aligned perpendicularly to the [110] direction. In ahoneycomb layer, the neighboring Co2+ moments are

Figure 1.	Laue pattern of Co4Nb2O9 recorded at BL18, MLF/J-PARC, and temperature dependence of the integrated intensity of 002
magnetic Bragg reflection.

34

MLF Annual Report 2015

Research and Development Highlights

800

FC

R = 8.38%
wR = 15.72%
600
C 2/c'
400
200
0

10 K
0

200

400

600

800

Fo
Figure 2.	Comparison between observed and calculated intensities of the magnetic reflections, and a refined magnetic
structure of Co4Nb2O9.

arranged in opposite directions. The antiferromagnetic
honeycomb layers stack along the trigonal axis withoutchanging the spin orientation. The magnitudes of themagnetic moments of Co2+ at distinct crystallographic
positions, denoted as Co(1) and Co(2), are 3.5 μB and2.6 μB, respectively. Both magnetic moments are cantedby around 20° away from the basal plane. From the result of the measurement of the magnetoelectric effect,
this compound has non-zero off-diagonal terms of thelinear magnetoelectric tensor. The magnetic structure isconsistent with the anisotropy of the magnetoelectriceffects [4].
4. Conclusion
We revised the magnetic structure of magnetoelectric multiferroic Co4Nb2O9 by using single crystal

neutron diffraction. The in-plane components of theCo2+ magnetic moments are aligned antiferromagnetically, which induces off-diagonal terms of the linear
magnetoelectric tensor.
References[1] E. F. Bertaut et al., J. Phys. Chem. Solids, 21, 234(1961).
[2] E. Fischer et al., Solid State Commun. 10, 1127
(1972).
[3] Y. Fang et al., Sci. Rep. 4, 3860 (2014).
[4] N. D. Khanh et al., Phys. Rev. B, 93, 075117 (2016).
[5] V. Petricek et al., Z. Kristallogr. 229, 345 (2014).
[6] K. Momma and F. Izumi, J. Appl. Crystallogr. 44,
1272 (2011).

N. D. Khanh1,2, N. Abe1, H. Sagayama3, A. Nakao4, T. Hanashima4, R. Kiyanagi5, Y. Tokunaga1, and T. Arima1
Department of Advanced Materials Science, University of Tokyo; 2Department of Physics, Tohoku University; 3Institute of Materials Structure
Science, KEK; 4Neutron R&D Division, CROSS-Tokai; 5Materials and Life Science Division, J-PARC Center

1

35

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MLF Annual Report 2015

Spin Excitations in Hole-Overdoped Iron-Based
Superconductivity
1. Introduction
Since the superconducting phase of iron pnictides
lies beside the static antiferromagnetic (AFM) ordering
phase, significant efforts have been focused on examining their spin dynamics. In order to clarify the role ofmagnetism for superconductivity in Fe-based superconductors, understanding the overall spin dynamics by using inelastic neutron scattering (INS) is indispensable.
INS studies on the spin fluctuations of non-doped
AFe2As2 (A = Ba, Sr or Ca) over the entire Brillouin zone
have clarified that the spin dispersion can be well described by the J1-J2 model. However, it is unclear whether the model, which is based on a localized spin picture,
is valid because the carriers show an itinerant character.
To establish a definitive model of magnetism in a widehole-doping range, we report the overall spectra ofspin fluctuations in hole-overdoped Ba1-xKxFe2As2 obtained by the INS technique.
2. Experiments
Single crystals of Ba0.5K0.5Fe2As2 (Tc = 36 K) andKFe2As2 (Tc = 3.4 K) were grown by the KAs self-flux
method [1].
The INS measurement was performed using the
Fermi chopper spectrometer 4SEASONS in J-PARC [2].
We co-aligned 160 and 300 single crystals with x = 0.5(~5 g) and x = 1 (~5 g), respectively. We employed themulti-Ei method with incident neutron energies of Ei =31, 65, 110, 202, 409, 720 meV for Ba0.5K0.5Fe2As2 and Ei =30, 75, 149, 423 meV for KFe2As2. The incident beam wasparallel to the c-axis.

(a) x = 0.5, Ei = 409 meV, 0.7 ≤ H ≤ 1.3

3. Results
We describe the (H, K) plane with orthorhombic notation, even though the superconducting Ba1-xKxFe2As2
has a tetragonal crystal structure to facilitate comparison with non-doped BaFe2As2. In x = 0.5, clear incommensurate peaks appeared around the (±1, 0) and(0, ±1) splitting along the longitudinal direction witha wave vector of (±2δ, 0) and (0, ±2δ), respectively,
where δ = 0.06 at E = 13 meV. The (1±2δ, 0) position
corresponds to [π(1±2δ,0)] in the ab plane and (0.5±δ,
0.5±δ) in tetragonal notation. As the energy increases,
spin excitations start to split along the transverse direction corresponding to (±1±2δ, K) or (H, ±1±2δ) andreach the magnetic zone boundary with merging signals from the next zone boundaries. Figure 1(a) shows
the dispersion cuts along the transverse direction (1, K)
in Ba0.5K0.5Fe2As2. A clear spin wave-like dispersion wasobserved up to E = 200 meV, similarly to the case of x =0 and 0.33 [3].
In x = 1, on the other hand, the dispersive spin excitations reach the zone boundary around E = 80 meV,which is considerably lower than the energy for x = 0.5(Fig.1(b)). Instead, a vertical dispersion with a chimneylike structure was observed from E = 80 meV up to
200 meV (Fig.1(c)). This chimney-like structure cannot
be explained by the J1-J2 model, suggesting this structure has originated from itinerant character of electrons. In x = 0.5, signals of the chimney-like structure
can also be found above E = 200 meV, but they are lessclear than those in x = 1.

(b) x = 1.0, Ei = 149 meV, 0.38 ≤ H ≤ 0.98(c) x = 1.0, Ei = 423 meV, 0.2 ≤ H ≤ 1.8

300

240

80
200

100

Energy (meV)

Energy (meV)

Energy (meV)

220
60
40
20
0
-3.0 -2.0 -1.0
0 1.0
[1, K] (r.l.u.)

2.0

3.0

0
-3.0 -2.0 -1.00
1.0 2.0[0.68, K] (r.l.u.)

200
180
160
140
120

3.0

100
-3.0 -2.0 -1.0 0 1.0 2.0 3.0[1, K ] (r.l.u.)

Figure 1.	Dispersion cuts of (a) Ba0.5K0.5Fe2As2 and (b) KFe2As2 along the K direction, respectively. The solid lines are a guide to the eye. The
vertical white-dashed lines depict the magnetic zone boundaries. (c) High-energy spin excitation of KFe2As2 with Ei = 423 meV.

36

MLF Annual Report 2015

Research and Development Highlights

Figure 2. Phase diagram of Ba1-xKxFe2As2. Symbols denote Tc (open circles), The Néel temperature TN (open squares), the total fluctuating magnetic moment <m2> (closed circles), bandwidth of the spin wave W (closed squares), and the incommensurability δ (closed diamonds).

4. Discussion
We summarize the phase diagram of this system inFig. 2. The present observations demonstrate that theenergy scale of the dispersive spin wave is robust uponhole doping up to x = 0.5, which is followed by a rapid
decrease up to x = 1. The smaller band width of the spinwave leads to a less-effective magnetic exchange coupling J according to the Heisenberg model. The smallvalue of J in KFe2As2 is consistent with the fact that its
electronic interaction strength U is quite large.
The chimney-like structure can originate from particle-hole excitations, which define the itinerant character of the spin fluctuations. Note that the chimney-likestructure resembles the spin excitations in the itinerant
AF metals such as Cr [4]. The present results show thatthe bandwidth decreases and the chimney-like dispersion appears with hole doping. This is qualitatively
consistent with DFT + DMFT calculations [5], which also
supports the view that cause of the chimney-like dispersion could be the particle-hole excitations.
The suppression of Tc in hole-overdoped (Ba,K)
Fe2As2 can rather be attributed to the reduction of J,
which remains almost constant from the non-doped tothe optimum-doped region and is followed by a rapid
reduction in the overdoped region. The J dependenceof the superconductivity has also been suggested instudies on spin resonance. Stronger magnetic correlation leads to a larger energy split between the resonance and the superconducting gap energy. In fact,
the resonance energy in overdoped (Ba,K)Fe2As2 approaches the superconducting gap energy with doping
up to x = 0.77 [6], which can result from the reductionof J. These results lead to the conclusion that there is astrong relationship between magnetism and superconductivity in Ba1-xKxFe2As2. This work has been publishedin Sci. Rep. [7].
References[1] K. Kihou et al., J. Phys. Soc. Jpn., 85 034718 (2016).
[2] R. Kajimoto et al., J. Phys. Soc. Jpn., 80 SB025 (2011).
[3] M. Wang et al., Nat. Commun., 4 2874 (2013).
[4] Y. Endoh et al., J. Phys. Soc. Jpn., 75 111002 (2006).
[5] Z. P. Yin et al., Nat. Phys., 10 845 (2014).
[6] C. H. Lee et al., Sci. Rep., 6 23424 (2016).
[7] K. Horigane et al., Sci. Rep., 6 33303 (2016).

K. Horigane1, K. Kihou2, K. Fujita3, R. Kajimoto4, K. Ikeuchi5, S. Ji6, J. Akimitsu7, and C. H. Lee2
Graduate School of Natural Science and Technology, Okayama University; 2National Institute of Advanced Industrial Science and Technology(AIST); 3Aoyama Gakuin University; 4J-PARC Center, Japan Atomic Energy Agency; 5Neutron R&D Division, CROSS-Tokai; 6Max Plank
POSTECH Center for Complex Phase Materials; 7Research Center of New Functional Materials for Energy Production, Storage, andTransport, Okayama University

137Research and Development Highlights

MLF Annual Report 2015

Tetra-Ortho-Tetra Type Phase Transitions andInhomogeneous Magnetism in Sr2VO4
1. Introduction
Sr2VO4 is attracting renewed attention as a candidate compound for a d1 Mott insulator showing novel
spin-orbital magnetism. It has a tetragonal K2NiF4 structure with the space group I4/mmm at room temperature. The V4+(3d1) is octahedrally coordinated with six
ligand oxygen ions, where the octahedron is elongatedalong the c axis. The crystal field partially lifts the threefold degeneracy of the t2g orbitals by splitting theminto dxy and dyz/dzx orbitals with dxy having a higher
energy. Thus, the single d-electron would occupy theunquenched dyz/dzx orbitals in case of a negligible spinorbit interaction. However, it has been pointed out thatthe spin-orbit coupling may be large enough to split
the dyz/dzx state into two Kramers doublets [1]. It wasalso suggested that a magnetic octupole order would
be the ground state of Sr2VO4.
Recently, several groups successfully synthesizedhigh quality polycrystalline samples. The magnetic
susceptibility (χ) and heat capacity measurements
confirmed that the compound successively undergoes
three phase transitions at Tc0 ∼ 10 K, Tc1 ∼ 100 K, and Tc2∼ 130 K [2,3]. Regarding the magnetic properties, the χ
showed a sudden drop just below Tc1 and a clear hysteresis was observed in the magnetization measurement
below Tc0. A previous muon spin relaxation (mSR) study
reported an anomalous magnetic ordered state with residual magnetic fluctuation, which has been observedin several geometrically frustrated magnets, in the temperature (T) range of 1.8 K < T < Tc0 [4].
To gain a further insight into the three phase transitions in Sr2VO4, we performed synchrotron radiation
x-ray diffraction (SR-XRD) and mSR experiments on
polycrystalline sample [5]. We carried out the SR-XRD
experiment at the BL-8A Photon Factory (KEK-PF) anda mSR measurement was made at the D1 instrument at
J-PARC MUSE above 4.2 K. Then, we extended the mSR
measurement down to 30 mK by using the dilution refrigerator furnished on the M15 beamline at TRIUMF,
Canada.
2. Synchrotron radiation x-ray diffraction
Above Tc2, the SR-XRD patterns were successfully indexed by a tetragonal structure with the I4/mmm spacegroup as reported in the previous study [2]. Figure 1
shows the T variation of the half width at half maximum
38

Figure 1.	Temperature dependence of the half width at half
maximum (HWHM) of the selected peaks for the SRXRD patterns [5].

(HWHM) for the selected diffraction peaks. In the T rangeof Tc1 < T < Tc2, the HWHM of the 200 and 420 peaks increased with decreasing T, although we could not findany additional peaks in the SR-XRD patterns. On theother hand, the 110, 004, and 002 peaks did not exhibit
broadening within the experimental accuracy. These
results might be attributed to the existence of an orthorhombic phase for Tc1 < T < Tc2. The absence of broadening in the 110 peak suggests no diagonal distortion
along the <110> direction. It also excludes the coexistence of two tetragonal phases, which had been suggested in a previous study [2]. The enhancement in the
HWHM for 420(200) peak is explained by the tiny splitting of the peak into 420(200) and 240(020) peaks dueto the expansion and contraction of the two tetragonala axes. We confirmed clear difference between tetragonal I4/mmm and orthorhombic Immm space groups in
the reliability factor (Rwp) of the Le Bail analysis. For instance, Rwp = 9.5% for I4/mmm and Rwp = 8.6% for Immm
at 114 K.
However, the HWHMs of the 420 and 200 peaks
show sudden decrease just below Tc1 and become identical to ones above Tc2 within the experimental uncertainty, as shown in Fig. 1. We obtained similar valuesof Rwp with the I4/mmm and Immm structures, for instance, Rwp = 9.7% for I4/mmm and Rwp = 9.4% for Immm
at 66 K. These results suggest that the intermediate orthorhombic phase appears in the Tc1 < T < Tc2, whereas
tetragonal phases appear in the Tc0 < T < Tc1 and Tc2 < T.

MLF Annual Report 2015

3. Muon spin relaxation
Figure 2(a) shows zero-field (ZF)-mSR spectra at
300 K and 80 K (i.e., above and below Tc1). There is nosign of an emergence of spontaneous internal magnetic field, such as oscillation and/or fast damping, below
Tc1. This immediately leads us to the conclusion that nolong-range magnetic order is present crossing Tc1.
We show mSR spectra at 30 mK measured at ZF andlongitudinal-field (LF) of 100 mT in Fig. 2(b). As shownin Fig. 2(b), a rapid depolarization develops below Tc0.
This data clearly demonstrates the absence of a conventional long-range magnetic order at the base T.
The initial fast depolarization exhibits a gradual suppression when LF increases and is nearly quenched at
LF = 100 mT. Surprisingly, the spectra exhibit a slow
exponential decay over a long time even at 30 mK irrespective of LF, which may be attributed to a residual
spin fluctuation. These features can be observed fromthe magnetic ordered state with widely distributed

Figure 2.	(a) Zero-field (ZF) μSR time spectra at 300 K and
80 K. (b) μSR spectra at 30 mK under ZF and longitudinal-field (LF) of 100 mT [5].

Research and Development Highlights

spontaneous local field (Bloc) at the muon site and slow
persistent spin dynamics.
We adopted the Gaussian-broadened Gaussian(GbG) function as a recursive function for the curve
fitting [6], which is appropriate for inhomogeneous
magnetic ordered states with distributed Bloc. From theanalysis, we estimated the mean spontaneous internal
field at the muon site to be 12.1(7) mT. According to ourHartree potential calculation, the potential minima fora muon are located around the (0.50,0.24,0.69) position. Assuming randomly oriented 1mB V d-electron moments, we obtained the hyperfine coupling constant,~52 mT/mB, at the relevant muon site. Thus, we roughly estimated the ordered moment at the V site to be~0.2mB. This value is much smaller than the dipole moment for the V4+(3d1) ion with quenching of the orbital
moment, meff ~ 1.7mB for S = 1/2.
Finally, we briefly discuss the origin of the inhomogeneous magnetism. Imai et al. revealed that there issevere competition between many spin-orbital orderpatterns due to the coexistence of ferromagnetic andantiferromagnetic interactions and the associated effect of frustration in Sr2VO4 from their first-principal
calculation [7]. We suggest that the observed broad Bloc
distribution and persistent spin dynamics are signatures of the severe competition between the possible
spin-orbital ordered patterns in Sr2VO4.
References[1]	G. Jackeli and G. Khaliullin, Phys. Rev. Lett. 103,
067205(2009).
[2]	H. D. Zhou et al., Phys. Rev. Lett. 99, 136403 (2007).
[3]	R. Viennois et al., J. Physics : Conf. Ser., 200, 012219(2010).
[4]	J. Sugiyama et al., Phys. Rev. B, 89, 020402(R) (2014).
[5]	I. Yamauchi et al., Phys. Rev. B, 92, 064408 (2015).
[6]	D. R. Noakes and G. M. Kalvius, Phys. Rev. B, 56, 2352
(1997).
[7]	Y. Imai et al., Phys. Rev. Lett., 95, 176405 (2005).

I. Yamauchi1,*, K. Nawa2,3,**, M. Hiraishi1, M. Miyazaki1,***, A. Koda1,4, K. M. Kojima1,4, R. Kadono1,4, H. Nakao4,5, R. Kumai4,5,
Y. Murakami4,5, H. Ueda2, K. Yoshimura2, and M. Takigawa3
1
Muon Science Laboratory and Condensed Matter Research Center, Institute of Materials Structure Science KEK; 2Department of Chemistry
Graduate School of Science, Kyoto University; 3Institute for Solid State Physics, University of Tokyo; 4The Graduate University for Advanced
Studies (Sokendai); 5Photon Factory and Condensed Matter Research Center, Institute of Materials Structure Science, KEK*Present address: Department of Physics, Graduate School of Science and Engineering, Saga University; **Present address: Institute ofMultidisciplinary Research for Advanced Materials, Tohoku University; ***Present address: Graduate School of Engineering, MuroranInstitute of Technology

39

Research and Development Highlights

MLF Annual Report 2015

Lattice Dynamics and Crystal Fields in the Rare Earth
Pyrochlores R2Ti2O7 (R = Tb, Dy, Ho)
1. Introduction
The title compounds are rare earth pyrochlores,
materials in which the magnetic rare earth ions form apyrochlore lattice of corner sharing tetrahedrons (the titanium ions form a second interpenetrating pyrochlore
lattice but are non-magnetic). The pyrochlore lattice is
one of the most frustrated three-dimensional lattices
known, and the three compounds have a long history
in the study of highly frustrated magnetism [1]. With R= Dy, Ho, the materials are spin ices [2] with emergent
magnetic monopole excitations [3], while with R = Tb,a non-frustrated counterpart to the spin ice state is expected, so the spin liquid state, which appears instead,is an on-going puzzle.
The crystal field scheme of a compound based onrare earth ions is very important, since it controls basic
single ion properties, such as the size of the magnetic
moment and anisotropy, as well as more complex ones,
such as matrix elements for tunneling of the magnetic
moments, all important quantities in spin ice physics.
The phonon band structure is also important, since itallows us to understand properties, such as thermal
expansion and the lattice heat capacity. Knowledge ofboth crystal field and phonons is essential for understanding interactions between crystal field and phonontransitions. Such interactions are strong in Tb2Ti2O7, andmay also contribute to spin-lattice relaxation processesof interest in the spin ices. Little is known about the lattice dynamics of rare earth pyrochlores, and the crystal
field scheme of Dy2Ti2O7 has not previously been determined experimentally due to the perceived difficultyof neutron scattering on samples containing natural
isotopic abundance dysprosium. We planned to use
the 4SEASONS spectrometer at J-PARC to rectify this
0

4

6

8

10 0

a

40
Energy (meV)2situation by measuring both crystal field levels andphonon density of states in Dy2Ti2O7 (we measured theother two compounds at ISIS using MERLIN).
2. Experimental
The properties of spin ices derive in part fromtheir strongly anisotropic magnetic moments, which
are due to a large crystal field splitting, with the firstlevel in Dy2Ti2O7 expected at ~30 meV. So, to measure
the crystal field scheme, it was necessary to search fortransitions from the ground state at low temperature,
up to a reasonably high energy (e.g 100 meV) to ensure that all levels were located. However, it was also
useful to seek transitions amongst excited states thatappear at a higher temperature as the lowest groundstate transitions are populated, but may themselves
have quite small energies, if the excited states are notwidely separated. 4SEASONS [4] is particularly suitable
for this task because of the possibility to collect several
incident energies at once by repetition rate multiplication [5]. Indeed, although we eventually measured with
Ei = 300 meV to ensure we had really found all possiblelevels, in fact we could have used just the setting of Ei =153 meV, which also allows to collect with Ei = 55, 28, and17 meV, as eventually the highest level was at 93 meV.
The simultaneously collected lower incident energies
provide good resolution at lower energy levels. The
problem of the absorption cross section of dysprosium
was handled by ensuring that the sample thickness did
not exceed 0.5 mm, the optimum thickness for our lowest incident energy. After subtracting the backgroundof the aluminum sample can, we obtained clean data at
5 and 200 K, and a full set of transitions.

1

2

3

4

5 0

10

20

30

40

50

2

4
6
|Q| (Å−1)

8

10

c

b

30
20
10
0

0

2

4
6
|Q| (Å−1)

8

10 0

2

4
|Q| (Å−1)

60

Figure 1. Crystal field transitions in Ho2Ti2O7 (a), Dy2Ti2O7 measured on 4 SEASONS (b), and Tb2Ti2O7 (c).

40

MLF Annual Report 2015

3. Results
From the data [6], we extracted energies of the crystal field transitions [7] and phonon density of states [8].
In Dy2Ti2O7, their wave-vector dependence exactly follows the magnetic form factor of Dy3+, allowing theirunambiguous identification. Only one was difficult todistinguish, but our crystal field calculations showedthat it was very weak and likely overlapping another ofthe highest energy transitions. Although the composition of the ground state doublet was strongly dominated by |mj = +/-15/2> components, as expected,
it was important to verify it experimentally. The firstexcited level at E~21 meV was somewhat lower than
expected. We compared the phonon density of stateswith the other two compounds, for which we also performed density functional calculations [8]. In this way,
we were able to assign the symmetries and energies ofphonons in all three compounds, and to establish thatthe phonon energies undergo a minor softening as one

a

0.02

LEHE

gNW(E) (meV−1)

0.01

Ho2Ti2O7
Calculation

0

Tb

b

0.02

Dy
Ho

0.01

R2Ti2O7
T = 200 K

0

0

20

40
60
Energy (meV)

80

100

Figure 2.	Phonon density of states in the R2Ti2O7 pyrochlores(R = Tb, Ho, Dy) extracted from the powder inelastic
neutron scattering data and compared with density functional calculations for Ho2Ti2O7.

Research and Development Highlights

moves to heavier rare earths. We expect this conclusion
to apply quite generally across the series of rare earthtitanate pyrochlores. We have been able to use ourquantification of the lattice dynamics to understandanomalies in the temperature dependence of the lattice expansion of all three compounds [9], and our combined understanding of the crystal field and phonon
levels to propose both a quantitative model for hightemperature spin flipping in the spin ices by an Orbach
mechanism [10] and a new example of a crystal fieldphonon bound state in Tb2Ti2O7 [7].
References[1]	J. S. Gardner, M. J. P. Gingras, and J. E. Greedan, Rev.
Mod. Phys. 82, 53 (2010).
[2]	S. T. Bramwell and M. J. P. Gingras, Science 294,
1495 (2001).
[3]	C. Castelnovo, R. Moessner, and S. L. Sondhi, Nature
451, 42 (2008).
[4]	R. Kajimoto et al., J. Phys. Soc. Jpn. 80, SB025 (2011).
[5]	M. Nakamura, R. Kajimoto, Y. Inamura, F. Mizuno,
M. Fujita, T. Yokoo, and M. Arai, J. Phys. Soc. Jpn. 78,
093002 (2009).
[6]	Y. Inamura, T. Nakatani, J. Suzuki, and T. Otomo, J.
Phys. Soc. Jpn. 82, SA031 (2013).
[7]	M. Ruminy, E. Pomjakushina, K. Iida, K. Kamazawa,D. T. Adroja, U. Stuhr, and T. Fennell, Phys. Rev. B 94,
024430 (2016).
[8]	M. Ruminy, M. N. Valdez, B. Wehinger, A. Bosak,
D. T. Adroja, U. Stuhr, K. Iida, K. Kamazawa, E.
Pomjakushina, D. Prabakharan, M. K. Haas, L.
Bovo, D. Sheptyakov, A. Cervellino, R. J. Cava, M.
Kenzelmann, N. A. Spaldin, and T. Fennell, Phys.
Rev. B 93, 214308 (2016).
[9]	M. Ruminy, F. Groitl, T. Keller, and T. Fennell, Phys.
Rev. B 94, 174406 (2016).
[10]	M. Ruminy, S. Chi, S. Calder, and T. Fennell, submitted.

T. Fennell1, M. Ruminy1, K. Iida2, and K. Kamazawa2Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut; 2Comprehensive Research Organization for Science and Society(CROSS)

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Research and Development Highlights

MLF Annual Report 2015

Neutron Diffraction up to 41.2 T- the New Record
Established at the J-PARC NOBORU Beamline
1. Introduction
Through the combined efforts of scientists working at materials discovery and specialized high-field
laboratories worldwide, a steady flux of novel materials
displaying exotic phases and phase transitions at highmagnetic fields is emerging. Typical material classes aresuperconductors, multiferroics, magnetoelectrics andquantum magnets. In many such cases, the identification of the magnetic propagation vector(s) is a significant step towards a full understanding the microscopic
physical processes responsible for the occurrence of
these phases. Short of a full determination of the magnetic structures at elevated fields, the propagation
vector(s) provide strong constraints on theory.
For many years, neutron scattering experiments
dedicated to understanding the response of materials
subjected to magnetic fields were limited by the 15 T
provided by commercially available Oxford Instruments
cryomagnets. Laboratory equipment is, however, capable of measurements at far greater fields. Neutron
scattering has therefore failed to make a large impact
on the research on several topical materials where theintrinsic magnetic energy scales are such that the phenomena of interest (quantum phase transitions, magnetization plateaux, etc) occur beyond 15 T.
Recently, two developments have significantly
boosted the range of magnetic fields achievable at neutron sources, thereby bringing within reach new quantum phases. One is the development, at the Helmholtz
Center Berlin, of a Laue diffractometer (EXED) centeredon a hybrid high-field magnet combining resistive andsuperconducting coils to reach a maximum DC field of
26 T [1, 2]. The second development, promising evenlarger magnetic fields is the introduction of pulsed-fieldtechnology. Compared to the hybrid magnet setup,
the pulsed-field solution is significantly cheaper, andprovides promising perspectives for further increases
in the maximum field. It has been successfully demonstrated in combination with neutron, synchrotron x-ray
and free electron laser x-ray diffraction [3-6].
2. Pulsed-field setup at NOBORU
At J-PARC MLF beamline 10 (NOBORU), a 500kJ capacitor bank and a 50-T mini-solenoid pulsed
magnet are installed. Until now, the system has beenused to provide magnetic fields of up to 40 T with an
42

8 millisecond pulse width. The sample of interest is
mounted inside the 12-mm mini-solenoid bore of a
specially-built insert for a standard cryostat. The sample
temperature can be controlled by the cryostat, while
the magnet is immersed in a liquid nitrogen bath. By
precisely timing the onset of the field pulse relative tothe arrival of a “white” neutron beam at the sample position, it is possible to perform Laue diffraction experiments at cryogenic temperatures and very high fields.
However, the much desired increase in field range
comes at the expense of a significant reduction in the
count rate achievable. This is caused by the need to cool
the apparatus and sample after each field pulse. In theexperiment described below, the typical cooling time
between each 8-millisecond pulse was 18 minutes formagnetic fields in the range 30-41 T.
3. Results on LiNiPO4Here we present the results of our studies of themagnetoelectric Lithium orthophosphate LiNiPO 4 at
NOBORU. In LiNiPO4 application of a magnetic fieldalong the crystallographic c-axis causes the development of an electrical polarization P = αH along the aaxis. The magnetoelectric coefficient αxz is among thelargest in transition metal compounds. Previous neutron diffraction experiments, extending to 17.3 T, haverevealed a complex sequence of commensurate andincommensurate magnetic phases in LiNiPO4 for fields
along c, and have demonstrated how its magnetoelectricity is controlled by field-induced spin canting in thecommensurate antiferromagnetic ground state.
Motivated by pulsed-field magnetization studies
reaching 22 T [7], that we have extended and complemented by electric polarization measurements up to
55 T, we have engaged in a quest to determine thecharacteristic propagation vectors of the magnetic
phases for fields larger than 17.3 T [8, 9]. The specificgoal of the NOBORU experiment was to focus on thefield range from 30 T to 41 T, where our bulk data indicate two phase transitions around 37 T and 39 T, thelatter one separating a non-magnetoelectric phase,denoted phase VI, from a higher-field magnetoelectricphase, denoted phase VII. The results shown in Figure 1
demonstrate the power of the pulsed-field technique.
For a single-crystalline sample with a mass of 370 mg
and spin S = 1 Ni2+ ions, the characteristic propagation

MLF Annual Report 2015

Figure 1.	Pulsed-field neutron Laue diffraction data obtainedon a 370-mg single crystal of magnetoelectric
LiNiPO4 with the field applied close to the c-axis [9].
The data are produced by collecting all neutron
counts that correspond to a field at the sample
position in the ranges 39-40.5 T (phase VII, upper
panel) and 37-39 T (phase VI, lower panel).

vectors of the high-field phases can clearly be identified. Fits of the data indicate that the magnetic Bragg
peaks in phases VI and VII occur at (0 2/3 0) and (0 1 0),
within error. Both data sets correspond to about 300
field pulses or about 12 seconds of effective counting
time at a beam power of 200 kW. The largest field applied in our experiment was 41.2 T. To the best of ourknowledge, this is the highest magnetic field ever employed in a pulsed-field neutron diffraction experiment.
Work is now ongoing to analyze the neutron diffraction
data obtained at NOBORU, and to correlate them withthe measured electric polarization in phase VII [9].
4. Conclusion and perspectives
In our experiment, we successfully employed thepulsed-field Laue diffraction technique. In the process,we reached a record-high magnetic field, 41.2 T, andmanaged to determine the magnetic propagation vectors of all magnetic phases of interest. The success of theexperiment was due to a combination of factors such as
the high-flux “white” beam of NOBORU, the reliability

Research and Development Highlights

and endurance of the pulsed-field equipment and – importantly - suitable sample characteristics. All magnetic
propagation vectors known in the Li-orthophosphatefamily, which apart from LiNiPO4, includes Fe, Co andMn sister compounds, lie along (010). Moreover, thesepeaks have substantial magnetic structure factors.
This means that we could execute the technically challenging experiment with a substantial degree of confidence that the high-field phases of interest would also
have propagation vectors of the form (0K0), and thatthey would be observable on the relevant timescale of
10 seconds.
The favorable circumstances offered by LiNiPO 4
will not be present in all compounds and all high-field
phases. On the other hand, they are not unique either,as shown by previous publications, e.g. [3, 4]. Therefore,
it seems certain that pulsed-field Laue diffraction will
become an increasingly important part of the neutron
scattering toolbox, and that many exciting high-fieldmagnetic phases in a diverse range of material classes
are now within reach. From a technical perspective,
increases of the maximum field are feasible, and further improvements of the neutron instrumentation
and beam power will guarantee the future success ofpulsed-field Laue diffraction.
References[1] P. Smeibidl, A. Tennant, H. Ehmler and M. Bird, J.
Low. Temp. Phys 159: 402-405 (2010).
[2] O. Prokhnenko et al., Review of Scientific Instruments
86, 033102 (2015).
[3] S. Yoshii et al., Phys. Rev. Lett 103, 077203 (2009).
[4] H. Nojiri et al., Phys. Rev. Lett 106, 237202 (2011).
[5] Z. Islam et al., Synchrotron Radiation News, 25:6,
5-9 (2012).
[6] S. Gerber et al., Science 350, 949-952 (2015).
[7] V. M. Khrustalyov, V. N. Savitski and N. F. Kharchenko,
Czechoslovak Journal of Physics 54, D27-D30(2004).
[8] R. Toft-Petersen, E. Fogh et al., submitted to PhysicalReview B.
[9] E. Fogh, T. Kihara et al., work in progress.

E. Fogh1, T. Kihara2, R. Toft-Petersen1, M. K. Sørensen1, H. Suto2, Y. Matsuda2, Y. Narumi2, K. Oikawa3, H. Nojiri2, and N. B. Christensen1
Department of Physics, Technical University of Denmark; 2Institute for Materials Research, Tohoku University; 3Neutron Science Section,
J-PARC center

1

43

Research and Development Highlights

MLF Annual Report 2015

Measurement of Neutron Capture Cross Section of 99Tc
1. Introduction
Long-lived fission products (LLFPs) in nuclear spent
fuel have been an issue to deal with in nuclear power industry. The currently-planned geological method of nuclear waste disposal has been disputed by the publicity.
The proposed solution for this long-standing issue isnuclear transmutation, in which LLFPs are transmuted
into shorter-lived or stable isotopes through neutroninduced reactions [1]. Among LLFPs, technetium-99
has the highest priority to transmute due to its highfission yield and radiotoxicity. The design of a nuclear
transmutation system for 99Tc requires reliable neutron
nuclear data of 99Tc in a wide range of neutron energy.
This motivated us to perform our present work. We
measured the neutron capture cross section of 99Tc with
the Accurate Neutron-Nucleus Reaction Measurement
Instrument (ANNRI) [2, 3] in MLF of J-PARC. An intense
neutron beam from the spallation neutron source of
MLF allows us to study neutron-induced reactions witha small amount of a sample, such as radioactive materials. With the high-intensity neutron beam of MLF, theneutron capture cross section of 99Tc was measured
from the thermal to keV neutron energy region. In particular, an effort was made to expand the high-energy
limit of measurement to over 100 keV.
2. Experiments
A sealed 99Tc sample was used in the measurements. A metal 99Tc pellet with a diameter of 6.3 mm
was sealed in an aluminum container with an outer
diameter of 9 mm. The radioactivity of the sample was
52 MBq. The 99Tc sample was placed at a sample position with a flight path length of 27.9 m from the MLF
spallation neutron source.
Neutron capture gamma-rays from the sample
were detected with NaI(Tl) detectors. Figure 1 shows
the layout of the ANNRI-NaI(Tl) detectors. Two NaI(Tl)detectors had been installed in ANNRI. One detector
was located at a 90° angle with respect to the neutron beam axis. The other detector was at 125°. The
NaI(Tl) detectors were shielded from background neutrons and gamma-rays with borated material, Pb andenriched-6Li compound. In addition, the cosmic-ray
background was reduced by the anti-coincidence technique with annular plastic detectors surrounding the
NaI(Tl) detectors. In 2015, the background was reduced
even more. A neutron shield, made of enriched 6Li, wasadded to the beam duct. The NaI(Tl) detectors were44

Figure 1. NaI(Tl) detectors of ANNRI.

shielded from scattering neutrons from the sample,
which could reach the detectors and induce capture
events of 127I(n,g)128I in the detector material.
Signals from the NaI(Tl) detectors were fed into atime digitizer FAST ComTec MPA4T [4]. The use of conventional analog modules was minimized because theanalog modules were easily paralyzed by strong gamma-ray busts, called gamma flash, that are emitted fromthe neutron source when the pulsed proton beam hits
the spallation target. Instead of pulse-height analysis
with an analog amplifier, we used pulse-width analysis
technique with the fast time digitizer [5].
In addition to the 99Tc sample run, we conductedmeasurement runs with no sample, a dummy Al case,a graphite sample, a boron sample and a gold sample.
The blank and dummy case runs were done for background estimations. The graphite run was used to estimate the background of scattering neutrons at the
sample. The boron run was used to derive the incident
neutron spectrum from 478 keV gamma-ray counts of
the 10B(n,ag)7Li reaction. With the gold sample measurement, we checked the data reduction flow bycomparing the derived cross section with the standard
197Au(n,g)198Au cross section.
The proton beam power was approximately
200 kW. The pulsed proton beam was operated in the
single-bunch mode. The single-bunch mode operation
brought significant benefits to our present work. This
allows us to analyze resolved resonances with a finetime resolution of 100 ns in a simple way. Otherwise,
the double-bunch mode operation, which is normally
adopted in the MLF beam operation, changes each resolved resonance into doublet peaks, requiring complicated resonance data analysis.

MLF Annual Report 2015

After background subtractions, the net TOF spectrum of 99Tc was divided by the incident neutron TOF
spectrum, providing relative cross section data. A saturated 99Tc resonance at 5.6 eV was used to normalize therelative cross section to the absolute value.
3. Results
The preliminary results are shown in Fig. 2. The neutron capture cross section of 99Tc was determined in theenergy region from thermal to a few hundred keV. The
fast signal processing technique, based on the pulsewidth analysis method, successfully expanded thehigh-energy measurement limit of the NaI(Tl) system
to over 100 keV.

Figure 2.	The neutron capture cross section of 99Tc. Only statistical errors in the keV energy region are shown.
Corrections for neutron self-shielding and multiple
scattering have not been made.

4. Future Plans
We measured successfully the neutron capture crosssection of 99Tc using the NaI(Tl) detectors of ANNRI/MLF

Research and Development Highlights

in the energy range from thermal to a few hundred keV.
However, the results are still preliminary. Necessary corrections, such as self-shielding and multiple scattering,are underway. In addition, the pulse-height weighting
technique [6] will be applied to obtain accurate crosssection data. In the resolved resonance region from eV
to a few keV, resonance parameters will be extracted.
After finalizing the data analysis, the present crosssection data will contribute 99Tc nuclear data evaluations in nuclear data libraries such as JENDL-4.0 [7] andENDF/B-VII.1 [8].
Acknowledgements
The present study includes the result of “Researchand Development for accuracy improvement of neutron nuclear data on minor actinides” entrusted to
the Japan Atomic Energy Agency by the Ministry of
Education, Culture, Sports, Science and Technology ofJapan (MEXT).
References[1] W. S. Yang et al., Nucl. Sci. Eng. 146 291 (2004).
[2] M. Igashira et al., Nucl. Instr. Meth. Phys. Res. A600
332 (2009).
[3] Y. Kiyanagi et al., J. Kor. Phys. Soc. 59 1781 (2011).
[4] https://www.fastcomtec.com/products/mpa/
mpa4t0/[5] T. Katabuchi et al., Nucl. Instr. Meth. Phys. Res. A764
369 (2014).
[6] R. L. Macklin and J. H. Gibbons, Phys. Rev. 159 1007
(1967).
[7] K. Shibata et al., J. Nucl. Sci. Technol. 48 1 (2011).
[8] M. B. Chadwick et al., Nucl. Data Sheets 112 2887
(2011).

T. Katabuchi1, M. Igashira1, K. Terada2, A. Kimura2, S. Nakamura2, T. Nakao2, O. Iwamoto2, N. Iwamoto2, K. Mizuyama2, H. Harada2,
J. Hori3, and K. Kino4
1
Laboratory for Advanced Nuclear Energys, Tokyo Institute of Technology; 2Japan Atomic Energy Agency; 3Research Reactor Institute, Kyoto
University; 4Faculty of Engineering, Hokkaido University

45

Research and Development Highlights

MLF Annual Report 2015

Measurement of Low-Energy Positive Muons from
Metal Foil

46

1. Introduction
The goal of this experiment is to establish themuon deceleration method for the muon linac commissioning in the J-PARC E34 experiment [1]. The muon
linac, which will be the first of its kind in the world, isalso one of the key developments for the transmission
muon microscope and future projects, such as the neutrino factory. In our project, the conventional surface
muons (4 MeV) are decelerated and then injected into
the muon linac. The initial stage of the muon linac [2] isa radio frequency quadrupole (RFQ), which has alreadybeen completed [3]. Muon deceleration is required toperform the muon linac commissioning as soon as the
new muon beamline (H-line) is ready.
In the past, it has been observed that μ+ with kinetic
energy of sub keV are emitted from a thin Al foil withefficiency of 10-4 per incident muon [4]. The decelerated muons from the thin Al foil can be extracted andaccelerated to the injection energy of the RFQ (5.6 keV)by the SOA lens. In the previous experiment, the phasespace distributions of decelerated μ + were not measured. Because the RFQ acceleration efficiency depends
on the phase space distributions of the injected beam,
those should be measured. As a first step, in this experiment, we aim to demonstrate the muon deceleration
with the thin Al foil and acceleration by the SOA lens.

system had been developed in a test bench and muon
beam line, which has been described in [6].

2. Experimental method
The experimental layout is shown in Fig. 1. The
muon beam at the MUSE D2 area is used with a momentum of 25 MeV/c. Some of the beam muons may
marginally pass the thin Al foil with very small remaining energy. The decelerated μ+ goes to electro-static acceleration and focusing (SOA lens). It acquires kinetic
energy of 7 keV at the end of acceleration. Then, there isan electro-static deflector for energy and charge separation after a pair of electro-static quadrupoles. Finally,μ+ reaches the detector installed downstream of thedeflector, followed by a pair of quadrupoles. The detector is a microchannel plate (MCP) surrounded by a scintillator counter consisting of a plastic scintillator plate,wave length shifting fiber and SiPM.
The experimental apparatuses had been constructed (Fig. 2) in J-PARC MLF area 1 with support from
the MLF Muon Section. Details about the construction
and commissioning can be found in [5]. The detector

Figure 2. Photo of the experimental setup.

Surface muon beam
Al for Mu– production

Detectors

Electro-static lensElectric quadrupoles
Electric deflector

Figure 1. Layout of the experiment.

Electric quadrupoles

Thin Al foil and SOAlens in main chamber
Electric deflector

Control lack

Detector chamber

3. Results
Figure 3 shows timing distribution observed by the
MCP detector. The signal event timing is evaluated to
be about 900 nsec by the GEANT4 simulation and we
observed successfully events at the expected timing.
The events around 2700 nsec are considered to be protons knocked out from the foil surface by the injectedmuon beam.
Figure 4 shows charge distribution observed by the
MCP detector. The red (green hatched) plot shows the
distribution of the on-timing (off-timing) events. Those
distributions are normalized by the number of events inthe lower charge regions. Because the charge amountof the muon signal is estimated to be larger than thatof the off-timing background, the difference of the distributions in the higher charge regions is thought to beMLF Annual Report 2015

Figure 3. Timing distributions observed by the MCP detector.

Research and Development Highlights

Figure 5.	Muon beam evolutions in the RFQ simulated by
PERMTEQM.

based on the MC simulation [4]. Figure 5 shows the expected muon beam evolution in the RFQ by PERMTEQM.
The expected beam intensity after the RFQ is about afew Hz with 1 MW primary proton beam. In order to obtain more precise estimates, further measurements arenecessary.

