Progress of Facilities
Supercomputer Center
The Supercomputer Center (SCC) is a part of theMaterials Design and Characterization Laboratory (MDCL)of ISSP. Its mission is to serve the whole community ofcomputational condensed-matter physics of Japan, providing
it with high performance computing environment. In particular, the SCC selectively promotes and supports large-scalecomputations. For this purpose, the SCC invites proposals forsupercomputer-aided research projects and hosts the Steering
Committee, as mentioned below, that evaluates the proposals.
The ISSP supercomputer system consists of two subsystems: System B is intended for larger total computational
power and has more nodes with relatively loose connections
whereas System C is intended for higher communication
speed among nodes. System B is SGI ICE XA / UV hybrid
system that consists of FAT nodes with large memory,
CPU nodes based on Intel Xeon, and ACC node enhanced
by GPGPU accelerator. Its theoretical performance is 2.6
PFLOPS. System C is HPE SGI 8600 with 0.77 PFLOPS.
Replacement of the System B is scheduled in Autumn 2020.
The new machine will be much more powerful (more than by
the factor of 2) than the current System B in its peak performance.
In addition to the hardware administration, the SCC
puts increasing effort on the software support. Since 2015,
the SCC has been conducting “Project for advancementof software usability in materials science (PASUMS)”. In
this project, for enhancing the usability of the ISSP supercomputer system, we perform some software-advancement
activity such as developing new application software thatruns efficiently on the ISSP supercomputer system, adding
new functions to existing codes, helping in releasing private
codes for public use, and writing/improving manuals for
public codes. Two target programs were selected in fiscal
year 2019 and developed software were released as abICSClass

Max Points

Application

System B

System C

A

100

100

any time

B

1k

500

C

10k

D
E

(proposal made by S. Kasamatsu (Yamagata U.)) and TeNeS(proposal made by N. Kawashima (ISSP)).
All staff members of university faculties or publicresearch institutes in Japan are invited to propose research
projects (called User Program). The proposals are evaluatedby the Steering Committee of SCC. Pre-reviewing is doneby the Supercomputer Project Advisory Committee. In fiscal
year 2019, totally 276 projects were approved. The total
points applied and approved are listed on Table. 1 below.
Additionally, we supported post-K and other computationalmaterials-science projects through Supercomputing Consortium for Computational Materials Science (SCCMS).
The research projects are roughly classified into thefollowing three (the number of projects approved):
First-Principles Calculation of Materials Properties (145)
Strongly Correlated Quantum Systems (36)
Cooperative Phenomena in Complex, Macroscopic
Systems (128)
In all the three categories, most proposals involve bothmethodology and applications. The results of the projects arereported in 'Activity Report 2019' of the SCC. Every year 3-4
projects are selected for “invited papers” and published at
the beginning of the Activity Report. In the Activity Report
2019, the following three invited papers are included:
1. "Development of Open-Source Parallelized Tensor
Network Softwares: mptensor and TeNeS", Satoshi
MORITA (ISSP) and Naoki KAWASHIMA (ISSP)
2. "Disorder-Free Glass Transitions of Spins and Orbitals
in a Frustrated Pyrochlore Magnet", Kota Mitsumoto(Osaka U.), Chisa Hotta (U. Tokyo), and Hajime Yoshino(Osaka U.)
3. "First-principles calculation of thermophysical properties of solids with strong phonon anharmonicity",
Terumasa TADANO (NIMS)
Numberof
Projects

Total Points
AppliedApproved

System B

System C

System B

System C

17

1.7k

0.9k

1.7k

0.9k

twice a year

88

82.8k

4.7k

58.3k

4.1k

2.5k

twice a year

183

1446.2k

91.2k

612.0k

63.7k

10k

2.5k

any time

5

26.9k

2.0k

26.9k

2.0k

30k

2.5k

twice a year16

445.0k

41.0k

249k

34.7k

0

0

0

0

0

SCCMS

S

twice a year32

218.9k

103.5k

218.9k

103.5kTotal

276

2058.3k

312.3k

1180.7k

267.8kTable 1. Research projects approved in 2019
The maximum points allotted to the project of each class are the sum of the points for the two systems; Computation of one node for 24 hours corresponds to one point for the CPU nodes of System B and System C. The
FAT and ACC nodes require four and two points for a 1-node 24-hours use, respectively.