Figure 4. Charge distributions observed by the MCP detector.

due to the muon signal.
In conclusion, we demonstrated successfully muon
deceleration with the thin Al foil and acceleration by
the SOA lens. The transport efficiency of the SOA lensand a series of the electric apparatuses is being estimated by the GEANT4 simulation. Based on this study, theapplied voltage to the electric apparatuses is tuned inorder to measure the phase space distributions in next
experiment.
4. Prospects
The expected beam rate after the RFQ acceleration
at the H-line is estimated based on measured deceleration efficiency and expected phase space distributions

5. Acknowledgement
The authors are pleased to acknowledge the support from J-PARC MUSE facility by providing a stablebeam during the experiment. We would like to thankJ-PARC MUSE staffs for their support during the slow
muon beamline assembly. This work was supported by
JSPS KAKENHI Grant Numbers 15H03666.
References[1] J-PARC E34 conceptual design report, 2011.
(unpublished)[2] M. Otani et al., Phys. Rev. Accel. Beams, 19, 040101,
2016.
[3] Y. Kondo et al., Proceedings of 6th International
Particle Accelerator Conference, 2015, THPF045.
[4] Y. Kuang et al., Phys. Rev. A 35, 3172 (1987), ibid.
Phys. Rev. A 39, 6109 (1989).
[5] M. Otani et al., PASJ2015 Proc. (Tsuruga, Japan,2015), WEOM02.
[6] R. Kitamura et al., JPS 71st Annual Meeting, 2016,
19aAH1.

M. Otani1, T. Adachi2, K. Bongho3, Y. Fukao1, Y. Ikedo2, K. Ishida4, M. Iwasaki4, S. Kanda5, N. Kawamura2, Y. Kondo6, T. Mibe1, Y. Miyake2,
Y. Nagashima7, K. Ninomiya8, S. Okada4, N. Saito9, K. Shimomura2, T. Suzuki7, A. Yabuuchi10, M. Yoshida11, and R. Kitamura5
1
Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK-IPNS); 2Muon Science Laboratory, HighEnergy Accelerator Research Organization (KEK-IMSS); 3Department of Physics, Soul University; 4Advanced Meson Science Laboratory,
Nishina Center for Accelerator-Based Science, RIKEN; 5Department of Physics, the University of Tokyo; 6Japan Atomic Energy Agency(JAEA); 7Department of Physics, Tokyo University of Science; 8Osaka University; 9J-PARC Center; 10Research Reactor Institute, Kyoto
University; 11Accelerator Laboratory, High Energy Accelerator Research Organization

47

Research and Development Highlights

MLF Annual Report 2015

Neutron Phase Imaging with Absorption Grating
Fabricated by Imprinting Gd-Based Metallic Glass
1. Introduction
The conventional neutron radiography, that is,neutron imaging based on the neutron beam attenuation contrast, has been widely used in the field of nondestructive inspection. In some cases, however, theneutron absorption-contrast imaging is not sensitive
enough to identify the small differences in elemental
composition or density. The high penetration powerof a neutron is not suitable for observing thin objects
either.
Recent developments in that field included someneutron phase-contrast imaging techniques [1], which
utilize the wave nature of neutrons and achieve higher sensitivity. We have started to develop the neutron
phase imaging at BL22 RADEN [2] in J-PARC/MLF with
the Talbot-Lau interferometer [3], which is a more powerful and stable device optical system compared to the
crystal-based ones.
As shown in Fig. 1, the Talbot-Lau interferometerconsists of three gratings. Periodic intensity patterns
are formed behind the middle phase grating (G1) by the
Fresnel diffraction due to G1. The analysis of a specificpattern with the most downstream absorption grating(G2), indicates the presence of a moiré fringe at the imaging detector. The changes in a neutron wave causedby the object are propagated into the moiré fringe.
From the variations in mean intensity, phase, and amplitude of the moiré fringe, absorption-, differentialphase-, and visibility-constant-images are obtained at
one-time measurement. The most upstream absorption grating (G0) prepares an array of line sources whichenables the phase imaging with low coherent neutron
beams.

The quality of G2 is the most important of the three
to produce clear moiré fringes and achieve a fine spatial
resolution. The fabrication of such G2s usually requires
placing a neutron absorber into the grating grooves,which has a high-aspect ratio between its height andwidth. Recently, we adapted the imprinting method [4]of gadolinium-based metallic glass to fabricate G2, andperformed the Talbot-Lau interferometry with the prototype G2.
2. Development of gratings
A set of gratings was designed for the neutron
wavelength of 5 Å. The grating ruling patterns were
fabricated on silicon wafers with 4-inch diameter and525-mm thickness, applying the photolithography technique and Inductively Coupled Plasma (ICP) etching
method. The pitch and aperture width of G2 is 180 mm
and 48 mm, respectively. Silicone paste, including gadolinium oxide, was rubbed into its grooves as a neutron
absorber. G1 is a p/2 phase grating for 5-Å-neutrons
with 9.0-mm-pitch, 50% duty cycle, and 17-mm-highteeth. G2 is another absorption grating with 8.6-mmpitch and 50% duty cycle. Since the groove width of G2
is finer than that of G0, the above method of absorberfilling is not applicable to G2.
In the new method for G2, that is, the imprinting method, melted gadolinium-based metallic glass(Gd60Cu25Al15) was pressed against the grating substrate. The metallic glass in the super cooled liquidstate easily soaked into the grooves. Figure 2 shows the
cross-section of a prototype G2 observed by a scanningelectron microscope.

Figure 1. Schematic diagram of Talbot-Lau interferometer.

48

MLF Annual Report 2015

Research and Development Highlights

4. Result
By using G2 with gadolinium-based metallic glass,
we observed a moiré fringe with the high visibility of
68%. Figure 3 shows the resultant images of the TalbotLau interferometry. The shadow of the aluminum rod is
not clear in the absorption-contrast image, whereas its
edges are sharply enhanced in the differential-phaseand the visibility-contrast images.

Figure 2. Cross-section of prototype G2 observed by SEM.

3. Experiment
The demonstration experiment was performed at
the BL22 RADEN on J-PARC/MLF. Three gratings werealigned on an optical bench mounted on rubber vibration insulator. We were able to control the relative
distances and angles of gratings by high accuracy
pulsed-motor-driven stages. The distance between G0
and G1 was 1553 mm, and between G1 and G2 78 mm.
A combination of an electro-multiplying chargecoupled device (EM-CCD) camera and ZnS(Li) scintillator was used as a neutron imaging detector. This
imager had a field of view of about 3.2 × 3.2 cm2 (1004× 1002 pixels) and spatial resolution of about 180 mm.
We performed absorption-, phase-, and visibilitycontrast-imaging with the Talbot-Lau interferometer byusing the central wavelength of 5 A (Dl/l = 18%). The
test sample was an aluminum rod with 5-mm diameter,
located just in front of G1. The moiré fringes were analyzed with phase stepping method, where they were
scanned by shifting the G2 position horizontally fivetimes in the step of the fifth part of its pitch. The exposure time was 300 s at each G2 position.

Figure 3.	Resultant images of Talbot-Lau interferometry foraluminum rod. (Left) absorption-contrast imaging. (Middle) Differential-phase-contrast imaging.
(Right) Visibility-contrast imaging.

5. Summary and prospects
The phase imaging with the Talbot-Lau interferometer was successfully demonstrated at the BL22 RADEN
in J-PARC MLF. The G2, newly fabricated by the imprinting method, worked well, achieving a moiré fringe withhigh visibility.
We are going to apply the Talbot-Lau interferometry to pulsed beams for more precise measurement,
and to polarized beams for magnetically sensitive
measurement.
References[1] I. S. Anderson et al., “Neutron Imaging andApplications”, Chap. 8 (Springer Science+ BusinessMedia, 2009).
[2] T. Shinohara et al., J. Phys. Conf. Ser. 746, 012007(2016).
[3] F. Pfeiffer et al., Nat. Phys. 2, 258-261 (2006).
[4] M. Sadeghilaridjani et al., Intermetallics 78, 55-63(2016).

Y. Seki1,6, T.Shinohara1,6, J. D. Parker2,6, K. Kato3, W. Yashiro4,6, A. Momose4,6, and H. Kato5
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Neutron R&D Division CROSS-Tokai; 3Department ofMaterials Science, Graduate School of Engineering, Tohoku University; 4Institute of Multidisciplinary Research for Advanced Materials;
5Institute for Materials Research, Tohoku University; 6JST, ERATO, Momose Quantum Beam Phase Imaging Project1

49

Neutron SourceNeutron Source

MLF Annual Report 2015

Progress of the Neutron Source Section
1. Failures in mercury target vessel
In April, 2015, the operational beam intensity for theneutron production target was ramped up to 500 kW,
half of the rated intensity of 1 MW. During the operatingtime on April 30, dew point in the helium vessel, in which
the neutron production mercury target was inserted, increased, suggesting a leak from the target vessel. Target
vessel’s triple-walled structure consists of a mercury
vessel, inner and outer water shrouds, where the water
shroud is bolted to the inner mercury vessel. The pointof failure was located at a welded interface between the
inner and outer water shrouds in the vicinity of a bolton target vessel’s bottom (see Figure 1). Our analysis
confirmed that the diffusion bonding interface between
the water shrouds was detached by welding thermal
deformation in the fabrication process, followed by seal
welding failure by the crack propagation induced by repeated thermal stress caused by beam trips.

Figure 1.	Schematic drawing of the specific location of the
failure on the water shroud of the target vessel.

The regular target vessel replacement was scheduled for the 2015 summer shut down period. However,at the time of the incident, the fabrication of the next
target vessel has not yet been completed. Because thestructural design of the next target vessel was the same,
we repaired the seal welding around all bolts to the full
penetration welding before replacement. After the target replacement, user operation with the new target
52

vessel was started from October 21.
After a 164-MWh operation at 500 kW on November
20, sensors, installed on the interstitial space between
the mercury vessel and the water shroud, activated.
Then we detected a pressure change in the coolingchannel of the water shrouds. It indicated a failure in the
inner water shrouds. Since it was difficult to inspect theinside of the target vessel at MLF, the specific failure location could not be identified. After reviewing the fabrication process and the analytical studies, we concluded
that pressure wave induced stress might have expanded a crack at certain location, creating a leak path.
These problems forced us to re-design the target
vessel to improve robustness. From this point of view,
we changed the structure of the front part of the target
vessel to eliminate welds and bolts in the high-stressregion. We will also improve the inspection technique
to detect fine cracks at the welds.
To ensure more reliable operation, we replaced thetarget vessel with an alternative with a mechanically robust structure. However, the replacement does not equip
the gas micro-bubbles injection system, which is necessary for stable operation with an intensity higher than
300 kW. Therefore, we restarted the MLF user operation
with a beam intensity of 200 kW from February 20, 2016.
2.	New data related to pressure wave mitigation in
the mercury target
In October, 2015, a part of the target front, the“beam window”, was cut out to investigate the cavitation damage. It was the first observation of the target
front structure with a double-walled build, aiming at reducing the damage by faster mercury flow in a narrow
channel. With the replica method, we found the cavitation damage with a maximum size of about 25 mm in abelt along the horizontal mercury flow in a disk-shaped
sample. (see Figure 2) The information was useful to understand the mechanism, causing cavitation damage
in the narrow channel and the mitigation effect on thedamage by the faster mercury flow.
New data on the pressure wave mitigation by thegas micro-bubbles injection was also taken for the 1-MW
equivalent proton beam pulse with a laser-doppler vibrometer. The measured displacement velocity on thetarget vessel is shown in Figure 3. The maximum displacement velocity for the 1-MW case is equivalent tothe velocity obtained for the 310 kW without gas microbubbles. This indicates that the pressure wave generated

MLF Annual Report 2015

in mercury for the 1-MW operation could be mitigated to
one-third by introducing a gas micro-bubbles injection.

Figure 2.	Photograph of the disk-shaped specimen cut out
from the target front.

Figure 3.	Displacement velocity on the mercury target vessel measured with a laser Doppler vibrometer. The
red line represents the result for the 1-MW equivalent proton pulse injection on the target with gas
micro-bubbles. The blue line stands for the 310-kW
case without gas micro-bubbles.

Neutron Source

3.	Performance degradation of the helium refrigerator of the cryogenic hydrogen circulation system
In November, 2015, the performance of the helium
refrigerator of the cryogenic hydrogen circulation system for the moderators deteriorated. We found out thatwater has accumulated in the heat exchanger of the helium refrigerator. We regenerated the charcoal, whichmight have been the source of the water contamination, and also conducted related purification during the
shut-down period for the target replacement.
Unfortunately, the quality of the performance
could not improve yet, due to another possible cause,such as oil contamination. The measure we took was toreduce the helium flow to suppress the source of contamination at the compressor of the refrigerator. We
also introduced an operating scheme that stops the operation for purification for 6 days after a 3-week operating period. For the operating periods from February 20
to the end of March, 2016, the performance deterioration was at an acceptable level. We’ll take every measure to solve this problem in the summer shut-down
period in 2016.
4. Progress of spare components fabrication
2015 was the third year of a 6-year project to prepare moderators and a reflector. The fabrication of acoupled moderator and a reflector was completed
and they were delivered to the J-PARC site. Currently,
the fabrications of a de-couple moderator and a poisoned moderator are in progress. For these moderators,
new material of Au-In-Cd alloy with a composition of
74.9:0.5:24.6 in at% will be installed.

H. Takada
Neutron Source Section, Materials and Life Science Division, J-PARC Center53

Neutron Source

MLF Annual Report 2015

Failure Cause Investigations and Design Improvementsof the Mercury Target Vessel
1. Introduction
In 2015, we experienced twice failures of the mercury targets, caused by coolant water leak from thewater shroud, when the facility was operating with aproton beam power of ca. 500 kW. The neutron source
facility had to be shut down for the total period of about
5 months to investigate the reasons for those failures
and to replace the mercury targets. So, thorough investigations of the failure mechanisms and the design improvements of the mercury target were carried out toprevent similar incidents.
Based on the investigation results so far, the causeof the failure is assumed to be the failure of bonding
interface and welds initially generated in the course of
fabrication. After the consecutive failures of the J-PARC
mercury target, we improved the target design andpaid special attention to the soundness of the welding
lines. In this report, we will outline the water leak incidents and the new design of the mercury target.
2. Outline of the mercury target
Figure 1 shows the schematic view of the mercury target and its vertical cross-section. The mercury
target is made of Type 316L stainless steel. The weightis 1.6 tons and the total length is 2 m. The front part,
whose length is 1050 mm, has multi-walled structure,i.e. the double-walled water shroud covers the mercury
vessel to confine the mercury contamination in the water shroud, if mercury leaks out of the mercury vessel.
Mercury flows through the mercury vessel and coolant
water flows through the water shroud to remove theheat load of spallation reactions in the mercury target.
The intermediate space between the mercury vessel and the water shroud is filled with helium gas andthree leak detectors are installed in the space. The design pressure of the mercury and the coolant water is
0.5 MPa and that of the helium gas is 0.2 MPa.
Figure 2 shows the structure of the mercury target. The water shroud consists of external and internal
vessels. There are ribs on the internal vessel and its top
surface is fixed together with the external vessel by diffusion bonding. The water shroud is bolted on the mercury vessel at 177 positions to endure an inner heliumgas pressure of 0.2 MPa.

54

Mercury target

Coolant
water

Material䠖SUS316L
Weight䠖1.6 t
Length䠖2 m

Mercury

Water shroud
Mercury vessel

Proton beam

Vertical cross section of the target
viewed from the target front
External vesselof water shroud

Bolts

Coolant waterInternal vesselof water shroud

Mercury

HeliumMercury vessel

Figure 1. Schematic view of the mercury target.

Bolts

Deffusion
Bonding
interface
Ribs

External
vesselInternal
vesselWater
shroudMercury vessel

Figure 2. Structure of the mercury target.

3. Small water leakage trouble
On April 30, 2015, when the mercury target was operated with a proton beam power of 513 kW, the waterleak detector in the drain pipe of the helium vessel detected a leak incident and the beam operation stopped.
The coolant water of the water shroud was drained andthe mercury target was moved to the maintenance area
to investigate the failure. When the coolant channel of
the water shroud was pressurized with helium gas to0.16 MPa, the visual inspection revealed a water drop

MLF Annual Report 2015

growing gradually on the bottom side of the mercury
target. Next, the coolant channel was evacuated andthe water drop shrank, which showed that the place
where the water drop was found was the failure’s location. The total proton energy injected into the mercury
target was 670 MW.hour.
The failed mercury target was replaced with a newone, which was repaired based on the failure analysesof the failed target, during the maintenance period in
the summer of 2015. The user beam operation resumed
from October 27 with beam power of 505 kW, but the
mercury target failed again on November 20. The total
proton energy was only 170 MW.hour. Since the failure
was a water leak into the helium layer this time, finding
the failure’s location, which was on the inside of the internal vessel, was extremely difficult. The efforts to findthe problematic location and the investigations of whatcaused the failure are still going on.
In both incidents, the total amount of leaked water
was estimated to be several liters at maximum.

structure and procedure of the mercury target. An inspection by ultrasonic test showed failures of the diffusion bonding interface beside the bolts where thefailure was assumed.
The phenomenon was also simulated by using FEM(Finite Element Method) code, LS-DYNA. In the simulation, the initial temperature of the bolt head was set
at 1400°C, the melting point of stainless steel. Then thetemperature was decreased to room temperature andthe stress field generated by the material contraction
was analyzed. Figure 4 shows the simulation result ofstress component perpendicular to the diffusion bonding interface. It can be seen that tensile stress, far larger
than the tensile strength (480 MPa) of stainless steel,
was generated at the diffusion bonding interface. Thislarge stress could have caused the failure of the diffusion bonding interface. The structure at the problem
location after the TIG welding of the bolt head was assumed to be just like in Figure 5. The length of the diffusion bonding interface was only 2 mm at the failed
location. After the beam operation started, the mercury
target was exposed to repetitive temperature swings
due to the frequent proton beam stops, which caused
fatigue failure of the seal welding and the water leak
path was completed.

Seal welding Bolt
External vessel

TIG welding
A Leak path3 5 33 8

4. Failure analyses of the mercury targets
Because the first failure was a water leak of the mercury target, the failure’s location could be found easily
by visual inspection. Figure 3 shows the structure of themercury target at that spot, which is the vertical crosssection of the cut-out model shown in Figure 2. A water
drop was found at the welded interface between theexternal and internal vessels, where seal welding wasused. Seal welding is TIG welding without groove andits depth is shallow, i.e. less than 1.5 mm. This type of
welding does not ensure structural strength. The designof the water shroud relied on diffusion bonding to secure the structural strength of the water boundary andthe seal welding was used only to fill up the interface
line between the external and internal vessels. Basedon the structure at the leak location, it was evident thatthe water leak path was formed by failures of both the
diffusion bonding and the seal welding.
In the incident investigations, we found a suspicious procedure of fabrication to be the cause of thefirst failure. After the external and internal vessels were
fixed together with diffusion bonding, the water shroud
was bolted on the mercury vessel and then the bolt
head was TIG welded to seal the helium layer. We suspected that large heat input by TIG welding of the bolt
head caused the large thermal stress and failure of the
diffusion bonding interface.
This assumption was verified by a partial mockup
mode of the failure’s location, fabricated with the same

Neutron Source

Water

Internal vessel
HeliumMercury vessel

Diffusion bonding
interface (DBI)
Figure 3.	Cross section of the mercury target at the failed
location.

Seal welding lineσz [MPa]
4.6 GPa

Bolt
Figure 4.	Simulation result of thermal stress around the failed
location.

55

Neutron Source

MLF Annual Report 2015

5. Design improvements of the mercury target
Overall, the causes of these troubles are considered to be in the welding and bonding part in the highheat load area of the mercury target. In order to prevent such troubles in the next target design, diffusion
bonding will not be used and the welding part will beminimized. Figure 6 shows the design improvements of
the next mercury target. The water shroud in the front
part of the mercury target, where the heat load is highduring the beam operation, will be integrated with themercury vessel. Parts of the mercury target will be fabricated by using wire-EDM and the welding line will be
reduced more than 30%. Adopting the integrated design for the rear part would be difficult, but we will apply improvements to reduce the welding. Inspections
to secure the good quality of the welds are also important. The fabrication of the new target will proceed withmore rigorous inspections of the welds by Radiographic
Test (RT) and Ultrasonic Test (UT). We have started thedesign and fabrication of the new mercury target toachieve the beam power of more than 500 kW.

Though the reason of the second failure has notbeen clarified yet, one probable cause is the hot cracks
in the TIG welding line, which were found in the mockup
model of the internal wall of the water shroud. Mockup
models of some places, which were suspected to be thecause of the second failure, were fabricated to investigate
the soundness of the welding lines. After detail observations, tiny cracks were found at some places on the welding lines and the heat-affected zones. The details of theinvestigation results will be reported in the near future.

Close‐upof DBI

Welding depthSealwelding

Water

Diffusion bonding
interface (DBI)

2 mm

Figure 5.	Structure of the water shroud after the DBI failure(Detail A of Figure 3).

Rear

Design in
the past

Bolts

Rear part

Front

Red line : Welds

Front part

Vertical cross‐section
Mercury

Water
Water
shroudMercury
vesselFigure 6. Improved design of the new mercury target.

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

56

HeliumMLF Annual Report 2015

Neutron Source

The Status of the Cryogenic Hydrogen System
1. Introduction
At MLF, a cryogenic hydrogen system provides
cryogenic hydrogen to the moderators at supercriticalpressure of 1.5 MPa, with para-hydrogen concentrationof more than 99% and temperature lower than 20 K,
generating high-performance pulsed cold neutron
beams.

For a normal operation, the dew-point of the helium gas has been constant at about -80°C, and concentration of impurities, such as nitrogen, oxygen,methane and carbon oxide has been almost 0 ppm,
respectively. After the operation from April to May,
2015, on the other hand, about 100 ppm of nitrogenconcentration in helium gas was detected in the ADS.
Furthermore, the dew-point at heat exchangers No. 1
and No. 2 was -45°C at room temperature. We thoughtthat nitrogen and moisture from the charcoal of oil
separator (OS-5) was the cause of the performance
deterioration.
In the 2015 summer shut-down period, therefore,
we replaced the charcoal of OS-5 to reset the impurities contained in the charcoal. After regenerating fresh
charcoal by heated nitrogen gas, we restarted the refrigerator operation in October. However, from the firstday, the pressure difference began to increase again,
and 21 days later, the temperature at the outlet of heatexchanger No. 2 rose from 78.5 K to 81 K. This time, it affected the heat exchange balance between helium andhydrogen, leading to unfavorable hydrogen temperature rise in the hydrogen circulation system. Finally, in
3 weeks, the user operation was interrupted.

2. Performance deterioration of the refrigerator
The cryogenic hydrogen system consists of a helium
refrigerator system and a hydrogen circulation system,
as shown in Fig. 1. In the helium refrigerator system, helium gas flows from a compressor to oil separators, anactivated charcoal, and a cold box, then returns to thecompressor. The cold box has three heat exchangers, anadsorber (ADS) and a turbine.
The typical scheduled period of cryogenic hydrogen system’s operation is approximately 3 months
continuously for the neutron scattering experiments in
MLF. This operation had performed well until December,2014. However, since January, 2015, the pressure differences at heat exchangers No. 1 and No. 2 and the ADS
increased rapidly much earlier than the previous operation, as shown in Fig. 2.

He, H2 cylinder storage room

Compressor room
Compressor

He cylinders

Oilseparators

Stuck
He buffer tank

Activatecharcoal(OS-5)

Liq. nitrogen tank

To blanket
To H2 loop

H2 cylinders

MLF building
Safety box
H2 pumps

Heater

TurbineCold box

HX3

HX2

He flow

HX1

Accumulator
Ortho-para
Hydrogenconverter

Adsorber
(ADS)

H2-He
HX
HeaterH2 flow

Moderators
CM
PM
DM

Helium blanket

N2 flow

Helium refrigeration system

Hydrogen circulation system

Figure 1. The cryogenic hydrogen system.

57

MLF Annual Report 2015

15

50

14

45

13

40

2015.10.21 - 11.12

12
11

Pressure difference (kPa)

Pressure difference (kPa)

Neutron Source

2015.04.05 - 05.07

10
92015.03.04 - 04.01
2013.01.10 – 04.10

8

2014.04.10 – 07.02
7

2015.04.05 - 05.07

30

2015.03.04 - 04.01

25
20
15
10

2012.03.28 – 07.04

2014.10.30 – 12.22

6

2015.10.21 - 11.12
35

2013.01.10 – 04.10
2014.04.10 – 07.02

2014.10.30 – 12.22

5

2012.03.28 – 07.04
0

5
0

10

20

30

40

50

60

Operating period (days)

70

80

90

0

100

20

30

40

50

60

Operating period (days)

70

80

90

100

Figure 2(a).	Pressure difference at heat exchangers No. 1 andNo. 2.

Figure 2(b). Pressure difference at the ADS.

In December, we regenerated again not only the
charcoal of OS-5, but also the heat exchanger and the
ADS to remove sufficiently the moisture. As soon as thetest operation was started in January, the pressure difference at the heat exchangers and the ADS began torise in the same or somewhat faster changing rate thanduring the previous operation. We analyzed the massconcentration of gases, sampled from the exchangers
and the ADS, with a quadrupole mass spectro-analyzer
and found that the water was undetectable. Anotherinspection of the inlet filter of the cold box detected reaction with oil when it was illuminated by black light.
This suggested that oil contamination could be the suspected cause of the performance deterioration.
Any oil contamination removal treatment would
require stopping the operation for several months, because such an irregular maintenance would take a longtime to arrange. This was unacceptable in view of supplying users with stable neutron beams. Therefore, wehave taken the following countermeasures. We reduced
the helium flow in the compressor that uses a large
amount of lubrication oil, in order to suppress the levelof oil exhaust to the downstream. We observed previously that, after the impurities at the heat exchangers
and the ADS were removed with helium for 5 to 6 days,
the pressure difference dropped to its initial value, Wechanged the operation cycle, so that the 3-week refrigerator operation is followed by a 6-day maintenance,
comprising of warm-up, purification and cool-down. As
expected, this operation cycle worked well for the user
operation started from February.
3. Future plans
In the 2016 summer maintenance period, we willtake further necessary measures. For example, the ADS
will be replaced with a new one because most of thepressure difference is generated there. The heat exchangers will be cleaned by Freon to remove the oil
contamination. The activated charcoal of the oil separators will be replaced with a new charcoal to improve
the performance. An inspection of the piping connecting the compressor and the cold box has also beenplanned. Until then, we will continue the intermittent
3-week operation followed by the 6-day maintenance.

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

58

10

MLF Annual Report 2015

Neutron Source

Present Status of the Spare Moderator and the Reflector
Fabrication
1. Introduction
Due to an accumulated-irradiation-damage, thestructural material of the moderator and reflector, suchas aluminum alloy, will reach its design value (20 DPA)
around 2021. A fabrication of the spare moderator andreflector is moving ahead with a plan since 2013 toward
these replacements. This year, the fabrication of a coupled moderator, reflector and reflector plug were justcompleted. The remaining two decoupled moderators
will be fabricated in 2018. Here we report the fabrication status of the coupled moderator and the reflector.
2. Coupled moderator and reflector fabrication
In the spare moderator design, the invar joint withthe lowest thermal expansion was adopted to improve
the special fabrication, such as an asymmetrical setting at an elbow-shaped bend in the cryogenic (hydrogen) pipe due to thermal shrinkage of aluminum andSS316L, which was employed for the previous moderator design. The invar joints, such as invar-A6061 andinvar-SS316L, were developed by the friction weld
method [1] to be used in the cryogenic pipe and implemented in the coupled moderator. Many tests, such asappearance inspection, dimensional check, welding
inspection, cooling test, etc., were performed until the
coupled moderator fabrication was completed. Figure 1
shows the cooling test of the coupled moderator. It was
conducted to evaluate the thermal load and thermal
shrinkage of the hydrogen pipe by using nitrogen gas(100 ~ 140 K). It was confirmed that the measured thermal load, < 60 W, was roughly the same as the design
value. The thermal shrinkage at a maximum position
was also measured by X ray transmission under cold
temperature, as shown in Fig. 1, resulting in a reasonable shrinkage, < 2 mm, as shown in Fig. 2. The adoption of invar alloy with lower thermal expansion thanin the one previously used, facilitated the fabrication.
In the previous decoupled moderator and reflector,
the Silver-Indium-Cadmium (Ag-In-Cd) decoupler was
utilized to produce neutron beams with sharp pulse
shape, newly, Gold (Au), instead of Ag, was selected toreduce dramatically the radioactivity of the used components without sacrificing the neutronic performance.
The bonding between Au-In-Cd and aluminum alloy(A5083), which is a part of the structural material of thereflector, is required for the purpose of heat removal

X ray
Cooling test standtransmission

・Liquid N2 flow
・Flow rate: ~20 g/sec
・Temp control.
: 100 ~ 140 K

Measurement
・Thermal load:< 60 W
・Thermal shrinkage:< 2 mm @max.

Coupled moderator

Figure 1. Cooling test of 2nd coupled moderator.

< 2 mmRoom temp.
140 K

HydrogenHdpipe
Figure 2.	X ray transmission of hydrogen pipe.
	Thermal shrinkage of hydrogen pipe was measured
at 140 K, resulting in reasonable shrinkage, < 2 mm.

59

Neutron Source

MLF Annual Report 2015

and thermal stress. The optimal bonding condition(100 MPa pressure, 535°C temperature and 1 hr holding time) was found for Au-In-Cd coin-shaped small
test piece (3 cm in diam. × 2 mm in thick) by adopting a
Hot Isostatic Pressing (HIP). However, there were criticalAcknowledgment
We thank for the cooperation of Metal Technology
Co. Ltd. in fabricating the spare coupled moderator andin the reflector assembly. We also thank the NAT staff for
their help with the Au-In-Cd material preparation.

Proton injection
hole

Reflector

Figure 3. Dimensional check of reflector fabrication.

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

60

engineering issues in terms of large sized bonding between Au-In-Cd and A5083 alloys to implement an actual reflector. We have investigated the HIPing processwith respect to the surface condition, size and heat
capacity of large-sized Au-In-Cd. Finally, we successfully implemented the Au-In-Cd decoupler into the actual reflector assembly. During the fabrication process,many inspection tests were also conducted to confirm
the design, as shown in Fig. 3.

References[1] M.Harada et al., Journal of Nucl. Mat. Vol. 398 (2010)
pp. 93-99.
[2] M. Ooi et al., Journal of Nucl. Mat. Vol. 450 issue 1-3(2014) pp. 117-122.

MLF Annual Report 2015

Neutron Source

Modification of the Integral Control System for
Sustainable Upgrade of Instruments
1. Introduction
A general control system (GCS) operates in MLF tosupply safely and efficiently muon and neutron beams.
The GCS comprises several subsystems, such as an integral control system (ICS) for controlling target systems,a personnel protection system (PPS) for preventing exposure of personnel to high radiation, shared servers,
networks and a timing distribution system [1, 2]. Since
the first proton beam injection in 2008, the GCS has
been modified according to the annual upgrade of thetarget systems and the annual incremental upgrade to
the user apparatuses [3, 4].
2. Modification of ICS in GCS
Figure 1 shows a conceptual structure of the ICS
in the GCS. It consists of a monitor and operation (MO)system and a programmable logic controller (PLC) linksystem. The MO system comprises administrative control PCs (ACP), database servers, data storage servers,
and so on. For sustainable long-term operation, an upgraded MO system based on experimental physics andindustrial control system (EPICS) was built in 2013 [5,6]. The upgraded MO system has operated in parallelwith the previous MO system for over a year, and has
been debugged. In 2015, the MO system was replacedcompletely with the upgraded one after shutting down
the previous one.
The PLC system, shown in Fig. 1, includes PLCs, suchas general control panels (GCP), remote input/output(I/O) panels, and local control panels (LCPs) for eachequipment. These PLCs are connected through duplicate optical networks for PLC link, called the NETH.
Station numbers (no.) and a shared memory area areallocated to these PLCs. The GCP-I, denoted by stations
1 and 2, manages the I/O panels and LCPs through the
NETH main-loop. The I/O panels, shown as stations 3
and 5 in Fig. 1, have several stations under their NETH
sub-loops. These sub-loops enable increment of instruments without increasing stations under the main-loop.
In 2014, 34 stations under the main-loop and 6 stations
under the sub-loops operated in the ICS.
Because data transmission through the NETH-loop
is executed by transferring from the internal memoryarea of the PLC to the shared memory area of the NETH
link, however, the amount of data transmitting throughthe main-loop is limited by the address number of theMonitor and Operation (MO) System
Administrative Control PCs (ACP)
Web
serverEthernet
Data Storage
server(Main/Sub)

Data Baseserver(Main/Sub)

Station 37, 38
GCP-II(Main/ Sub)
Station 29, 41
LCP
Station 27, 40
LCP
Station 24, 39
LCP
Station S3
LCP

PLC link
systemStation 1, 2
GCP-I
(Main/Sub)

LCP
Ethernet

NETH-main-loop

Station 3, 35
RemoteI/O Panel
FLnet

Station 5, 36
RemoteI/O Panel
NETH-sub
-loop

LCP

Station S1
LCPStation S2
LCPFigure 1.	Conceptual structure of the integral control system(ICS) in the MLF general control system (GCS). The
ICS consists of a MO system and a PLC link system.
41 stations under the main-loop and 6 stations under the sub-loops operate in the ICS. Stations 35
through 41 have been added anew in 2015.

transferable internal memory. In addition, the amountof data transmitting between the main-loop and the
sub-loops is limited by the address number of theshared memory allocated to the I/O panels. Therefore,
frequent increments of instruments cause lack of address numbers of both the transferable internal memory and the shared memory allocated to the I/O panels.
As a result, it has been difficult to create new stations
both under the main-loop and the sub-loops for significant upgrades of instruments in the near future. For
maintaining sustainable upgrades of instruments, thefollowing modifications of the PLC link system were
performed in 2015.
(1) The address number of the shared memory wasincreased significantly by expanding the transferable internal memory areas. Moreover, these61

Neutron Source

MLF Annual Report 2015

increased addresses were divided between stations
35 through 41, which were created anew under the
NETH main-loop.
(2) Stations 35 and 36 were allocated to the existing
I/O panels to enable increment of instruments under the sub-loops.
(3) Stations 37 and 38 were allocated to the GCP-II,
which was added anew to the main loop. The GCP-II
reduced the processing loads of the GCP-I by sharing station managements with it.
(4) Stations 39, 40 and 41 were allocated to the existing LCPs, which have managed muon S line instruments. These LCPs will also manage muon H line
instruments, whose number will be increased soon.
3. Summary
The PLC link system of the ICS was modified tomaintain sustainable long-term upgrades of instruments. Significant modification of a muon user PPS LCP
to increase the user apparatuses of the muon H line, theupgrade of the MLF monitor LAN used by the monitoring camera system [7], and so on, have been also carried out in 2015.
References[1] K. Sakai et al., Nuclear Inst. and Meth. A600, (2009)75.
[2] K. Sakai et al., MLF Annual Report 2012, (2013) 75.
[3] K. Sakai et al., JAEA Conf. 2015-002 (2015) 593.
[4] K. Sakai et al., Progress in Nuclear Science andTechnology Vol. 4, (2014) 264.
[5] K. Sakai et al., MLF Annual Report 2013, (2014) 66.
[6] M. Ooi et al., JPS Conf. Proc. 8, (2015) 036007.
[7] M. Ooi et al., MLF Annual Report 2014, (2015) 67.

K. Sakai1, M. Ooi1, A. Watanabe2, and Y. Kato1
Neutron Source Section, Materials and Life Science Division, J-PARC Center; 2Accelerator Section III, Accelerator Division, J-PARC Center

162

Neutron ScienceNeutron Science

MLF Annual Report 2015

Neutron Science Section
1. User Program
The user program of the 2015A period started on
April 19 with 18 neutron instruments and commissioning activities for 2 beam lines with 500-kW power andwas interrupted on April 30 due to a target vessel problem - cooling water leakage outside the vessel. The target
was replaced in the summer, and we resumed the user
program on October 27, but it was interrupted again on
November 20 due to another problem with the neutron
target – water leakage inside the vessel. The second target was replaced with the old model target, which was
not equipped with any pitting mitigation system, such asa bubbler, a double inner wall and so on, so we resumed
the user program on February 20 with 200-kW power.
In the general proposals for the 2015A period, 168
neutron proposals were approved and 33 proposals
were reserved from the 281 proposals submitted by the
MLF Advisory Board after the Neutron Science Proposal
Review Committee. However, we decided to cancel thecall for proposals for the 2015B period in order to accommodate the 2015A experiments. Moreover, we had
to carry over a total of 70 experiment days from 2015 to
the 2016A period.

The upgrades of the operating instruments advanced by using grant-aids, such as the NEDO “Research& Development Initiative for Scientific Innovation of
New Generation Batteries” (RISING) project. In the project, in-operando measurement of batteries was realized on SPICA at BL09. The Construction of the neutron
spin echo (NSE) spectrometers VIN ROSE at BL06 wascontinued by Kyoto University and KEK. After refinement of the NSE signal in October, 2015, an effective
200 kHz TOF-MIEZE (Modulated IntEnsity by Zero Effort)
signal was observed successfully (Fig. 2). POLANO at
BL23, funded by the JFY2012 supplemental budgets of
Tohoku University and KEK, is expected to accept thefirst neutron beam in FY2016. The first inelastic scattering experiment will be performed with 3He spin filterand spin analyzer of Fe/Si supermirror system (Fig. 3).
The construction and part of the commissioning on
the energy-resolved neutron imaging system, RADEN
at BL22, have been finished and it was opened to theuser program as a public beam line instrument from the2015A period.

2. Instruments
The layout of the neutron instruments at MLF as ofthe end of JFY 2015 is shown in Fig. 1.

Figure 2. MIEZE spectrometer of VIN-ROSE.

Figure 1.	Layout of the neutron instruments at MLF as of JFY
2014. BL06 & 22 had proceeded to the commissioning and user program phases respectively in this fiscal year. BL23 remained under construction.

64

Figure 3. Spin analyzer system of POLANO.

MLF Annual Report 2015

3. International Activities
We hosted the Workshop on Neutron Wavelengthdependent imaging-7 (NEUWAVE-7), held from May 31
to June 3 at the Ibaraki Cultural Center in Mito. (Fig. 4) It
was attended by 55 pariticipants from Japan, U.S., U.K.,
Denmark, Switzerland, Germany and other countries.
We had 29 presetations on instruments and facilities reports, developments on intruments and methods, applications and so on. After this workshop, on June 4, we
held the 2nd International Advisory Committee Meetingon RADEN(BL22) in Tokai, whith comittee members
Dr. E. H. Lehmann (PSI), Dr. B. Schillinger (TUM), Dr. N.
Kardjilov (HZB), Dr. W. Kockelmann (ISIS), Prof. Y. Saitoh(Kyoto U.) and Prof. T. Nakanishi (U. of Tokyo).
On July 30, we held the 1st Japan-Korea Joint
Workshop on Polarized Neutron Reflectometry at the
J-PARC Center. At this workshop, possible international
collaboration between Korea and Japan was discussed.
We had 18 participants (11 from Japan, 7 from Korea)
and 10 presentations.
From December 2 to 5, we hosted the joint school of
the 7th AONSA Neutron School and the 3rd MLF School(Fig. 5). The school was supported and sponsoredby the Asia-Oceania Neutron Scattering Association(AONSA), the Japanese Society for Neutron Science(JSNS), the International Atomic Energy Agency (IAEA),
the Society of Muon and Meson Science of Japan, theComprehensive Research Organization for Scienceand Society, the University of Tokyo, the Institute for
Solid State Physics, the Institute of Materials Structure
Science, the High Energy Accelerator Research
Organization, the Ibaraki Prefecture and the AustralianInstitute of Nuclear Science and Engineering. 41 young
researchers and graduate students from Japan, Korea,
Australia, Indonesia, India, China, Taiwan, Malaysia,

Figure 4.	Participants in the Workshop on Neutron Wavelength-dependent imaging-7 (NEUWAVE-7).

Neutron Science

United States and Iranparticipated in the school.
Unfortunately, J-PARC had no neutrons or muonsbeams at the school, but the participants enjoyed coldexperiments on 11 neutron beam lines and one muon
instrument, followed by comprehensive lectures onneutron and muon sciences.
4. Resultant outcomes
The research activities in neutron science at MLF
resulted in more than 110 papers. The number includes
articles in influential journals such as Nature Physics
and Nature Communications.
The PLANET beam line group won the Technology
Prize of the Japanese Society for Neutron Science for thedevelopment of the powder diffractometer specializingin high-pressure experiments, PLANET. Susumu Ikeda,
a professor emeritus of KEK, received the Achievement
Prize from the Japanese Society for Neutron Science forhis contributions to the pulsed neutron scattering facility and observation of hydrogen in materials.
We distributed 5 press releases on scientific outcomes and technical development from our beam lines:
Just a touch of skyrmions: Skyrmions have been widely touted as providing the basis for new high-density
memory devices because of their small size and relative
stability. It was found that manipulation of skyrmions—tiny nanometer-sized magnetic vortices at the surfaceof magnetic materials— is possible by using mechanical energy. (October 13, 2015)
Comprehensive use of neutrons, X-rays and supercomputers for the development of tire rubber:
Development of high-performance tire technology
by Sumitomo Rubber Industries, Ltd. (ADVANCED 4D
NANO DESIGN) was announced by the company. It wasestablished that atomic scale structure and dynamics

Figure 5.	Group photo at the farewell party of the joint
school of the 7th AONSA Neutron School and the
3rd MLF School.

65

Neutron Science

MLF Annual Report 2015of tires by neutrons, X-rays and computer simulations
were used to improve inconsistent performances of the
car tires, namely, fuel consumption, gripping and wear
resistance. (November 12, 2015)
Diffusion process analysis of super ionic conductor
towards all solid-state ion battery: The diffusion pathof Li ion was revealed with the combinational technique of powder diffraction and quasi-inelastic measurements. The estimated diffusion distance of Li ion by
structural modeling based on powder diffraction datais consistent with the one estimated by the momentum
dependence of quasi-inelastic intensity. This techniquewill likely be applied to other super ionic materials.
(January 20, 2016)
Hydride-ion conduction makes its first appearance:
The first electrochemical reaction based on hydrideions in an oxide-based solid-state cell for potential

next-generation batteries was demonstrated. It was
examined how the structure of their oxyhydride compounds changed with composition and synthesis conditions. The characteristics of the electronic structure
was also studied and suggested an ionic Li-H bond in
the compound, namely the existence of H- in the oxides. (March 18, 2016)
Solid electrolytes open doors to solid-state batteries: Newly synthesized two-crystal materials show
great promise as solid electrolytes. All-solid-state batteries built using the solid electrolytes exhibit excellent
properties, including high power and high energy densities, and could be used in long-distance electric vehicles. By the powder diffraction technique, it has beenshown how the lithium ions move fast in the structureof their compounds even at room temperature. (March
22, 2016)

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

166

MLF Annual Report 2015

Neutron Science

BL01: 4D-Space Access Neutron Spectrometer 4SEASONS
1. Introduction and Statistics
4SEASONS is a thermal neutron Fermi-chopper
spectrometer for inelastic scattering measurements,and one of the Public Beamlines in MLF [1]. The momentum-energy region for this spectrometer occupies
the middle of the momentum-energy space coveredby all MLF spectrometers [2]. In the 2015A term, 18
General Use proposals, including 1 Urgent Proposal
and 1 Trial Use Proposal, were applied for, and 12 ofthem were approved. 8 proposals were submitted byinternational users. The major research fields, reflected in the proposals, were strongly correlated electron systems and magnetism, which dominated 83%of the General Use proposals in 2015. In addition to
the General Use proposals, 2 Strategic Use proposals
for the Element-Strategy Project for electronic materials were submitted and approved. Unfortunately,
more than half of the approved proposals had to be
postponed for 2016, and the call-for-proposals for the
2015B term was canceled because of an unexpectedlong-term shutdown of MLF.
2. Detectors
The detector installation, which has been in progress through 2013 and 2014, continued in fiscal year
2015 and 13 new pieces were installed. Now, the maximum horizontal scattering angle is 90.7°. Although thisvalue is still lower than the designed one, 130.5° [1], it issubstantially larger than the initial value, 54.5°. We expect the increased scattering angle to make the experiments for lattice dynamics more feasible.
3He detector is vulnerable to vibration, especiallywhen the electric power is supplied. Our experience
with the big earthquake in March 11, 2011, reminded
us of the importance of the protection of the detectors
against earthquakes. Accordingly, we introduced an interlock system to prevent detector damage caused bythat type of disaster. It is connected to seismometers
placed in the experimental halls. Once it detects anearthquake whose intensity is bigger than some specified value, it cuts the electric power supply to the detectors. The interlock system is expandable to adopt other
input signals of incidents. We have connected the system to the vacuum gauge of the scattering chamber, sothat it could also cut the power to the detectors in thecase of an unexpectedly rapid vacuum break.

3. Preparing for Magnet
So far, no magnets are available on 4SEASONS,
though the dimension of the sample environment attachment flange of the scattering chamber can accommodate the common-use 7-T magnet in MLF. Many ironcomponents, surrounding the sample area, and theturbomolecular pumps with magnetic bearings, areattached just below the sample position, which makes
it difficult to use magnets on the instrument. Becauseof that, we are investigating stray fields, taking into account the iron components with special considerationof the field intensity on the turbomolecular pumps. To
validate our calculations, we operated the commonuse magnet on 4SEASONS for the first time (Fig. 1), andmeasured the intensity of the magnetic field at several
points around the magnet. Although the maximum
applied field in this test operation was only 1 T, the observed values were consistent with the calculations. We
are continuing the numerical calculations of the strayfield to find an appropriate measure to protect the turbomolecular pumps against the field and estimate themaximum available field on the instrument.

Figure 1. The common-use magnet being installed on
4SEASONS by the technical supporting staffs of
MLF.

67

Neutron Science

MLF Annual Report 2015

Figure 2. Web interfaces of the new instrument control system of 4SEASONS. (Left) Integrate Server to control the devices and run
measurements. (Right) Sequence Server to manage measurement sequences.

4. Instrument Control System
Many of the instruments in MLF, including
4SEASONS, utilize instrument control systems based on
the control software framework IROHA. Recently, a newcontrol software framework, called IROHA2, has beendeveloped to replace IROHA [3]. We developed a new
instrument control system based on IROHA2, and madeit available for user experiments. This new control system enabled us to control different devices uniformly
and to introduce new devices easily. Furthermore, users
can control the instrument intuitively and remotely using web-based user-interfaces (Fig. 2).

5. Extension Floor
Since 4SEASONS has the smallest dimension among
the existing chopper spectrometers in MLF, it has a limited work area to operate the devices and to prepare
for experiments. To expand the work area of the instrument, we constructed an extension floor between theshielding house and the wall of the experimental hall(Fig. 3). The extension floor is designed in a way to connect seamlessly to the roof of the shielding house.
References[1] R. Kajimoto, M. Nakamura, Y. Inamura, F. Mi-zuno, K.
Nakajima, S. Ohira-Kawamura, T. Yokoo, T. Nakatani,
R. Maruyama, K. Soyama, K. Shibata, K. Suzuya, S.
Sato, K. Aizawa, M. Arai, S. Wakimoto, M. Ishikado,
S. Shamoto, M. Fujita, H. Hiraka, K. Ohoyama, K.
Yamada, and C. H. Lee, J. Phys. Soc. Jpn. 80, SB025(2011).
[2] H. Seto, S. Itoh, T. Yokoo, H. Endo, K. Nakajima,
K. Shibata, R. Kajimoto, S. Ohira-Kawamura,
M. Nakamura, Y. Kawakita, H. Nakagawa, T.
Yamada, BBA - General Subjects, doi:10.1016/j.
bbagen.2016.04.025.
[3] T. Nakatani, Y. Inamura, T. Ito, and T. Otomo, JPS
Conf. Proc. 8, 036013 (2015).

Figure 3. The extension floor under construction.

R. Kajimoto1, M. Nakamura1, Y. Inamura1, T. Nakatani1, K. Kamazawa2, K. Ikeuchi2, K. Iida2, M. Ishikado2, and H. Kira2
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2R&D Division, Neutron Science and Technology Center,
CROSS

1

68

MLF Annual Report 2015

Neutron Science

BL02: Current Status of the Broadband Micro-eV
Quasielastic and Inelastic Neutron Spectrometer DNA
1. Introduction and Specification
DNA, a time-of-flight (TOF) near-backscattering
spectrometer (n-BSS), is a unique instrument amongspallation pulsed neutron facilities over the world interms of n-BSS equipped with a high-speed pulse-shaping disc-chopper [1]. Neutron beam from the coupledmoderator which provides most intense but broadest
pulse among all three moderators in MLF is handled
flexibly in pulse width by this chopper with keeping
intensity and making symmetrical pulse in a TOF spectrum. Si crystal analyzers with back-coated by neutron
absorber extremely reduces unfavorable backgroundscattering of the instrument so as to reach signal-tonoise ratio of ~105. Those factors gave big advantage
to enlarge application fields to dynamical behaviors
of atoms and spins in bio-molecules [2], soft-materials
and strongly-correlated electron system in nanosecond
timescale or in micro-eV energy region.
The overview of DNA is shown in Fig. 1(a). The
pulse-shaping chopper, the first key device for DNA, islocated relatively upstream in neutron guide at 7.75 mfrom the moderator since time for slit opening at thisposition becomes the origin of TOF analysis. The chopper disk has four slits with two types of different slit
sizes (3 with 30 mm slit and 1 with 10 mm slit), which
gives us adjustability of energy resolution as well as rotational speed change does. Another merit of the pulse
shaping chopper is to realize scanning method over awide energy-transfer range with keeping high energy
resolution by changing phase of slit opening relative topulse trigger.
The Si111 crystal analyzers, the second key device for DNA, installed in the vacuum vessel cover the
scattering-angle ranges from -30 degrees to +150 degrees in the horizontal plane and from +21 degrees
to -14 degrees in the vertical direction (Fig. 1(b)). The
analyzer spherical surface is divided to the upper andthe lower parts centering on different positions upwardand downward by 102 mm of the scattering center(sample position), respectively. Neutrons scattered by

Table 1. Instrumental specifications of DNA.
Items
Specification
Neutron source (NS)
Coupled Liquid H2 Moderator
L1 (source-sample)
42 [m]
L2 (sample-analyzer)~2.3 [m]L3 (analyzer-detector)~2.0 [m]Pulse sharpening chopper (PS-chopper)
Max speed: 300 Hz at ~7.5 m from NS(Present Max speed: 225 Hz by 4 slits on one disc)
Crystal Analyzer
Crystal and reflection index
Si(111)Si(311) in test
Bragg angle of analyzers~87.5 [deg.]
Energy resolution~2.4 [meV]: Si(111) with 10 mm Slit @225 Hz~3.5 [meV]: Si(111) with 30 mm Slit @225 Hz~14 [meV]: Si(111) without PS-chopper~12 [meV]: Si(311) with 10 mm Slit @225 Hz.
Momentum range
0.07 < Q < 1.86 [A-1]: Si(111)
1.0 < Q < 3.80 [A-1]: Si(311) in plan
Scan energy range:
Si(111): -40 < E/meV < 100: Single pulse scan around Ef-400 < E/meV < 600: Multi pulse scan around Ef-500 < E/meV <1500:
without PS-chopper in second frame
Si(311): -150 < E/meV <300: Single pulse scan around Ef(the specifications by the end of March 2016)

Figure 1. DNA 3D view (a) and inside of scattering vessel (b).

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MLF Annual Report 2015

the sample are energy-analyzed with near back-scattering condition of at Bragg angle qB ~87.5 degree) andthen countered by position-sensitive 3He gas detectors(PSD) arranged on the same circumference of the scattering center upward and downward shifted (Fig. 1(b)).
These arrangements of the analyzer units and the detectors enable us to angle-resolve scattered neutrons
in horizontal and vertical directions two-dimensionally,
and therefore, this spectrometer has a potential to conduct experiment even for single crystalline sample.
2. Application
The optimal combination of the major spectroscopic devices: pulse shaping chopper, Si crystal analyzer and so on, it became possible to measure the S (Q, E)
with micro-eV high energy resolution, high beam intensity at the sample position and quite low instrumental

background. Taking advantage of this feature, the sciences research field using DNA will be expanded not
only for quasi- elastic neutron scattering but also forinelastic neutron scattering with very precise energy
resolution.
References[1] Kaoru SHIBATA, Nobuaki TAKAHASHI1, Yukinobu
KAWAKITA, Masato MATSUURA, Takeshi YAMADA,Taiki TOMINAGA, Wataru KAMBARA, Makoto
KOBAYASHI, Yasuhiro INAMURA, Takeshi NAKATANI,
Kenji NAKAJIMA, and Masatoshi ARAI., JPS
Conference Proceedings, 8, 036022 (2015).
[2] S. Fujiwara, T. Yamada, T. Matsuo, N. Takahashi, K.
Kamazawa, Y. Kawakita, and K. Shibata: Journal of
the Physical Society of Japan, 82, SA019 (2013).

K. Shibata1, Y. Kawakita1, M. Matuura2, T. Tominaga2, T. Yamada2, K. Nakajima1, W. Kambara1, M. Kobayashi2, Y. Inamura1,
T. Nakatani1, and S. Kasai2
1
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Neutron R&D Division, CROSS-Tokai

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Neutron Science

Current Status of IBARAKI Biological Crystal
Diffractometer iBIX
1. Introduction
IBARAKI biological crystal diffractometer called iBIX
was constructed at BL03, MLF, to perform high throughput single crystal neutron structure analysis mainly forbiological macromolecules in various life processes(2008) [1]. To achieve a high performance, we developed successfully a new photon-counting two-dimensional detector system using scintillator sheets andwavelength-shifting (WLS) fiber arrays for the X/Y axes.
In 2012, we upgraded the 14 existing detectors and installed 16 new detectors for the diffractometer of iBIX
(Fig. 1). The total solid angle of detectors subtended by asample and the average detector efficiency increased by
2 and 3 times, respectively [2]. The total measurement
efficiency of the present diffractometer was on one order of magnitude from the previous one coupled with
the increasing of the accelerator power. In the end of
2012, it became possible to use iBIX regularly to investigate biological macromolecules in user experiments.
The final specifications of the iBIX are shown in Table 1.

Figure 1. Inside of the iBIX Diffractometer.

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

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

2. Current status
In 2015, the accelerator power of J-PARC increased
to 400 ~ 600 kW. We accomplished the following in collecting a full data set about biological macromolecules
for neutron structure analysis by using iBIX. The maximum unit cell size was 110 × 110 × 70 Å. The average
sample volume was about 2 ~ 3 mm3, the average measurement time was about 7 ~ 10 days. If the accelerator
power reaches 1 MW, the total measurement time or
the sample size will be reduced by half.
At the beginning of 2015, we distributed two press
releases on the scientific outcomes, which have madethe most of the capabilities of the neutron diffraction
experiment by using iBIX;
1)	The neutron crystal structure of the PcyA-BV complex was determined at room temperature. It wasobserved that approximately half of the BV boundto PcyA was BVH+ , a state in which all four pyrrole
nitrogen atoms were protonated (N-protonated),
and both of the lactam structures of BV were preserved in wild-type PcyA. Those results will provide
crucial information for elucidating the unique catalytic mechanisms of PcyA [3].
2)	The neutron crystal structures of inveting cellulose
unliganded and libanded PcCel45A were determined at room temperature. Those results indicate
the key role of multiple tautomerizations of asparagine residues and peptide bonds, which are
finally connected to the other catalytic residue via
typical side-chain hydrogen bonds, in forming the“Newton’s cradle”–like proton relay pathway of thecatalytic cycle [4].
3. Development
In order to improve the quality of the integrated
intensity of weak reflections, we developed a profilefitting method for the peak integration of the data reduction software STARGazer. To determine the proper
fitting functions, four asymmetric functions were evaluated using strong intensity peaks. The Gaussian function convolved with two back-to-back exponentials
was selected as the most suitable fitting function for
TOF diffraction data by iBIX. A profile-fitting algorithm
for the integration method was developed and the integration component was implemented in STARGazer.
The profile-fitting component was applied to the TOF
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diffraction data set of standard protein samples obtained by iBIX. From the results, the integrated intensities and model structure obtained by the profile-fitting
method were more accurate than those of the summation-integration method, especially at higher resolution
shells [5]. We already prepared its user manual and the
distribution package of the data reduction software, including the profile-fitting component.
To respond to user’s needs, we developed a newpiece of equipment for sample environments, a coolingsystem for capillary-enclosed samples. The temperatureof a capillary enclosed sample is maintained at around
0°C Both the peltier cooling system, mounted on the goniometer head, and the N2 gas flow cooling system wereused for sample cooling in order to prevent the condensation of dew inside the capillary. This equipment canbe mounted on the three-axe goniometer. In 2016, we
will attempt to test measurement with this equipment.
4. Future prospects
In the future, the accelerator power of J-PARC will
be increased to 1 MW. iBIX should be available regularly
for full-data set measurement of sample size of 1 mm3.
We will continue to develop the data reduction software and beamline instruments, in order to improve theaccuracy of intensity data obtained from small samples.
Furthermore, we will validate whether it is possible toconduct full-data measurement, its reduction and thestructure analysis of the sample with a large unit cell(132 × 132 × 132 Å) by using iBIX.

We should be able to complete successfully thedevelopment of utility equipment for sample environments (heating, extension system for polymer sample,
pulse laser system and cooling system for capillary-enclosed samples). And then, in 2016, we will start applying this equipment in user experiments.
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] M. Unno, K. Ishikawa-Suto, K. Kusaka, T. Tamada,
Y. Hagiwara, M. Sugishima, K. Wada, T. Yamada, K.
Tomoyori, T. Hosoya, I. Tanaka, N. Niimura, R. Kuroki,
K. Inaka, M. Ishihara, K. Fukuyama J. SynchrotronRad. 20 (2013) 994-998.
[4] A. Nakamura, K. Igarashi, K. Kusaka, S. Fushinobu,
Y. Higuchi, T. Ishida, T. Yamada, Ichiro Tanaka, S.
Kaneko, K. Ohta, H. Tanaka, K. Inaka, N. Niimura, M.
Samejima J Science Advances (2015) e1500263.
[5] K. Kusaka, T. Hosoya, T. Yamada, K. Tomoyori, T.
Ohhara, M. Katagiri, K. Kurihara, I. Tanaka and N.
Niimura J. Am. Chem. Soc., 137 (2015) 5452–5460.
[6] N. Yano1, T. Yamada1, T. Hosoya, T. Ohhara, Ichiro
Tanaka and K. Kusaka Scientific report 6 (2016) inpress.

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

1

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MLF Annual Report 2015

Neutron Science

Current Status of Accurate Neutron-Nucleus Reaction
Measurement Instruments, ANNRI (BL04)
1. Introduction
In the J-PARC facility, the proton beam power intensity reached approximately 500 kW in 2015, which
was moew than 20-fold increase, compared to the first
20-kW beam shot in 2009. Increasing the beam powerof the facility allows its users to obtain a much larger
amount of experimental data yields than before.
In the ANNRI facility, two different types of γ-ray
detector systems are operated for the neutron capture cross-section measurement. One is a germanium
detector system (Ge system), which has very fine γ-ray
energy resolution, the other is an NaI detector system(NaI system) with the capability of measurement in awide neutron-energy range. Since the current DAQ system for the Ge system was designed in 2009, its counting rate performance is almost saturated for the recent
J-PARC proton beam power. In order to adapt well tothe recently improved J-PARC performance, a new DAQ
system has been developed.
In addition, a new Li-glass neutron detector system(Li-glass system) for the total cross-section measurement was installed recently. A new DAQ system for the
Li-glass system must be developed, because the current DAQ system cannot be applied to the Li-glass detector signals as is.

of signals. As the trigger signal reaches the facility by
several micro-seconds delay, compared to the fastest
neutron event (the so-called “gamma-flash”), each trigger is delayed by about one acceleration cycle in orderto acquire the gamma-flash events as well.
Figure 1 shows the schematic diagram of the
J-PARC/MLF/ANNRI facility and the data flow of the
DAQ system.

2. New DAQ system specification
The new DAQ system is designed by TCP/IP protocol based client-and-server model in order to perform
simultaneous measurements at two different locations.
The role of the client-side application is to gather datafrom each ADC and send it to the server-side. The server-side application receives data from each client, build
the event data sequence, and save them to the disk.
Each client is controlled by a common signal issued
from the server-side application.
As a consequence of the client-and-server model
design, the DAQ system can accept additional detector systems flexibly, by just creating new clients andconnecting them to the server side. Additionally, in thecase of a new detector system being installed, only a
new client application is necessary for its integration.
Signals from the J-PARC beam monitor were used
to measure time-of-flight events. Trigger signals issued
from the J-PARC facility were distributed to the ANNRI
counting room and divided to the appropriate number

3.	Total cross-section measurement system development
In order to measure the total neutron cross-section,
two Li-glass scintillators with different characteristics
were prepared. One was the 6Li enriched type (>90%)
scintillator (GS20) and the other was the 7Li enriched
type (>99.99%, GS30). Since the neutron detection by
the Li-glass scintillator is followed by a 6Li(n,α)t reaction, the enrichment of the 7Li isotopes hinders theneutron detection efficiency. The low neutron detection efficiency of the GS30 scintillator allows its usage
for estimating the amount of γ-ray background. Two different volumes, 1 × 50 × 50 mm and 10 × 100 × 100 mm,
of glasses were prepared for each of the scintillators.
Figure 2 shows the pulse height spectrum registered by the GS20 scintillator. The 1-mm scintillator has
better energy resolution than the 10-mm one becauseof its light-collection efficiency. For the neutron detection by using a Li-glass detector, the main background
event is due to γ-rays. In order to remove the γ-ray effect,

Figure 1.	Schematic view of the J-PARC/MLF/ANNRI facility
and the data flow of the DAQ system.

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MLF Annual Report 2015

Figure 2.	Pulse height spectrum of GS20-type neutron detectors. The green solid line represents the 1-mm-thickscintillator, and the red solid line the 10-mm-thickone.

Figure 3.	The γ-ray background estimation using the GS30
scintillator. The solid line shows the time-of-flight
spectrum by the GS20 scintillator and the dashedline depicts the GS30 scintillator.

a GS30 scintillator was used. From the measurement in
the same experimental setting for both GS20 and GS30,
the γ-ray background amount is estimated by the GS30
spectrum. The amount of the γ-ray background wasestimated using black resonance filter, located at the
upstream side of the ANNRI beamline. Figure 3 shows
an example of GS30 γ-ray background estimation. The
black resonance locations are reproduced well by the
GS30 spectrum.
4. Count rate performance
In the new DAQ system, two different types of ADCs
are prepared. One is the CAEN [1] v1724 peak sensitive
type ADC. The other is the CAEN v1720 charge integrate
type ADC. In case of the v1720 ADC board, no self-trigger
signal will be established while a gate signal is open. The
dead time, caused by a trigger signal, will never be extended by the pile-up signal. By the way, the dead time,caused by the pile-up rejection logic, will be extended
with probability proportional to the event rate. In thev1724 case, both dead time by trigger signal and pile-up
rejection logic will be extended depending on the event
rate. The counting efficiency of the DAQ system was determined by careful analysis of the different behavior.
Figure 4 shows the counting efficiency. The Figureon the left depicts the Ge detector with different shaping time settings. The Figure on the right shows the difference between 1-mm-thick and 10-mm-thick Li-glass.
Typically, the system works with 50 kHz for Ge detectors
and 100 kHz for Li-glass detectors.
The authors would like to thank the accelerator andtechnical staff at J-PARC for operating the accelerator
and the neutron production target and for their other

T. Nakao
Nuclear Data Center, Nuclear Science and Engineering Center, JAEA

74

Figure 4.	The counting efficiency of the DAQ system. The upper Figure shows the acceptable event rate of the
Ge detectors with different shaping time. The lower
Figure shows the difference of the counting ratecapability of the 1-mm (solid line) and the 10-mm(dashed line) Li-glass scintillators.

experimental support. The present study includes theresult of “Research and Development for accuracy improvement of neutron nuclear data on minor actinides”
entrusted to the Japan Atomic Energy Agency by the
Ministry of Education, Culture, Sports, Science andTechnology of Japan (MEXT).
Reference[1] http://www.caen.it/MLF Annual Report 2015

Neutron Science

Present Status of BL05 (NOP)
1. Introduction
BL05 (NOP) is a beamline to carry out fundamental
physics experiments using neutrons. The beamline isdivided at its upstream into three branches to conduct
different experiments in a parallel way [1]. The present
status of the ongoing experiments at BL05 (NOP) will bereported here.
2. Measurement of the neutron lifetime
A neutron decays into a proton, an electron, andan antineutrino. The lifetime is an important parameterfor the unitarity of the CKM matrix or the primordial bigbang nucleosynthesis. However, recently reported values for the neutron lifetime deviate significantly from thesystematic errors. An experiment to measure the neutron
lifetime with a pulsed beam is ongoing at BL05 (NOP). The
lifetime is measured as the ratio of the electron events tothe 3He(n,p)3H events caused by precisely doped 3He gas
using a time-projection chamber (TPC) [2].
Physics data have been collected for about 4 week
by the TPC. Then the data were analyzed by using
Monte Carlo simulation.
For cross check and demonstration of our TPC andgas handling system, we measured the reaction crosssection of 14N(n,p)14C, which has been previously measured with an accuracy of 1.6% with scale factor of 1.54.
Our preliminary result was 1.864(3) barn, whose accuracy was 0.3%, consistent with the mean value fromprevious measurements (Fig. 1).
3. Ultracold neutron production by Doppler shifter
Ultracold neutrons (UCNs), which have energy less

14
N(n,p)14C
626 keVthan ~250 neV (velocity of 6.8 m/s), are utilized for various precision measurements in fundamental physics.
A Doppler shifter is working to produce UCNs on theBL05 (NOP) beamline [3]. It reflects very cold neutrons(VCNs) with velocity of ~136 m/s with a moving mirror
with 68 m/s and produces neutrons with velocity of lessthan 20 m/s. The UCN intensity is 160 cps at 1 MW.
A UCN storage have been demonstrated using a polished stainless steel vessel. The vessel has two valves toshut UCN up for storage and extraction. The measured
UCN storage time was 270 sec at maximum (Fig. 2). An
aluminum filter on the exit port at the Doppler shifter
shortened the storage time to 180 sec, which could beinterpreted that the low-energy UCNs below the Fermi
potential of Al (54 neV) were cut, so that the higher energy of the UCNs increased the collisions at the wall.

Figure 2.	Storage time of UCNs in the stainless storage vessel [5]. The maximum storage time was 270 sec(black). Al filter on the exit of the Doppler shifter
shortened the storage time to 180 sec (blue). The
worsening of the vacuum (few Pa) also decreased
the storage time to 162 sec.

3

He(n,p)3H
764 keV

Present value
σ = 1.864 ± 0.005 [b]0.3% accuracy

Figure 1.	Energy spectrum of 14N(n,p)14C and 3He(n,p)3H reactions (left). Cross sections of 14N(n,p)14C, previous and present [4] (right).
The present cross-section (preliminary) was consistent with the mean value of previous results.

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4.	Development of a sub-micron position sensitive
neutron detector using nuclear emulsion
We have been developing a neutron detector withspatial resolution of less than 1 µm by loading 6Li into
fine-grained nuclear emulsion. By exposure to thermal

Figure 3.	An example of a neutron absorption event by 6Li
observed under an optical microscope with an epiillumination system (surrounded by a red ellipse).
A pair of tracks of an alpha particle and a triton in
back-to-back topology were recognized [6].

neutrons, tracks from neutron capture events were observed. From their grain density, the spatial resolution
was estimated. The detection efficiency was also measured at BL05 with cold neutrons, and we concluded
that it was consistent with the expected value [6].
References[1] K. Mishima, Neutron network news (Hamon), vol25,
No2 (2015) 156-160.
[2] Y. Arimoto et al., Nuclear Instruments and Methods inPhysics Research A, 799 (2015) 187-196.
[3] S. Imajo et al., Progress of Theoretical and Experimental
Physics 2016.1 (2016) 013C02.
[4] R. Kitaraha et al., JPS Autumn meeting, Miyazaki
University (2016).
[5] R. Katayama et al., JPS Autumn meeting, Osaka City
University (2015).
[6] N. Naganawa et al., “A neutron detector with spatial
resolution of submicron using fine-grained nuclear
emulsion” https://arxiv.org/abs/1612.04544

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

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Neutron Science

BL06: Commissioning Status of VIllage of Neutron
ResOnance Spin Echo Spectrometers (VIN ROSE)
1. Introduction
Kyoto University and KEK have been installing jointly two types of neutron spin echo (NSE) spectrometerswith neutron resonance spin flippers (RSFs) at BL06,
that is, a neutron resonance spin echo (NRSE) instrument and a modulated intensity by zero effort (MIEZE)
instrument.
Today, the NSE technique is an essential spectroscopic technique, which has achieved the highest
energy resolution with neutrons as a probe [1]. NSEwith RSFs is a rather new approach [2]. Furthermore,
the combination of NSE and a pulsed neutron source
makes possible to scan a wide spatiotemporal spacevery efficiently. The beamline has been named “VIN
ROSE” (VIllage of Neutron ResOnance Spin Echo spectrometers) and it will spawn a new field of spectroscopic methods [3].

(a)2. Commissioning Status at BL06
The project has been started in FY2011, and thefirst neutron beam has been accepted in FY2014. The
first MIEZE signal was observed in the end of FY2014.
Figure 1 shows a recent photo (a) and the schematic
top view of BL06 (b).
A highlight of the progress achieved in FY2015 was
the quantitative analysis of the time-of-flight MIEZE
signal. Because the combination of time-of-flight and
MIEZE (TOF-MIEZE) is a novel approach, its detailed
verification is still ongoing. In the case of continuous
neutron sources, the geometric restriction for MIEZE
is very tight, that is, a very accurate setting for the distances between the source, flippers, and the detector
is required. On the other hand, this requirement can berelaxed by the TOF-MIEZE method, which was investigated both theoretically and experimentally by using
BL06 [4]. In Fig. 2, the measured TOF-MIEZE signal andthe corresponding 200-kHz power spectrum is exhibited, where the position of the second spin flipper was
displaced by 80 mm. The corresponding power spectrum shows a slight deviation from 200 kHz, while theclear TOF-MIEZE signal is observed at that condition.
Further theoretical evaluation is now in progress, whichis urgently needed for quantitative conversions fromMIEZE signals to intermediate scattering functions.
3. Summary
The current status of BL06 VIN ROSE was briefly described. The main progress in FY2015 was the quantitative verification of TOF-MIEZE. This result is essential
to evaluate quantitatively the intermediate scattering(b)

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

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functions. The other advancements are as follows: a
500-kHz MIEZE signal was tested and its feasibility wasproved, and prototypes of two-dimensional elliptic
mirrors for the NRSE spectrometer were developed andtested at the beamline. Based on these fundamental
developments, experiments with some standard samples will be planed for FY2016.

Figure 2.	Bottom: experimentally observed TOF-MIEZE signal
with effective 200 kHz and 80 mm displacement of
the second flipper. Top: corresponding power spectrum by Fourier transformation.

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

H. Endo1,2, M. Hino3, T. Oda3, N. L. Yamada1,2, H. Seto1,2, and Y. Kawabata3
Neutron Science Section, Materials and Life Science Division, J-PARC center; 2Institute of Materials Structure Science, KEK; 3Kyoto
University Research Reactor Institute178

MLF Annual Report 2015

Neutron Science

Current Status of the Super High Resolution Powder
Diffractometer, SuperHRPD
1. Introduction
SuperHRPD has the world’s highest resolution
among the TOF neutron powder diffractometers of thesame type. In fiscal year 2015, an unscheduled long
shutdown due to neutron source problems resulted in
shortage of beam time. Four general proposals and apart of the S-type project of 2014S05 were carried out
during that limited beam time. The beam time, available for developmental study of the instrument, wasinsufficient.

this measurement. Figure 2 shows the TOF resolution
dependence in each detector area (a1~a8 & a1’). All
plotted data points of the resolution were calculated by

0.14

0.12

0.10

Backward banka8 : 2θ < 150°
a7 : 150° ~ 153°
a6 : 153° ~ 156°
a5 : 156° ~ 159°
a4 : 159° ~ 162°
a3 : 162° ~ 167°
a2 : 167° ~ 170°
a1 : >170°
a1': >170° horizontal part

resolution / %2. Updated resolution using powder samples
In FY2014, we installed a new detector system using an 8-mm diameter Position Sensitive Detector (PSD)
at all backward banks. The overall resolution of thepowder sample improved from ∆d/d = 0.1% to 0.08%,
and reached resolution ∆d/d = 0.04% using limited highangle detectors [1]. In FY2015, with the enhancementof the beam power, we tried to collect data in a more
limited detector area (Fig. 1). We divided the backward
detector area along the Debye ring, and the area of thedifferent scattering angle 2θ was defined as the a8 froma1. In addition, we defined the horizontal part of thehighest scattering angle area as a1’. The NIST standard
silicon powder (SRM640d) was measured using a 6 mm
in diameter standard sample holder at beam power of
400 kW, and it took 14 hours to obtain the results from

0.08

0.06

0.04
fitting function : asymmetric PseudoVoigt
all backward banka8 : 2θ < 150°
a7 : 150° ~ 153°
a6 : 153° ~ 156°
a5 : 156° ~ 159°
a4 : 159° ~ 162°
a3 : 162° ~ 167°
a2 : 167° ~ 170°
a1 : >170°
a1' : >170° horizontal part

0.02

0.00

20

40

60

80
100
tof / µsec

120

140

160x103

Figure 2.	Resolution variation in each detector area. a8 - a1
and a1’ correspond to the divided area of the backward bank detector shown in Fig. 1.

a8
a7
a6
a5
a4

a3
a1 a2

a1'

Figure 1.	SuperHRPD backward bank detector. We divided the detector area along the Debye ring. The parts shown by hatching are
the newly specified area (a1’).

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intensity / arb.unit

NIST Si Powder SRM6640d
a1' : 2θ > 170° horizontal part
1000 fitting function : asymmetric pseudo-Voigt
Resolution ∆d/d =0.0365(1)%Incident beam

800
600
400
200
0

77.9

78.0
tof /µsec

78.1

78.2×103

Figure 3.	Diffraction peak of the horizontal part of the highest
scattering angle area (a1’). We achieved 0.0365(1)%resolution in Δd/d.

fitting of Bragg peaks in a diffraction pattern observedin each detector area using the asymmetric pseudoVoigt function. It was possible to achieve a resolutionof less than 0.1%, except for the a7 and a8 areas, where2θ was smaller than 153°. With the data obtained byadding all backward detectors (black circle and dashedline), the achieved resolution was less than 0.08%. In
the newly defined a1’ area (blue square), it achieved lessthan 0.04%. Figure 3 shows a peak fitting result of the
a1’ area. The function used for fitting is the asymmetricpseudo-Voigt, as described above. As the Figure indicates, a very sharp peak in the left-right symmetry was
obtained. The resolution indicates Δd/d = 0.0365(1)%,this value is equivalent to the one evaluated using asingle crystal silicon in June, 2008 [2]. This result showsthat it is possible to carry out experiments with the best
possible resolution for a powder sample by using a limited detector area.
3. Current status of the 14-Tesla Magnet
We purchased a 14-Tesla magnet from Oxford
Instruments PLC. A feature of this magnet is a window
design created specifically for high-resolution experiments. The high-angle side window is aiming for observation of very small structure distortion with highFigure 4.	14-Tesla magnet photo and drawings. The window
design created specifically for high-resolution experiments; 1) Open to the high- and low-angle bankside. 2) Large azimuth angle as wide as possible.

resolution, the low-angle side is for observation of themagnetic scattering peaks, by consistently maintaining
a large azimuth angle, it is possible to detect efficiently
the scattered neutrons (Fig. 4).
In the beginning of this fiscal year, we carried out
off-site excitation test outside of MLF and were able
to confirm the occurrence of a stable maximum magnetic field of 14 Tesla. Thereafter, the magnet was transported to the MLF SuperHRPD building, where it wasassembled and adjusted. Recently, the vacuum leak test
was completed, and now we are working urgently to
prepare the magnet for commissioning on-site.
4. Future Plans
Further in this study, we plan to complete the initialstage of the development research of SuperHRPD, andreach a stage of expanded and stable scientific research.
References[1] S. Torii, P. Miao, S. Lee, M. Yonemura and T. Kamiyama,
MLF Annual Report 2014, 88-89 (2014).
[2] S. Torii, M. Yonemura, Surya Panca Putra Y T, J.
Zhang, P. Miao, T. Muroya, R. Tomiyasu, T. Morishima,
S. Satoh, H. Sagehashi, Y. Noda and T. Kamiyama, J.
Phys. Soc. Jpn. 80 (2011) SB020.

S. Torii1,2, P. Miao1,2, S. Lee1,2, Y. Ishikawa1,2, M. Yonemura1,2, 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

Battery Studies on the Special Environment Neutron
Powder Diffractometer using Operando Techniques
1. Introduction
The “in situ” techniques have been the world’s standard to investigate reactions or structure changes, while
preserving the reaction systems or sample environments.
On the other hand, the “operando” method is used for thesame type of targets, but it results in destruction of samples, especially in operative conditions. SPICA has beendeveloping as a dedicated diffractometer for battery
studies using operando measurements. Elucidating reaction mechanisms occurring in practical operations is crucial for the future development of battery technologies.
In 2010, the design and construction of SPICA began with a grant from foundation supported by RISING(Research & Development Institutive for Scientific
Innovation of New Generation Batteries). The construction of the main components of SPICA has been almost
completed. Some testing measurements were carriedout on SPICA. In 2015, the operando diffraction and imaging of commercial batteries were measured. From
the diffraction data, structure changes, depending on
charge rate, were observed. The lithium-ions’ distribution and concentration were successfully determined by
Rietveld analysis. The observations under high current
drain revealed inhomogeneous reactions, a structural
relaxation after discharge, and a shift in the lithium concentration ranges with cycling in the electrode matrix.
2.	Developing of SPICA and analysis methods for
operando measurements
Figure 1 shows a typical procedure of operando
measurements, followed by structural analysis. Afterthe operando measurements, some data reduction processes are necessary to analyze diffraction data by the
Rietveld method. Therefore, data reduction software
was created for operando measurements. In MLF, alldetected scattered neutrons were stored as the event
data. In the operando measurements, all scattered neutrons are recorded in a computer storage at once. Fromthe event data, an amount of diffraction data, which depend on the integrated time for each time-resolved diffraction pattern, is needed. Manyo-lib were enhanced
to create effectively a data set. As a result, the data reduction speed increased more than 10 times.
After the data reduction process, structure determination using the Rietveld method was necessary. The
huge number of diffraction patterns is generated from

Figure 1.	Scheme of automatic structure refinements for adataset of operando measurements.

operando measurements. Structure determination was
not important for the users because the understanding
the structural changes is more valuable for their work.
Therefore, an automatic structure analysis process has
been developed by improving “Z-Rietveld”. Z-Rietveld
can handle a data set, which includes multi-diffraction
patterns from an operando measurement and refinement structures cyclically. In this structure refinements
cycles, In the sequential refinement process, the refined
crystal structure is used to be as the new crystal structure model to refine the next diffraction pattern.
3.	Operando measurements and refinements of18650-type lithium-ion battery
Figure 2(A) depicts the powder neutron diffractometer, SPICA, and Figure 2(B) shows a typical operando
measurement geometric condition. A 18650-type commercial lithium-ion battery was put on the sample position of the SPICA diffractometer. The diffraction data81

Neutron Science

MLF Annual Report 2015

were collected under a constant current drain condition. The 18650-type lithium-ions battery has cylindricalshape and contains 5 components, a cathode electrode,
anode electrode, polymer separators, electrolyte and abody of the cell, as shown in Figures 2(C) and 2(D).
The typical refinement result of the operando multiple data set was shown in Figure 3. It contains all thediffraction peaks from the battery components, i.e.
Lix(Ni, Mn, Co)O2 (NMC) as the cathode, graphite (C) as
anode, Al, Cu as a current corrector and a battery cell
(Fe). The structure refinements were carried out by the
program, Z-Rietveld. The good agreement factor, Rwp
and the goodness of fit factor, S of the refinemenst wereobtained. This indicated that the automatic refinement
provided reasonable structural parameters for the individual phases of the experimental diffraction data during battery operation. The lattice parameters, the ratioof the phases present in the cell, and the structural parameters of each phase were automatically refined by
the automatic Rietveld refinement routine developedby a powder-diffraction group in J-PARC.
The operando diffraction data set for the automaticrefinement verifications by Z-Rietveld was collected using the 0.1 C rate. The lithium composition in both thecathode and the anode was directly determined by the
Z-Rietveld for the region, where stage 1 and 2 phases

coexist in the anode. Figure 4 shows the compositionchanges of both electrodes as a function of the capacityof the lithium battery. The lithium compositions at bothelectrodes were lineally changed. They were consistent
with the lithium content changes by electrochemicalmeasurements. Therefore, these results of structurerefinements indicate that 1) the automatic refinement
verifications by Z-Rietveld work well and 2) the direct
measurement of the lithium content is possible during
battery operation. This information of quantitative lithium concentration analysis will provide basic battery
reaction data to clarify the deterioration mechanism
during cycling and under high-temperature operationand storage conditions.

Figure 3.	Rietveld-refined neutron diffraction pattern. Example of the Rietveld-refinement pattern after the automatic refinement process. Green dashes indicate
the positions of Bragg reflections for the battery
components.

Figure 4.	Lithium-composition changes for cathode (a) andanode (b) materials as a function of the capacity of
the lithium cell.

Figure 2.	Illustration of the diffractometer, SPICA (A) and theschematic view of the operando experiments (B).
Outline drawing of the cylindrical 18650-type commercial battery cell (C) and the inside of the cell.

Acknowledgement
This work was supported by the RISING project. The
neutron scattering experiment was approved by the
Neutron Scattering Program Advisory Committee of
IMSS, KEK (Proposal No. 2009S10, 2014S10).

M. Yonemura1,2, Y. Ishikawa1, S. Torii1, and T. Kamiyama1,2Institute of Materials Structure Science, KEK; 2Sokendai (The Graduate University for Advanced Studies)

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Neutron Science

BL10: NOBORUIn FY 2015, most of the general use proposals at
BL10 were postponed for the next year, because of thetarget incidents at MLF on April 30 and November 20,
2015.
This year, we performed the periodical measurements for neutron intensity, neutron spectra and pulse
shape at BL10 with a proton beam power up to 0.5 MW.
Fig. 1 shows the thermal and cold neutron reaction
rates measured by the Au foil activation method by thesame settings in April, 2015, October, 2015, and March,
2016, as a function of the proton beam power. The
neutron reaction rate of the Au foil corresponds to theneutron intensity. An Au foil was located at 12.8 m fromthe moderator’s surface. To derive the thermal and cold
neutron intensity, irradiation with/without a 1 cm2 Cdcollimator was performed. We confirmed that the neutron intensity was almost proportional to the proton
beam power up to 0.5 MW.
The pulse shapes of the cold neutrons, ca. En <10 meV, are very sensitive to the para-H2 content of themoderator. A two-dimensionally aligned mica crystal
has been used to measure the pulse shape of cold neutrons since 2008. This year, a standard powder sample,
NIST SRM660 (La11B6), was also measured in the same

experimental setting. The powder diffraction has an advantage when used for the reproducible measurement
for the pulse shape of the thermal and cold neutrons.
The powder sample contained in a cylindrical vanadium cell, 5 mm in diameter and 40 mm in height, was set
on a sample position of NOBORU, 14.0 m from the decoupled moderator (DM). A zero-dimensional 1/2-inch
3He counter was set at 1.0 m from the sample at 2θ =170°. In spite of a small solid angle of the single counter, an adequate counting statistics for the pulse shapeestimation was obtained in a one-day measurement at
500 kW. The measured pulse shapes agreed well withthe simulated ones, as shown in Fig. 2. The estimatedfull-width at half-maximum of the latest data, plotted
as a filled triangle in Fig. 3, shows good agreement withthe expected pulse width (= Dt1/2(cal.)) as well as theprevious pulse shape measurements. The result supports the 100% para-H2 condition in the JSNS moderator, which is realized at beam power of at least 500 kW.

1 10–16
Reaction rate of Au foil (reaction/atom/s)

y = –7.9449e–19 + 1.6252e–16x

Measured value
in Apr. 2015

8 10–17

Figure 2. Powder diffraction pattern of La11B6 at 500 kW.

Measured value
in Oct. 2015

6 10–17Fitted linear line

4 10–17

2 10–170

R = 0.99918

Measured value
in Mar. 2016

0

0.2

0.4

0.6

0.8

1

Proton beam power (MW)Figure 1.	Measured neutron reaction rates of Au foil in April,2015, October, 2015 and March, 2016.

Figure 3.	Pulse width at half and 1% maximum of the observed peaks and the calculated ones of DM of JSNS.

K. Oikawa and M. Harada
Neutron Science Section, Materials and Life Science Division, J-PARC center83

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MLF Annual Report 2015

Recent Developments in BL11 PLANET
1. Introduction
This year, we worked on the following developments:(i) Reducing the background by shielding incident
beam optics.
(ii) Increasing the scattering intensity by applying neutron transparent anvils for the experiments using
the 6-axis press.
Here, we introduce the results of these developments.
2.	Reducing the background by shielding incident
beam optics
In the experiments using Paris-Edinburgh press, afocusing mirror is normally employed to increase thebeam flux at the sample position, in which the focusing
mirror, made of supermirrors with mirror index of m =4 and length of 1.2 m, is placed in front of the sample.
This mirror increases the neutron flux by a factor of
about 2.3 for neutrons with wavelength of λ = 1.5 Å andlarger. This mirror is effective in detecting weak sample
peaks located at relatively large d-spacing, but that also
increases the intensity of the background. Then, reduction of the background is urgently needed to maximize
the benefit.
Analysis of the 2-dimentional pattern, taken by two
detector banks, revealed that the background is generated by the incident mirror itself, as well as gaps between the mirror and other components installed at the
upstream. To reduce the background, shielding of B4C
rubber with 5 mm thickness was attached on the surface of the tube holding the mirror (Fig. 1), and the gapof the optical devices was covered by cadmium plateswith thickness of 0.5 mm.

Figure 2 and 3 show the 2-dimensinal pattern and1-dimensional pattern constructed from it, respectively.
By adding the above-mentioned shielding, the parenthetic scattering in the 2-dimensional patterns wasfound to be successfully eliminated. Correspondingly,
the background in the 1-dimensional pattern was significantly reduced. These findings suggest that theshielding has worked effectively.

Figure 2.	Comparison of the 2-dimenional patterns without(upper) and with (lower) shielding of B4C rubber(left: North bank, right :South bank).

Figure 3.	Comparison of the 1-dimenional patterns with (red)and without (blue) shielding of B4C rubber. The ratio
is also shown by a green line.

Figure 1.	Tube holding the focusing mirror, on which the B4C
rubber is attached.

84

3.	Increasing the scattering intensity with the use ofneutron transparent anvils
In the data collection at high-pressure and hightemperature condition, a 6-axis press equipped with
6-6 compression system [1] is normally used. It uses anvils made of tungsten carbide (WC) with small neutrontransparency. In that case, the incident beam is introduced into the sample through the gap between theMLF Annual Report 2015

anvils and the scattered neutrons are detected throughother gaps (Fig. 4). Since the gap is drastically reduced
at high pressures (typically to c.a. 0.8 mm at 7.5 GPa),
the window for neutron detection is significantly limited and the scattering intensity from the sample is decreased correspondingly. To avoid such decrease, we
faced the challenge to collect the neutrons through theanvils, not through the gap, by using the neutron transparent anvils.
As an anvil material, yttrium toughened zirconia(ZrO2) (Tohoku ceramic, TCZ-ZM) was selected, basedon ref. [2]. The photo of both kinds of anvils is shownin Fig. 5
In the on-beam test, anvils with shape identical tothe original one (with height of the anvil 21 mm and sizeof the anvil top 10 mm) was used for ease of comparison. Fig. 6 compares the load dependence of intensity
along the position-sensitive detector (PSD) between
WC and ZrO2 anvils. The scattering intensity taken with
ZrO2 was found to remain unchanged regardless of theapplied load, while the one taken with WC anvils significantly decreased.
The pixel dependence indicates that the neutron
eventually passes though the ZrO2 anvils, since the distribution is widely spread and the width is not affectedby the gap. Correspondingly, the Bragg peak of the

Neutron Sciencesample (NaCl 220) didn’t show significant decrease in
its intensity (Fig. 7). Compared to the WC anvils, the integral intensity of the Bragg peak was found to increaseby a factor of 1.5 at 1.3 GPa.

Figure 5.	Comparison of the WC (left) and the ZrO2 anvils(right). The top of the ZrO2 is blackened after use
since the pressure transmitting medium, made ofaluminum sticks to the surface.

Figure 6.	Comparison of the load dependence of intensity
along the position-sensitive detector (PSD) between the WC (left) and the ZrO2 anvils (right).

Figure 7.	Comparison of the load dependence of intensity of
NaCl220 peak between the WC (left) and the ZrO2
anvils (right).

Figure 4.	Diffraction geometry in the experiments using a
6-axis press. The figure is reprinted from Nucl. Instrum. Methods Phys. Res. A780, 55 (2015) with permission from Elsevier.

References[1] N. Nishiyama et al., High Press. Res., 28, 307 (2008).
[2] K. Komatsu et al., High Press. Res., 34, 494 (2014).

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

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MLF Annual Report 2015

High Resolution Chopper Spectrometer at BL12
1. Introduction
The High Resolution Chopper Spectrometer (HRC)
is being operated at BL12 to study the dynamics incondensed matters with high resolutions using relatively high energy neutrons. A research project using
the HRC is being conducted to observe a wide rangeof correlated electron systems. In FY2014, we enteredthe 2nd phase of our project, where we will improve
the performance of the HRC in the following points:(1) detector system at low angles for high-energy experiments, (2) Fermi choppers for higher resolution andlower background, (3) sample environments, (4) completing the installation of detectors at high angles, and(5) computational environment for easy operation ofexperiments.
2. Instrumentation in FY2015
The lowest temperature of 0.6 K was confirmed forthe 3He circulation type refrigerator. To achieve such
low temperatures, a large number of radiation shieldings made of aluminum are mounted surrounding thesample. The scattering from the shieldings produces
huge background noise. Fig. 1(a) shows ring-like scatterings from the shielding, which is comparable to or
larger than the spots of the Bragg scattering from asingle crystal sample. The ring-like scatterings weresignificantly reduced by operating the oscillating radialcollimator (ORC), as shown in Fig. 1(b). Also, in the inelastic spectra, the huge phonons from the shieldings
were greatly reduced by ORC (Fig. 1(c) and (d)). Thus,

(a)

(c)

now this refrigerator can be used for inelastic neutron
scattering experiments.
The control and analysis software programs, named
YUI and HANA, respectively, developed individually for
HRC, have been almost completed. In YUI, new tools,
such as sample environment devices, were introduced
and the automatic controls of devices in connection
with the operation of DAQ were improved. In HANA, thefollowing improvements were performed.
For the plot of S(Q,w) for a single crystal sample,
a striped pattern appeared along Q a dependent on
the step width of Qb, as shown in Fig. 2(a). This wascaused by the difference in the numbers of detectors
contributed to each pixel. By applying to this plot thedetector number normalization function, which was
already applied to the plot for a powder sample, thestriped pattern disappeared, as shown in Fig. 2(b). For
the plot of S(Q,w) for a powder sample, a jaggy pattern
appeared when the step width of Q was smaller than
the instrumental resolution. By applying to this plot thesmoothing function for detector width, which was already applied to the plot for a single crystal sample, thejaggy pattern disappeared. Fig. 2(c) shows the intensityof the inhomogeneity caused by the inhomogeneous
detector efficiency or the difference of the solid angles
of detectors viewing the sample. This inhomogeneity disappeared by correcting the detector efficiency,
as shown in Fig. 2(d). Also, the mask function was introduced to remove detector areas unwanted for the
analysis.

(a)

(b)

(b)

Qc

(d)

Qb

Qb
(c)

(d)

Qa

Figure 1.	Effect of the oscillating radial collimaotor (ORC). Elastic scattering without ORC (a) and with ORC (b), inelastic scattering without ORC (c) and with ORC (d).

86

Qc

Qa

Figure 2.	Improvement of HANA. S(Q,ω) plot for a single
crystal sample without (a) and with (b) the detector number normalization function, without (c) andwith (d) correcting the detector efficiency.

MLF Annual Report 2015

In the initial construction, we installed 128 pieces of 2.8 m detectors to cover scattering angles of f
= 3° – 42°. Later, more than 128 pieces could be purchased, which made it possible to cover f = −31° – 62°
in January, 2014. Some detectors in the later installation
showed an inhomogeneous counting efficiency in thepositional dependence. The maker discovered a defectin the detector structure of 88 detectors and re-manufactured all of them. We installed them again in January,
2015, however, the inhomogeneity was not improved.
Engineers of the maker inspected and tuned them on
HRC in September. Finally, they found that 6 pieces
required repair, we installed living detectors to covercontinuous f. We checked the counting on beams in
October. Although several detectors still showed inhomogeneity, which could be corrected in the analysis, westarted experiments.
Below, we will describe other instrumentations.
Following the success of the neutron Brillouin scattering(NBS) on HRC, new detectors for low angles and a vacuum flange to mount these detectors were approved.
The detectors were mounted in pairs along the scattering beam to increase the counting rate. Some B4C liners
mounted on the inside surface of the vacuum scattering chamber blocked the scattering neutrons from thesample from reaching the detectors. Those liners were
replaced by thinner ones to improve the neutron counts(but the problem could not be resolved completely).
The vacuum system for the vacuum scattering chamber
can be operated with a simple procedure on the control panel. Since there were some failures in controllingthe cryopump, the original controller for the cryopump
was removed and the cryopump was operated directly
form the control panel. The regular maintenance forthe cryopump was performed. The T0 chopper was designed for 4000 hours of running time at 100 Hz operation. The first machine was removed from the beam line
in 2013, and the second machine is currently being operated. The maintenance, which consists of replacement

Neutron Scienceof components damaged during the operation and thecontinuous running for realizing a smooth rotation of
the mechanical bearings, was performed for the firsttime within a period of 4 months. This experience wasvery informative for planning the future maintenance.
Electric noise, picked up with detector cables, produces
a huge amount of unwanted event data. The detector
cables were shielded to reduce the noise. We mounted
the superconducting magnet and confirmed the maximum magnetic field of 10 T on HRC. After several experiments in February, 2015, a leak occurred between
the liquid helium vessel and its vacuum surrounding,and repairs were started.
3. Scientific Results
On HRC, high resolution experiments in conventional energy momentum space and neutron Brillouinscattering experiments can be performed, and of theopportunities in sub-eV neutron spectroscopy are also
explored. We obtained good results, which have been
described in this report. One of the remarkable results
was a study of spin waves in a metallic ferromagnet
SrRuO3 [1], which was obtained by the success of NBS
on HRC. We found that the spin wave gap nonmonotonously depends on the temperature and can be
described as a function of the anomalous Hall conductivity. In SrRuO3, a band crossing due to spin orbit interaction produces the Berry phase and acts as a magnetic
monopole in the momentum space. This is the originof the anomalous Hall effect in SrRuO3. Our experimentshowed for the first time that monopoles in the momentum space could be detected by inelastic neutron
scattering, in other words, the Berry phase is observable in inelastic neutron scattering. The details of thesefindings are described in a separate report.
Reference[1] S. Itoh et al., Nat. Commun. 7, 11788 (2016).

S. Itoh1,2, T. Yokoo1,2, T. Masuda3, H. Yoshizawa3, M. Soda3, Y. Ikeda3*, S. Ibuka1,2, M. Yoshida3, T. Hawai1,2, T. Asami3, R. Sugiura3,
D. Kawana3, Y. Kawamura3, T. Shinozaki3, Y. Ihata4
1
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*Present address: Tohoku University

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MLF Annual Report 2015

BL14 AMATERAS
1. Introduction
FY2015 was the seventh year of operation of
AMATERAS, a cold-neutron disk-chopper spectrometer.
We continued the user program, which was temporarily
interrupted due to problems at the neutron target. We
also contributed to international collaborations (experiments in the framework of the Korea-Japan collaboration program in neutron science and participation in
the 7th AONSA Neutron School). In this fiscal year, we
encountered mechanical problems of the equipmentof AMATERAS, one of which was serious. The goodnews was that we had a new technical out-sourcing
staff, Mr. Daisuke Wakai who succeeded the former staff
Ms. Kaori Kamoshida.
2. User program, international activities & out-comes
In FY2015, the user program at MLF was seriouslyinterrupted due to problems at the neutron target. In
the 2015A period, we scheduled 12 general proposals(three of them were carried-over subjects from 2014B),
four project research proposals (one of them was acarried-over subject from 2014B) and two elementarystrategy initiative proposals (one of them was a carriedover subject from 2014B). We completed nine subjects
and partially did five subjects. The remaining subjects
will be carried out in FY2016.
AMATERAS joined the 7th AONSA Neutron School/
the 3rd MLF School held in December. Two students
participated and studied quasi-elastic neutron scattering (QENS) experiment and data analysis for ionic liquid. They learned how to prepare a liquid sample withproper quantity and thickness in a double cylindricalcontainer and set it to a cryostat (Fig. 1). Since there wasno neutron beam, they analyzed QENS data previously
measured by the instrument group. From a curve fittingwith a jump diffusion model, they reduced the diffusion
constant at several temperatures and the activation energy of the diffusion mode. We hope that the neutron
experiment will become one of the tools to be used intheir future research activities.
In this fiscal year, AMATERAS had a guest fromthe Korea Atomic Energy Research Institute (KAERI),
Dr. Ji-Yong So, in the framework of the Korea-Japan collaboration program in neutron science. He is the person
in charge of a cold-neutron disk-chopper spectrometer,
DC-TOF at HANARO at KAERI and stayed at MLF for twomonths to learn the actual operation of instruments
and the user-program at AMATERAS. He also carried out
88

Figure 1. 
( Top) Two students of the 7th AONSA Neutron
School/the 3rd MLF School and staff members of
AMATERAS. From the left, Mr. D. Wakai (J-PARC),
Dr. B. Li (J-PARC), Dr. T. Kikuchi (J-PARC), Dr. A. B. Khan
(Jamia Millia Islamia Univ.), Prof. X. Li (Univ. Tokyo),Dr. Y. Kawakita (J-PARC). (Bottom) Students instructed on sample mounting by Dr. Kawakita.

measurements on quasielastic scattering from block copolymers and inelastic scattering of phonons in steels
to compare the performance between AMATERAS and
DC-TOF.
On November 12, 2015, Sumitomo Rubber Co.,
Ltd., issued a press release titled “ADVANCED 4D
NANO DESIGN — New technology of developing rubbers for high-performance tires in combination withSPring-8•J-PARC•KEI,” [1], part of that investigation was
done on AMATERAS. Seven scientific papers (reviewed)
on the results from AMATERAS were published in 2015.
Also, two academic dissertations were completed in
March, 2016, partially using results from AMATERAS.
3. Instrumental activities
We have updated each component of AMATERAS in
FY2015, as follows. Firstly, the guide mirrors at the final

MLF Annual Report 2015

Neutron Science

Figure 2.	Replacement of supermirror of the final section of
AMATERAS beam-transport.

Figure 3.	The floor is covered with tiles of B4C (1 cm thickness). The upper surface of tiles are covered withflooring material.

section were replaced to new ones with higher m-values (Fig. 2). Their alignment was investigated after the
replacement, and it was found that the displacementof each mirror was settled within 1 mm compared to
the results in 2013. Secondly, we added utilities, suchas electric distribution board, cooling water and helium
recovery lines, to increase the capacity for operationof various sample environment accessories for users’
experiments. Thirdly, we made efforts to reduce thebackground by placing B4C tiles on the floor under thevacuum scattering chamber (Fig. 3). The tiles absorb
neutrons, some of which come from the floor, resulting
in reduction of the time-independent background. Thisbackground was eventually reduced by ~12% in thewhole area covered by PSD’s, especially by ~25% at thelower area. We should also note that we just launchedrefurbishment of the vane between the detector banks
in the vacuum chamber. Because the vacuum chamberis pressed vertically when it is evacuated, the vane isslightly bent, which causes useless pixels in the data.
A newly designed and attempted method was to keep
pulling the vane vertically, even when the chamber was

evacuated. Since this refurbishment was quite effective,
we will continue it in FY2016. Moreover, we also madeother minor updates, such as installation of IROHA2,
which is a common software framework for the instrument control in MLF, and a control system for the radialcollimator.
In FY2015, which is the seventh year since theoperation of AMATERAS has been started, someproblems, related to aging, are becoming obvious atseveral components. Anomalous vibration was foundat a high-speed disk-chopper, so we decided to restrict
temporarily its operation at the maximum speed. In ahigh-voltage power supply, unconventional fluctuationof the voltage was detected when ramping up the voltage. Furthermore, one of the compressors operating
the cryopump system also broke, though two others
are still working. We are planning to fix all of them thenext fiscal year.
Reference[1] see http://j-parc.jp/ja/topics/2015/Press151112.
html (in Japanese).

K. Nakajima, S. Ohira-Kawamura, Y. Kawakita, and T. Kikuchi
Neutron Science Section, Materials and Life Science Division, J-PARC center89

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MLF Annual Report 2015

Upgrading TAIKAN
1. Introduction
The small and wide angle neutron scattering instrument TAIKAN (BL15) has been developed and upgradedto analyze microstructures or hierarchical structuresof substances in various scientific fields precisely andefficiently with a 1MW spallation neutron source in
J-PARC [1]. In FY2015, it was upgraded further to perform measurement in a horizontal magnetic field andlow-q measurement.

4. Future prospect
The focusing-geometry SANS system of TAIKAN
is completed in combination with magnetic beam focusing devices: a quadrupole magnet, two sextupole
magnets, and three radio-frequency gradient spin flippers. After the completion of the combination, qmin will
be extended down to 0.0005 A-1, the targeted value of
TAIKAN.

2.	Upgrading for measurement in a horizontal magnetic fieldA cryogen free split-pair superconducting magnet(horizontal field magnet) with wide aperture angle of
90° was developed for wide angle neutron scattering
measurement of magnetic and superconducting materials (Fig. 1). The magnet has been used to apply magnetic field up to 4 Tesla to a sample and cool the sample
down to 1.6 K from RT.
3. Upgrading for low-q measurement
A focusing-geometry SANS method has been adopted for the measurement in a q range of 0.0005– 0.005 A-1. For the method, an ultra-small-angle detector is used. Figure 2 shows the scattering profile ofmesoporous silica measured by TAIKAN with the new
scintillation detector with an active size of 127 mm
in diameter and spatial resolution of about 0.5 mm.
The profile shows that qmin can be extended down to
0.0008 A-1 with the detector.

Figure 1. A 4 Tesla split-pair superconducting magnet.

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).

Figure 2. Scattering profile of mesoporous silica measured by TAIKAN, to which a new ultra-small-angle detector was installed.
J. Suzuki1, S. Takata2, K. Ohishi1, H. Iwase1, T. Morikawa1, Y. Kawamura1, and M. Sahara1
R&D Division, CROSS-Tokai; 2Neutron Science Section, Materials and Life Science Division, J-PARC Center

1

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Sample changers for High-Throughput Measurement at
the SOFIA Reflectometer
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 ResearchComplex (J-PARC) [1, 2]. Due to the high-flux beam of
the J-PARC, the exposure time for one measurement isdrastically shortened in compared to those at the JRR-3
research reactor and the KENS spallation source. Table 1
shows the list of typical samples, sample size (and beamsize), accessible Q range, and exposure time for fullQ-range measurement at the SOFIA reflectometer withthe proton power of 500 kW. Even though the beam
power is still half of the planned value, 1 MW, the required
time is over 10 times less than the time required at the
JRR-3 and KENS. On the other hand, time loss caused bychanging samples, and/or temperature becomes more
prominent with the decrease of the time required forcounting neutrons. This means that a sample changer isa key factor for high throughput measurements in orderto take a full advantage of the high flux beam.
2. Sample changer for ambient temperature
So far, the SOFIA has been equipped with a sample
stage with a motor for horizontal movement, which enables us to change samples remotely. Here, the number of samples to be measured at a time is limited by
the motion range of the stage. As the range is 300 mm,
seven samples can be measured at a time for 2-inch(50.8-mm) substrates in diameter. This means that the
total time for the measurement is expected to be lessthan 4 hours, if the substrates are coated with deuterated polymers. The time for the measurement is tooquick for an overnight run. Hence, a modification on
the sample stage was made to increase the number ofsamples for one measurement run.
Figure 1 shows a photograph of samples mounted
on the new sample stage. As the motion range in horizontal direction is limited due to the interference withthe surrounding components, a vertical translation
stage with a long-motion range, 110 mm, was introduced. This enables us to add stages above the samples
and mount more samples on the additional stages. If
the thickness of the stage is 10 mm and the gaps between the stages are 20 mm, four stages can be used at
a maximum, that is, fourfold samples can be measured
at one experiment run.

Figure 1.	Photograph of samples mounted on the new sample stage.

Table 1.	List of typical samples, sample size (and beam size), accessible Q range, and exposure time required for full Q range measurement at the SOFIA reflectometer with proton power of 500 kW.
Sample interface
air/Si

Sample size (Beam size)

Q range250.8 mmØ (30 × 40 mm )2

air/protonated polymer/Si

50.8 mmØ (30 × 40 mm )air/deuterated polymer/Si

2

Exposure time-1

3/4 hour-1

1 hour< 2 nm< 2 nm-1

50.8 mmØ (30 × 40 mm )< 4 nm

1/2 hourair/D2O

25 mL (40 × 40 mm2)

< 2 nm-1

1/4 hourair/no reflection water

25 mL (40 × 40 mm2)

< 1 nm-1

3 hours

2-1

1 hour-1

Si/D2O

76.2 mmØ (30 × 50 mm )2

< 2 nmSi/protonated polymer/D2O

76.2 mmØ (30 × 50 mm )< 2 nm

1 hourSi/deuterated polymer/H2O

76.2 mmØ (30 × 50 mm2)

< 2 nm-1

1 hour91

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In addition, an auto sample adjustment routine
was implemented in the measurement program of the
SOFIA. This routine adjusts precisely the position andincident angle of the sample surface to the neutrons,
which is required before a neutron reflectivity measurement. It frees us from the necessity to adjust samples
and can extend further the total measurement time
for one experiment run by performing the auto adjustment before the reflectivity measurement.
3. Temperature controlled stages
To control efficiently sample’s temperature, twosample stages were newly developed: one is for hightemperature (from room temperature to 250°C) andthe other is for low temperature (from 0°C to 100°C).
The high-temperature stage consists of two evacuablechambers and a silicon block with a rubber heater is installed in each chamber (Fig. 2). The size of the silicon
block is 153 mm in the direction of the horizontal translation, on which three 2-inch substrates can be mounted. The purpose of this stage is to keep the two silicon
blocks thermally isolated, so that the temperature canbe controlled independently. This means that we canchange the temperature of a silicon block during ameasurement for a sample on the other block, which
avoids the time loss when the temperature changes.
Similarly, the low temperature stage consists of two
cupper blocks with peltier elements in a chamber witha water circulation path (Fig. 3). The temperature of thetwo blocks can be controlled independently, and drygas flow can be introduced in the chamber to avoid thecondensation of water vapor on the sample. The sizeof the cupper block is 192 mm in the direction of thehorizontal translation, on which three 2-inch substrates
can be mounted.
The temperature of the stages can be controlled by
the measurement program of the SOFIA. By repeating
the measurement and temperature control alternately,a sequence of temperature variation experiments canbe performed without the time loss when the temperature changes automatically.

Figure 2.	Photograph of the temperature-controlled stage
for high temperature.

Figure 3.	Photograph of the temperature-controlled stage
for low temperature.

4. Conclusion
For high throughput measurements, the verticaltranslation stage and temperature stages were developed. The former resulted in an increase in the number of samples and total measurement time for one
measurement run in combination with the software of
the SOFIA. The latter can complete the sequence of thetemperature variation experiments also in combination
with the software. We should note that the extension of
one measurement run can make time for sample preparation, data reduction, and/or taking a rest. We believe
the development here makes the experiment at the
SOFIA more efficient and productive.
References[1] N. L. Yamada et al., Euro. Phys. J. Plus, 44 (2011) 9424.
[2] K. Mitamura et al., Polymer J., 45 (2013) 100.

N. L. Yamada1, 2
Neutron Science Section, Materials and Life Science Division, J-PARC center; 2Institute of Materials Structure Science, KEK

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BL17: Polarized Neutron Reflectometer SHARAKU using
2-D MWPC with Indivisual Readout System
1. Introduction
Polarized neutron reflectometry is one of the powerful methods to investigate various phenomena on
the surfaces and interfaces of a variety of films with layered structures, such as magnetic multilayers, polymer
films, and biological membranes. The polarized neutronreflectometer SHARAKU [1], named after the famous
Japanese ukiyo-e artist, was constructed at BL17 of
MLF in J-PARC and we have continued to utilize it in theuser program in 2015 [2-5]. SHARAKU has suitable options for the measurement of specular reflectivity, offspecular reflectivity, grazing incidence diffraction (GID),
and grazing incidence small-angle neutron scattering(GISANS). In order to enable these measurements, theinstrument is equipped with a zero-dimensional (0-d)
He-3 detector and a two-dimensional (2-d) positionsensitive neutron detection system [6]; it consists of amulti-wire proportional chamber (MWPC) with helium-3
gas and its own data reduction software. In this report,
we describe the specifications of the two-dimensional
MWPC system at BL17 and its applications to neutron
specular and off-specular reflection measurements.
2. Demonstration of the MWPC system
Figure 1 shows a view of the SHARAKU reflectometer with the 0-d detector and Fig. 2 shows a setup of
the 2-d MWPC installed at a distance of 2500 mm fromthe sample position (L1 + L2 = 18 m). The MWPC [2]has a neutron sensitive area of 128 × 128 mm2. It consists of a 256-channel detector element (x: 128 lines,
y: 128 lines), each wire’s signal is read out by amplifier-shaper-discriminator (ASD) individually to meet thedemands for fast counting response and high spatial
resolution for measurements at intense pulsed neutron
sources. The full width at half maximum (FWHM) of thespatial error is 1.8 mm.
Figure 3 shows a neutron transmission image of B4C
slits located between the vacuum chamber and MWPC.
The inset intensity profiles, which are integrated along
the X or Y axis, are nearly flat and the neutron distribution data is used to produce uniformity correction data.
Figure 4 shows the reflectivity profiles of a Nickel
thin film with a thickness of 200 nm, coated on a silicon substrate measured by using the 0-d counter and
MWPC. By using both detectors, we could obtain equal
specular reflectivities down to 10-5. In this measurementmode, the 2-d MWPC works similar to the 0-d detector,
and the detected counts are integrated over the specular reflection area.
As shown in Fig. 5, a non-polarized intensity mapof off-specular reflection has been measured for a Ni/Ti
multilayer with d = 10 nm and 20 bilayers at beam power of 300 kW. In this measurement, we focused on thesmall q-region between 0.1 < qz < 0.8 nm-1 and 0.001 <qx < 0.01 nm-1 , and the direct beam and specular beam
were protected by using B4C slits to decrease the neutron background. In order to get credible results, wemeasured the reflections in the same q-region by using
thr 0-d detector and obtained almost equal off-specularreflection profiles.

Figure 1. SHARAKU with 0-d detector.

Figure 2. MWPC setup.

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0.8
32000

0.7

28000
24000

0.6

20000
16000

0.5

12000

0.4

6000
4000

qz

(nm-1)

0.3
0.2
0.1- 0.015- 0.010qx- 0.0050.000(nm-1)

Figure 3.	A neutron transmission image of B4C slits (S9) detected by the 2-D MWPC with a neutron sensitive
area of 128 × 128 mm2.

Figure 5.	Off-specular intensity map from Ni/Ti multilayer
with d = 10 nm and 20 bilayers.

(GID), and grazing incidence small-angle neutron scattering (GISANS), the 2-d MWPC with individual read out
system has been installed and a commissioning test has
been conducted. The function of the 0-d detector measurement worked well, and weak diffuse scattering has
been observed in the low q-region.

Figure 4.	Neutron reflectivity profiles of Nickel thin film witha thickness of 200 nm detected by the 0-d detector
and MWPC.

3. Conclusions
In order to enable surface scattering measurements
on off-specular reflectivity, grazing incidence diffraction

References[1] M. Takeda et al., Chinese J. Phys. 50 (2012).
[2] K. Amemiya et al., JPS Conference Proceedings 834004 (2015).
[3] T. Ueno et al., JPS Conference Proceedings 8 034008(2015).
[4] Y Sakaguchi et al., Journal of Physics; Conference
Series 619 012046 (2015).
[5] K. Akutsu et al., Proceedings of the 12th Annual
Meeting of Particle Accelerator Society of Japan 7276 (2015).
[6] K. Toh et al., J. of Instrumentation, Vol.9 (2014).

K. Soyama1, D. Yamazaki2, N. Miyata3, K. Akutsu3, S Kasai3, T. Hanashima3, J. Suzuki3, and M. Kubota4
Materials and Life Science Division, J-PARC Center; 2Neutron Instrumentation Section, Materials and Life Science Division, J-PARC Center;
3Neutron R&D Division, CROSS-Tokai; 4Materials and Life Science Division, Quantum Beam Science Directorate, JAEA

1

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SENJU 2015
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, and also designed for taking diffraction intensities
of small single crystals with less than 1.0 mm3 down to
0.1 mm3 in volume [1]. Just after the launch of SENJU in
2012, continuous commissioning and upgrading havebeen carried out.
In 2015, we developed an anvil-type high pressure
cell and performed the first measurement of magneticreflection under high pressure at SENJU. We also upgraded the software for device control, IROHA, and fordata processing, STARGazer for SENJU.
2.	O bservation of magnetic reflections underhigh-pressure
Measurement of the magnetic neutron reflections
under high pressure condition is a powerful experimental tool to understand the relationship between
magnetic property and structural change by pressure
at atomic level. Thus, we have developed high pressure sample cells for SENJU. In the previous report [2],we showed a piston-cylinder type high pressure cell.
In FY2015, we developed another type of high pressure cell, self-clamped opposed type hybrid anvil (HA)
cell [3], for SENJU (Fig. 1). The HA cell consists of a pairof tungsten carbide and single crystal sapphire anvils;
it can reach higher pressure than a piston-cylindercell. By using this HA cell, we carried out the magnetic

Figure 1. Photograph of the HA cell.

reflection measurement under high pressure. A CeSb
single crystal (0.9 × 0.9 × 0.33 mm3) was set in the HA
cell and pressurized up to 2 GPa. The cell was cooled
down to 2.7 K by using a closed-cycle refrigerator. The
pressure was determined by the ruby fluorescencemethod. As shown in Fig. 2, we successfully observed
distinct pressure induced magnetic reflections from thetype-IA anti-ferromagnetic phase of CeSb. This was thefirst example of observation of magnetic reflection under high pressure and low temperature in SENJU.
3.	Upgrading of the device control software: from
IROHA to IROHA2
IROHA is MLF standard software to control detectors, sample environment devices and neutron opticaldevices. Recently, IROHA was upgraded to a new version with browser-based user interface, IROHA2 [4]. In
FY2015, we started to use IROHA2 instead of IROHA as
device control software of SENJU. IROHA2 made easier
the remote monitoring of the measurement status of
SENJU, e.g. from J-PARC Research Building or IQBRC
Building. New device control middleware for T0 anddisc choppers designed for IROHA2 was also installed.
Consequently, the choppers of SENJU were placed under the control of the SENJU control cabin and automatic shifting from the 1st frame to the 2nd frame became
possible. The commissioning of IROHA2 continued during the summer shutdown period and we began to use
it from November, 2015.
4.	U pgrading of the data processing software:
STARGazer for SENJUSoftware for data processing, i.e., making a reflection (HKLF) file from raw data, and data visualizationis one of the essential components of a single-crystal
diffractometer. For SENJU, a program called “STARGazer
for SENJU” is used for data processing and visualization.
In FY2015, an update of STARGazer for SENJU was
introduced, with the following developments:
1. Automatic exclusion of powder rings in thepeak search process.
2. Automatic intensity integration of satellite reflections in the peak-integration process.
The first one was developed to improve the reliability of the peak search process. The diffraction images
measured by SENJU usually contain the powder patternof aluminum that comes from the ra-diation shields of acryostat and/or sample mounting pin. When the sample
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Figure 2. Pressure-induced magnetic reflections from a CeSb crystal at 2 GPa and 2.7 K observed by SENJU (2nd frame).

size is small and the intensities of the Bragg reflections
are weak, the powder pattern seriously decreases thereliability of the peak search process and makes the UBmatrix determination difficult. The new function automatically estimates the peak widths of both the X andY directions and removes the peaks when the widthof the Y direction is much broader than that of the X
direction.
The second one was developed to process satellite
reflections, which have non-integral indexes effectively
caused by modulated structures. In the function, users
can input indexes of more than one modulation vector in the peak integration process. The function thencalculates and outputs the integrated intensities of thecorresponding satellite reflections, not only the firstorder reflections but also the high-order ones. This new
function should help to determine intricately modulated structures or slight change of magnetic structure byphase transition more accurately.
References[1] T. Ohhara et al., J. Appl. Cryst., 49 120 (2016).
[2] T. Ohhara et al., MLF Annual Report 2013, 106(2013).
[3] T. Osakabe et al., J. Phys. Soc. Jpn. 79, 034711 (2010).
[4] T. Nakatani, Y. Inamura and K. Moriyama, Proc. 7th
MLF Symposium (2016).

T. Ohhara1, R. Kiyanagi1, A. Nakao2, T. Hanashima2, K. Munakata2, T. Moyoshi2, and T. Kuroda2
Neutron Science Sectioin, Materials and Life Science Division, J-PARC center; 2Neutron Science and Technology Center, CROSS-Tokai

1

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Neutron Science

Engineering Sciences in TAKUMI
1. Introduction
TAKUMI is a neutron diffractometer (ND) for various
studies in materials engineering. TAKUMI functioned
almost flawlessly during JFY2015, but unfortunately
many experiments had to be stopped or not conducted
at all, due to the unexpected stoppage of the beam operation caused by a problem with the neutron source.
Some enhancements, related to new devices and methodology, have been performed using the limited beamtime. The details are as follows.
2. Enhancements during JFY2015
2.1 Supplementation of the 90° scattering detector bank
TAKUMI has a pair of 90° scattering detector banks,and each of them was designed with an angular area of±15° horizontally and ±20° vertically [1]. Seven modulesof scintillator detectors of ENGIN-X type with 360 horizontal-channels were designed to be added to eachbank. However, only five modules were installed in eachbank during the construction due to the limited budget. Two modules were purchased and installed within
two years since JFY2014, and the current appearance of
TAKUMI is shown in Fig. 1. The commissioning of the detectors is under progress and will continue in JFY2016.

Sports, Science and Technology, Japan. This new device isdesigned to heat the specimens by induction heating andcool them by gas injection. The highest rates for heating
and cooling are about 30°C s-1. It can also apply compressive deformation with the highest rate of 100 mm s-1. The
first neutron diffraction data on steels was conducted atthe 300 kW accelerator operation. Diffraction patterns extracted with the interval time of about 1 s could be used
to determine the occurrence of phase transformation
during thermo-mechanical processes [2]. The accelerator operation will be 1 MW in near future, so that shortertime resolution would be achievable. Hence, the in-situ
neutron diffraction experiment using this new device isbelieved to simulate current industrial steel processing(thermo-mechanically controlled processing). An example of the experiment is shown in Fig. 2.

A
850C,'γ

A+10C/sstraining–30C/s10s΄holdingBcoolingBαFigure 2.	An example of a thermo-mechanical program andappearances of the specimen during the process.

1370mm
805mm

Neutrons
217mm

Sensive Area
1m 20cm

Figure 1.	The current appearance of TAKUMI with 6 modulesof scintillator detectors in each bank.

2.2 Thermec-mastor installation & commissioning
A new sample environmental device for simulating
thermo-mechanical processes of materials (thermecmastor) has been installed in a collaboration between a
research group in Kyoto University and TAKUMI, withina scheme of Elements Strategy Initiative for Structural
Materials supported by the Ministry of Education, Culture,

2.3 Profile analysis
The information of elastic strain (lattice strain),dislocation density, dislocation character and crystalline size is very important to understand the relation
between microstructures and mechanical properties,
however, the dislocation and crystallite size information
did not receive enough attention because of the ND limitations and the difficulties in the analysis. TAKUMI adopted an advanced analysis method, the convolutional
multiple whole profile (CMWP) fitting [3] that made it
possible to perform profile analyses to extract dislocation and crystallite size information from its diffraction
patterns. From a demonstration of tensile deformationof martensite steel, the dislocation densities were interestingly kept almost unchanged, though the tensilestress increased with increasing the plastic strain, while
significant increase of the correlation between the dislocations was observed [4]. An example of CMWP fitted
diffraction pattern of martensite steel is shown in Fig. 3.
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Event data of electric field
Figure 4.	A schematic illustration showing the principle ofcondition filtering data reduction for stroboscopic
measurement.

Figure 3.	An example of CMWP fitted diffraction pattern ofmartensite steel.

2.4 Stroboscopic measurement
In-situ measurements during cyclic tests or operations like high frequency fatigue, cyclic electric field ofpiezo sensor, etc. need sub-second acquisition time.
However, the short collecting time for a specific condition within a cycle provides data with poor quality.
Meanwhile, summing neutron data obtained in a cycle
will be meaningless, because the different conditions
will be averaged to zero. A stroboscopic measurement
and a condition filtering data reduction have been developed in TAKUMI, and preliminary tests with a fatigue
test of steel and a cyclic electric field of a piezoelectricmaterials in a stacked-type actuator have been done.
The principle of condition filtering data reduction forstroboscopic measurement is shown schematically in
Fig. 4. By using this method, the diffraction patterns at
specific conditions during cyclic tests can be extractedwith sufficiently good statistics. From the cyclic electricfield test of a piezoelectric materials in a stacked-type

actuator, crystal plane dependences of the lattice strain
due to the inverse piezoelectric effect and the hysteresis loop in both the lattice strain and domain switchingwere observed [5].
3. Summary
Some enhancements were completed at TAKUMI
using the limited beam time in JFY2015. Successfully
done were the supplementation of the 90° scattering
detector banks, thermec-mastor installation and commissioning, profile analysis, and stroboscopic measurement. Some of them have also been used by TAKUMI
users in their experiments.
References[1] S. Harjo et al., Mater. Sci. Forum, 524-525 199 (2006).
[2] A. Shibata et al., CAMP-ISIJ, 28 341 (2015).
[3] G. Ribarik & T. Ungar, Mater. Sci. Eng. A528 112(2010).
[4] T. Kawasaki et al., JPS Conf. Proc., 8 031009 (2015).
[5] T. Kawasaki et al., Acta Cryst., A71 s349 (2015).

S. Harjo1, T. Kawasaki1, K. Aizawa1,2, T. Ito3, and K. Sakasai41
Neutron Science Section, Materials and Life Science Division, J-PARC center; 2Technology Development Section, Materials and Life Science
Division, J-PARC center; 3Neutron R&D Division, CROSS-Tokai; 4Neutron Device Section, Materials and Life Science Division, J-PARC Center98

MLF Annual Report 2015

Neutron Science

The Current Status of the Versatile Neutron
Diffractometer, iMATERIA
1. Introduction
Ibaraki prefecture, local government of Japan’s area
where the J-PARC sites are located, has decided to build
a versatile neutron diffractometer (IBARAKI Materials
Design Diffractometer, iMATERIA [1]) to promote industrial applications for the neutron beam in J-PARC.
iMATERIA is planned to be a high-throughput diffractometer that could be used by materials engineers andscientists in their materials development work like thechemical analytical instruments.

total length of 14.0 m. The instrumental parameters
are listed in Table 1. There are four detector banks, including a low-angle and small-angle scattering detector bank. The angular coverage of each detector bankis also shown in Table 1. The rotation speeds for the
disk-choppers are the same with a pulse repetition rateof 25 Hz for the most applications (SF mode). In thiscase, the diffractometer covers 0.18 < d (Å) < 2.5 withΔd/d = 0.16% and covers 2.5 < d (Å) < 800 at three detector banks of 90 degree, low angle and small angle
with gradually changing resolution. When the speed of
the wavelength selection disk-choppers is reduced to12.5 Hz (DF mode), we can access a wider d-range, 0.18
< d (Å) < 5 with Δd/d = 0.16%, and 5 < d (Å) < 800 with
gradually changing resolution with doubled measurement time from SF mode.
Table 1.	Instrumental parameters of iMATERIA. L2 is the scattered flight path. The d-range (q-range) for each bankis the maximum value for 2-measurement mode.

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

The applications of neutron diffraction in materials
science are (1) to do structural analyses of newly developed materials, (2) to clarify the correlation between
structures and properties (functions), and (3) to clarify
the relation between structural changes and improvements of functions, especially for practical materials.
To achieve those purposes, a diffractometer with superhigh resolution is not required. The matching amongintermediate resolution around Δd/d = 0.15%, high intensity and wide d coverage is more important.
This diffractometer is designed to look at a decoupled-poisoned liquid hydrogen moderator (36 mm,
off-centered) (BL20), and to have the incident flightpath (L1) of 26.5 m with three wavelength selection
disk-choppers and straight neutron guides with aL1
26.5 mGuide length
Position of Disk choppers

High
Resolution
Bank
SpecialEnvironment
Bank
Low
Angle
Bank
Small
Angle
Bank

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

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

2. Current status
All of the four banks, high-resolution bank (BSbank), special environment bank (90 degree bank), lowangle bank and small-angle bank are operational. It
takes about 5 minutes (DF mode) to obtain a ‘Rietveldquality’ data in the high-resolution bank at 500 kW
beam power for about 1 g of standard oxide samples.
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Figure 2 shows a typical Rietveld refinement pattern
for LiCoO2 sample, cathode material for LIB, at the highresolution (BS) bank by the multi-bank analysis functionof Z-Rietveld [2]. It takes 20 min at DF mode to collect
the available Rietveld data, due to the high neutron absorption cross section for natural Li (ssNat = 70 barn).

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

scheme, “1 × 132”, is the measurement of 132 spectra ata single sample geometry. The results by both schemashow good similarity, which indicate the validity of the
new scheme without sample rotation. The result of an
EBSD measurement for the same sample also matchedwell the above results.
This rapid measurement scheme needs to both ahigh resolution and a wide range of scattering angle, i.e.
the features of iMATERIA. Since the new scheme can determine the bulk average texture with a single neutron
exposure for 3 ~ 5 minutes (using single frame mode@500 kW), it is an optimal method for in-situ texture
measurement. The achievement described above has
been attracting researchers from metallurgy and otherrelated industries, who are newcomers to the field of
neutron sciences.

3. Sample Environments
The automatic sample changer is the most important sample environment for high-throughput experiments. Our automatic sample changer [3] consists ofsample storage, elevating system of two lines, two setsof pre-vacuum chambers and a sample sorting system.
We can handle more than 600 samples continuously atroom temperature without breaking the vacuum of thesample chamber.
The V-furnace (~900°C), the crio-furnace (4 K) andthe 1 K crio are ready for experiments. The gas furnace(~900°C) will also be in operation soon.
5. Rapid Measurement Scheme for Texture
The crystallographic texture measurement system
was optimized by applying Rietveld texture analysis [4].
The optimized measurement scheme made it possible
to do quantitative texture measurements in several
minutes. 132 spectra corresponding to different sample
directions were simultaneously measured and the data
were analyzed by MAUD software [5]. Figure 3 showsthe ϕ2 = 45° sections of the orientation distributions inEuler space for ferrite and austenite phases in a rolledsheet of NAS64 duplex stainless steel. The results listed
under “5 × 36” were obtained by the conventional measurement scheme requiring measurement of 36 spectra
at 5 different sample geometries. The newly suggested

Figure 3.	φ2 = 45° sections of the orientation distributions inEuler space for (a), (c) ferrite and (b), (d) austenite
phases in a rolled sheet of NAS64 duplex stainlesssteel [4]. The descriptions of schemes “5 × 36” and “1× 132” can be found in the text.

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.
[4] Y. Onuki et al., J. Appl. Cryst. 49 (2016) 1579-1584.
[5] Wenk, H. –R. et al., Powder Diffr. 25 (2010) 283-296.

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

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Status of the High Intensity Total Diffractometer(BL21, NOVA)
1. Introduction
Total scattering is a technique to analyze noncrystalline 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 (Dd/d ~0.5%) in J-PARC. It is easy to adapt NOVA to a very wide
field: liquids, glass, local disordered crystalline, magnetic structure of long lattice constant, and so on. The observation of the hydrogen position in materials is one of
the most important scientific themes of NOVA.

3. Auto-sample changers
For effective measurements with intense neutron
flux NOVA, the auto-sample changers are essential: atemperature-controlled (20 K ~ 500 K) auto-sample exchanger, which can load 18 samples, and an ambient
temperature auto-sample exchanger, which can load
40 samples, were introduced in the end of FY 2014. In
FY 2015, refinement of sample exchanging mechanism
as well as safety verification and software drivers for the
automatic operation of sample changers were combined with neutron scattering data acquisition.

2.	Development of a cell for hydrogen gas atmosphere
For the hydrogen gas atmosphere measurement(~ 10 MPa), single-crystal sapphire cell was used but
the signal-to-noise ratio at high-Q range is fatal for PDF
measurements. It is necessary to use material with small
coherent cross-section, such as vanadium. However, vanadium is known as a hydrogen-absorbing metal. To
realize the vanadium cell for hydrogen gas atmosphere,
two measures were taken: thermal treatment to preventhydrogen absorption at the surface and a double-wallstructure to relax the strain caused by lattice expansionof the sample in a hydrogen absorption process.

Acknowledgement
Operation and developments of NOVA was performed under the S1-type program (2014S06) approved by the Neutron Scattering Program Advisory
Committee of IMSS, KEK. The development of the cell
was supported by Photon and Quantum Basic Research
Coordinated Development Program from the Ministryof Education, Culture, Sports, Science and Technology,
Japan.

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

1

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Current Status of the Energy-Resolved Neutron Imaging
System “RADEN”
1. Introduction
A pulsed-neutron instrument, named EnergyResolved Neutron Imaging System “RADEN”, has been
constructed at the beam line of BL22 in the Materials andLife Science Experimental Facility (MLF) of J-PARC [1].
The primary purpose of this instrument is to perform
energy-resolved neutron imaging experiments througheffective utilization of the pulsed nature of the neutron
beam, making it the world’s first instrument dedicatedto pulsed neutron imaging experiments. After the firstneutron beam transport in Nov. 2014, commissioning
study using neutron beam has started. From the 2015
period, RADEN started to accept user proposals. Abouthalf of the beam time in FY2015 was used by the instrument group for a commissioning study of the instrument, 1/4 was allocated to the project use and the rest
was utilized by users.
2. Technical development at RADEN
Together with the commissioning study, the RADEN
instrument members continued the technical development on neutron imaging. At first, the CCD camera typedetector was converted into a much brighter system byusing a high-reflectivity single mirror (Fig. 1). This improvement shortened the distance between the CCD
camera and the scintillator screen, and now we canfocus on a small area of the scintillator and easily secure 100 µm spatial resolution. Then, the polarization
analysis system for the magnetic field imaging experiment was improved to obtain uniform polarization distribution in the beam (Fig. 2). Based on the numericalsimulation of the magnetic field and conservation of
the neutron spin direction along the neutron trajectory,
we evaluated the expected performance of the systemand confirmed it experimentally [2]. As a result of theexperiments, neutron polarization of over 90% was
obtained at the range of neutron wavelength longer
than 3 Å. The polarization distribution image confirmedthat the standard deviation along the vertical direction
was 2.0% in contrast with the one along the horizontal direction of 0.3%. This indicated that the magnetic
field connection was good enough to preserve theneutron spin direction. In addition, a new neutron imaging technique using interference of neutron beams,
named neutron phase imaging, has been developing
using pulsed neutrons [3]. The key of this technique ispreparing the precise absorption grating to construct
a Talbot-lau interforometer. We fabricated absorption
grating by using the imprinting technique of metallic
glass [4], and this grating finally allowed us to observe
very high visibility of moire pattern around 60% at the
wavelength of 5 Å.

Figure 1. New CCD camera type detector system using single mirror (left) and obtained image using test chart (right).

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Figure 2. Polarization analysis system of RADEN.

3. User programs and project use
RADEN started to accept general user programsand trial use proposals from FY2015, and 7 of the 10
submitted proposals were approved. About half ofthem were regarding the Bragg edge imaging technique. The field of proposals covered material science,industrial application, and metal archaeology. Two proposals were conducted as project use. Within this proposal, magnetic field imaging of a model electric motor
was performed and succeeded to visualize polarization
change due to the change in the magnetic field inside
the motor. In addition, Bragg edge imaging of a bent
steel sample revealed the spatial distribution of the microstructure of the sample, such as texture variations,crystallite size, and phase [5]. Each quantity was compared with the one obtained by neutron diffraction experiment and that confirmed its value’s validity.
4. Summary
RADEN started user programs together with thecommissioning study from FY2015. Several energyresolved neutron imaging experiments, such as magnetic-filed imaging of a model motor and Bragg edge

imaging of a steel sample, were performed in the user
program. Technical developments of the CCD camera
type detector and the polarization analysis system were
performed, and their performance was improved. In addition, for the first time, a new imaging technique using neutron interferometry was conducted with pulsed
neutrons.
Acknowledgement
This work was partially supported by JST ERATO
Momose Quantum Beam Phase Imaging Project andby Photon and Quantum Basic Research Coordinated
Development Program from the Ministry of Education,
Culture, Sports, Science and Technology, Japan.
References[1] T. Shinohara et al., J. Phys: Conf. Series 746 012007(2016).
[2] K. Hiroi et al., JAEA-Technology 2016-021 (2016).
[3] ERTO Momose Quantum Beam Phase Imaging
Project.
[4] W. Yashiro et al., Jpn. J. Appl. Phys. 55 048003 (2016).
[5] Y. Su et al., Mater. Sci. Eng. A675 19-31 (2016).

T. Shinohara1,3, T. Kai1, K. Oikawa1, T. Nakatani1, M. Segawa1, K. Hiroi1, Y. Su1, H. Hayashida2, J. D. Parker2,3, Y. Matsumoto2, S. Zhang2,
W. Ueno1,3, Y. Seki1,3, and Y. Kiyanagi4
1
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Neutron R&D Division, CROSS-Tokai; 3JST, ERATO, Momose
Quantum Beam Phase Imaging Project; 4Nagoya University

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Status of Polarized Neutron Spectrometer POLANO (BL23)
1. Introduction
POLANO is a chopper type spectrometer with a polarization analysis capability, now under construction
at the Materials and Life Science Experimental Facility(MLF), J-PARC. In 2012, the full-scale construction began under a joint project between KEK and Tohoku
University [1-4]. The construction and development ofdevices have been underway in the year 2015. After theconstruction is completed, we will assess the radiation,
then, POLANO will be approved as a proper neutron
beam line and the commissioning will start.
Our principal concept for designing POLANO is toachieve higher-energy polarization analysis of inelastic scattering beyond a reactor-based neutron source.
We target the energy range over Ef = 40 meV using the
combination of SEOP for a polarizer and bender supermirror as an analyzer of m = 5 to 5.5. In the second
phase, we will focus on a realization of even higher energy experiments (0 meV < ∆E < 100 meV) with a widesolid-angle SEOP/MEOP analyzer. In order to achievea high-flux polarized neutron experiment, we plan toadopt the cross correlation method. R&D of the correlation chopper is now underway. In this article, we report
the current status of the construction and design of the
POLANO spectrometer.
2. Beyond the reactor neutron source
As mentioned above, POLANO is targeting relatively high-energy polarization analysis, which had notbeen realized so far. The energy range up to 100 meV
contains many significant scientific topics, particularlyin the field of the so-called strongly correlated electron

systems. In the light of recent discoveries in materialscience, many of the observed complex phenomena
are largely caused by entangled physical degrees of
freedom of spins, charges, orbitals, and even lattice
vibration. Although the polarized neutron technique
has been developed and used for many years, the application of the time-of-flight (TOF) method has only
started in the recent years. In particular, with regard
to the inelastic spectrometer, the polarized neutron
technique finds limited practical use in wide scattering
angle instruments. By combining the polarized neutron
technique and the TOF method (pulsed neutron technique), we are going to put in practice the high-energy
polarization analysis in POLANO. The schematic beamline design is depicted in Fig. 1.
3. Status of the POLANO beam line
Converging 4Qc guide tubes optimized for 110 meV
neutron energy are aligned in the beam line (Fig. 2).
These tubes can efficiently transport neutrons at sample
position. Several devices are placed in the intersectionof the beam line. In particular, choppers are one of the
key devices ensuring the success of the inelastic neutron
scattering experiments. POLANO utilizes four different
types of choppers. The T0 chopper can eliminate gamma flash and fast neutrons. Disk choppers (slow-rotating
band choppers and fast-rotating correlation choppers)
are used for the cross-correlation method. The correlation chopper has been newly developed. The Fermi
chopper is for selecting incoming (incident) neutron energy rotating at 600 Hz. These choppers, except the correlation chopper, have been installed in the beam line.

Figure 1. Schematic drawing of the POLANO beam line with several devices’ arrangement.

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Figure 2.	Installing operation of the 4 m super mirror guidetube in the beam line.

Figure 3. Installed position-sensitive detector array.

Since a large vacuum chamber and a get-lost-tube
had already been placed, we proceeded with the installation of detectors at the back of the vacuum chamber.
Figure 3 shows the installed position-sensitive detectors(PSD) at a detector bank (back of the vacuum chamber).
The PSD with 60 cm effective length, 3/4” diameter,
10 atm of 3He gas pressure, and SKYN2 feedthrough developed in MLF and 32 PSD that we adopted, have been
positioned in a detector bank covering the scattering
angle of about 20°. In the vertical direction, there arethree layers of PSD arrays. In the horizontal (central) layer, all the scheduled PSD are installed (from -20° to 120°).
Beyond the construction operation, we continue
our efforts to develop new devices and technology forneutron science. One of those developing items is helium spin filter for polarization of neutron spins [5]. And
the others are magnetic environment and devices forthe polarization experiment [6], a new high-speed rotating disk chopper [7], dynamical nuclear polarization(DNP) technique, data acquisition and analysis system,and so forth.

4. Future plans
Within the next few years POLANO has to start user
programs for scientific research. Therefore, the construction will be completed and radiological assessment will be finished and approved in 2016.
References[1] T. Yokoo et al., J. Phys. Soc. Jpn., 82 SA035 (2013).
[2] T. Yokoo et al., J. Phys. Conf. Series 502 012045(2014).
[3] K. Ohoyama et al., J. Phys. Conf. Series 502 012051(2014).
[4] T. Yokoo et al., EPJ. Web of Conferences 83 03018(2015).
[5] T. Ino et al., J-PARC Annual Report 2015 vol. 2
pp.109-110.
[6] M. Ohkawara et al., J-PARC Annual Report 2015
vol. 2 pp.106-108.
[7] T. Yokoo et al., J-PARC Annual Report 2015 vol. 2
pp.111-112.

T. Yokoo1,2, M. Fujita3, S. Itoh1,2, N. Kaneko1,2, S. Sugai1,2, M. Ohkawara3, T. Ino1,2, Y. Nambu3, and M. Sakaguchi1,2
Neutron Science Section, Materials and Life Science Division, J-PARC Center; 2Institute of Materials Structure Science, KEK; 3Institute forMaterials Research, Tohoku University

1

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Magnetic Devices and Environment for Polarization
Experiments at POLANO
1. Introduction
The polarization neutron spectrometer POLANO,
now under construction at BL23 of MLF, will be an indispensable instrument for investigations of magnets andstrongly correlated electron systems under a collaboration between KEK and Tohoku University. For accurate
polarized neutron scattering experiments, control ofmagnetic fields along the neutron pass is quite important to keep the polarization. Figure 1 shows a typicalalignment of the magnetic-field devices of POLANO.
Neutrons go through the devices from the left of the
Figure to the right. The system consists of a solenoid
coil for a 3He polarizer, a vertical guide magnet with permanent magnets, a Helmholtz coil with additional threecoils, which generate horizontal magnetic fields in anarbitrary direction, which is called 3D Helmholtz coil inthis report, a fan-shaped guide magnet that generates
magnetic fields between the sample position and thepolarization analyzer, and the supermirror analyzer.

guide magnet [1].
Recently, we revised the designs of the fan-shaped
guide magnet and the 3D Helmholtz coil to minimize
the dead angles of the neutron beam. In this report, we
will explain the new magnetic-field devices and the results of calculation and observation on the test benchof the magnetic fields.
2. Design of a 3D Helmholtz coil
We have two 3D Helmholtz coils for POLANO,
which control the direction of the magnetic field at the
sample position. The first 3D Helmholtz coil, which iscalled Coil-a in this report, is shown in Fig. 2(a). The covered angle of each horizontal magnetic field coil is thesame as the one shown in Fig. 2(a). The vertical partsof the horizontal magnetic field coil (black) form darkangles shown as red parts in Fig. 2. To reduce these darkangles, we produced a new coil (Coil-b), on which thecovered angle of horizontal magnetic field coils were
not the same; the angle between the two pillars is 135°,
135° an 90°; this makes the dark angle relatively small,as shown in Fig. 2(b). The diameter of Coil-b is 660 mm,
which is smaller than that of Coil-a (690 mm). The innerdiameter of the both coils is 360 mm.

Figure 1.	A typical alignment of the magnetic field devices at
BL23. The beam goes through from the left to theright.

For spectrometers in reactor facilities, the magnetic-field devices are optimized in each polarized neutron
experiment. However, it is difficult to optimize magnetic fields in spectrometers at J-PARC because of limitedaccess space in the vacuum chambers. Therefore, optimization of magnetic fields devices by calculations andobservations by off-beam mode is necessary. We havecalculated the optimized alignments of magnetic-fielddevices by finite elements method software, ANSYS
and FEMTET. Moreover, to confirm the calculations, wehave prepared a test bench, which consists of a verticalguide magnet, a 3D Helmholtz coil, and a fan-shaped
106

Figure 2.	Upper figure of the two 3D Helmholtz coils. The
gray part indicates horizontal magnetic field coils.
Depicted in black are the vertical parts of the horizontal coils, which make a dark angle. The darkangle is shown in yellow. The arrows indicate thedirection of the neutron beams.

Figure 3 shows the Coil-b on the test bench. To confirm the effect of the change of the coil design to magnetic fields, we measured magnetic field distribution
along the beam pass in the test bench using 3D gaussmeter to obtain the magnitude of the magnetic field.

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15 G, the magnetic fields in this region will be increasedby the leak magnetic fields from the polarization analyzer, in which magnetic field of 400 G is generated at
the center of the polarizer. The calculation using ANSYS
indicates that the enhancement of the magnetic fields
at 750 mm by the polarization analyzer is estimated to
be about 15 G. Thus, the depolarization at the bottom
at 750 mm can be neglected in POLANO. These results
indicate that Coil-b can be used in POLANO.

Figure 3.	A picture of the test bench for measurement ofmagnetic fields. In this picture, Coil-b is installed.

Figure 4 shows the position dependence of themagnitude of the magnetic field. The direction of themagnetic field at the sample position was vertical, thecurrent of the 3D Helmholtz coils was 10 A. The horizontal axis is the position from the right edge of the verticalguide magnet. We measured the magnetic fields at thebeam center. The red and blue lines in Fig. 4 show theobserved magnitude of the magnetic fields using Coil-aand Coil-b, respectively. As shown in Fig. 4, the magnetic field using Coil-b is smaller than that using Coil-a at
the minimum at about 100 mm in the gap between thevertical guide magnet and the 3D Helmholtz coils, andat 750 mm at the gap between the 3D Helmholtz coils
and the fan-shaped vertical guide magnet. This is due tothe change of the outer diameter of the 3D Helmholtz
coils. Based on the calculations of depolarization along
the beam pass, the polarization can be kept when themagnitude of the magnetic field is larger than 15 G up
to E = 100 meV. Thus, the depolarization at the bottom at 100 mm can be neglected for Coil-b. Though
the magnetic field at the bottom at 750 mm is close to

Figure 4.	Observed magnitude of the magnetic fields in thetest bench with Coil-a (red) and Coil-b (blue).

3.	Effect of the design change of the fan-shaped
guide magnet
The fan-shaped guide magnets are a device toconnect magnetic fields between the 3D Helmholtz
coil and the polarization analyzer, which consists of
two fan-shaped iron plates and neodymium magnets.
The neodymium magnets are set at the both ends ofthe iron plates. Since the first fan-shaped magnet has aslight dark angle by the neodymium magnets and thealuminum plate, which supports the two iron plates,
the design was revised recently to reduce the dark angle. In the revised version of the fan-shaped magnet,
the shape of the edge of the iron plates and the position of the neodymium magnets have been changed,
as shown in Fig. 5. Moreover, in the revised version, thetwo fan-shaped iron plates are supported at a scattering angle of 90°. The dark angle of the revised version
by the support wall is at the same angle of that by the
3D Helmholtz coil to minimize the dark angle.
By calculations using FEMTET, we confirmed thedifference of the magnetic fields generated by theoriginal and the revised fan-shaped magnet. Only the
fan-shaped magnets were included in the calculations.
Figure 6 shows the results of the calculations of thegenerated magnetic fields by the original (blue) andthe revised (red) fan-shaped magnets. The origin of the

Figure 5. Revision of the fan-shaped guide magnet.

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Figure 6.	The calculated magnetic fields in the fan-shaped
guide magnet. The red and blue lines indicate themagnetic fields of the original and revised designs,
respectively.

Figure 7.	The calculated magnetic fields distribution from thevertical guide magnet to the revised fan-shaped
guide magnet.

horizontal axis in Fig. 6 is the center of the iron plate.
The calculation was made at the beam center.
As shown in Fig. 6, the largest difference of themagnetic field is at most 1.4 G, which is much smaller
than the magnitude of the magnetic field at the maximum, meaning that the effect on the magnetic fields by
the revision is negligible.
We also confirmed the effect of the revision on
the magnetic field distribution in the test bench using
FEMTET. In the calculation, the vertical guide magnet,
Coil-b, and the revised fan-shaped magnet were included. The current of Coil-b is 10 A. Figure 7 shows theresult of the calculation. There is a minimum at 750 mm
between Coil-b and the revised fan-shaped guide magnet. Though the minimum magnetic field at 750 mm issmaller than 15 G, the magnetic field is enhanced by
the leak fields from the polarization analyzer, as it was
explained earlier. Thus, the depolarization at the bottom around 750 mm can be negligible.
Reference[1] K. Ohoyama, T. Yokoo, S. Itoh, M.Sakaguchi,
M.Ohkawara, Y.Nambu, T. Ino, N.Kaneko, MLF
ANNUAL REPORT 2014, 55-57.

M. Ohkawara1, K. Ohoyama2, T. Yokoo3,4, S. Itoh3,4, M. Sakaguchi3,4, M. Fjita1, Y. Nambu1, T. Ino3,4, and N. Kaneko3,4
Institute for Materials Research, Tohoku University; 2Ibaraki University; 3Neutron Science Section, Materials and Life Science Division,
J-PARC Center; 4Institute of Materials Structure Science, KEK

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Development of an in-situ Polarized 3He Neutron Spin
Filter in POLANO
1. Introduction
A 3He neutron spin filter (NSF) is one of the essential devices in POLANO for polarization of the incident
neutron beam. It is required to be operated in-situ toprovide a stable neutron polarization, and the spin-exchange optical pumping (SEOP) method is employed
to polarize the 3He gas. We have designed a compact
whole-in-one 3He NSF system that fits well in the limited space between the disk choppers and the sample
chamber. The conceptual design of the NSF system has
been fixed and it is now under construction. In the earlystage of the commissioning of POLANO in FY2016, the
3He NSF is going to be installed, and the test run will
begin.
2. Conceptual design of the 3He NSF on POLANO
The necessary elements for an in-situ polarized 3He
NSF are (1) a 3He cell, (2) a homogeneous magnetic fieldwith neutron guide fields, (3) a high-power laser with
optical components for the optical pumping of Rb, (4) aheater to achieve the appropriate vapor densities of RB
and K, and (5) adiabatic fast passage (AFP) spin flippingof polarized 3He. A schematic view of the 3He NSF on
POLANO is shown in Fig. 1.

at 2 to 3.5 atm, and their effective 3He thickness ranges
from 10 to 35 atm-cm for polarizing neutrons with energies of 10 – 100 meV. They are so-called K-Rb alkali hybrid SEOP cells where K and Rb are filled in appropriate
mixing ratio for efficient optical pumping [1]. The 3He
gas pressure inside the cells increases as high as ~7 atm
at the operating temperature of 250°C. Research on
fabricating glass cells that can tolerate such high pressures is in progress.

Figure 2.	3He cells, Iori (left) and Kiyoshi (right). Both are withdiameters of 60 mm; the lengths are 60 mm and100 mm, respectively.

2.2 Magnetic field
A solenoid and compensation coils at both solenoid
edges with Permalloy magnetic shield were designed
and constructed together with additional two identicalsolenoids, each arranged upstream and downstream(Fig. 3). The downstream solenoid provides the spin
guide field for polarized neutrons, and the upstreamsolenoid is placed in a symmetric position to ensure ahomogeneous magnetic field at the 3He cell position.

Figure 1.	Schematic view of the 3He NSF on POLANO. All essential elements are packed in a laser shield box
with a size of 60 cm by 60 cm by 25 cm.

2.1 3He cell
We are preparing cylindrical cells made of GE180
aluminosilicate glass with a diameter of 60 mm andlength of 60 to 100 mm. The cells are filled with 3He gas

Figure 3.	A magnetically shielded solenoid (center) and additional two identical solenoids. The downstreamsolenoid (right) provides an axial magnetic fieldwith a strength of > 2 mT to keep the neutron polarization, and the upstream solenoid (left) provides
a symmetric magnetic field for the 3He cell.

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2.3 Polyimide heater
In SEOP, hot air blowers (compressed air blow-ers)
are commonly used to keep 3He cells at an elevatedtemperature because they do not interfere with thehomogeneous magnetic field, while the conventional
electric heaters produce unnecessary magnetic fields.
However, due to the limited space for the 3He NSF,
non-magnetic polyimide heaters that can be used up
to 300°C are being developed. Specially arranged nonmagnetic heater element sandwiched by two thinpolyimide films is designed not to produce unwanted
magnetic fields for the 3He cell.

Figure 4.	A prototype polyimide heater. This flexible heater
is designed to wrap the cylindrical oven made ofaluminum. The heating power is 270 W, and the
maximum temperature is 300°C.

2.4 AFP NMR spin flip
Neutron spin flipping is essential in polarized neutron scattering, and neutron spin flip devices are commonly used. In 3He NSF, however, polarized 3He nuclei
can be reversed by the adiabatic fast passage (AFP)
method [2], instead of neutron spins. Such an AFP flipping technique is equipped in the 3He NSF system on
POLANO [3]. A uniform RF magnetic field is produced
by a cosine-theta coil arranged inside the aluminumoven for AFP (Fig. 5).

Figure 5.	The AFP drive coil is arranged inside the aluminumoven to provide a uniform RF field for AFP spin flips.

3. Safety and future upgrading
The controllers for the in-situ polarized 3He NSF system will be equipped with various safety mechanisms,
such as interlocks for the laser and the heater, to meet
the J-PARC safety standards. The 3He NSF will be continuously operated for a long period, and the durabilityof the system is another key issue.
Although the goal at the first stage is to operate the
3He NSF safely and steadily, the system will be upgradedin three directions. They are to increase the polarizationof 3He, to enlarge the cell size to cover a wider beamprofile, and to increase the effective 3He thickness forpolarizing higher energy neutrons. Preparation of highquality 3He cells is the key for these improvements.
References[1] E. Babcock, I. A. Nelson, S. Kadlecek, and T. G. Walker,
Phys. Rev. A 71, 013414 (2005).
[2] A. Abragam, The Principles of Nuclear Magnetism,
Oxford University Press (1961).
[3] T. Ino et al., J. Phys.: Conf. Ser. 340, 012006 (2012).

T. Ino1,2, M. Ohkawara3, T. Yokoo1,2, Y. Nambu3, M. Fujita3, K. Ohoyama4, S. Itoh1,2, H. Kira5, H. Hayashida5, K. Kakurai5, K. Sakai6,7,
and T. Oku6
1
Institute of Materials Structure Science, KEK; 2Neutron Science Section, Materials and Life Science Division, J-PARC Center; 3Institute forMaterials Research, Tohoku University; 4Ibaraki University; 5CROSS-Tokai; 6Technology Development Science Section, Materials and Life
Science Division, J-PARC Center; 7Neutron Source Section, Materials and Life Science Division, J-PARC Center110

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Development of Choppers in POLANO
1. Introduction
POLANO is the chopper type spectrometer withpolarization analysis capability, now under construction at the Materials and Life Science Experimental
Facility (MLF), J-PARC [1-4]. Not to mention the chopper
spectrometers for almost all pulse neutron instruments,
the “chopper” is one of the most significant devices. The
roles of the chopper are shaping the neutron pulse,
eliminating unwilling neutrons, determining the band
width of the neutron wave length, choosing the neutron velocity, and so forth. The following choppers are
particularly useful for the POLANO experiment, namely
T0 chopper, slow rotating disk chopper, and Fermi chopper. A time-distance diagram of an individual chopperis shown in Fig. 1.

Figure 1.	Time-distance diagram showing the opening andclosing sequence of several types of choppers.

2. T0 chopper
The T0 chopper is a nimonic chopper to eliminate
gamma flash and fast neutrons in the very early time(t ~ 0) of the pulses. When the blade center is initially positioned on the beamline, it takes t0 = (w+Dw)/(2pRf ) forthe blade to be removed from the beam cross-section,
where w is the width of the neutron beamline, w+2Δw
is the width of the chopper blade, R is the rotational
radius of the chopper blade, and f is the rotational frequency. If this T0 chopper is located at a distance L fromthe neutron source, neutrons with energies less than E0= (1/2)mN(L/t0)2 are transmitted through the T0 chopperand utilized on the spectrometer, and the intensities
of high energy neutrons, i.e., neutrons with energies
larger than E0, are reduced, where mN is the neutronmass. The blade that rotates and obstructs unwillingneutrons is normally made of massive material, so it isheavy. Its weight is almost 130 kg and it is fabricatedfrom combination material, which includes Inconel
X-750 and stainless steel. Experiments at POLANO aresomewhat with higher energycomparing to standard
inelastic scattering experiments (a range of sub-eV in
the future), up to 100 Hz rotational speed is realized
similar to the one that is developed for HRC [5]. The jitter of maximum 5 ms corresponds to the 1 mm blade
clearance and can be well controlled. Chopper housing
also made of stainless steel (SUS304) is equipped with
“one-touch operation” for cooling water, vacuum line,
and electricity. The manufactured POLANO T0 chopperis shown in Fig. 2(a).

Figure 2.	A suite of choppers developed for POLANO. a) T0 chopper, b) slow-rotating disk chopper (installed in beamline with neutron guide tubes), c) Fermi chopper.

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3. Disk chopper
We are using two types of disk chopper. One is a
slowly-rotating (25 Hz) disk chopper, which can define
the time window (band width) of incoming neutron
pulses, as you can see in Fig. 1. A pair of choppers isplaced in the beam line. Each chopper has a rotating
disk with diameter φ716.4 mm. At the beam cross-section, enriched B4C and epoxy resin are coated as a neutron absorber in order to obstruct the neutron beam.
The set chopper in the beam line with neutron guidemirrors is depicted in Fig. 2(b).
The other type of disk chopper is a fast-rotating
chopper utilized for the cross correlation method. This
type of chopper, with quite a different structure, hasbeen developed recently. Two big difficulties complicate the design of a disk that rotates with fast speed.
With a large disk like a class of 1 m diameter, the forthat the edge of the disk will be over a few thousand MPa
to begin with. This forth can easily break a metal plateor even strong carbon fibers. Secondly, the disk musthave 2N-1 open and close sequences (slits and slots). In
our case, N = 8, there are 255 sequences in total. This
complicated disk structure yields stress concentration
all over the place. So now we are testing equipmentwith low spec model. The diameter of the disk (spindle)is φ768 mm, and its weight is almost 100 kg.
4. Fermi chopper
The Fermi chopper is used as a neutron velocity
selector to monochromatize incoming neutron energy(wave length). At a pulsed neutron source, the Fermi
chopper is used for neutrons over a wide energy range

up to the eV region. It consists of a slit package rotating in synchronization with the production timing ofpulsed neutrons. The Fermi chopper opens when it
rotates to a position with the slit direction parallel tothe incident neutron beam, and neutrons pass throughthe slit; the slit-opening time (chopper-opening time,Δtch) determines the energy resolution of the chopper
spectrometer.
Unlike the other choppers, the Fermi chopper musthave quite fast rotational speed to obtain reasonableenergy resolution. In case of HRC, its speed is 600 Hz
maximum. We have already spent long time and efforts
to develop the Fermi chopper [6], and now we have avery reliable and satisfactory chopper for the POLANO
experiments. Figure 2(c) shows the Fermi chopperfor POLANO. This is a HRC type of chopper rotating at
600 Hz, which is controlled with less than 0.5 ms phaseaccuracy. The slit called sloppy-type yields around 2.5%energy resolution energy resolution with respecting toincident neutron energy Ei.
References[1] T. Yokoo et al., J. Phys. Soc. Jpn., 82 SA035 (2013).
[2] T. Yokoo et al., J. Phys. Conf. Series 502 012045(2014).
[3] K. Ohoyama et al., J. Phys. Conf. Series 502 012051(2014).
[4] T. Yokoo et al., EPJ Web of Conferences 83 03018(2015).
[5] S. Itoh et al., NIMA 661 86 (2012).
[6] S. Itoh et al., NIMA 661 58 (2012).

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

1

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Neutron Science

Sample Environment at MLF
1. Introduction
The SE team is in charge of preparation, maintenance and development of the beamline (BL)-common
SE equipment, and provides assistance to users concerning the operation of the equipment. The team has
12 members: 7 from JAEA and 5 from CROSS, and is divided into sub-teams of cryogenics and magnets, hightemperature, high pressure, soft-matter, etc. A pulsed
magnet system, a low-temperature and high-pressure equipment and hydrogen equipment are underdevelopment.
The status and activities of the SE team in JFY2015
are summarized in this report.
2. Cryogenics and magnets
There are three pieces of BL-common equipment
managed by the SE cryogenic and magnet sub-team:a vertical-field superconducting magnet (Fig. 1(a)), a3He-4He dilution refrigerator (DR) insert (Fig. 1(b)) anda bottom-loading 3He cryostat (Fig. 1(c)). We operated
the superconducting magnet at BL15 and BL18 for users’ experiments in JFY2015. The two other cryostats areunder commissioning. After the test operation of the

Figure 1.	Photographs of the BL-common equipment managed by the SE cryogenic and magnet sub-team:(a) superconducting magnet, (b) DR insert, (c) 3He
cryostat, (d) 4He cryostat.

DR insert was carried out by setting it into the superconducting magnet, we confirmed that the systemachieved 50 mK as the base temperature without asample. We have also performed commissioning of the
3He cryostat, to find out how to operate the system inthe temperature range from 0.3 to 300 K. In this fiscal
year, a top-loading 4He cryostat was newly added to our
BL-common equipment (Fig. 1(d)). This cryostat is a wet
system and can be used with the DR insert. These threecryostats, including the new 4He cryostat, are going to
be opened for the users’ experiments in 2016B after further commissioning.
To make the operation of the cryostats convenient
for users, we plan to introduce IROHA2, the common
software framework for the instrument control in MLF.
In JFY2016, we will start it with the super-conducting
magnet.
3. High temperature equipment
The high temperature sub-team has a niobium furnace and a furnace for small-angle neutron scattering(SANS) and neutron reflectivity (NR) as the BL-common
SE equipment. The niobium furnace is available in vacuum and in rare gas. Until last year, only argon gas wasavailable as rare gas. In this year, we improved the system and helium gas is available for high temperatureexperiments. The maximum temperature is 800°C under rare gas atmosphere and is 1600°C in vacuum. The
sample rotation controller has been upgraded and thesample rotation can be controlled easily with a touch
panel. The improved furnace sys-tem was used on BL14
for users’ experiment in JFY2015. The furnace for SANS
and NR was installed as the second BL-common furnaceand operated on BL15 up to 800°C in February, 2016
(Fig. 2).
4. A pulse magnet system
The activities of the SE pulsed magnet team started
in the second half of JFY2014. We have developed aprototype of a pulse magnet system in J-PARC MLF. The
pulse magnet system consists of a pulsed power supply,a solenoid coil and a sample stick. The coil is installed in
the sample stick and is connected with the power supply through a coaxial cable. Figures. 3 (a) and (b) show
the developed sample stick and coil, respectively. The
stick is to be installed in the orange cryostats. The pulse
test had been performed on the coil. In the experiment,
the coil was cooled to 77 K by liquid nitrogen. When113

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MLF Annual Report 2015

mounting the PE press to goniometer stage of BL11 andBL15 were also prepared (Fig. 4). We have started thedesign of the cryostat for cooling the PE press in orderto realize a low temperature and high pressure environment. It is planned to be introduced in the next FY.

Figure 2. New furnace used on BL15.

Figure 4. PE press mounted on the goniometer stage of BL15.

Figure 3. (a) The developed sample stick and (b) the coil.

6. Soft-matter
A rheometer is the most powerful tool for the studyof the viscoelasticity behavior of soft matter, such as
polymer solutions, gels, and liquid crystals. As shown in
Fig. 5, the rheometer (MCR302), purchased from Anton
Paar, and a box capable of preventing condensation
were installed for Rheo-SANS experiments on BL15 in
JFY2015. The system can operate in the temperature
range from 223 K to 423 K with vaporizer system using
liquid nitrogen.

the maximum charged voltage in the capacitors of thepulsed power supply was 1.4 kV, output current of approximately 4.5 kA in the coil was obtained. Linear B-I
characteristics of the coil were obtained up to 30 Tesla.
The system is to be employed to perform neutron scattering experiments in the MLF in the near future.
5. High pressure
We introduced the VX-6 type Paris-Edinburgh (PE)press as the first BL-common equipment to comply
with users’ requests. In this FY, we have started its commissioning at room temperature. It was confirmed thatthe pressurization was carried out successfully and safely within the range of specification. The jig stands for

Figure 5.	The rheometer and its box on the goniometerstage of BL15.

T. Aso1, Y. Yamauchi2, M. Ishikado3, S. Ohira-Kawamura4, M. Watanabe2, K. Munakata3, S. Takata4, Y. Sakaguchi3, K. Ohuchi3,
M. Obinata3, R. Takahashi5, S. Isomae5, and T. Oku2
1
Neutron Source Section, Materials and Life Science Division, J-PARC Center; 2Technology Development Section, Materials and Life Science
Division; 3Neutron R&D Division, CROSS-Tokai; 4Neutron Science Section, Materials and Life Science Division, J-PARC Center; 5Nippon
Advanced Technology co.

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Neutron Science

Progress of Data Analysis Software
1. Progress in FY2015
We will report our work in several fields: the improvement of the NeXus [1] interface prepared in Manyo
Library [2, 3] between data-containers and NeXus files,
the publication of User’s Manual of Manyo Library andthe production of the Utsusemi binary package installer.
2. Manyo Library
Our basic concept of maintaining the analysis environment for neutron scattering experiments in MLF
is to provide a framework, which has common andgeneric analysis functionalities for that type of experiments. The framework, “Manyo Library” (ML), is a standard framework for developing data analysis software,
which has been installed on the 16 instruments in MLF.
ML is a high-performance C++ framework and class library designed to handle large amounts of data. The
class library is wrapped by the Python user interface
created by SWIG. Users can perform data reduction andanalysis on the C++ library through the Python interface. The framework is available on various operating
systems: Linux, MacOSX and Windows. The binary installer and packages have also been prepared.
“ElementContainer”(EC) is a simple and fundamental
data container in ML, and a one-dimensional histogram
where the error values can be stored in an EC, where any
number of vector<double> objects are handled with
their names. Basic mathematical arithmetic-operatorsand statistical operators provided in ML can operate ECs
with error-propagation. Data containers for two- andthree-dimensional histograms, “ElementContainerArray”(ECA) and “ElementContainerMatrix” (ECM), are prepared, and raw data and analysis data are stored in the
EC family on ML. Figure 1 shows the structure of ECM.
The number of vector objects in an EC is Nv. Any number of EC and ECA objects can be stored in an ECA and
ECM, and the number of EC and ECA in a container is
NEC and NECA, respectively. The procedures for memory

allocations and their garbage collections have been prepared in the containers. Users can build data analysis
software in Python environment by using the operators
prepared in the C++ library; ML provides a rapid prototyping environment for data analysis software.
3. New Binary File Format
The size of data files handled on ML is getting larger
with increasing the intensity of proton beams producing pulsed neutron beams in MLF. Currently, our concern
is how to improve the efficiency of reading and writing
data files on the framework. Histogram data stored incontainers can be stored in NeXus format by using NeXus
C-API on ML. The NeXus format is a standard format inmany neutron, X-ray and muon facilities in the world andcan be read by any operating system. A new interface
between the EC family and NeXus files was developedby using the HDF5 C-API library [4], and a new data filestructure was also defined while preserving the NeXus
format. The new data structure, where the number ofgroups and depth of the hierarchical structure have been
decreased, will be simpler than the one used now.
We completed the prototype of the new interface
in ML. The efficiency values of reading and writing
three-dimensional histograms stored in ECM from/to
NeXus files with the present and new interface havebeen obtained and shown in Table 1. The measurements were performed on Ubuntu Linux (64-bit) withan Intel Core i5-4460 3.2 GHz processor and 16 GB
memory. The size of vectors stored in an EC is 4000,
and the data size of the NeXus files are 4.0 and 1.3 GB at(Nv,NEC,NECA)=(3,100,300) and (3,10000,1), respectively.
The structures and dimensions of the former and latterdata sets are the same as those of the three-dimensional histogram data produced by the chopper- spectrometer and the powder diffractometer in MLF. The writing
and reading efficiency of the new interface is about 1.6
and 4 times larger than that of the present one.

Figure 1.	Structure of the EC family defined in ML. The number of vectors, EC and ECA in an EC, ECA and ECM are Nv, NEC and NECA, respectively.

115

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MLF Annual Report 2015

Table 1.	Comparison between the new and present interfaces regarding the efficiency of reading and writing NeXus files from/to
ECM. Tw and Tr are the writing and reading times in seconds with the interface developed in this study, and the numbers in
the parentheses are those with the present interface. Nv, NEC and NECA indicate the dimensions of ECM.

The data I/O rate on ML can be increased with the
new interface, and we will develop and integrate it into
ML in 2016. We also decided to keep the present interface to allow reading of the older data files in the MLF
file archiver.
4. User’s Manual
A User’s Manual of ML in Japanese was published asa JAEA report, and can be obtained from “http://dx.doi.
org/10.11484/jaea-testing-2016-001”. The table of contents of the manual is shown in Table 2. An English version of the User’s Manual will be completed in near future.
Table 2. Table of Contents of the User’s Manual.

5. Utsusemi and Binary-Packaging
ML is widely utilized as a base architecture in data
treatment and analysis of actual measurements in MLF
at J–PARC. One of the applications of ML to data analysis and visualization is the ‘Utsusemi’ software [5].
Utsusemi is the series of software written in C++,
based on the ML framework and Python, to analyze andvisualize the neutron scattering data with a graphicalinterface (GUI). Utsusemi has been adopted extensively
by a lot of instruments and users in MLF because it offers useful functions, for example a flexible histogram
creation from event recorded data, produced by thecommon data acquisition system in MLF.
However, the general users have difficulties installingand using Utsuemi, including ML, on their own PCs, because the software and the codes run only on the LinuxOS. This means that the users must construct a Linux
environment before using our software. Such a complex
116

installation hinders users’ ability to analyze data at theiroffices and to prepare quickly their results’ output.
To solve this problem, we have produced a binary application and installer software executable on
Windows and Mac OS, as shown in Figures 2 and 3. The
binary installers are easy to use because they conformwith the rules for each OS and include all binary applications of both ML and Utsusemi with the required software libraries. They work on 64-bit Windows 7, 8.2 and10 or Mac OS 10.10 (Yosemite) and 10.11 (El Capitan).
After the installation, the users can launch several
GUI applications by double clicks and run many functional codes with command-line interface (CUI). The
main GUI application, called ‘SequenceEditor’, enables
the users to execute step-by-step commands for data
reduction with Utsusemi. Also installed are some visualization software applications with GUI, such as 1 or
2-dimension plotters and data-slice software for a single
crystal sample. In addition, CUI on Python Interpreter tohandle functions is also available by using the commandprompt application on Windows or the terminal application on Mac OS. So, the installed software environment
with SequenceEditor as central software is the same as
the one used on the actual instruments. Therefore, users
can not only start analysis without confusion but also
execute users’ own analysis scripts, if needed.
Although these binary applications and installers
have worked very well, only the MLF staffs and a limited
number of users are able to use them because of someongoing problems with the license. We have initiated aprocedure at JAEA to make Utsusemi an open-source
software for effective distribution among users.

Figure 2.	Binary Installers, for Windows on the left and for
MacOS on the right.

MLF Annual Report 2015

Neutron Science

perfection. On the other hand, we know that our distribution of information, especially the documentation
concerning our work, is still insufficient. Therefore, we
continue to produce documents and have a plan toprepare immediately a portal web site. On that site, wewill show the information about our software, including the ML User’s Manual and provide binary software
to be downloaded by users. The site will be launched in
FY 2016.

Figure 3. Screenshot of Utsusemi running on Windows 7.

6. Future Plans
As shown above, our data analysis software has
been steadily developed to reach a high degree ofReferences[1] http://www.nexusformat.org/[2] Jiro Suzuki et al., Nucl. Instr. and Meth. A 534, 175(2004).
[3] Jiro Suzuki et al., Nucl. Instr. and Meth. A 600, 123(2009).
[4] https://www.hdfgroup.org/[5] Y. Inamura, T . Nakatani, J. Suzuki and T. Otomo, J.
Phys. Soc. Jpn. 82 (2013), SA031-1 – SA031-9.

J. Suzuki1,2, Y. Inamura3, T. Ito4, and T. Nakatani3
Computing Research Center, KEK; 2Information System Section, J-PARC Center; 3Neutron Science Section, Materials and Life Science
Division, J-PARC Center; 4Neutron R&D Division, CROSS-Tokai

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MLF Annual Report 2015

High-Pressure Operation of Two-Dimensional Gaseous
Neutron Detector

3. Results
Figure 1 shows the pulse-height distributions under neutron irradiation by changing the supplied voltage to anode wires. A signal-pulse peak of neutrons
can be observed clearly. This result indicates that the
majority of the spurious events generated in the lower channels as a result of electronic noise and gamma
events can be easily suppressed using a discriminator. A

12
Anode voltage (V)Measured signal (arb. unit)

2. Developed system and irradiation tests
A developed neutron detection system consists of a
256-channel detector element (x: 128 lines, y: 128 lines)
equipped into a pressure vessel, amplifier-shaperdiscriminator boards, optical signal transmission devices, position encoders, and a fast data-acquisition
device. The specially-fabricated pressure vessel has
256 feedthroughs, insulated by alumina ceramics, forsignals and 6 connectors for high voltage. The vessel
could withstand pressures of up to 0.8 MPa. A dedicateddetector element with 256 output connectors was alsofabricated for use in the pressure vessel. Experiments
were performed using a gaseous mixture of He and carbon tetrafluoride (CF4) at a total pressure of 0.8 MPa (He/
CF4 = 0.71/0.09). Under this gas condition, the thermal
neutron detection efficiency was 87%. Neutron irradiation was performed by using a Cf-252 neutron source.

flat-field image and the histogram of the pixel contentsof the flat-field image are shown in Fig. 2. The histogram
was evaluated by fitting it with a Gaussian function. The
image showed good homogeneity, and the average
pixel count was 262, with a standard deviation of σ =20.3, corresponding to an average gain spread of approximately 7.7%. The measured gamma-ray sensitivityof the detector was 1.1 × 10-7 by using a Co-60 gammaray source with the intensity of 7.0 × 105 Bq.

10

2700
2600
2500

8
Neutron signals

6
4
2
0

0

50
100
Pulse height (ch)

400
350

Standard deviation: σ = 20.3
Average gain spread: σ/N = 7.7%

300
250
200
150
100
50
0
150

200

250
300
Counts/pixel

118

350

400

Figure 2.	Histogram of count distribution of the flat-field image and measured flat-field image under Cf-252
neutron irradiation.

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

1150

Figure 1. Pulse-height distribution of anode lines.

Number

1. Introduction
In a two-dimensional gas-based neutron detector,
the thickness of the conversion gap should be madeas small as possible to prevent the occurrence of theparallax effect of incident neutrons. Therefore, it is necessary to increase the gas pressure of the detector toachieve high detection efficiency. However, increasing
the gas pressure decreases the output signal strength.
To measure the small output signals, the supply voltage
must be increased to boost the gas gain of the detector
element. Therefore, we have developed a pressure vessel and a dedicated two-dimensional multiwire-type
detector element for individual signal line readout toensure satisfactory detector system operation even athigh pressure.

MLF Annual Report 2015

Neutron Science

Accessible Length Scale of the In-Plane Structure in
Polarized Neutron Off-Specular Scattering Measurement
1. Introduction
Layered magnetic structures exhibit interestingand important magnetic properties, such as exchange
coupling between layers, giant magnetoresistance,
and tunnel magnetoresistance, which are not present in the bulk. These anomalous magnetic behaviors
arise from the structure in the out-of-plane and/or inplane directions reduced to the nm range. To elucidate
those mechanisms and to open the possibility of new
applications, it is important to obtain information on
the in-plane magnetic structure. Off-specular scattering(OSS) using polarized neutrons is a unique and powerful technique to observe correlations of small magnetic
objects in layered systems. Since the OSS has its own
accessible range and resolution of the lateral component of the momentum transfer q, it is important toverify, if the length scale of the in-plane structure of thesample matches the in-plane q-range and resolution.
The in-plane q-resolution corresponds to the in-planecomponent of the coherence volume or, in other words,
the length scale of the measurement,. The interpretation of the data can be different, if the lateral dimensionof the in-plane structure of the sample is sufficiently
small or large compared with the in-plane componentof the coherence volume in that dimension. OSS only
measures a limited range of the in-plane componentof q due to the restriction in the scattering geometry,making difficult the access to the lateral correlation
length smaller than 100 nm. This study discusses theaccessible in-plane q-range of the OSS using polarized
neutrons to illustrate the limitation of the accessible lateral correlation length of the OSS.
2. Results
Let us assume a scattering geometry where sample surface is parallel to the (x, y) plane and neutrons
incident on the sample are scattered within the (x, z)
plane [1]. The OSS data can be analyzed in the framework of the distorted wave Born approximation given
by Toperverg et al [2]. The lateral correlation length
for the magnetic scattering ξ, corresponding to thelength of an area, in which the spins are aligned to thesame direction, can be determined by the scattering
intensity dependence on qx. Since q is oriented close
to parallel to the z-axis in the OSS, qx is smaller than afew percent of |q| for most cases. Although the qx-range
can be increased by increasing qz, this causes anotherproblem - reduction of the scattering intensity. In general, it is difficult to obtain enough scattering intensity
over the full qx-range for qz > 0.5 nm-1. This limits theaccessible qx-range to |qx| < 0.01 nm-1. To understandthis, let us consider the qx-dependence of the structure factor in the simulation. Since the coupled areas
with uniform orientation of the spins are modeled asrectangular boxes with lengths of 2ξ within the plane,
the structure factor is found to be proportional to theLorentzian function, 1/{1+(qx • ξ)2}. Figure 1 shows the
structure factors proportional to the Lorentzian profiles

Figure 1.	Structure factors proportional to the Lorentzian function, 1/{1+(qx • ξ)2}. Green, black, red, and blue lines
indicate the profile with ξ = 400, 200, 100, and 50 nm, respectively.

119Neutron Science

MLF Annual Report 2015

for different values of ξ. The full width at half maximumof the Lorentzian function becomes comparable to theaccessible qx-range with decreasing ξ. This means that
only a small part of the full peak profile is measured,making the determination of ξ more ambiguous. The
condition of qx,max • ξ » 1 needs to be taken into accountwhen performing the OSS measurement, where qx,max isthe maximum value of |qx| in the measurement [3].
3. Conclusions
We discussed the accessible range of the in-planecomponent of q and the relation between the in-planecomponent of the coherence volume and length scaleof the in-plane structure of the sample for the OSS measurement using polarized neutrons. To determine accurately ξ, the condition of qx,max • ξ » 1 has to be satisfied,

which usually corresponds to ξ > 100 nm. Grazing incidence small angle scattering measurement is needed
to obtain qualitative information on the in-plane structure with a length scale smaller than that.
References[1] R. Maruyama, T. Bigault, A. R. Wildes, C. D. Dewhurst,
K. Soyama, and P. Courtois, Nucl. Instr. and Meth.
Phys. Res. A819 37 (2016).
[2] B. P. Toperverg, Appl. Phys. A74 (Suppl.) S1560(2002).
[3] R. Maruyama, T. Bigault, A. R. Wildes, C. D. Dewhurst,
T. Saerbeck, D. Honecker, D. Yamazaki, K. Soyama,
and P. Courtois, submitted to J. Phys.Conf. Series,(Proceedings of PNCMI 2016).

R. Maruyama
Neutron Instrumentation Section, Materials and Life Science Division, J-PARC Center

120

Muon Scinece

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MLF Annual Report 2015

Status of J-PARC MUSE
Because of the fire caused by the power supply forthe septum magnet at the muon D-line on January 16,
2015, we had to stop all operations of J-PARC for one
and a half months. Thanks to the tremendous efforts by
the members of the J-PARC task force, it became possible to restart the neutrino and neutron operations in
the end of February, 2015. Although we were about torestart the muon experiments in the end of April, wefaced another problem due to a water leakage from theneutron target. This shortened the period of the MLF
beam time in October, 2015, but unfortunately, we hada third problem with the neutron target in November.
Finally, we managed to restart the MLF operation in theend of February, 2016. Since MLF had to adopt the No.2
neutron target which cannot accept beams with power
higher than 300 kW, the proton intensity was restricted
to be less than 200 kW.
1.	A new superconducting decay muon solenoid at
the D-Line
For Phase 1, one graphite target was installed, fromwhich four sets of the secondary lines were designed
to be extracted and extended into two experimental
halls (toward the west wing, one decay-surface muonline, the D-line and one ultra slow muon line, the U-line,
and towards the east wing surface muon line, theS-line, and possibly one high-momentum muon line,
the H-line). In the beginning, we managed to install theD-line, a superconducting decay/surface channel witha modest-acceptance (about 40 mSr) pion injector. The
D-line was originally constructed with the re-used superconducting magnet that had been utilized at KEKMSL for more than 30 years, which had cold bore (innerbore radius of φ 12), with beam windows at the inlet
and outlet. In the summer shutdown period of 2015,
we replaced the re-used superconducting magnet witha new one that has warm bore (inner bore radius of φ20), without a beam window, with the purpose to extract lower momentum intense negative muons, which
otherwise are stopped at the beam windows. Details of
the beam commissioning results will be introduced onanother occasion.
2. S-line
On October 29, 2015, we extracted successfullyat the S-line surface muons with a momentum of
28 MeV/c. Figure 1 shows the extracted positron andmuon beams signals, exhibiting the double-bunchedpulse structure observed by using a thin scintillating
counter situated at the beam extraction window at the
S1 area. The beamline commissioning was further accelerated by installing a µ SR spectrometer, which was
fabricated for the element strategy research project
for electron materials. The automatic tuning program,called ForTune, can tell the beamline parameters to provide a well-focused muon beam at the sample position
by gathering µ-e decay events, which are counted by
Kalliope µ SR detectors assembled in the spectrometer.

Figure 1.	The extracted positron and muon beams signals, exhibiting the double-bunched pulse structure observed by using a thin
scintillating counter situated at the beam extraction window in S1.

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MLF Annual Report 2015

3. U-LineAt the U-line, we have successfully observed ultraslow muons on February 21, 2016, as shown in Fig. 2.
As many as 35 ultra-slow muons per second by laser
resonant ionization of muoniums evolved from hottungsten (2000 K) were experimentally detected by a
MCP, a number, which is higher than the one detectedby the devices developed by KEK and RAL (20 m+/s) at
the RIKEN/RAL. In addition to reaching the highest intensity in the world, it is expected that with the quality improvement of the pulsed laser, we can achieve

Muon Scinece

an ultra-slow muon beam with narrower energy width,
which has the potential to improve the depth resolution in the sample. After further enhancement of thelaser power (Lyman-a 1.7 mJ/pulse to 71 mJ/pulse and355 nm laser ~100 mJ/pulse/cm2 to 350 mJ/pulse/cm2)
and improving the transmission efficiency of the ultraslow muon, we expect to generate a much more intense ultra-slow muon beam at the experimental ports
to pioneer new techniques, which will allow the muonscience to be expanded into a variety of new nano-scientific fields.

Figure 2. Rate of the ultra-slow muons with current of magnetic bending (mass separating) magnet.

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, H. Ooishi1,2, K. M. Kojima1,2, R. Kadono1,2, W. Higemoto2,3, and T. U. Ito2,3
1
Muon Science Laboratory, High Energy Accelerator Research Organization (KEK); 2Muon Science Section, Materials and Life Science
Division, J-PARC center; 3Advanced Science Research Center, Japan Atomic Energy Agency (JAEA)

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Muon Target System - Renovation of a Scraper Unit
A variety of materials and life science research has
been carried out with the pulsed muon beams with theworld’s highest intensity, generated using the pulsed
proton beams from the accelerator (3 GeV, 25 Hz,
333 mA) at J-PARC. A rotating target made of an isotropic
graphite for muon generation is located in the proton
beam line between the 3-GeV Rapid Cycle Synchrotron(RCS) and a neutron target. In the summer maintenanceperiod of 2014, the spent fixed target was replaced withthe rotating target [1]. This rotating target is running infull working order with beam power of 0.5 MW.
Two scrapers made of oxygen-free copper, used for
stopping scattered components of the proton beam,
are placed at the downstream of the muon rotatingtarget in series. The upstream scraper is called scraper
No. 1, hereinafter referred to as SC. The approximate dimensions of the SC are 300 mm width, 700 mm height,
and 700 mm length in the direction of the beam axis.
Circular through-hole of the inlet with diameter 74 mm
has been drilled in the SC with a beam axis as the center. The radius of the hole is increasing toward the beam
downstream. The heat load on the SC, due to scattering of the proton beam on the target, is about 19 kW in
the 1-MW beam power operation. This heat is removed
with two cooling water lines. The cooling water pipes
are embedded in the SC with a hot isostatic press method to avoid thermal resistance on the interface of thebonding. K-type thermocouples, enclosed in stainlesssteel sheathes, are mounted on the upstream and sidesurfaces of the SC to measure the temperature of the SC.
The temperatures with thermocouples mounted on theupper and lower sides of the upstream surface of the
SC and the temperatures at the inlet and outlet of thecooling water flowing through the SC are all shown in
Table 1 in the case of the fixed and the rotating targets.
Table 1. Temperatures of SC at 0.3 MW (°C).
(°C)
Fixed
targetRotating
target

Upper

Lower

Side

Water
inlet

Water
outlet

45

32

28

22.4

23.6

73

41

26

19.4

21.1

Temperatures after the updates to the rotatingtarget, especially the upper one, were higher than theones before the updates. The temperature differences124

inside the SC must be less than 100°C, so that the thermal stress does not exceed the elastic limit of a copper.
If the temperatures measured with the thermocouples
are correct, the beam power for the SC could be increased to 0.6 MW. The beam losses of the fixed and therotating targets should be the same since both targets
have the same thickness (2 cm). Therefore, the scatteredcomponents of the proton beam do not contribute to
the temperature rise. Then, we evaluated carefully thereason why the temperatures of the SC when the rotating target was used were higher than those in the caseof the fixed target. When using the fixed target, the copper jacket jointed to the graphite is cooled directly withthe cooling water. On the other hand, the rotating target
is cooled only by thermal radiation. Then, the temperature of the rotating target is higher than that of the fixed
target. A halo monitor for measuring scattered components of the proton beam is mounted on the upstream
surface of the SC, as shown in Fig. 1. To avoid charge-upof the signal cables of the halo-monitor, a cover is located, facing the rotating target. The temperature of thecover is increased by thermal radiation from the rotating target. The heat of the cover is hardly dissipated because it is in vacuum. Therefore, the halo monitor coveris hot during the beam irradiation. The thermal radiationfrom the hot cover raises the temperature of the thermocouples. Because the temperatures are utilized for interlocks to protect the SC, it is decided to replace the SC.

Figure 1. Picture and schematic view of the used SC.

In the summer maintenance period of 2015, we replaced the SC. This replacement work is similar to thechange of the fixed target with a rotating target in 2014.
A halo monitor was not installed in the newly-manufactured SC. Thermocouples were attached behind theboring structure, as shown in Fig. 2, so that thermocouples do not receive direct thermal radiation from therotating target.

MLF Annual Report 2015

Figure 2.	Pictures of the new SC (left) and enlarged view near
the thermocouple (right).

The evaluation of the induced radioactivity, generated by the beam irradiation, has been carried out witha Monte Carlo code PHITS version 2.76 and an induced
radioactivity calculation code DCHAIN-SP [2]. We evaluated the accumulated radioactivity in the SC, and thenmeasures were taken to reduce the radiation dose on
the surface of the cask storing the SC to reduce the radiation exposure of workers during the transportationof the SC. Table 2 shows the induced radioactivity of the
SC after 14 cooling days, followed by irradiation witha proton beam at 0.3 MW for 10 years, including thesafety margin. The total radioactivity, which is the sumof all of the radionuclides was about 20 TBq. Shieldingof the cask with an iron wall with a thickness of 20 cm
has been calculated for this radioactivity with PHITS.
The estimated dose rate at the surface of the cask was
0.43 mSv/h and is not too high for the work.
Table 2. Induced radioactivity of the SC at 0.3-MW operation.
no. nuclide
1 Co 58
2 Co 60
3 H 3
4 Co 57
5 Ni 63
6 Fe 55
7 Mn 54
8 Cr 51
9 V 4910 Co 56

[Bq]
3.85E+12
3.13E+12
2.36E+12
2.26E+12
2.11E+12
1.31E+12
1.22E+12
7.70E+11
6.08E+11
5.87E+11

[%]
19.25
15.67
11.81
11.29
10.54
6.56
6.08
3.85
3.04
2.94

γ-ray energy
811keV
1332keV 1173keV
122keV
beta17keV
5.9keV
835keV
320keV
4.5keV
847keV 1238keV

half life
71d
5.3y
12y
272d
100y
2.7y
312d
28d
330d
77d

Muon Scinece

In July and August of 2015, the cooling water pipes,
electrical wires, the vertical drive mechanism unit andthe vacuum flange were removed, and a cask base forthe cask installation was mounted over the SC assembly. The new SC and vacuum storage container (madeby MIRAPRO Co., Ltd.) were delivered on August 25. The
vacuum storage container for storing the used SC was
installed in the temporary storage. On September 3, thecask was mounted on the cask base and the used SC
was pulled out from the proton beam line using a cranein the cask by remote control. The SC was stored in thevacuum storage container with a shielding in the temporary storage. The radiation dose rate of the used SC was
1.5 Sv/h at a distance of 7 cm from the SC surface. The
radiation dose rate at the cask surface was 0.15 mSv/h.
It was estimated that the residual radioactivity of the SC
was around 7 TBq from comparison with calculations
with PHITS and DCHAIN-SP. The difference between
the original estimate (20 TBq) and the measured values(7 TBq) was primarily due to the fact that the excessively
setting the beam irradiation period on the safe side in
the calculation with PHITS. The new SC with the cask was
introduced into the proton beam line on September 8.
The removal of the cask and the cask base, the restoration of the cooling water pipes and electrical wires,
vacuum pumping (ultimate vacuum: 3*10-5 Pa or less)and the interlock test were completed by the end of
October. As of 2016, the new SC is running smoothly
in the 0.2-MW operation. The measured temperature of
the new SC at 0.5-MW operation in the second half of2015 was 42°C, which is close to the design value. It was
confirmed that the temperature measurement of the
new SC was suitable even at 2-MW operations.
If the halo monitor is removed, the used SC can beused as a spare SC. We are planning to remove the halo
monitor by remote control after the next fiscal year.
[1] S. Makimura et al., Development of Muon Rotating
Target at J-PARC/MUSE, Journal of Radioanalyticaland Nuclear Chemistry 305 (2015) 811-815.
[2] T. Sato et al., Particle and Heavy Ion Transport Code
System PHITS, Version 2.52, J. Nucl. Sci. Technol.
50:9, 913-923 (2013).

S. Matoba1, 2, S. Makimura1,2, N. Kawamura1,2, Y. Matsuzawa1, 3, and M. Tabe,1, 4Muon Science Section, Materials and Life Science Division, J-PARC; 2Muon Science Laboratory, High Energy Accelerator Research
Organization (KEK); 3Nippon Advanced Technology Co., LTD (NAT); 4Seekel Co., LTD1125

Muon Scinece

MLF Annual Report 2015

Development of a Kicker System and Safety Measures
for the Septum Power Supply at D-line
1. Introduction
Kicker and the following septum are used at the
D-line to separate a double pulse muon beam into twosingle pulses and feed them simultaneously to two experimental areas (D1, D2). However, the kicker noise associated with the ignition of the kicker power supply
has been affecting adversely the nearby particle detectors. A saturable inductor was installed at the output ofthe pulse forming network, and was tested whether it
could eliminate the noise.
As for the septum power supply, a small-size auxiliary transformer was newly added in the winter of 2015
to feed a low current for lower energy muons. However,
the transformer (AC 420 V to 38 V) was burned during the first commissioning of the low-output current
mode operation when the AC 420 V was turned on at
the main breaker. After the accident, a review committee was organized to investigate its cause and to consider the necessary safety measures.
2. Kicker System
2.1 Saturable Inductor
The kicker noise source is the surge voltage at about
10 MHz that occurs with the ignition of the thyratron todischarge the charged Pulse Forming Network (PFN).
Alternatively, a saturable inductor (SI) was considered
to eliminate the surge without delaying the rise-time.
The SI is made of saturable ferrite cores, and has theability to work as a large inductance at the onset of thesurge voltage/current. Subsequently, the inductancedecreases sharply due to saturation of the ferrite as thecurrent increases. In the circuit simulation code, SPICE,
the SI can be modeled as

20 kV. The diagram of the kicker system with the SI isshown in Fig. 1.

Figure 1. Kicker system with the saturable inductor.

Figure 2 shows the results of the SPICE calculations
and the installed saturable inductor. It can clearly beseen that the surge current peaks due to a multiple reflection at both ends of the transmission line are eliminated, while the rising point is shifted, but the rise-timeof the kicker current is unchanged. From top are shown
the currents I1, I2 and I3 as indicated in Fig. 1.
The saturable inductor is composed of a stack of
10 ferrite cores with 161 and 61 mm in outer and innerdiameters, respectively, and 25 mm in thickness. The
housing cavity is shown in Fig. 2 (right).

Lsat (I) = L0 (Ae-α|I| + 1),
where L0 is the air-core inductance and I the current.
Two kinds of ferrite were tested and their characteristics are summarized in Table 1. The present parameters
are optimized for the initial charging voltage of PFN atTable 1.	Parameters of the saturable inductors optimized for
20 kV operation.
Type
I
II

126

A
29.0
189.0

a
0.00130.0023

Bandwidth>80 MHz
12 MHzPower loss
12.5 W
2.6 W

Figure 2.	Analysis results with SPICE for the case with (red)and without (blue) SI, and a stack of 10 ferrite coresand its housing cavity installation.

2.2 Results and Discussion
The results obtained in this trial did not reproduce
the smooth load current that was expected in the calculations. Figure 3 shows the excitation curve with/without SI. The flat top has a ringing of about 10 MHz forboth cases. It was found that the frequency characteristic of the ferrite described in the manufacturer’s data

MLF Annual Report 2015

Muon Scinece

sheet was only valid for excitation of 10 Gauss. The actual flux density in our system, however, reaches ~1.5 T.
Therefore, it could be assumed that the saturable inductor would not block the high frequency surge current.

Figure 3. Kicker load current (I2) with/without SI.

3. Safety Measures for the Septum Power Supply
3.1 Safety Measures
The power supply, modified by adding a small-size
auxiliary transformer, is shown in Fig. 4. If the thermal interlock of the transformer and the switch at the secondary winding are implemented correctly, these measureswould be sufficient from a safety point of view. It was
found that the output current could not be stabilized
by using the added transformer because of a differencein the feedback parameters between the low and highcurrent modes. Then, the new power supply comprises
two independent power supplies for high and low current modes. Their outputs are connected in parallel tothe load, as shown in Fig. 5. The selection of high or low
current mode is made by exclusive switching at the output. Even if the exclusive switching fails, like in the casewhen both switches are switched on simultaneously, afast-blow fuse (300 A) protects the low output current
power supply from damages.

Figure 5.	New design of the septum power supply. Two independent power supplies for high and low current modes are connected in parallel to the load
through an exclusive switch.

3.2 Control of the two-power-supply system
A PLC (programmable logic controller) is used tocontrol the septum power supply. For the low current
power supplies, PLCs of the same series (Yokogawa FAM3) were adopted, and they are connected through an
FA-Link, as shown in Fig. 6.

Figure 6. New control system of the septum power supply.

The typical interlock items of the septum power
supply are listed in Table 2.

Table 2. Typical interlock items of the septum power supply.

Figure 4.	The AC input part of the modified power supply toinclude the low output current mode.

Switch failure
Fuse failure
Overheat of transformer and switching transistor
MC (IC-contactor) answer back error
Output over current and voltage
Fan alarm
Low current power supply output over current and voltage
Low current power supply output fuse failure
Low current power supply over heat
Low current power supply fan alarm
PLC link error

127

Muon Scinece

MLF Annual Report 2015

4. Summary
A saturable inductor was installed and tested for
its ability to eliminate the kicker noise upon the nearby
particle detectors. It was found, however, that the saturable inductor could not block the surge current due tothe insufficient frequency bandwidth. A plan to installa Low-Pass-Filter in place of the saturable inductor is inprogress. As for the septum power supply, an independent power supply system was adopted to cover a wide
range of output current, instead of using an auxiliarytransformer.

Acknowledgements
Concerning the issue of the safety measures forthe septum power supply, the authors express their
gratitude to Dr. T. Takayanagi and Mr. N. Kubo fromthe J-PARC Accelerator division and Materials and Life
Science Facility (MLF) division, respectively, for theirthorough discussions at the review committee on safety and technical issues.

H. Fujimori1, Y. Kobayashi1, Y. Irie1, K. Kojima1, N. Kawamura1, A. Koda1, Y. Ikedo1, S. Sakata2, M. Meguro2, M. Tampo1, K. Hamada1,
N. Kurosawa2, T. Adachi1, P. Strasser1, W. Higemoto3, K. Shimomura1, and Y. Miyake1
1
Muon Science Laboratory, High Energy Accelerator Research Organization (KEK-MUSE); 2Nippon Advanced Technology Co. Ltd. (NAT);
3Advanced Science Research Center, Japan Atomic Energy Agency

128

MLF Annual Report 2015

Muon Scinece

The Status of U-Line
We generated successfully the Ultra Slow Muon
beam for the first time at J-PARC in fiscal year 2015. This
result was accomplished by many upgrades, especially
improvement of the laser system and optimization of
the muonium (Mu) production target.
The Ultra Slow Muon beamline at J-PARC
The Ultra Slow Muon beam, which has quite low
kinetic energy, small beam size, and small time distribution, is desired to probe surface, interface, andmulti-layer properties of materials. In J-PARC, a muon
beamline was constructed for it [1, 2].
The layout of the Ultra Slow Muon beamline isshown in Fig. 1. Surface muons are transported to the
Mu production target. A part of the muons stopped in
the target evaporate as muoniums. The pulsed lasers
ionize them to generate the Ultra Slow Muons. Static
voltage applied to the target accelerates them up to
30 kV. A dipole magnet, electrical bends, and electricalquadruples transport them to μSR setups.

The progress in fiscal year 2015
In this fiscal year, we installed the positron counters
to measure the number of muons stopped around the
Mu production target. By using them, we tuned the surface muon beam to the Mu production target.
By using simulation code SRIM [3], we estimatedthe best thickness of the muonium target, which maximizes the density of the stopping muons around therear surface of the target. Based on the simulation, we
exchanged the target from 100 μm (50 μm degrader +50 μm target) to 75 μm (25 μm degrader + 50 μm target).
We tuned the Ultra Slow Muon beamline by using
the thermal ionized Li+ and the laser ionized H+. The laser ionized H+ was also used to optimize the overlap of
the lasers.
After implementing these updates and improving
the laser system, we generated successfully the Ultra
Slow Muon beam on February 21st, 2016. As shown in
Fig. 2, the time of flight (TOF) of the Ultra Slow Muon
to the focusing point F3 was 0.7 μs, which agrees withthe simulated TOF. The yield of the Ultra Slow Muon was
below 0.01 [μ+/s] in the beginning. By the end of March,
it rose up to 7 [μ+/s] at the focusing point F3.

Figure 2.	Time distribution of the events measured by thedetector at F3. Laser emitted at 0 ns.

Figure 1.	Layout of the Ultra Slow Muon beamline at J-PARC.
The focus points in the beamline are shown as F1,
F2, F3, F4A, and F5A.

Laser system for Ultra Slow Muon generation
Ultra-slow muons can be generated in resonant optical ionization by simultaneous irradiation of 122.09 nm
light, which is the muonium Lyman-α resonance wavelength and corresponds to the 1S-2P transition of muonium, and 355 nm light. Therefore, the high-energy
coherent Lyman-α light source is a very important element for the generation of high-power ultra-slow muon.
129Muon Scinece

MLF Annual Report 2015

2

5s

[1

/2

/2
2

[3

5s

× 10−3

as seen in Fig. 4. Accordingly, the optimized PAr/PKr ratio
was changed to 3 for hydrogen Lyman-α. The value ofthe ratio is almost the same as the theoretical predictionof the phase matching condition [5]. The stability of the
Lyman-α output pulse energy was also improved. The
time evolution of the Lyman-α pulse energy is shown in
Fig. 5. A slow variation of output energy was obtained
when the gas mixer was not applied. On the other hand,a rapid increase and stable output were obtained using
gas mixer.

vacuum gage

Kr

TMP
Ar

0.001

3

Ar

1
0
−1
−2
−3
−4
−5
0.105

0.11

w/ mixer
w/o mixer

Kr

0.115

0.12

0.125

0.13

λ[µm]
Figure 3.	Calculated dispersion near the electric dipole resonances of Kr and Ar.

In our last report, the optimized mixture ratio forhydrogen Lyman-α was PAr/PKr ≈ 5 when the maximum
pulse energy was obtained [4]. However, we had problem not only with the reproducibility but also with thelong-term instability, due to the gases mixing process.
The Ar and Kr gases were sequentially supplied from ahigh-pressured gas cylinder to the gas cell. However,the process cannot produce a perfect gas mixture at thegas cell and the result is a different gas mix ratio distribution, which depends on the location of the gas cell.
To overcome the problem, we introduced a gas mixer,
which consists of mass flow controllers and a staticmixer, to simultaneously fill krypton and argon gases,

Lyman-a intensity (arb. units)2χ(1) (λ)

212.556 nm
820 or 845 nm

static mixer

4130

122 nm212.556 nm
820 or 845 nm

Figure 4.	The newly installed Ar-Kr gas mixer and mixture gas
cell for stable Lyman-α generation.

]]

In order to generate intense Lyman-α light, wechose a method of two-photon resonance four-wavemixing in Krypton. A coherent 212.556 nm pulse for twophoton excitation and a tunable near-infrared pulse
are required for the method. The tunable near-infrared
source can tune the wavelength around 820.649 nm
and 845.015 nm to generate resonant Lyman-α for a
muonium and a hydrogen atom, respectively.
The output pulses at 212.556 nm and the near-infrared from all-solid-state laser and subsequent wavelength conversions were independently loosely focusedand coaxially superposed in the middle of a 1-m longkrypton-argon mixture gas cell to make the interaction
length long and the suitable mode-matching. Kr andAr gas mixing ratio was adjusted to satisfy the phasematching in four-waves, since the Kr gas has negative
dispersion at the Lyman-α wavelength region. The calculated susceptibility of Kr and Ar is shown in Fig. 3.

0.00080.00060.00040.0002

0

0

1000

2000

3000

4000

Time (sec.)
Figure 5.	Time evolution of measured Lyman-α pulse energy
for hydrogen without (blue plots) and with (redplots) gas mixer when the gas ratio and total pressure were fixed to PAr/PKr ≈ 3 and 2400 Pa.

The generation of muonium Lyman-α was also
carried out using the gas mixer. The optimum gas ratio of argon and krypton and the total pressure were
PAr/PKr ≈ 5.5 and 3600 Pa, respectively. Even if we use thegas mixer, the Lyman-α output decreasesafter a continuous operation over 10s hours. We are investigating the problem under the assumption that there is a

MLF Annual Report 2015

contamination inside the gas cell and/or a deteriorationof the gas cell windows.
In conclusion, we installed an efficient gas mixer toimprove the stability of Lyman-α generation. Thus, weensured a continuous successful operation of the laser
system to generate ultra-slow muons and subsequent
beam line tuning.

Muon Scinece

References[1] P. Strasser et. al., J. Phys.: Conf. Ser. 551 012065(2014).
[2] T. Nagatomo et. al., JPS Conf. Proc. 2 010102 (2014).
[3] J. F. Ziegler, http://www.srim.org/[4] N. Saito et al.. Opt. Exp. 24 (2016) 7566-7574.
[5] O.A. Louchev et al.. Phys. Rev. A 84 (2011) 033842(1-9).

T. Adachi1,2, Y. Oishi1,2, W. Higemoto2,3, Y. Ikedo1,2, T. U. Ito2,3, T. Iwashita4, M. Iwasaki5, R. Kadono1,2, Y. Miyake1,2, J. G. Nakamura1,2,
A. D. Pant1,2, N. Saito5, K. Shimomura1,2, P. Strasser1,2, E. Torikai3,6, S. Wada5, A. Yabuuchi7, and I. Yamauchi8
1High Energy Accelerator Research Organization (KEK); 2J-PARC Center; 3Japan Atomic Energy Agency (JAEA); 4Nippon Advanced
Technology Co., Ltd. (NAT); 5RIKEN; 6University of Yamanashi; 7University of Kyoto; 8University of Saga

131

Muon Scinece

MLF Annual Report 2015

Commissioning of the Muon S-Line and the General
Purpose µSR Spectrometer ARTEMIS
2. Beamline tuning
The tuning process of the muon beam was accelerated by the installation of the automatic tuning
program ForTune, which had been developed at the
U-line and generalized for usage at any muon beamline
described by the parameter files. The beam profile, as
measured by a scintillator screen furnished with gatedimage-intensifier and cooled CCD camera [2], is shownin Fig. 2.
SSL1-20x50-SSl2-1-50x20-delay101700-20s.tif
3

Y [mm]

1. Introduction
The surface muon beamline (S-Line) in experimental hall No.1 was installed and endorsed for muon
beam delivery by the facility inspection in FY2014 [1].
Beamline commissioning was resumed after a longsuspension period of summer shutdown and safety inspection of the beamline magnets; at last, a muon beam
was successfully delivered to the S1 area on October 29,
2015. A thin scintillating detector (50 mm in diameter,
1.5 mm in thickness) was placed at the beam extraction
window (180 mm in diameter), and the beam was observed as in Fig. 1 (top panel). Utilizing the time of flight(TOF) difference between the prompt positron andmuon signals, we were able to tune the beamline transmission momentum; the momentum distribution of
the muon was thus obtained as in Fig. 1 (bottom panel).

× 10
400
60
350

1700.0

40

300
20

250

0

200

−20

150
100

−40

50
−60
−80

−60

−40

−20

0

20

40

60

80
X [mm]

0

Figure 2.	Muon beam profile after tuning. The spot size is~28 mm FWHM in x and y direction.

Figure 1.	Top: time spectrum of the first beam at the S1 experimental area, as measured by the light output ofa scintillator placed at the beam exit. Bottom: muon
beam momentum distribution, as derived from TOF
method.

132

3. ARTEMIS: General purpose µSR spectrometer
The µSR spectrometer’s manufacture was sponsored by the Element Strategy grant and it had thesame hardware design as the D1-µSR spectrometer,
which had been used for the user programs since2014. The 1280 channels of positron counters, covering
21.2% of the 4π solid angle, have all been constructedby the Kalliope detector system [3]. As shown in Fig. 3,
the installed µSR spectrometer is equipped with a flypast chamber, a vacuum chamber, in which the sample
on a conduction-type cryostat cold head is suspended
in vacuum, so that the muon flies away from the sample
measurement area, if it misses the sample.
After the tuning of the beamline to maximize therate for regular-sized sample of 16 × 16 mm, the measurement rate became approximately 40 M events/
hour, which is comparable to the rate available at thesimilarly powered (200 kW) facility RIKEN/RAL port 2.

MLF Annual Report 2015

Before correction

Muon Scinece

Volume2014

Volume2012

After correction= 50 ns

Spectrum distortion due toelectronics origin.

= 300 ns

Figure 3.	The S1 spectrometer with the flypast chamber installed. Drs. Koda (in blue jacket) and Hiraishi are
working on sample installation to the flypast chamber.

Figure 4.	Comparison of the µSR time spectra between theolder Volume2012 and the newer Volume2014 analog boards. The top panel is before, and the bottom
after the pileup correction.

4. Upgrade of Kalliope detector system
With the previous operation of the D1-spectrometer,
we know that the Kalliope detector system has a deadtime of τ~300 ns, with a poor 2nd pulse detection efficiency due to a transient property (undershooting) of
the analog signal. These features originate from theVolume2012 ASIC (Application Specific Integrated
Circuit) used in Kalliope. With the 200 kW operation of
MLF, the distortion of the pulsed µSR spectrum is not
as severe, as we have experienced in the 500 kW operation in 2014. However, in preparation for the 1 MW operation in the coming years, we have developed a new
ASIC called Volume2014, and installed a new analog
board, which has the same input/output characteristics
as the older Volume2012 design.
In Fig. 4, we compare the µSR spectrum of silver,which is supposed to be time independent. As shownin the top panel, the spectrum (asymmetry plot of theforward/backward counters along the beamline) bends
down early in the process, due to the count-loss of
positron events with a non-zero dead time of the detectors. The count-rate of this measurement is 200 M
events/hour, which is the measurement with full-open
slit setting and large enough specimen to stop the full
beam. This count rate is equivalent to the regular sized

specimen (16 × 16 mm) in the 1 MW operation. We corrected the count-loss using the well-known formulawith the detector deadtime τ,
Ncorr = Nobs/(1-Robs τ)
where, Robs is the instantaneous count rate and Nobs
and N corr are observed and corrected counts. For
Volume2012, the deadtime parameter τ~300 nsec isrequired to correct the count loss. For Volume2014,
the parameter is improved to τ~50 nsec. What is more
important is that the spectrum distortion at < 1 µsec is
eliminated in Volume2014 with better transient signal
properties. With the upgrade to Volume2014, the S1µSR spectrometer is ready to be used at the 1 MW operation; we named this S1 µSR spectrometer ARTEMIS(Advanced Research Targeted Experimental Muon
Instrument at S-line). It will be used for measurementof Element Strategy materials under the S1-type experiment 2013MS01.
References[1] A. Koda et al., MLF Annual report (2014).
[2] T. U. Ito et al., Nucl. Inst. Method A, 754 (2014) 1.
[3] K. M. Kojima et al., J. Phys: Conf. Ser., 551 012063,(2014).

A. Koda1,3, P. Strasser1,3, K. M. Kojima1,3, Y. Nakatsugawa1,3, T. U. Ito2,3, M. Aoki 4, H. Lee1,3, M. Hiraishi1,3, H. Okabe1,3, S. Takeshita1,3,
R. Kadono1,3, and J-PARC Muse staff and Open-It collaboration
1Muon Science Laboratory, High Energy Accelerator Research Organization(KEK); 2Advanced Science Research Center,Japan Atomic Energy
Agency (JAEA); 3Muon Section, Materials and Life science Division, J-PARC Center

133

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MLF Annual Report 2015

Present Status of the H-line
A brand-new beam line, the H-line, is planned to beconstructed as the 4th beam line in MUSE. The new beamline is designed to have a large acceptance, momentum
tunability, and ability of kicker magnet and Wien filter
use. This beam line will provide an intense beam for experiments, which require high statistics and need to occupy the experimental areas for relatively long period.
Several experiments in the field of fundamental physics
studies have been proposed for the H-line [2-4].
In MUSE, it is possible to extract 4 muon beam lines
from the existing muon production target. The H-line isextracted to the south-east direction in experimental
hall #1.
At the primary stage of the MUSE construction, only
the D-line and the frontend magnets in the S-line were
installed, and then the frontend magnets in the U-line
were installed in 2009. In the H-line, temporary radiation-shield blocks were placed. J-PARC has been operated since 2008, and thus, the activation around the muon
production target becomes more and more serious byeach passing year. According to the evaluation using aMonte-Carlo code [5], the dose rate beside the target

chamber was estimated to be close to 1 Sv/h, and thesummer shutdown in 2012 was the actual time limit to
install the frontend magnets in the H-line. Thus, the installation of the frontend devices was completed mainly
in 2012 and partially in 2014, as shown in Fig. 2 and 3.
In the other high-intensity beam line in MUSE, theU-line, we adopted only axial focusing magnets to obtain high transmission efficiency [6]. On the other hand,in the H-line, the beam captured by an axial focusinglarge-aperture solenoid magnet is transmitted throughbending magnets, although these non-axial focusing
magnets increase the beam loss. To compensate for thisand improve the transmission efficiency, large aperturemagnets and other devices are adopted in the H-line. A
typical size of the aperture is 600 mm in diameter.

HB1

HGV1

φ600 pillow seal

HS1a

HS1b

Figure 2. Installed frontend devices in the H-line.

H lineH1 exp. area

HB2

S lineFigure 1.	A layout plan of experimental hall #1 in the first phase.

134

Figure 3.	Picture taken after completing the installation of
the frontend devices in the H-line.

MLF Annual Report 2015

The conceptual design work of the major components in the experimental hall, i.e. magnets, vacuum
components and so on, has been almost converged forthe first phase of the H-line, in which the beam line isconstructed up to the first experimental area, as shownin Fig. 1. Currently, the detailed mechanical design work
is in progress. In order to provide a sufficient muon
beam to all planed experiments in the H-line, design
work is performed with the collaborators of the proposed experiments.
The designing work of the radiation shield was
performed in the same way in the other beam lines [5].
Along the beam line, a few meter-thick concrete shields
will be necessary to enclose the streaming neutronsand other radiation sources. Because the H-line adopts
large aperture devices, the effect of the streaming neutrons will be more serious than on the other beam lines.
The evaluation of the streaming neutrons is important
not only for radiation safety but also to check its effecton the detectors and other devices in the experimental
area. Figure 4 shows a typical result of the simulation.
While the proton beam is on, the dose rate in the experimental area is expected to reach 100 mSv/h, and noone can enter to the area even if no beam is delivered.
By inserting a beam blocker which is a 40-cm thick copper block, the dose rate is decreased by a factor of ten.
Both the beam blocker and switching off HB2 guarantee the personnel’s safety from the radiation, and compose the personal protection interlock system.

(a) blocker out(b) blocker in

100 µSv/h

10 µSv/hMuon Scinece

In 2014JFY, a supplemental budget was secured toreinforce the radiation shield against a 1-MW protonbeam. A part of H-line’s shield was designed and fabricated to unite the reinforcement shield in experimental
hall #1. These shield blocks were delivered in the end of
March, 2015, and temporarily stored in the experimental hall and they are still there at present, as shown in
Fig. 5. With regard to the radiation safety, the modification of the shield, shown in Fig. 6, was submitted to theregulatory agency.
In the summer shutdown of 2015, these blocks will
be assembled in the H-line shield.

Figure 5.	The radiation shield, temporarily stored in experimental hall #1.

Figure 6.	Drawing of the shield modifications awaiting approval.

blocker

Figure 4.	A typical simulated result of the radiation dosearound the H-line. To enter the experimental area,
a beam blocker is inserted on the right while noblocker is used on the left.

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

N. Kawamura1,2, MuHFS collab., DeeMe collab., and g-2/EDM collab.
1Muon Science Section, Materials and Life Science Division, J-PARC; 2Muon Science Laboratory, High Energy Accelerator Research
Organization (KEK)135

MLF Safety

MLF Safety

MLF Annual Report 2015

Research Safety(Periodic Inspection)
In 2015, the Nuclear Regulatory Commission conducted its periodic inspection of MLF. To keep the radiological license, the periodic inspection at MLF must
be conducted every 5 years. During the periodic inspection, several examinations of dose rates, interlocks
and signs and document confirmation were done inMay, July and November. Although several troubles at
the accelerators and MLF caused a delay in the examination schedule, the periodic inspection did not findany serious problems and the radiological license was
extended.
(Radiological License Upgrade)
Although we normally have two chances to apply
for a radiological license upgrade in a year, only one application was submitted in FY2015.
The application for a radiological license upgrade
was approved on April 18, 2016, with updates for thefollowing items:(1) Installation of neutron beam line BL23
(POLANO),(2) Addition of storage and usage of several sealed
radioisotopes (RI) (Am-241 and Am-243),(3) Extension of the usage area of RI after the newbeam line installation and(4) Interlock for entering the proton beam line areas after operation.
2. Chemical safety
The chemical-safety team performed successfully
safety checks of chemical materials brought by users, such as specimen and reagents, to determine the138

toxicity and the chemical stability of substances withactual physical form, such as powder, solid, liquid andgas. The safety of those materials was confirmed by theindividual beamline staffs. As a result, there were no serious problems when the experiments were performed.
Figure 1 shows a trend for a number of chemical materials for safety check. In 2015, because of shorter available
beam time (approximately 62 days), the total numberof chemical materials decreased, compared with 2014
(approximately 118 days).
6000

Number of chemical materials

1. Radiation safety(Measurement of shieling performance of all neutron
beamlines with increase of the proton beam power)
Toward the 1-MW operation permitted in the radiological license issued last year, we plan to measure thedose rates at all estimation points in MLF, following theincrease of the proton beam power in order to confirm
the shielding performance. In 2015, we measured thedose rates at the 450-kW operation in March and at the
560-kW operation in April. As a result, it was confirmedthat the dose rates measured at all estimation points inthe operation were lower than the entered values in theapplication, even if the measured values were scaled to
the 1-MW operation.

5000
4000
3000
2000
1000
0

2009 2010 2011 2012 2013 2014 2015
Year

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

The risk assessment of chemical materials for various works at the office is mandated from 2016, so thechemical-safety team has conducted a study of a method for it.
3. User brought equipment safety
There are many user-brought pieces of equipmentin MLF, for example cryostats, magnets, furnaces, gaschamber systems, etc. So, the equipment safety team,which consists of electrical safety staff, mechanicalsafety staff and general technical staff, checks various
user-brought pieces of equipment. The total number ofsafety checks was 49 in 2015.
The approved equipment is permitted to be usedin experiments for 1 year. Firstly, the safety check is
performed about the specifications of the interlock system, electric circuits, cable specifications and terminal
treatments, monitor system, etc. Next, it is confirmed
whether the interlock system operates correctly ornot. Figure 2 shows parts of the permission sheet as an
example.

MLF Annual Report 2015

MLF Safety

These cranes are used by technical staffs or constructors to change an experimental setup during the beamtime and perform maintenance in the summer season.
Figure 3 shows the statistics of total crane usage in bothexperimental halls as a function of every month. The usage frequency is highest in October, because the maintenance must be completed in October. The trend andnumbers of every month are similar to those of 2014.
The safety and effective schedules of crane usage
are planned by the crane safety team. Also, that teamchecks the mechanical sling, lifting sling, etc., every
month and replaces the old ones with new ones, if necessary. Furthermore, a crane operator, who wants to use
the cranes in the experimental halls, needs to attend
hands-on training by the crane safety team staff before
the actual operation. A crane work team, to comply
with the rules, is required to include a crane operator,
slinging operator and observer.
As a result, there are no serious troubles in thecrane operations.

Figure 2. Permission sheet for user-brought equipment.

4. Crane safety
There are 2 cranes in each experimental hall (experimental hall No.1 and experimental hall No.2).

Number of crane usage25

in-house staff
constructor

20
15
10
5
0

4

5

6

7

8

9 10 11 12 1

2

3

Month
Figure 3. Trend of the total crane usage in one year.

M. Harada1, M. Ooi1, M. Sekijima1, T. Kai2, Y. Kasugai3, K. Aizawa4, S. Ono4, N. Kubo4, W. Kambara4, M. Sawabe4, K. Suzuya2,
N. Kawamura5, Y. Sakaguchi6, and T. Yamashita6
1
Neutron Source Section; 2Neutron Science Section, Materials and Life Science Division, J-PARC center; 3Radiation Safety Section, Safety
Division, J-PARC Center; 4Technology Development Section, Materials and Life Science Division, J-PARC center; 5Muon Science Section,
Materials and Life Science Division, J-PARC Center; 6Neutron R&D Division, CROSS-Tokai

139

MLF Operations in 2015

MLF Operations in 2015

MLF Annual Report 2015

Beam Operation Status at MLF
In Japanese Fiscal Year (JFY) 2015, the beam operation at the MLF started on April 19, 2015, with a beam
power of 500 kW. Table 1 shows the scheduled timeand availability in JFY 2015, which reflects the originalplan made before JFY 2015. On April 14, just before thestart of JFY 2015, the beam power was increased from400 kW to 500 kW after confirmation of the beam loss
status. The radiation dose around the target station for
600 kW was confirmed to be smaller than the conservative designated value.
Two failures of the cooling water channel at the mercury target (Target #5 and #7) occurred in JFY 2015, so
the overall availability shown in Table 1 was worse than in
the past years. The first malfunction of the cooling channel at Target #5 happened on April 30. Due to the first
failure, we had to stop the beam until the end of June,
although it was planned to be supplied up to the end ofthat month. On November 20, the second malfunction
happened at Target #7, which was just exchanged during the summer shutdown period. Three months wererequired to rectify this failure, including checking thehealth of the replaced target, which was Target #2. Since
the replaced target did not have the helium bubbler tomitigate cavitation erosion at the target vessel, the beam
power was determined to be lower than 200 kW.

Additionally, a relatively long beam stop period was
required to complete the purification of the cryogenic
system for the neutron moderator. In JFY 2015, the purification was done twice, from Nov 12th to Nov 16th andfrom Mar 7th to Mar 14th. Figure 1 shows the trend of thebeam power and its availability during JFY 2015. Afterreplacement of Target #2, relatively high availability
was achieved, except during the cryogenic system refreshment period.

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

Table 1. Run cycle, scheduled time and availability.

142

Run

Duration

62
63
64
65
66
67
Overall

Apr 19 – May19
May 22 – Jun 25
Oct 29 – Nov 11
Nov 15 – Dec 24
Jan 16 – Feb 27
Feb 21 – Apr 4

Scheduled time Modified schedule time
(h)
(h)
655
730
324
889
880
941
4429

655
730
324
899
210
941
3759

Beam time(h)Availability tomodified schedule
(%)

221.2
0
281.7
59.2
33.4
735.8
1331.2

25.0
0
86.9
6.6
15.9
78.2
35.4

MLF Annual Report 2015

MLF Operations in 2015

Users at the MLF
In the fiscal year 2015, there were two long periods(total 5 months) of shutdown of neutron and muon
beam operation due to target incidents occurred in April
and November, 2015. Therefore, the number of the MLF
users in this fiscal year decreased by 30 percent compared with that of the previous year. The beam operation was resumed in February 2016 with beam power of

200 kW. The unconducted experiments in 2015A due tothese incidents were postponed to 2015B by cancellingthe call for the proposals in 2015B. The transition of thenumber of users at the MLF is summarized in Table andFigure for domestic and foreign users of neutron andmuon experimental facilities.

Table 1. The number of domestic and foreign users in the period of fiscal year.
FY2008FY2009FY2010FY2011FY2012FY2013

FY2014FY2015

Domestic Foreign Domestic Foreign Domestic Foreign Domestic Foreign Domestic Foreign Domestic Foreign Domestic Foreign Domestic Foreign
Users
Users
Users
Users
Users
Users
Users
Users
Users
Users
Users
Users
Users
Users
Users
Users
Neutron
Muon

107
95

317
12

303

18
18

476
14

432

40
0

38

259
44

238

50
2

708
21

628

23

42

8

21

80

2

46

12
95
FY
Y 20082008
00

Muon (Foreigners)

38
14
432

2
21
21

628

20
01
10
FY 20102011
FY 2011201
01
12FY 20122013
FY 2013

711

113

476

91
11

78

83
69

13

59

900

78
113

750

11
50
50

50

559

13

10
59
83

711

399

238
FY 20092009

50

Muon (Japanese)

42
44

303

10

Neutron (Foreigners)

46
80

824

61

Neutron (Japanese)

8

18

399

56

10

2

449

600
450
300

476

F 20142014
FY

10

FY 2015150
0Figure 1. The number of domestic and foreign users in the period of fiscal year.

143

MLF Operations in 2015

MLF Annual Report 2015

MLF Proposals Summary – FY2015
The call for J-PARC MLF 2015B General Use Proposals were canceled, because of the long downtime for maintenance of the neutron target, machine time allocated to 2014B and 2015A was shifted to 2015B.
Table 1. Breakdown of Proposals Numbers for the 2015A Rounds.
2015A
Beam-line

Instrument

Full Year

Submitted

Approved

GUGU

Submitted
PU/S

IU

Approved
ES

IU

ES

BL01

4D-Space Access Neutron Spectrometer - 4SEASONS

18(2)

13(1)

3

1

2

3

1

2

BL02

Biomolecular Dynamics Spectrometer - DNA

20(1)

17(1)

2

1

0

2

1

0

BL03

Ibaraki Biological Crystal Diffractometer - iBIX

(100-b)‡

6

3

0

0

0

0

0

0

†

3

3

16

0

0

15

0

0

BL04

Accurate Neutron-Nucleus Reaction Measurement Instrument ANNRI

12

7

2

1

0

2

1

0

(b)

BL05

Neutron Optics and Physics - NOP

5

3

1

0

0

1

0

0

BL08

Super High Resolution Powder Diffractometer - S-HRPD

11

7

2

0

0

2

0

0

BL09

Special Environment Neutron Power Diffractometer - SPICA

0

0

1

0

0

1

0

0

BL10

Neutron Beamline for Observation and Research Use - NOBORU

8

7

3

1

0

3

1

0

BL11

High-Pressure Neutron Diffractometer - PLANET

9

8

0

1

0

0

1

0

BL12

High Resolution Chopper Spectrometer - HRC

13

8

4

0

0

4

0

0

BL14

Cold-neutron Disk-chopper Spectrometer - AMATERAS

25

10

4

1

1

4

1

1

BL15

Small and Wide Angle Neutron Scattering Instrument - TAIKAN

29(2)

15(2)

4

2

2

4

2

2

BL16

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

14

13

1

0

0

1

0

0

BL17

Polarized Neutron Reflectometer - SHARAKU

13

9

1

1

1

1

1

1

BL18

Extreme Environment Single Crystal Neutron Diffractometer - SENJU

24

12

2

2

1

2

2

0

BL19

Engineering Diffractometer - TAKUMI

28

13

3

1

1

3

1

1

BL20

Ibaraki Materials Design Diffractometer - iMATERIA

0

BL21

High Intensity Total Diffractometer - NOVA

(100-b)‡

15

6

0

0

0

0

0

(b)†

23

23

14

0

0

14

0

0

22

12

4

0

0

4

0

0

BL22

Energy Resolved Neutron Imaging System - RADEN

10

7

2

1

0

2

1

0

D1

Muon Spectrometer for Materials and Life Science Experiments - D1

29(1)

20(1)

3

1

0

3

1

0

D2

Muon Spectrometer for Basic Science Experiments - D2

12(2)

9(1)

2

1

0

2

1

0

U

Muon U
Total

0

0

1

0

0

1

0

0

349

225

75

15

8

74

15

7

GU : General Use
PU : Project Use or Ibaraki Pref. Project Use
S : S-type Proposals
IU : Instrument Group Use
ES : Element Strategy† : Ibaraki Pref. Exclusive Use Beamtime (β = 80% in FY2014)‡ : J-PARC Center General Use Beamtime (100-β = 20% in FY2014)( ) : Proposal Numbers under Trial Use Access System or P-type proposals (D1,D2) in GU

144

PU/S

MLF Annual Report 2015

MLF Operations in 2015

800
700

Proposals

600

278

142

500
400

126

42

300

45

20

200

34
67

214

FY2008FY2009

100
0

293

309

460

422

469

FY2011FY2012FY2013

FY2014

Approved

321

255

FY2010

Not Approved

FY2015

Proposal Round
Figure 1. MLF Proposal Numbers over Time.

KEK,
25, 7%

Universies (Japan)
Companies (Japan)

JAEA, 59, 16%
Foreign Organizaons,
45, 12%

Universies (Japan),167, 45%

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

Research Instutes (Jaapan),3, 12%
43
Companies (Japan),30, 8%

Figure 2. Origin of Submitted Proposals by affiliation - FY2015.

Q1, 15, 5%
P9, 7, 2%
Q2, 22,
7%

P7, 2020, 6%
P6, 26, 8%

P1, 82, 27%
P2 18
P2,
18, 6%

P5, 79, 26%

P3, 40, 13%

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 – FY2015.

145

MLF Operations in 2015

MLF Annual Report 2015

MLF Division Staff 2015
Head

Masatoshi Futakawa (Until May, 2015)

		

Toshiji Kanaya (From June, 2015)

Deputy Head

Hideki Seto		

Kazuhiko Soyama

Neutron Source Section

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

Yuko Kato

Motoki Ohi

Katsuhiro Haga (Sub-Leader)

Tomoyuki Kawasakii

Kenji Sakai

Katsuhiro Aoyagi

Hidetaka Kinoshita

Masakazu Seki

Tomokazu Aso

Hiroyuki Kogawa

Mitsuaki Sekijima

Shinpei Fukuda

Kazuma Maekawa

Hideki Tatsumoto

Kouhei Hanano

Shin-ichiro Meigo

Makoto Teshigawara

Masahide Harada

Hideki Muto

Toshitsugu Uchida

Shoichi Hasegawa *Takashi Naoe

Hideki Ueno

Mitsunori Hirane

Norio Narui

Takashi Wakui

Miyuki Hoshino

Masaaki Nishikawa

Zhihong Xiong

Masato Ida

Gaku Noguchi

Shizuka Yoshinari

Kenji Imahashi

Kazutaka Nomura

Tetsuya Kai *Ken-ichi Oikawa *Neutron Science Section

*: additional duties<JAEA>

146

Kenji Nakajima (Leader)

Tetsuya Kai

Hiroshi Nakagawa *Yukinobu Kawakita (Sub-Leader)

Ryoichi Kajimoto

Shoji Nakamura *Kazuya Aizawa *Wataru Kambara *Mitsutaka Nakamura

Koichi Akita *Kouji Kaneko *Takashi Ohhara

Kazuhiro Aoyama

Chiho Katagiri

Ken-ichi Oikawa

Satoru Fujiwara *Seiko Kawamura

Asami Sano

Hideo Harada *Takuro Kawasaki

Kunieda Satoshi *Masahide Harada *Naoko Kawase

Mariko Segawa *Stefanus Harjo

Tatsuya Kikuchi

Kaoru Shibata

Takanori Hattori

Atsushi Kimura *Naoko Shimizu

Kousuke Hiroi

Ryoji Kiyanagi

Takenao Shinohara

Tomonori Hosoya

Masato Kubota *Yuhua Su

Yasuhiro Inamura

Kazuo Kurihara *Kentaro Suzuya

Takaaki Iwahashi

Bing Li

Shin-ichi Takata

Nobuyuki Iwamoto *Futoshi Minato *Tarou Tamada *MLF Operations in 2015

MLF Annual Report 2015

Itaru Tamura *Shuichi Wakimoto *Yousuke Tou *Masao Watanabe *Dai Yamazaki *<KEK>Shinichi Ito (Sub-Leader)Takashi Ino

Kaoru Taketani

Hideki Seto

Takashi Kamiyama

Shuki Torii

Hitoshi Endo

Naokatsu Kaneko

Norifumi Yamada

Haruhiro Hiraka

Kenji Mishima

Testuya Yokoo

Takashi Honda

Fumiya Nemoto

Masao Yonemura

Soshi Ibuka

Hidetoshi Oshita

Kazutaka Ikeda

Toshiya Otomo

Technology Development Section

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

Wataru Kambara

Motoki Ohi *Takayuki Oku (Sub-Leader)

Kazuhiro kawakami

Kenji Sakai *Tomokazu Aso

Hiroyuki Kogawa *Kaoru Sakasai *Chikako Doda

Naoya Kubo

Masaki Sawabe

Wu Gong

Kentaro Moriyama

Kentaro Suzuya *Katsuhiro Haga *Mitsutaka Nakamura *Shin-ichi Takata *Masahide Harada *Tatsuya Nakamura *Kazue Tanaka

Yasuhiro Inamura *Takeshi Nakatani

Masao Watanabe

Tetsuya Kai *Shino Ono

Yasuhiro Yamauchi

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)

Katsunori Honda

Kentaro Toh

Noriko Amezawa

Ryuji Maruyama

Dai Yamazaki

Masumi Ebine *Tatsuya Nakamura

147

MLF Operations in 2015

MLF Annual Report 2015

Muon Science Section
<KEK>*: additional duties

Yasuo Kobayashi

Hirotaka Okabe

Ryosuke Kadono (Leader)

Akihiro Koda

Koichiro Shimomura

Naritoshi Kawamura (Sub-Leader)

Kenji Kojima

Patrick Strasser

Taihei Adachi

Shunsuke Makimura

Masato Tabe

Pant Amba Datt

Shiro Matoba

Soshi Takeshita

Hiroshi Fujimori

Yasuhiro Miyake

Yutaka Taniguchi

Koji Hamada

Junpei Nakamura

Motonobu Tanpo

Masatoshi Hiraishi

Yohei Nakatsugawa

Atsushi Yabuuchi

Li HuaYasuhisa Nemoto

Ichihiro Yamauchi

Yutaka Ikedo

Yu Oishi<JAEA>
Wataru Higemoto *148

Takashi Ito *MLF Operations in 2015

MLF Annual Report 2015

CROSS-Tokai Staff 2015
Director

Hideaki Yokomizo

Science Coordinators
Masatoshi Sato

Yoshiaki Fukushima

Neutron R&D Division*: additional duties

Jun-ichi Suzuki (Head)

Jun-ichi Suzuki *<Technical Support Group>

Kenichi Funakoshi (Head (Deputy))

Hiroki Iwase

Koji Kiriyama (Leader)
Takayoshi Ito (Sub-Leader)<BL01 Group><BL17 Group>

Yoshifumi Sakaguchi

Kazuya Kamazawa (Leader)

Jun-ichi Suzuki * (Leader)

Yukihiko Kawamura

Kazuhiko Ikeuchi

Noboru Miyata (Sub Leader)

Hiroshi Kira

Kazuki Iida

Tazuko Mizusawa

Motoyuki Ishikado

Kazuhiro Akutsu

Nobuo Okazaki<BL02 Group>

Makoto Kobayashi

Masato Matsuura (Leader)<BL18 Group>

Satoshi Kasai

Takeshi Yamada

Akiko Nakao (Leader)

Toshiaki Morikawa

Taiki Tominaga

Koji Munakata

Hideyuki Hiramatsu

Takayasu Hanashima

Yutaka Ebara

Taketo Moyoshi

Tetsuya Kuroda<BL11 Group>

Keiichi Ohuchi

Kenichi Funakoshi * (Leader)
Jun Abe<BL22 Group>

Masae Sahara

Shinichi Machida

Hirotoshi Hayashida (Leader)

Masashi Obinata

Joseph Don PARKER<BL15 Group>

Yoshihiro Matsumoto

Kazuki Ohishi (Leader)

Shuoyuan Zhang

Health and Safety Division*: additional duties

Toshiyuki Yamashita (Head)

Rei Ohuchi *Yukihiko Kawamura *Koji Kiriyama *149

MLF Operations in 2015

MLF Annual Report 2015

Utilization Promotion Division*: additional duties

Junichi Sato(Head)

Megumi Kawakami

Emi Takaha

Kenichi Funakoshi *(Head (Deputy))

Keiko Mikami

Aya Yamada

Asuko Ariga

Junko Ohta

Shinichi Yamaguchi

Toshiki Asai

Rei Ohuchi

Yoshiaki Fukushima *Sayaka Suzuki

Admin and Finance Division

150

Yasuo Seishi (Head)Mika Gunji

Mutsumi Shiraishi

Masaru Yokoyama (Head (Deputy))

Takashi Hikita

Tomoyuki Yabana

MLF Annual Report 2015

MLF Operations in 2015

Proposals Review System, Committees and Meetings

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

Director General
KEK

J-PARC
Center(JAEA/KEK)

Muon Instrument
Proposal Rev. Comm.

Muon Science
Proposal Rev. Comm.

President
CROSS
CollaboraonCommieeDirector
J-PARC

Director
CROSS-Tokai

All except Public Beamlines

Public Beamlines Only

MLF Advisory
Board

SeleconCommiee

RegisteredInstuon(CROSS)

Task Forces

All except Contract
Beamlines

Contract Beamlines
Only

All except Public
Beamlines

Public Beamlines Only

Neutron Instrument
Proposal Rev. Comm.

Contract Beamline
Evaluaon Comm.

Neutron Science
Proposal Rev. Comm.

Proposal
Evaluaon Comm.

Joint Meeng

Muon
Instrument
Proposals

Joint Meeng

Neutron Instrument
Proposals
Muon Program
Advisory Comm.

Muon Scienfic Proposals

Public Beamlines Only
All except Public Beamlines
Neutron Program
JAEA Research
CROSS Development
Advisory
Proposal Advisory Proposal Evaluaon
CommieeCommiee
Panel
Joint Meeng

Neutron Scienfic Proposals

Unified
Access Point

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

151

MLF Operations in 2015

MLF Annual Report 2015

Materials and Life Science Facility Advisory Board

Selection Committee (CROSS)

Kazuya Aizawa

Japan Atomic Energy Agency, Japan

Jun Akimitsu

Jun Akimitsu

Okayama University, Japan /Hiroshima University, Japan

Okayama University, Japan /Hiroshima University, Japan

Masaki Fujita

Tohoku University, Japan

Hiroshi Amitsuka

Hokkaido University, Japan

Michihiro Furusaka

Hokkaido University, Japan

Masaki Fujita

Tohoku University, Japan

Yasuhiro Iye (Chair)

Michihiro Furusaka

Hokkaido University, Japan

Japan Society for Promotion of
Science, Japan

Masatoshi Futakawa

Japan Atomic Energy Agency, Japan

Ryosuke KadonoHigh Energy Accelerator Research
Organization, Japan

Takashi Kamiyama

High Energy Accelerator Research
Organization, Japan

Toshiji Kanaya

Yuji Kawabata

Kyoto University, Japan

Hiroyuki Kishimoto

Sumitomo Rubber Industries, LTD.,Japan

Naoki Kishimoto

Research Center for Strategic
Materials, Japan

High Energy Accelerator Research
Organization, Japan

Yoshiaki Kiyanagi

Nagoya University, Japan

Tetsurou Minemura

Ibaraki Prefecture, Japan

Yuji Kawabata

Kyoto University, Japan

Atsushi Nakagawa

Osaka University, Japan

Yukinobu Kawakita

Japan Atomic Energy Agency, Japan

Mitsuhiro Shibayama The University of Tokyo, Japan

Yoshiaki Kiyanagi

Nagoya University, JapanJun Sugiyama

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

Kenya Kubo

International Christian University,Japan

Shinji Tsuneyuki

The University of Tokyo, Japan

Tetsurou Minemura

Ibaraki Prefecture, Japan

Toshio Yamaguchi

Fukuoka University, Japan

Yasuhiro Miyake

High Energy Accelerator Research
Organization, Japan

Atsushi Nakagawa

Osaka University, Japan

Kenji Nakajima

Japan Atomic Energy Agency, Japan

Toshiya Otomo

High Energy Accelerator Research
Organization, Japan

Hideki Seto

High Energy Accelerator Research
Organization, Japan

Mitsuhiro Shibayama The University of Tokyo, Japan
Kazuhiko Soyama

Japan Atomic Energy Agency, JapanJun Sugiyama

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

Jun-Ichi Suzuki

Comprehensive Research
Organization for Science andSociety, Japan

Masayasu Takeda

Japan Atomic Energy Agency, Japan

Toshio Yamaguchi(Chair)Fukuoka University, Japan
Term: through March 31, 2017152

Term: through March 31, 2017

MLF Annual Report 2015

MLF Operations in 2015

Neutron Advisory Committee (NAC)
NAC convened 23-24 February, 2016 at the J-PARC Research Center, TokaiGroup photo of NAC
Jean-Michel Poutissou (chair)
Hiroshi Amitsuka
Thomas Roser
Shinian Fu
Sergio Bertolucci
Robert Tschirhart
Robert Tribble
Donald F. Geesaman
Horst Stoecker
Hamid Aït Abderrahim
Paul Langan
Hidetoshi Fukuyama
Robert Robinson
Andrew Dawson Taylor

Neutron Advisory Committee (23-24 Feb. 2016)
Canada's National Laboratory for Particle and Nuclear Physics
Hokkaido University
Brookhaven National Laboratory
Institute of High Energy Physics
The European Organization for Nuclear Research
Fermi National Accelerator Laboratory
Brookhaven National Laboratory
Argonne National Laboratory
GSI Helmholtzzentrum für Schwerionenforschung GmbH
Belgian Nuclear Research Centre
Oak Ridge National Laboratory
Tokyo University of Science
Australian Nuclear Science and Technology Organisation
Science and Technology Facilities Council

Muon Advisory Committee (MAC)
MAC convened 14-15 February, 2016 at the KEK Tokai Campus, TokaiGroup photo of MAC
Francis Pratt (Chair)Toshiyuki Azuma
Klaus Jungmann
Kenya Kubo
Andrew MacFarlane
Yasuo Nozue
Prokscha Thomas
Jun Sugiyama

Muon Advisory Committee (14-15 Feb. 2016)
Rutherford Appleton Laboratory
RIKEN
University of Groningen
International Christian University
The University of British Columbia
Osaka University
Paul Scherrer InstituteToyota Central R & D Labs. Inc.

153

MLF Operations in 2015

MLF Annual Report 2015

Workshops, Conferences, Seminars and Schools in 2015
International Symposiums held jointly by
J-PARC MLF and CROSS-Tokai

2015 Quantum Beam Science Festa, (The 7th MLF
symposium and The 33th PF symposium)
15-16 Mar. 2016, Tsukuba International Congress Center, Ibarakith

The 8 Meeting on Collective Action for Nomadic
Small Angle Scatterers (canSAS VIII)
14-16 Apr. 2015, IBARAKI Quantum. Beam Research. Center,
IbarakiGroup Photo of 2015 Quantum Beam Science Festa

Workshops held by KEKGroup Photo of canSAS-VIII

6th Progress report meeting of J-PARC MUSE
27 Jul. 2015, KEK Tokai Campus, Ibaraki

The seventh workshop on NEUtron WAVElengthdependent imaging (NEUWAVE-7)

Workshop for Neutron Optics and Physics (BL05)

31 May - 3 Jun. 2015, Ibaraki Prefectural Culture Center, Ibaraki

19 Nov. 2015, Nagoya University, Aichi

Group Photo of NEUWAVE-7

Workshop for neutron total scattering (BL21)
24 Nov. 2015, KEK Tokai Campus, Ibaraki

Workshop for Neutron Optics and Physics(BL05,BL10)
1 Dec. 2015, KEK Tsukuba Campus, Ibaraki

Workshop for neutron inelastic scattering (BL12)
4 Dec. 2015, KEK Tokai Campus, Ibaraki

The 15th Japan-Korea Meeting on Neutron Science

Workshop for polarized neutron scattering (BL23)

6-8 Jan. 2016, Hotel Nongshim, Busan Korea

8 Dec. 2015, KEK Tsukuba Campus, Ibaraki

Conferences held jointly by J-PARC MLF andCROSS-Tokai
Collaborative Symposium of Elements Strategy
Initiative and Large Research Institutions 201521-22 Jan. 2016, Ito International Research Center, Tokyo154

MLF Annual Report 2015

Workshops held by CROSS-Tokai
The 15th CROSSroads of Users and J-PARC“structures and functions of materials”

MLF Operations in 2015

Workshops and Seminars held by CROSS-Tokaiand other organizations

7-8 Sep. 2015, IBARAKI Quantum. Beam Research. Center,2015 1st Workshop on Analytical Methods In Small
Angle Scattering

Ibaraki

8 Jul. 2015, KENKYUSHA EIGO Center, Tokyo
Photo of 2015 1st Workshop on Analytical
Methods In Small Angle ScatteringGroup Photo of CROSSroads 15

The 16th CROSSroads of Users and J-PARC“Recent progress on strongly correlated electron
systems and its future”

2015 Workshop on Materials Science
30 Jul. 2015, Essam Kanda Hall, Tokyo

14-15 Oct. 2015, IBARAKI Quantum. Beam Research. Center,
IbarakiPhoto of 2015 Workshop on Materials Science

Group Photo of CROSSroads 16

2nd Collaborative Symposium of Large ResearchInstitutions and Super computer KEI 2015
2 Sep. 2015, Akihabara UDX, Tokyoth

The 17 CROSSroads of Users and J-PARC”Condensed States of Strongly Correlated Electron
Systems”

Photo of 2nd Collaborative Symposium of Large
Research Institutions and Super computer KEI 201518-19 Jan. 2016, IBARAKI Quantum. Beam Research. Center,
IbarakiSeminar About The Industrial Application bySPring-8 in Kanagawa
3-4 Sep. 2015, KAWASAKI Sangyo Shinko Hall, Kanagawa
Group Photo of CROSSroads 172015 Workshop on Surfaces and Interfaces
1 Oct. 2015, KENKYUSHA EIGO Center, Tokyo

155

MLF Operations in 2015

MLF Annual Report 2015

Ibaraki Society for Promotion of Use of Neutrons”
2015 Meeting of Magnetic Materials”

2015 Workshop on Organic and Polymeric Materials
Neutron Structure Elucidation

6 Oct. 2015, Essam Kanda Hall, Tokyo

16 Feb. 2016, Essam Kanda Hall, Tokyo

2015 1st Workshop on Residual Stress and Strain

2nd Synchrotron Radiation・Neutron Linkage Use
Seminar13 Oct. 2015, Essam Kanda Hall, Tokyo

19 Feb. 2016, KENKYUSHA EIGO Center, Tokyo

Users Meeting of the CROSS Trial Use and Ibaraki
Beam Line FY2014
23 Oct. 2015, Kagaku-kaikan Hall, Tokyo

2015 1st Workshop on Structural Biology
17 Nov. 2015, Essam Kanda Hall, Tokyo

2015 Workshop on Neutron Science
25 Nov. 2015, KENKYUSHA EIGO Center, Tokyo

Photo of 2nd Synchrotron Radiation・Neutron
Linkage Use Seminar

Seminar About The Industrial Application by The
Neutron in Saitama

2015 2nd Workshop on Structural Biology

11Dec. 2015, Cultural Center “Sanazeria”, Saitama

10 Mar. 2016, KENKYUSHA EIGO Center, Tokyo

Ibaraki Society for Promotion of Use of Neutrons
2015 “Workshop on Texture Evaluation of Metal
Material”

2015 2nd Workshop on Residual Stress and Strain

15 Dec. 2015, KENKYUSHA EIGO Center, Tokyo

2015 Workshop on Soft Matter Neutron Scattering

1 Mar. 2016, KENKYUSHA EIGO Center, Tokyo

22 Mar. 2016, Essam Kanda Hall, Tokyo

2015 Workshop on Magnetic Materials
21 Dec. 2015, Essam Kanda Hall, Tokyo

2015 Z-Code Training Course
28-30 Mar. 2016, LMJ Tokyo, Tokyo

2015 Workshop on Battery Materials
12 Jan. 2016, KENKYUSHA EIGO Center, Tokyo

Schools in 2015
2015 Workshop on Non-destructive Visualization
and Analysis Methods

The 9th KEK Summer Challenge

20 Jan. 2016, Essam Kanda Hall, Tokyo

18-26 Aug. 2015, KEK Tsukuba Campus, Ibaraki

Photo of 2015 Workshop on Non-destructive
Visualization and Analysis Methods

2015 Workshop on Metallographic Structure
29 Jan. 2016, Essam Kanda Hall, Tokyo

Group Photo of the 9th KEK Summer Challenge
Credit : KEK

The 7th AONSA Neutron School 2015 / 3rd MLF
School
1-5 Dec. 2015, J-PARC Center, Ibaraki

156

MLF Annual Report 2015

MLF Operations in 2015

Award List
Particle Accelerator Society of Japan, Presentation
Award
Study of a corrosion resistant coating layer for metal magnetic cores using neutron reflectometry
Kazuhiro Akutsu (CROSS), August 2015
JAEA President’s Awards 2015, Research andDevelopment Prizes
The realization of high-pressure and high-temperatureneutron experiments on high-pressure neutron diffractometer PLANET
Takanori Hattori and Asami Sano (JAEA), October 2015

The JSNS Achievement Award
Observation of Quantum States of Hydrogen in Matter
Using a Pulsed Neutron Source
Susumu Ikeda (KEK), December 2015
The JSNS Best Poster Award
Neutron inelastic scattering study of magnetic excitation in quasi- one-dimensional quantum spin system of
BaCu2V2O8
Yuta Ishii, Hiroyuki Kimura (Tohoku Univ.), Kazuhiko
Ikeuchi (CROSS), Ryoichi Kajimoto (JAEA), Zhangzhen
He (CAS) and Mitsuru Itoh (Titech)

The JSNS Technology Award
Construction of high-pressure neutron diffractometer
PLANET and the realization of high-pressure and hightemperature neutron experiments
Takanori Hattori, Asami Sano (JAEA) & Hiroshi Arima(Tohoku Univ.), December 2015157

MLF Operations in 2015

MLF Annual Report 2015

MLF Publication 2015
1

S. Ohisa, Y.-J. Pu, N. L Yamada, G. Matsuba, and J. Kido
Molecular Interdiffusion between Stacked Layers by Solution- andThermal Annealing-Process in Organic Light Emitting Devices
ACS Appl. Mater. Interfaces 7 20779 (2015)

2

K. Komatsu, S. Machida, T. Matsubayashi, M. Watanabe, H. Kagi, A.
Sano-Furukawa, and T. Hattori
Crystal structure of magnesium dichloride decahydrate determinedby X-ray and neutron diffraction under high pressure
Acta Crystallographica B71 74-80 (2015)13

T. Matsukawa, Y. Yoshida, A. Hoshikawa, S. Okada, and T. Ishigaki
Neutron crystal structure analysis of stilbazolium derivatives forterahertz-wave generation
CrystEngComm 17 2616-2619 (2015)

14

M. G. Makowska, M. Strobl, E. M. Lauridsen, H. L. Frandsen, A. S.
Tremsin, T. Shinohara, and L. T. Kuhn
Phase Transition Mapping by Means of Neutron Imaging in SOFC
Anode Supports during Reduction under Applied Stress
ECS Transactions 68 1103 (2015)15

Y. Mizuno, Y. Matsuda, K. Suzuki, M. Yonemura, M. Hirayama, and R.
Kanno
Synthesis, crystal structure, and electrochemical properties of
Li1.2+xMn0.3Co0.2Ni0.3O2 (x > 0) for lithium-ion battery cathodes
Electrochemistry 83 820-823 (2015)

3

W. Gong, Y. Tomota, S. Harjo, Y. H. Su, and K. Aizawa
Effect of prior martensite on bainite transformation in nanobainite
steel
Acta Materialia 85 243-249 (2015)

4

T. Okuchi, N. Purevjav, N. Tomioka, J. Lin, T. Kuribayashi, L.
Schoneveld, H. Hwang, N. Sakamoto, N. Kawasaki, and H. Yurimoto
Synthesis of large and homogeneous single crystals of water-bearing
minerals by slow cooling at deep-mantle pressures
American Mineralogist 100(7) 1483-1492 (2015)
16

5

K. Ninomiya, M. K. Kubo, T. Nagatomo, W. Higemoto, T. U. Ito,
N. Kawamura, P. Strasser, K. Shimomura, Y. Miyake, T. Suzuki, Y.
Kobayashi, S. Sakamoto, A. Shinohara, and T. Saito
Nondestructive Elemental Depth-Profiling Analysis by Muonic X-ray
Measurement
Analytical Chemistry 87 4597-4600 (2015)

Y. Idemoto, Y. Sera, N. Ishida, and N. Kitamura
Average and Local Crystal Structure and Electronic Structure of
0.4Li2MnO3-0.6LiMn1/3Ni1/3Co1/3O2 Using First-principles
Calculations and Neutron Beam and Synchrotron X-Ray Sources
Electrochemistry 83 879-884 (2015)17

H. Mizoguchi, S. Park, H. Hiraka, K. Ikeda, T. Otomo, and H. Hosono
An anti CuO2-type metal hydride square net structure in
Ln2M2As2H(x) (Ln=La or Sm, M=Ti, V, Cr, or Mn)
Angewandte Chemie International Edition 54 2932-2935 (2015)

K. Nakajima, S. Ohira-Kawamura, T. Kikuchi, R. Kajimoto, N.
Takahashi, M. Nakamura, K. Soyama, and T. Osakabe
Beam-transport optimization for cold-neutron spectrometer
EPJ Web of Conferences 83 03011 (2015)18

J. Hori, H. Yashima, S. Nakamura, K. Furutaka, K. Y. Hara, H. Harada,
K. Hirose, M. Igashira, T. Katabuchi, A. Kimura, K. Kino, F. Kitatani, Y.
Kiyanagi, M. Koizumi, M. Mizumoto, T. Sano, Y. Takahashi, and Y. Toh
Neutron Capture Cross Section Measurement on 91Zr at J-PARC/
MLF/ANNRI
EPJ Web of Conferences 93 2004 (2015)

19

T. Yokoo, K. Ohoyama, S. Itoh, K. Iwasa, N. Kaneko, J. Suzuki, M.
Ohkawara, K. Aizawa, S. Tasaki, T. Ino, K. Taketani, S. Ishimoto, M.
Takeda, T. Oku, H. Kira, K. Hayashi, H. Kimura, and T. J. Sato
Polarized neutron spectrometer for inelastic experiments at J-PARC :Status of POLANO Project
EPJ Web of Conferences 83 03018 (2015)20

H. Harada, O. Iwamoto, N. Iwamoto, A. Kimura, K. Terada, T. Nakao,
S. Nakamura, K. Mizuyama, M. Igashira, T. Katabuchi, T. Sano, Y.
Takahashi, K. Takamiya, C. H. Pyeon, S. Fukutani, T. Fujii, J. Hori, T.
Yagi, and H. Yashima
Accuracy Improvement of Neutron Nuclear Data on Minor Actinides
EPJ Web of Conferences 93 6001 (2015)

21

A. Kimura, H. Harada, S. Nakamura, O. Iwamoto, Y. Toh, M. Koizumi,
F. Kitatani, K. Furutaka, M. Igashira, T. Katabuchi, M. Mizumoto, J.
Hori, K. Kino, and Y. Kiyanagi
Current activities and future plans for nuclear data measurements at
J-PARCThe European Physical Journal A 51 180 (2015)

22

K. Komatsu, K. Munakata, K. Matsubayashi, Y. Uwatoko, Y.
Yokoyama, K. Sugiyama, and M. Matsuda
Zr-based bulk metallic glass as a cylinder material for high pressure
apparatuses
High Pressure Research 35 254-262 (2015)

6

7

S. Takagi, Y. Iijima, T. Sato, H. Saitoh, K. Ikeda, T. Otomo, K. Miwa, T.
Ikeshoji, K. Aoki, and S.-I. Orimo
True Boundary for the Formation of Homoleptic Transition-Metal
Hydride Complexes
Angewandte Chemie International Edition 54 5650-5653 (2015)8

H. Shishido, S. Miyajima, Y. Narukami, K. Oikawa, M. Harada, T. Oku,
M. Arai, M. Hidaka, A. Fujimaki, and T. Ishida
Neutron detection using a current biased kinetic inductance detector
Applied Physics Letters 107 23601 (2015)

9T. Matsuo, T. Arata, T. Oda, K. Nakajima, S. Ohira-Kawamura, T.
Kikuchi, and S. Fujiwara
Internal dynamics of F-actin and myosin subfragment-1 studied byquasielastic neutron scattering
Biochemical and Biophysical Research Communications 459 493497 (2015)

10

11

12

158

η (5)-Semiquinone Complex: A Possible Dielectric Response
Mechanism
Chemistry A European Journal 21 9682-9696 (2015)

M. Sugiyama, N. Horikoshi, Y. Suzuki, H. Taguchi, T. Kujirai, R. Inoue,
Y. Oba, N. Sato, A. Martel, L. Porcar, and H. Kurumizaka
Solution structure of variant H2A.Z.1 nucleosome investigated bysmall-angle X-ray and neutron scatterings
Biochemistry and Biophysics Reports 4 28-32 (2015)
S. Taminato, M. Hirayama, K. Suzuki, N. L. Yamada, M. Yonemura, J. Y.
Son, and R. Kanno
Highly reversible capacity at the surface of a lithium-rich manganeseoxide: a model study using an epitaxial film system
Chemical Communications 51 1673 (2015)
M. Mitsumi, K. Ezaki, Y. Komatsu, K. Toriumi, et al.
Proton Order-Disorder Phenomena in a Hydrogen-Bonded Rhodium-MLF Annual Report 2015

23

K. Shimomura
Muonium in J-PARC; from fundamental toapplication
Hyperfine Interactions 235 89-95 (2015)24

K. Kawamura, M. Yashima, K. Fujii, K. Omoto, K. Hibino, S. Yamada, J.
R. Hester, M. Avdeev, P. Miao, S Torii, T. Kamiyam
Structural Origin of the Anisotropic and Isotropic Thermal Expansionof K2NiF4-Type LaSrAlO4 and Sr2TiO4Inorganic Chemistry 54 3896-3904 (2015)

25

26

27

28

29

M. L. Baker, T. Tanaka, R. Murakami, S. Ohira-Kawamura, K.
Nakajima, T. Ishida, and H. Nojiri
Relationship between Torsion and Anisotropic Exchange Coupling ina TbIII-Radical-Based Single-Molecule Magnet
Inorganic Chemistry 54 5732-5738 (2015)
K. Iwase, K. Mori, S. Tashiro, H. Yokota, and T. Suzuki
Crystal Structure Analysis of La2Ni6CoDx During Deuterium
Absorption Process
Inorganic Chemistry 54 8650-8655 (2015)
K. Li, H. Zheng, T. Hattori, A. Sano-Furukawa, C. Tulk, J. Molaison, M.
Feygenson, I. N. Ivanov, W. Yang, and H-K. Mao
Synthesis, Structure, and Pressure-Induced Polymerization of
Li3Fe(CN)6 Accompanied with Enhanced Conductivity
Inorganic Chemistry 54 11276-11282 (2015)
M. Futakawa
Material issues relating to high power spallation neutron sources
IOP Conference Series: Materials Science and Engineering 74
12001 (2015)
S. He, Y. Tomota, Y. Su, W. Gong, S. Harjo, and G. Zhao
Unusal Tempering Behavior of Fe-Cr-C Martensite
ISIJ International 55 686-690 (2015)

MLF Operations in 2015

E. Schrader, and I. Tanaka
Protonation State and Hydration of Bisphosphonate Bound to
Farnesyl Pyrophosphate Synthase
Journal of Medicinal Chemistry 58 7549-7556 (2015)
37

T. Wan, T. Naoe, and M. Futakawa
In-situ structural integrity evaluation for high-power pulsed
spallation neutron source – Effects of cavitation damage on
structural vibration
Journal of Nuclear Materials 468 321-330 (2015)

38

H. Kogawa,T. Naoe, H. Kyotoh, K. Haga, H. Kinoshita, and M.
Futakawa
Development of microbubble generator for suppression of pressure
waves in mercury target of spallation source
Journal of Nuclear Science and Technology 52 1461-1469 (2015)

39

K. Ikeuchi, M. Sato, S. Li, M. Toyoda, Y. Kobayashi, M. Itoh, P. Miao, S.
Torii, Y. Ishikawa, and T. Kamiyama
Detailed Study of the Phase Diagram of Fe-based Superconductor
Ba(Fe1-xCox)2As2 by Super High-Resolution Neutron Diffraction
Measurements
Journal of Physics 592 12071 (2015)

40

Y. Ikeda, H. Yoshizawa, S. Konishi, S. Araki, T. C. Kobayashi, T. Yokoo,
and S. Itoh
Caracterization of Ferromagnetic Order in CePd2P2
Journal of Physics: Conference Series 592 012013 (6 pages) (2015)

41

S. Konno, A. Suzuki, K. Nihei, K. Kuwahara, D. Kawana, T. Yokoo,
and S. Itoh
Intermultiplet transitions in filled skutterudite SmFe4P12
Journal of Physics: Conference Series 592 012029 (6 pages) (2015)42

Y. Sakaguchi, H. Asaoka, Y. Uozumi, Y. Kawakita, T. Ito, M. Kubota,
D. Yamazaki, K. Soyama, M. Ailavajhala, M. R. Latif, K. Wolf, M.
Mitkova, and M. W. A. Skoda
Dynamics of silver photo-diffusion into Ge-chalcogenide films: timeresolved neutron reflectometry
Journal of Physics; Conference Series 619 012046 (2015)30

Y. Oba, S. Morooka, H. Sato, K. Ohishi, J. Suzuki, and M. Sugiyama
Simultaneous characterization of precipitates and matrix in a steel
using small-angle neutron scattering and Bragg-edge transmission
analysis
ISIJ International 55 2618 (2015)
43

31

R. Kajimoto, M. Nakamura, Y. Inamura, K. Kamazawa, K. Ikeuchi,
K. Iida, M. Ishikado, K. Nakajima, S. Ohira-Kawamura, T. Nakatani,
W. Kambara, H. Tanaka, Y. Yamauchi, K. Aoyama, T. Hosoya, K.
Kiriyama, K. Aizawa, and M. Arai
Recent progress in the chopper spectrometer 4SEASONS at J-PARC
JAEA-Conf 2015-002 319-329 (2015)

G. Yoshida, K. Ninomiya, M. Inagaki, W. Higemoto, T. U. Ito, N.
Kawamura, K. Shimomura, Y. Miyake, T. Miura, K. M. Kubo, and A.
Shinohara
Muonic atom formation processes for carbon containing molecules
Journal of Physics: Conference Series 635 052047 (2015)

44

M. Nakamura, K. Ikeuchi, R. Kajimoto, W. Kambara, Th. Krist,
T. Shinohara, M. Arai, K. Iida, K. Kamazawa, Y. Inamura, and M.
Ishikado
MAGIC chopper: basic concept and experimental evaluation
JAEA-Conf 2015-002 339-348 (2015)

K. Tomoyori, Y. Hirano, K. Kurihara, and T. Tamada
Background elimination using the SNIP method for Bragg reflections
from a protein crystal measured by a time-of-flight single-crystal
neutron diffractometer
Journal of Physics: Conference Series 664 072049 - 042055 (2015)

45

Q. H. Zhang, Z. Zhai, Z. H. Nie, S. Harjo, D. Y. Cong, M. G. Wang, J. Li,
and Y. D. Wang
An in situ neutron diffraction study of anomalous superelasticity in astrain glass Ni43Fe18Ga27Co12 alloy
Journal of Applied Crystallography 48 1183-1191 (2015)

Y. Idemoto, R. Kawai, N. Ishida, and N. Kitamura
Characterization, average and electronic structures during charge–
discharge cycle in 0.6Li2MnO3–0.4Li(Co1/3Ni1/3Mn1/3)O2 solid
solution of a cathode active material for Li-ion battery
Journal of Power Sources 273 1023-1029 (2015)

46

G. Yoshida, K. Ninomiya, T. U. Ito, W. Higemoto, T. Nagatomo, P.
Strasser, N. Kawamura, K. Shimomura, Y. Miyake, T. Miura, K. M.
Kubo, and A. Shinohara
Muon capture probability of carbon and oxygen for CO, CO2, and
COS under low-pressure gas conditions
Journal of Radioanalytical and Nuclear Chemistry 303 1277-1281(2015)

47

S. Makimura, N. Kawamura, S. Onizawa, Y. Matsuzawa, M. Tabe,
Y. Kobayashi, R. Shimizu, Y. Taniguchi, H. Fujimori, Y. Ikedo, R.
Kadono, A. Koda, K. M. Kojima, K. Nishiyama, J. Nakamura, K.
Shimomura, P. Strasser, Y. Nakatsugawa, and Y. Miyake
Development of muon rotating target at J-PARC/MUSE

32

33

34

O. Kwon, M. Hirayama, K. Suzuki, Y. Kato, T. Saito, M. Yonemura, T.
Kamiyama, and R. Kanno
Synthesis, structure, and conduction mechanism of the lithium
superionic conductor Li10+δ Ge1+δ P2−δ S12
Journal of Materials Chemistry A 3 438-446 (2015)

35

K. Fujii, M. Shiraiwa, Y. Esaki, M. Yashima, S. J. Kimc, and S. Leec
Improved oxide-ion conductivity of NdBaInO4 by Sr doping
Journal of Materials Chemistry A 3 11985-11990 (2015)

36

T. Yokoyama, M. Mizuguchi, A. Ostermann, K. Kusaka, N. Niimura, T.

159

MLF Operations in 2015

MLF Annual Report 2015

Journal of Radioanalytical and Nuclear Chemistry 305 811-815(2015)
48

49

50

51

160

H. Tatsumoto, Y. Shirai, M. Shiotsu, Y. Naruo, H. Kobayashi, and Y.
InataniHeat Transfer Characteristics of a Horizontal Wire in Pools of Liquid
and Supercritical Hydrogen
Journal of Superconductivity and Novel Magnetism 28 1185-1188(2015)
M. Unno, K. Ishikawa-Suto, K. Kusaka, T. Tamada, Y. Hagiwara, M.
Sugishima, K. Wada, T. Yamada, K. Tomoyori, T. Hosoya, I. Tanaka, N.
Niimura, R. Kuroki, K. Inaka, M. Ishihara, and K. Fukuyama
Insights into the Proton Transfer Mechanism of a Bilin Reductase
PcyA Following Neutron Crystallography
Journal of the American Chemical Society 137 5452-5460 (2015)
Y. Ikeda, S. Suzuki, T. Nakabayashi, H. Yoshizawa, T. Yokoo, and S.
ItohTransport and Thermodynamic Studies of Stripe and Checkerboard
Ordering in Layered Nickel Oxides R2-xSrxNiO4 (R = La and Nd)
Journal of the Physical Society of Japan 84 023706 (5 pages) (2015)
R. Kajimoto, K. Tomiyasu, K. Nakajima, S. Ohira-Kawamura, Y.
Inamura, and T. Okuda
Development of Spin Correlations in the Geometrically Frustrated
Triangular-Lattice Heisenberg Antiferromagnet CuCrO2
Journal of the Physical Society of Japan 84 074708 (2015)

52

K. Kamazawa, M. Ishikado, S. Ohira-Kawamura, K. Kakurai, K.
Nakajima, Y. Kawakita, K. Yamada, M. Arai, and M. Sato
Spin Fluctuation in YBaFe4O7+δ with Geometrically Frustrated
Pyrochlore Lattice of Fe Spins
Journal of the Physical Society of Japan 84 104711 (2015)

53

Y. Ikeda, D. Ueta, H. Yoshizawa, A. Nakao, K. Munakata, and T.
OhharaSingle-Crystal Neutron Diffraction Study of the Heavy-Electron
Superconductor CeNiGe3
Journal of the Physical Society of Japan 84 123701 (2015)

54

Y. Kobayashi, S. Kototani, K. Ohishi, M. Itoh, A. Hoshikawa, T.
Ishigaki, and M. Sato
Identification of Various Coexisting Phases in Superconducting andNon-superconducting Samples of RbxFe2−ySe2
Journal of the Physical Society of Japan 84 44710 (2015)

55

M. Futakawa
Targetry overview — Various target concepts and expectable next
generation targets in power frontier applications —JPS Conference Proceedings 8 001002 (2015)

56

S. Harjo, T. Kawasaki, T. Hemmi, T. Ito, T. Nakamoto, and K. Aizawa
Thermal Strain in Superconducting Nb3Sn Strand at Cryogenic
Temperature
JPS Conference Proceedings 8 031001 (2015)

57

S. Hosokawa, J. Stellhorn, W.-C. Pilgrim, N. Boudet, N. Blanc, S.
Kohara, H. Tajiri, H. Kato, Y. Kawakita, and T. Otomo
A Combination of Anomalous X-ray Scattering and Neutron
Diffraction for Structural Characterizations of Zr45Cu45Ag10Metallic
Glass
JPS Conference Proceedings 8 31002 (2015)

58

K. Furuta, K. Mori, Y. Onodera, and T. Fukunaga
Local Structure of Lithium Ion Conducting Germanium Sulfide Glass:(Li2S)40(GeS2)60
JPS Conference Proceedings 8 31004 (2015)

59

S. Harjo, T. Kawasaki, W. Gong, K. Aizawa, and T. Iwahashi
Metastable Austenitic Steel Deformation at Low Temperature
JPS Conference Proceedings 8 031005 (2015)60

H. Suzuki, K. Kusunoki, M. Kanematsu, A. Tasai, Y. Hatanaka, N.
Tsuchiya, S. Bae, S. Shiroishi, S. Sakurai, T. Kawasaki, and S. Harjo
Application of Neutron Stress Measurement to Reinforced Concrete
Structure
JPS Conference Proceedings 8 031006 (2015)

61

K. Maruyama, Y. Arai, S. Sato, M. Sanada, T. Otomo, K. Suzuya, and K.
Itoh
Neutron Diffraction Study of Isotope Enriched Glassy Sm4Ti9O24
JPS Conference Proceedings 8 31007 (2015)

62

S. Tahara, Y. Kawakita, M. Nakamura, H. Shimakura, T. Kikuchi, Y.
Inamura, K. Nakajima, S. Ohira-Kawamura, T. Sunakawa, and T.
Fukami
Two Low-Energy Excitations in Superionic Conductors of RbAg4I5
and KAg4I5JPS Conference Proceedings 8 031008 (2015)

63

T. Kawasaki, S. Harjo, W. Gong, K. Aizawa, T. Iwahashi, Z. Shi, J. Li, Y.
Tomota, and T. Ungár
Dislocation Characteristics of Martensitic Steel Studied by In-Situ
Neutron Diffraction Experiment
JPS Conference Proceedings 8 031009 (2015)

64

R. Kiyanagi, Y. Matsuo, T. Ohhara, T. Kawasaki, K. Oikawa, et al.
Phase Transition and Internal Crystal Structure of Superprotonic
Conductor, Rb3-xKxH(SeO4)2
JPS Conference Proceedings 8 31012 (2015)

65

Y. Onodera, H. Nakashima, K. Mori, T. Otomo, and T. Fukunaga
Structure and conductivity of Na-P-S superionic conducting glasses
studied by neutron and X-ray diffraction
JPS Conference Proceedings 8 31013 (2015)

66

Y. Su, K. Oikawa, T. Kawasaki, T. Kai, Y. Shiota, H. Sato, T. Shinohara, Y.
Tomota, M. Harada, Y. Kiyanagi, and M. Arai
Microstructure and Residual Strain Distribution in Cast Duplex
Stainless Steel Studied by Neutron Imaging
JPS Conference Proceedings 8 31015 (2015)

67

D. S. Adipranoto, M. Yonemura, Y. Ishikawa, A. Hoshikawa, T.
Ishigaki, T. Kamiyama, Y. Uchimoto, and Z. Ogumi
Crystal-Local Structure Analyses for Cathode LIBs LiNi1−xCoxO2(0≤x≤ 1) by Neutron Diffraction
JPS Conference Proceedings 8 031017 (2015)

68

H. Arima, T. Kawamata, Y. Yokoyama, K. Sugiyama, and T. Otomo
Structural Study of Fe80B20 Amorphous Alloy by Anomalous X-ray
Scattering Coupled with Neutron Diffraction
JPS Conference Proceedings 8 31019 (2015)

69

K. Kino, M. Yonemura, Y. Ishikawa, and T. Kamiyama
Application of the J-PARC Neutron Beam to the Transmission
Measurement for a Li Ion Battery during Charge and Discharge
JPS Conference Proceedings 8 031021 (2015)

70

P. Xu, S. Harjo, T. Ito, Y. Morii, W. Gong, H. Suzuki, K. Akita, T. Suzuki,
Y. Tomota, and L. Lutterotti
Progress in Bulk Texture Measurement Using Neutron Diffraction
JPS Conference Proceedings 8 031022 (2015)

71

Y. Sakaguchi, H.hito Asaoka, Y. Uozumi, Y. Kawakita, T. Ito, M.
Kubota, D. Yamazaki, K. Soyama, M. Ailavajhala, K. Wolf, M.
Mitkova, and M. W. A. Skoda
Measurement of Transient Photo-Induced Changes in Thin Films
at J-PARC — Time-Resolved Neutron Reflectivity Measurements ofSilver Photo-Diffusion into Ge-Chalcogenide Films
JPS Conference Proceedings 8 031023 (2015)

72

A. Hoshikawa, Y. Yoshida, T. Matsukawa, and T. Ishigaki
Structure Analysis of Propane Hydrates
JPS Conference Proceedings 8 32001 (2015)

MLF Annual Report 2015

86

K. Hiroi, T. Shinohara, H. Hayashida, N. Wada, K. Oikawa, M. Harada,
T. Kai, and M. Arai
Development of AC Magnetic Field Imaging Technique Using
Polarized Pulsed Neutrons at J-PARC
JPS Conference Proceedings 8 35001 (2015)87

M. Harada, J. D. Parker, K. Oikawa, T. Kai, and T. Shinohara
Inner Observation of Canning Cadmium by Energy-Selective Neutron
Imaging at NOBORUJPS Conference Proceedings 8 35002 (2015)

88

R. Kajimoto, M. Nakamura, Y. Inamura, K. Kamazawa, K. Ikeuchi, K.
Iida, M. Ishikado, K. Nakajima, M. Harada, and M. Arai
Background Caused by Continuously Emitted High-Energy Neutrons
at the Chopper Spectrometer 4SEASONSJPS Conference Proceedings 8 036001 (2015)

89

K. Oikawa, M. Harada, T. Shinohara, T. Kai, M. Ooi, and Y Kiyanagi
Custom-Made Shutter Block for Imaging Instrument “RADEN” at
J-PARCJPS Conference Proceedings 8 036002 (2015)

90

N. L. Yamada, K. Mitamura, H. Sagehashi, N. Torikai, S. Sato, H.
Seto, M. Furusaka, T. Oda, M. Hino, T. Fujiwara, M. Kobayashi, and A.
Takahara
Development of Sample Environments for the SOFIA Reflectometer
for Seconds-Order Time-Slicing Measurements
JPS Conference Proceedings 8 036003 (2015)91

K. Tomoyori, K. Kurihara, T. Tamada, and R. Kuroki
Evaluation of the Resolvable Capacity of Bragg Reflections for a New
Diffractometer at J-PARC/MLF Designed for Protein Crystals with
Large Unit Cells
JPS Conference Proceedings 8 036004 (2015)

92

K. Amemiya, M. Sakamaki, M. Mizusawa, and M. Takeda
Magnetic Field Dependence of the Canted Spin Moment around theInterface between Ferromagnetic Ni and Antiferromagnetic FeMn
Revealed by the Polarized Neutron Reflectivity
JPS Conference Proceedings 8 34004 (2015)

M. Segawa, M. Ooi, T. Kai, T. Shinohara, H. Satoh, and M. Kureta
Development of a Three-Dimensional Computed Tomography
System using High-Speed Camera at a Pulsed Neutron Source
JPS Conference Proceedings 8 36006 (2015)93

M. Ooi, K. Sakai, A. Watanabe, A. Akutsu, S. Meigo, and H. Takada
Upgrade of Monitoring and Operation Systems for the MLF-GCS Baseon EPICS and CSS
JPS Conference Proceedings 8 036007 (2015)

S. Lee, Y. Ishikawa, P. Miao, S. Torii, and T. Kamiyama
Time of Flight Neutron Diffraction on NiO
JPS Conference Proceedings 8 034007 (2015)

94

H. Kira, H. Hayashida, H. Iwase, K. Ohishi, J. Suzuki, T. Oku, K. Sakai,
K. Hiroi, S. Takata, T. Ino, K. Ohoyama, M. Ohkawara, T. Shinohara, K.
Kakurai, K. Aizawa, and M. Arai
Demonstration study of small-angle polarized neutron scattering
using polarized 3He neutron spin filter
JPS Conference Proceedings 8 036008 (2015)

95

T. Oku, H. Hayashida, H. Kira, K. Sakai, K. Hiroi, T. Shinohara, Y.
Sakaguchi, T. Ino, K. Ohoyama, L.-J. Chang, M. Nakamura, J. Suzuki,
K. Aizawa, M. Arai, Y. Endoh, and K. Kakurai
Development of Compact Laser Optics for an In-Situ Spin-Exchange
Optical Pumping 3He Neutron Spin Filter
JPS Conference Proceedings 8 036009 (2015)73

H. Abe, T. Takekiyo, M. Shigemi, Y. Yoshimura, S. Tsuge, T. Hanasaki,
K. Ohishi, S. Takata, and J. Suzuki
Size-tunable confined water in a room temperature ionic liquid
JPS Conference Proceedings 8 033001 (2015)74

Y. Sekine, R. Kobayashi, S. Chi, J. A. Fernandez-Baca, K. Suzuya, F.
Fujisaki, K. Ikeda, T. Otomo, T. Ikeda-Fukazawa, H. Yamauchi, and H.
Fukazawa
Neutron Diffraction of Ice and Water in Hydrogels
JPS Conference Proceedings 8 33009 (2015)

75

H. Fukazawa, M.i Arakawa, H. Yamauchi, Y. Sekine, R. Kobayashi, Y.
Uwatoko, S. Chi, and J. A. Fernendez-Baca
Properties of Ferroelectric Ice
JPS Conference Proceedings 8 033010 (2015)

76

K. Akutsu, H. Iwase, Y. Nakatani, and T. Yoshimura
Structural study of gold nanoparticle/surfactant complex by SANS,SAXS, TEM, and EXAFS Techniques
JPS Conference Proceedings 8 033011 (2015)

77

78

79

80

81

82

MLF Operations in 2015

H. Iwase, N. K. Kawano, K. Akutsu, and T. Yoshimura
SANS and SAXS studies on the aggregates properties of a Geminitype amphiphilic dendrimer in solution
JPS Conference Proceedings 8 33012 (2015)
K. Azuma, N. Hariyama, Y. Kamata, N. L. Yamada, N. Torikai, and M.
Kawaguchi
Depth Distribution of Component for the Thin Films of Binary
Polystyrene Blends with Different Molecular Weights
JPS Conference Proceedings 8 033013 (2015)
K. Kodama, N. Igawa, S.-I. Shamoto, K. Ikeda, H. Ohshita, N.
Kaneko, T. Otomo, K. Suzuya, A. Hoshikawa, and T. Ishigaki
Local Lattice Distortion Caused by Short-Range Charge Ordering inTransition Metal Oxides
JPS Conference Proceedings 8 034002 (2015)

T. Ueno, K. Saito, N. Inami, T. Kojima, M. Mizuguchi, N. Miyata, K.
Akutsu, M. Takeda, K. Takanashi, and K. Ono
Structural and Magnetic Depth Profile Analysis of L10 FeNi Film by
Polarized Neutron Reflectometry
JPS Conference Proceedings 8 034008 (2015)

83

T. Mochiku, Y. Hata, A. Hoshikawa, T. Ishigaki, H. Yasuoka, and K.
HirataCr ystal Structure of the Fe1−xSr2YCu2+xO6+δ Magnetic
Superconductor
JPS Conference Proceedings 8 34009 (2015)
96

84

A. Nakao, H. Nakao, K. Ohoyama, S. Torii, J. Zhang, T. Kamiyama, Y.
Murakami, W. Kobayashi, and I. Terasaki
Magnetic and Crystal Structures of the Room Temperature
Ferrimagnet Sr3YCo4O10.5
JPS Conference Proceedings 8 034010 (2015)

N. Suzuki, M. Katano, M. Yonemura, and T. Kamiyama
Optimization of Radial Collimators for a Powder DiffractometerSPICA
JPS Conference Proceedings 8 036010 (2015)

97

S. Wakimoto, K. Ikeuchi, M. Arai, M. Fujita, R. Kajimoto, S.
Kawamura, M. Matsuura, K. Nakajima, and K. Yamada
Neutron Scattering Study of Spin Fluctuations in La2−xSrxCuO4 by
Four-Dimensional Mapping of Neutron Cross-Sections Using the
4SEASONS Chopper Spectrometer
JPS Conference Proceedings 8 034013 (2015)

M. Nakamura, Y. Kawakita, W. Kambara, K. Aoyama, R. Kajimoto, K.
Nakajima, S. Ohira-Kawamura, K. Ikeuchi, T. Kikuchi, Y. Inamura, K.
Iida, K. Kamazawa, and M. Ishikado
Oscillating Radial Collimators for the Chopper Spectrometers at MLF
in J-PARCJPS Conference Proceedings 8 036011 (2015)

98

K. Ishizuka, T. Kai, T. Shinohara, M. Segawa, and K. Mochiki

85

161

MLF Operations in 2015

MLF Annual Report 2015

Super-Resolution Processing for Pulsed Neutron Imaging System
Using a High-Speed Camera
JPS Conference Proceedings 8 36012 (2015)
99

T. Nakatani, Y. Inamura, T. Ito, and T. Otomo
The Control Software Framework of the Web BaseJPS Conference Proceedings 8 036013 (2015)

100 K. Sakai, T. Oku, H. Hayashida, H. Kira, K. Hiroi, T. Ino, K. Ohoyama,
M. Ohkawara, K. Kakurai, T. Shinohara, K. Oikawa, M. Harada, K.
Aizawa, M. Arai, Y. Sakaguchi, and J. Suzuki
Development Status of the NMR System for the Polarized 3He
Neutron Spin Filter (NSF) in the MLF at J-PARC
JPS Conference Proceedings 8 36015 (2015)
101 T. Ohhara, R. Kiyanagi, K. Kaneko, I. Tamura, A. Nakao, et al.
Current Status of an Extreme Environment Single Crystal Neutron
Diffractometer SENJU at J-PARC
JPS Conference Proceedings 8 36018 (2015)
102 H. Ohshita, M. Ishiwata, K. Iwase, F. Fujisaki, S. Muto, S. Satoh, T.
Seya, M. Sakaguchi, T. Otomo, K. Ikeda, N. Kaneko, and K. Suzuya
New Neutron Beam Monitor Based on GEM
JPS Conference Proceedings 8 36019 (2015)
103 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
The design and q resolution of the small and wide angle neutron
scattering instrument (TAIKAN) in J-PARC
JPS Conference Proceedings 8 36020 (2015)
104 M. Arai, M. Futakawa, H. Takada, K. Haga, S. Meigo, Y. Miyake, M.
Harada, K. Nakajima, R. Kajimoto, M. Nakamura, K. Suzuya, K.
Shibata, J. Suzuki, S. Takata, T. Nakatani, Y. Inamura, T. Nakamura, T.
Oku, K. Aizawa, K. Soyama, and Y. Kawakita
Present Status of the Materials and Life Science Experimental Facilityof J-PARCJPS Conference Proceedings 8 036021 (2015)
105 K. Shibata, N. Takahashi , Y. Kawakita, M. Matsuura , T. Yamada, T.
Tominaga, W. Kambara, M. Kobayashi, Y. Inamura, T. Nakatani, K.
Nakajima, and M. Arai
The Performance of TOF near Backscattering Spectrometer DNA in
MLF, J-PARC
JPS Conference Proceedings 8 36022 (2015)
106 S. SatohDevelopment of a New Exclusive Function for a 2012 Model 6Li Time
Analyzer Neutron Detector System
JPS Conference Proceedings 8 51001 (2015)
107 Y. Narukami, S. Miyajima, H. Shishido, A. Fujimaki, M. Hidaka, K.
Oikawa, M. Harada, T. Oku, M. Arai, and T. Ishida
Signal from a Single Neutron by using Current-Biased Kinetic
Inductance Detector made of Superconducting Nb Nanowire
JPS Conference Proceedings 8 051003 (2015)
108 S. Miyajima, Y. Narukami, H. Shishido, N. Yoshioka, A. Fujimaki, M.
Hidaka, K. Oikawa, M. Harada, T. Oku, M. Arai, and T. IshidaTime-Dependent Flux from Pulsed Neutrons Revealed bySuperconducting Nb Current-Biased Kinetic Inductance Detector
with 10B Converter Operated at 4 K
JPS Conference Proceedings 8 051004 (2015)
109 K. Haga, T. Naoe, T. Wakui, H. Kogawa, H. Kinoshita, and Masatoshi
Futakawa
Thermal Hydraulic Design of a Double-walled Mercury Target Vessel
JPS Conference Proceedings 8 051008 (2015)
110 D. Yamazaki, M. Nagano, R. Maruyama, H. Hayashida, K. Soyama,
and K. Yamamura

162

Neutron Focusing by a Kirkpatrick–Baez Type Super-Mirror
JPS Conference Proceedings 8 051009 (2015)
111 C. Ohmori, A. Koda, Y. Miyake, K. Nishiyama, K. Shimomura, A.
Schnase, E. Ezura, K. Hara, K. Hasegawa, M. Nomura, T. Shimada, K.
Takata, F. Tamura, M. Toda, M. Yamamoto, and M. Yoshii
High Temperature μ SR Experiments for Accelerator Developments
JPS Conference Proceedings 8 012025(1-5) (2015)
112 T. Osawa, K. Ninomiya, G. Yoshida, M. Inagaki, K. M. Kubo, N.
Kawamura, and Y. Miyake
Elemental Analysis System with Negative-Muon BeamJPS Conference Proceedings 8 025003(1-6) (2015)
113 S. Kanda, M. Aoki, Y. Fukao, Y. Higashi, T. Higuchi, H. Iinuma, Y.
Ikedo, K. Ishida, M. Iwasaki, R. Kadono, O. Kamigaito, D. Kawall,
N. Kawamura, A. Koda, K. M. Kojima, 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, Y. Ueno, M. Yoshida, and A. Yamamoto
Precision Measurement of Muonium Hyperfine Splitting at J-PARC
and Integrated Detector System for High-Intensity Pulsed Muon
Beam Experiment
JPS Conference Proceedings 8 025006(1-6) (2015)
114 Y. Nakatsugawa, M. Aoki, D. Bryman, M. Ikegami, Y. Irie, S. Ito, N.
Kawamura, M. Kinsho, H. Kobayashi, S. Makimura, H. Matsumoto,S. Meigo, T. Mibe, S. Mihara, Y. Miyake, H. Natori, H. Nishiguchi, T.
Numao, C. Ohmori, S. Ritt, P. K. Saha, N. Saito, Y. Seiya, K. Shimizu, K.
Shimomura, P. Strasser, Y. Takezaki, N. Teshima, N. D. Thong, N. M.
Truong, K. Yamamoto, K. Yamamoto, and M. Yoshii
Silicon Carbide Target for a Muon-Electron Conversion Search at
J-PARC MLF
JPS Conference Proceedings 8 025013(1-5) (2015)
115 R. Kitamura, G. Beer, K. Ishida, M. Iwasaki, S. Kanda, H. Kawai, N.
Kawamura, W. Lee, S. Lee, G. M. Marshall, Y. Matsuda, T. Mibe, Y.
Miyake, S. Nishimura, Y. Oishi, S. Okada, A. Olin, M. Otani, N. Saito, K.
Shimomura, P. Strasser, M. Tabata, D. Tomono, K. Ueno, and E. Won
Studies on Muonium Production from Silica Aerogel with
Substructure for the Muon g-2/EDM Experiment
JPS Conference Proceedings 8 025016(1-6) (2015)
116 H. A. Torii, H. A. Torii, M. Aoki, Y. Fukao, Y. Higashi, T. Higuchi, H.
Iinuma, Y. Ikedo, K. Ishida, M. Iwasaki, R. Kadono, O. Kamigaito,
S. Kanda, D. Kawall, N. Kawamura, A. Koda, K. M. Kojima, 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, E. Torikai, A.
Toyoda, K. Ueno, Y. Ueno, A. Yamamoto, and M. Yoshida
Precise Measurement of Muonium HFS at J-PARC MUSEJPS Conference Proceedings 8 025018(1-6) (2015)
117 M. Inagaki, K. Ninomiya, K. Fujihara, G. Yoshida, Y. Kasamatsu, M.
K. Kubo, W. Higemoto, N. Kawamura, T. Nagatomo, Y. Miyake, T.
Miura, and A. Shinohara
Muonic Atom Formation by Muon Transfer Process in C6H6 or C6H12
and CCl4 Mixtures
JPS Conference Proceedings 8 033004(1-6) (2015)
118 K. Ninomiya, M. K. Kubo, P. Strasser, T. Nagatomo, Y. Kobayashi, K.
Ishida, W. Higemoto, N. Kawamura, K. Shimomura, Y. Miyake, T.
Suzuki, A. Shinohara, and T. Saito
Elemental Analysis of Bronze Artifacts by Muonic X-ray Spectroscopy
JPS Conference Proceedings 8 033005(1-6) (2015)
119 A. D. Pant, Y. Sugawara, I. Yanagihara, G. P. Khanal, I. Shiraki, W.
Higemoto, K. Shimomura, K. Ishida, F. L. Pratt, E. Torikai, and K.
Nagamine
Hydration Effect on Electron Transfer in Cytochrome c Monitored by
μ SR

MLF Annual Report 2015

JPS Conference Proceedings 8 033007(1-5) (2015)
120 S. Itoh, T. Yokoo, T. Masuda, H. Yoshizawa, M. Soda, Y. Ikeda, D.
Kawana, T. J. Sato, Y. Nambu, K. Kuwahara, S. Yano, J. Akimitsu, Y.
Kaneko, Y. Tokura, M. Fujita, M. Hase, K. Iwasa, H. Hiraka, T. Fukuda,
K. Ikeuchi, K. Yoshida, T. Yamaguchi, K. Ono, and Y. Endoh
Science from the initial operation of HRC
JPS Conference Proceedings 8 034001 (6 pages) (2015)
121 K. Ohishi, Y. Kousaka, E. Proskurina, T. Ogura, A. Koda, J. Akimitsu,
and K. Inoue
Relation between Crystallographic and Magnetic Chiralities in a
Chiral Helimagnet CsCuCl3
JPS Conference Proceedings 8 034006(1-5) (2015)
122 T. U. Ito, W. Higemoto, K. Ninomiya, M. K. Kubo, N. Kawamura, andK. Shimomura
Online Monitoring of Negative Muon Beam Profiles at J-PARC MUSE
using a Gated Image Intensifier
JPS Conference Proceedings 8 036014(1-5) (2015)
123 M. Tampo, K. Hamada, N. Kawamura, M. Inagaki, T. U. Ito, K. M.
Kojima, K. M. Kubo, K. Ninomiya, P. Strasser, G. Yoshida, and Y.
MiyakeThe Development of a Non-Destructive Analysis System with
Negative Muon Beam for Industrial Devices at J-PARC MUSEJPS Conference Proceedings 8 036016(1-6) (2015)
124 T. Adachi, Y. Ikedo, K. Nishiyama, A. Yabuuchi, T. Nagatomo, P.
Strasser, T. U. Ito, W. Higemoto, K. M. Kojima, S. Makimura, J.
Nakamura, K. Shimomura, N. Kawamura, Y. Kobayashi, R. Kadono, Y.
Miyake, and E. Torikai
Tuning of Ultra-Slow Muon Transport System
JPS Conference Proceedings 8 036017(1-4) (2015)
125 S. Makimura, N. Kawamura, S. Onizawa, Y. Matsuzawa, M. Tabe, Y.
Kobayashi, R. Shimizu, H. Fujimori, Y. Ikedo, R. Kadono, A. Koda, K.
M. Kojima, K. Nishiyama, J. Nakamura, K. Shimomura, P. Strasser, M.
Aoki, Y. Nakatsugawa, and Y. Miyake
Present Status of Muon Production Target at J-PARC/MUSE
JPS Conference Proceedings 8 051002(1-8) (2015)
126 T. Hirata, H. Matsuno, D. Kawaguchi, T. Hirai, N. L. Yamada, M.
Tanaka, and K. Tanaka
Effect of Local Chain Dynamics on a Bioinert Interface
Langmuir 31 3661 (2015)
127 Y. Oda, D. Kawaguchi, T. Hirata, N. L. Yamada, S. Kanaoka, S.
Aoshima, and K. Tanaka
Density Profiles of Well-Defined Poly(methyl 2-propenyl ether) (PMPE)
Near Water Interface
Macromol. Symp. 350 99 (2015)
128 F. Chen, D. Peng, Y. Ogata, K. Tanaka, Z. Yang, Y. Fujii, N. L. Yamada,C.-H. Lam, and O. K. C. Tsui
Confinement Effect on the Effective Viscosity of Plasticized Polymer
Films
Macromolecules 48 7719 (2015)

MLF Operations in 2015transformation behavior studied by in-situ neutron diffraction
Materials Science and Engineering:A 631 153-159 (2015)132 H. Sato, T. Sato, Y. Shiota, T. Kamiyama, A. S. Tremsin, M. Ohnuma,
and Y. Kiyanagi
Relation between Vickers Hardness and Bragg-Edge Broadening
in Quenched Steel Rods Observed by Pulsed Neutron Transmission
Imaging
Materials Transactions 56 1147 (2015)
133 Y. Nii, T. Nakajima, A. Kikkawa, Y. Yamasaki, K. Ohishi, J. Suzuki, Y.
Taguchi, T. Arima, Y. Tokura, and Y. Iwasa
Uniaxial stress control of skyrmion phase
Nature Communications 6 8539 (2015)
134 M. Segawa, M. Ooi, T. Kai, T. Shinohara, M. Kureta, K. Sakamoto,and T. Imaki
Development of a pulsed neutron three-dimensional imaging systemusing a highly sensitive image-intensifier at J-PARC
Nuclear Instruments and Methods in Physics Research A 769 97(2015)
135 H. Hasemi, M. Harada, T. Kai, T. Shinohara, M. Ooi, H. Sato, K. Kino, M.
Segawa, T. Kamiyama, and Y. Kiyanagi
Evaluation of nuclide density by neutron resonance transmission at
the NOBORU instrument in J-PARC/MLF
Nuclear Instruments and Methods in Physics Research A 773 137(2015)
136 T. Nakamura, K. Toha, T. Kawasaki, M. Ebine, A. Birumachi, K.
Sakasai, and K. Soyama
A two-dimensional scintillation-based neutron detector withwavelength-shifting fibers and incorporating an interpolation
methodNuclear Instruments and Methods in Physics Research A 784 202(2015)
137 M. Hino, T. Oda, M. Kitaguchi, N. L. Yamada, S. Tasaki, and Y.
Kawabata
The ion beam sputtering facility at KURRI: Coatings for advanced
neutron optical devices
Nuclear Instruments and Methods in Physics Research A 797 265(2015)
138 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, andT. Yagi
Design and performance of high-pressure PLANET beamline atpulsed neutron source at J-PARC
Nuclear Instruments and Methods in Physics Research A 780 5567 (2015)

129 Z. M. Shi, W. Gong, Y. Tomota, S. Harjo, J. Li, B. Chi, and J. Pu
Study of tempering behavior of lath martensite using in situ
neutron diffraction
Materials Characterization 107 29-32 (2015)

139 Y. Arimoto, N. Higashi, Y. Igarashi, Y. Iwashita, T. Ino, R. Katayama, R.
Kitahara, M. Kitaguchi, H. Matsumura, K. Mishima, N. Nagakura, H.
Oide, H. Otono, R. Sakakibara, T. Shima, H. M. Shimizu, T. Sugino,
N. Sumi, H. Sumino, K. Taketani, G. Tanaka, M. Tanaka, K. Tauchi,
A. Toyoda, T. Tomita, T. Yamada, S. Yamashita, H. Yokoyama, and T.
Yoshioka
Development of time projection chamber for precise neutron lifetime
measurement using pulsed cold neutron beams
Nuclear Instruments and Methods in Physics Research A 799
187–196 (2015)

130 C. I. Cheon, H. W. Joo, K. W. Chae, J. S. Kim, S. H. Lee, S. Torii, and T.
Kamiyama
Monoclinic ferroelectric NaNbO3 at room temperature: Crystal
structure solved by using super high resolution neutron powder
diffraction
Materials Letters 156 214-219 (2015)

140 T. Hirata, H. Matsuno, D. Kawaguchi, N. L. Yamada, M. Tanaka, and K.
TanakaEffect of interfacial structure on bioinert properties of poly(2methoxyethyl acrylate)/poly(methyl methacrylate) blend films inwaterPhysical Chemistry Chemical Physics 17 17399 (2015)

131 Z. Shi, Y. Tomota, S. Harjo, Y. Su, B. Chi, J. Pu, and L. Jian
Effect of non-isothermal deformation of austenite on ferrite

141 K. Mori, K. Enjuji, S. Murata, K. Shibata, Y. Kawakita, M. Yonemura, Y.
Onodera, and T. Fukunaga

163

MLF Operations in 2015

MLF Annual Report 2015

Direct Observation of Fast Lithium-Ion Diffusion in a Superionic
Conductor: Li7P3S11 Metastable Crystal
Physical Review Applied 4 054008 (2015)
142 S. Hayashida, M. Soda, S. Itoh, T. Yokoo, K. Ohgushi, D. Kawana, H.
M. Rønnow, and T. Masuda
Magnetic model in multiferroic NdFe3(BO3)4 investigated by
Inelastic Neutron Scattering
Physical Review B 92 054402 (9 pages) (2015)

155 Y. Nakatsugawa
Search for muon to electron conversion at J-PARC MLF : Recent status
on DeeMe
PROCEEDINGS of SCIENCE(NUFACT2014) 93 (2015)

143 I. Yamauchi, K. Nawa, M. Hiraishi, M. Miyazaki, A. Koda, K. M.
Kojima, R. Kadono, H. Nakao, R. Kumai, Y. Murakami, H. Ueda, K.
Yoshimura, and M. Takigawa
Structural anomalies and short-range magnetic correlations in theorbitally degenerate system Sr2 VO4Physical Review B 92 064408(1-7) (2015)

156 K. Akutsu, M. Sahara, N. Miyata, T. Niizeki, S. Nagayama, Y.
Hasegawa, A. Shimomura, and M. Yoshii
Study of a Corrosion Resistant Coating Layer for Metal Magnetic
Cores Using Neutron Reflectometry
Proceedings of the 12th Annual Meeting of Particle Accelerator
Society of Japan 72-76 (2015)

144 K. Shimomura, R. Kadono, A. Koda, K. Nishiyama, and M. Mihara
Electronic structure of Mu-complex donor state in rutile TiO2
Physical Review B 92 075203(1-6) (2015)

157 S. Makimura, et al.
PRESENT STATUS OF MUON ROTATING TARGET AT J-PARC/MUSE
Proceedings of the 12th Annual Meeting of Particle Accelerator
Society of Japan 261-264 (2015)

145 T. U. Ito, W. Higemoto, A. Sakai, M. Tsujimoto, and S. Nakatsuji
Perturbation on hyperfine-enhanced 141Pr nuclear spin
dynamics associated with antiferroquadrupolar order in PrV2Al20
Physical Review B 92 125151(1-5) (2015)
146 I. Umegaki, H. Tanaka, N. Kurita, T. Ono, M. Laver, C. Niedermayer, C.
R üegg, S. Ohira-Kawamura, K. Nakajima, and K. Kakurai
Spinon, soliton, and breather in the spin-1/2 antiferromagnetic chain
compound KCuGaF6
Physical Review B 92 174412 (2015)
147 M. Hase, K. Nakajima, S. Ohira-Kawamura, Y. Kawakita, T. Kikuchi,
and M. Matsumoto
Magnetic excitations in the spin-1/2 tetramer substance Cu2
114Cd11B2O6 obtained by inelastic neutron scattering experiments
Physical Review B 92 184412 (2015)
148 T. Katabuchi, T. Matsuhashi, K. Terada, M. Igashira, M. Mizumoto,
K. Hirose, A. Kimura, N. Iwamoto, K. Y. Hara, H. Harada, J.-i. Hori, T.
Kamiyama, K. Kino, F. Kitatani, Y. Kiyanagi, S. Nakamura, and Y. Toh
Misassigned neutron resonances of Nd-142 and stellar neutron
capture cross sections
Physical Review C 91 37603 (2015)
149 K. Kino, M. Yonemura, Y. Kiyanagi, Y. Ishikawa, J. D. Parker, T.
Tanimori, and T. Kamiyama
First Imaging Experiment of a Lithium Ion Battery by a Pulsed
Neutron Beam at J-PARC/MLF/BL09
Physics Procedia 69 612-618 (2015)
150 S. Hayashida, M. Soda, S. Itoh, T. Yokoo, K. Ohgushi, D. Kawana,
and T. Masuda
Inelastic neutron scattering on multiferroics NdFe3(BO3)4
Physics Procedia 75 127 -133 (2015)
151 K. Iwasa, A. Yonemoto, S. Takagi, S. Itoh, T. Yokoo, S. Ibuka, C.
Sekine, and H. Sugawara
Nd-ion substitution effect on f-electron multipole order of PrRu4P12
Physics Procedia 75 179 -186 (2015)
152 H. Lee, S. Jo, T. Hirata, N. L. Yamada, K. Tanaka, E. Kim, and D. Y. Ryu
Interpenetration of Chemically Identical Polymer onto Grafted
Substrates
Polymer 74 70 (2015)
153 T. Hirata, H. Matsuno, D. Kawaguchi, N. L. Yamada, M. Tanaka, and T.
TanakaConstruction of a blood-compatible interface based on surface
segregation in a polymer blend
Polymer 78 219 (2015)

164

154 Z. Xiong, T. Naoe, T. Wan, M. Futakawa, and K. Maekawa
Mechanical Property Change in the Region of Very High-cycle
Fatigue
Procedia Engineering 101 552-560 (2015)

158 K. Terada, T. Katabuchi, M. Mizumoto, T. Arai, T. Saito, M. Igashira,K. Hirose, S. Nakamura, A. Kimura, H. Harada, J. Hori, K. Kino, and Y.
Kiyanagi
Measurement of neutron capture cross sections of Pd-107 at J-PARC/
MLF/ANNRI
Progress in Nuclear Energy 82 118-121 (2015)
159 S. Ajimura, et al.
On-site background measurements for the J-PARC E56 experiment: A
search for the sterile neutrino at J-PARC MLF
Progress of Theoretical and Experimental Physics 6 063C01 (2015)
160 D. Payra, M. Naito, Y. Fujii, N. L. Yamada, S. Hiromoto, and A. Singh
Bioinspired adhesive polymer coatings for efficient and versatilecorrosion resistance
RSC Advances 5 15977 (2015)
161 A. Nakamura, T. Ishida, K. Kusaka, T. Yamada, S. Fushinobu, I.
Tanaka, S. Kaneko, K. Ohta, H. Tanaka, K. Inaka, Y. Higuchi, N.
Niimura, M. Samejima, and K. Igarashi“Newton’s cradle” proton relay with amide –imidic acidtautomerization in inverting cellulase visualized by neutron
crystallography
Science Advances 1 e1500263 (2015)
162 N. Funamori, K. M. Kojima, D. Wakabayashi, T. Sato, T. Taniguchi,
N. Nishiyama, T. Irifune, D. Tomono, T. Matsuzaki, M. Miyazaki, M.
Hiraishi, A. Koda, and R. Kadono
Muonium in Stishovite: Implications for the Possible Existence of
Neutral Atomic Hydrogen in the Earth's Deep Mantle
Scientific Reports 5 8437(1-5) (2015)
163 K. Mori, K. Furuta, Y. Onodera, K. Iwase, and T. Fukunaga
Three-dimensional structures and lithium-ion conduction pathwaysof (Li2S)x(GeS2)100−x superionic glasses
Solid State Ionics 280 44-50 (2015)
164 K. Osamura, S. Machiya, S. Harjo, T. Nakamoto, N. Cheggour, and A.
NijhuisLocal strain exerted on Nb 3 Sn filaments in an ITER strand
Superconductor Science and Technology 28 45016 (2015)

MLF Annual Report 2015

Editorial Board

Editorial Board - MLF Annual Report 2015

Chief Editor

Toshiki Asai

Kaoru Sakasai
Neutron Instrumentation Section

CROSS-Tokai

Shin-ichiro Meigo

Takashi Naoe

Facility and Application Development Section

Neutron Source Section

Asami Sano-Furukawa

Kenji Mishima

Neutron Science Section

Neutron Science Section

Kenji M. Kojima

Naritoshi Kawamura

Muon Science Section

Muon Science Section

Kenichi Funakoshi

Taiki Tominaga

CROSS-TokaiCROSS-Tokai

Kazuhiko Ikeuchi
CROSS-Tokai

169