52

ISSP Activity Report 2019

Neutron Science Laboratory
The Neutron Science Laboratory (NSL) has been playing
a central role in neutron scattering activities in Japan since
1961 by performing its own research programs as well as
providing a strong General User Program for the universityowned various neutron scattering spectrometers installedat the JRR-3 (20 MW) operated by Japan Atomic Energy
Agency (JAEA) in Tokai, Ibaraki (Fig. 1). In 2003, theNeutron Scattering Laboratory was reorganized as the
Neutron Science Labora­tory to further promote the neutronscience with use of the instruments in JRR-3. Under the
General User Program supported by NSL, 12 universitygroup-owned spectrom­eters in the JRR-3 reactor are available for a wide scope of researches on material science. The
submitted proposals were about 300 and the visiting users
reached over 6000 person-day in FY2010. In 2009, NSL and
Neutron Science Division (KENS), High Energy Accelerator
Research Organization (KEK) built a chopper spectrometer,
High Resolution Chopper Spectrometer, HRC, at the beamline BL12 of MLF/J-PARC (Materials and Life Science
Experimental Facility, J-PARC) (Fig. 2). HRC covers wide
energy transfer (100 μeV < ħω < 0.5 eV and 0.03 Å-1 < Q <30 Å-1) ranges, and therefore becomes comple­mentary to theexisting inelastic spectrometers at JRR-3. HRC has accepted
general users through the J-PARC proposal system since
FY2011.
Triple axis spectrometers, HRC, a four-circle diffractometer, and a high resolu­tion powder diffractometer are
utilized for a conventional solid state physics and a varietyof research fields on hard-condensed matter, while in thefield of soft-condensed matter science, researches aremostly carried out by using a small angle neutron scattering(SANS-U) and/or neutron spin echo (iNSE) instruments.
The upgraded time-of-flight (TOF) inelastic scattering
spectrometer, AGNES, is available both for hard- and softmatter science. Our General User Program has produced
2064 publications and 284 dissertations until Jan. 29, 2020.
Their lists for the last 10 years is given in Activity Report on
Neutron Scattering Research which is available in ISSP and
NSL web pages.
Since the Great East Japan Earthquake on March 11,
2011, JRR-3 has been closed mainly from safety issues.
Hence, our domestic activity is only on HRC. To take recent
research examples, well-defined spin wave was successfully measured in the pressure-induced magneticphase in
CsFeCl3, and novel excitations near quantum criticality was
identified [1]. Another progress on HRC was that usageof superconducting magnet up to 5 T became available.

Fig. 2. Schematic view of HRC.

Field dependence of spin-wave spectra in 2D antiferromagnet Ba2MnGe2O7 was measured. Since 2012, NSL havemanaged User-Program Supports for Overseas Experiments.
Until March 30, 2020, 398 people (for 297 proposals) have
performed their experiments in various foreign facilities andpublished 106 papers. The lists for User-Program Supports
for Overseas Experiments are also available in Activity
Report on Neutron Scattering Research mentioned above.
As for international cooperative programs, NSL operates
the U.S.-Japan Coopera­tive Program on neutron scattering,
providing further research opportunities to material scientists
who utilize the neutron scattering technique for their researchinterests. In 2010, relocation of the U.S.-Japan triple-axis
spectrom­eter, CTAX, was completed, and it is now open tousers. NSL has another agreement with Australian Centre
for Neutron Scattering (ANSTO), which is the main foreign
facility for the User-Program Supports for Overseas Experiments.
JRR-3 will restart in February 2021 after long shutdown.
During the shutdown period, we have been concentrating
our efforts on upgrading the instruments and neutron beam
circumstances. Specific actions taken include: the installationof focusing collimation systems, such as focusing monochromator and focusing analyzer, and material lens; and the introduction of polarization optics together with the installation of
non-magnetization neutron shield. The neutron guides in the
Guide Hall have also been upgraded by replacing the existingones with super-mirror guides. These upgrades should resultin increase in neutron beam flux several times. The sample
environments such as cryostat and pressure cells have also
been upgraded. Of course, the normal General User Program
will also restart from FY2021. We are eagerly waiting forthat.
[1] S. Hayashida et al., Phys. Rev. B 97, 140405(R) (2018).

International MegaGauss
Science Laboratory

Fig. 1. Reactor hall of JRR-3. Three triple axis spectrometers are shownin the photo.

The objective of this laboratory (Fig. 1) is to study thephysical properties of solid-state materials (such as semiconductors, magnetic materials, metals, insulators, superconducting materials) under ultra-high magnetic field conditions.
Such a high magnetic field is also used for controlling the
new material phase and functions. Our pulse magnets, atmoment, can generate up to 87 Tesla (T) by non-destructive
manner, and from 100 T up to 1200 T (the world strongest
as an in-door record) by destructive methods. The laboratory

ISSP Activity Report 201953

is opened for scientists both from Japan and from overseas,
especially from Asian countries, and many fruitful results are
expected to come out not only from collaborative research
but also from our in-house activities. One of our ultimate
goals is to provide the scientific users as our joint researchwith magnets capable of a 100 T, millisecond long pulses ina non-destructive mode, and to offer versatile physical precision measurements. The available measuring techniques now
involve magneto-optical measurements, cyclotron resonance,
spin resonance, magnetization, and transport measurements.
Recently, specific heat and calorimetric measurements arealso possible to carry out with sufficiently high accuracy.
Our interests cover the study on quantum phase transitions (QPT) induced by high magnetic fields. Field-induced
QPT has been explored in various materials such as quantum
spin systems, strongly correlated electron systems and otherFig. 2. The building for the flywheel generator (left hand side) and along pulse magnet station (right hand side). The flywheel giant DC
generator is 350 ton in weight and 5 m high (bottom). The generator,
capable of a 51 MW output power with the 210 MJ energy storage, isplanned to energize the long pulse magnet generating 100 T without
destruction.

Fig. 1. Signboard at the entrance of the IMGSL.

Building C
Room
101-113

Alias

Type

Bmax

Pulse width
BorePower source

Applications

OthersElectro- Magnetic
Flux Compression

destructive

1200 Tμs
10 mm

5 MJ, 50 kV
2 MJ, 50 kV

Magneto-Optical
Magnetization

5K–
Room temperature

Horizontal
Single-Turn Coildestructive

300 T
200 T

μs
5 mm
10 mm

0.2 MJ, 50 kV

Magneto-Optical measurements
Magnetization

5 K – 400 K

VerticalSingle-Turn Coildestructive

300 T
200 T

μs
5 mm
10 mm

0.2 MJ, 40 kV

Magneto-Optical
Magnetization

2K–
Room temperature

0.9 MJ, 10 kV

Magneto-Optical measurements
Magnetization
Magneto-Transport
Hall resistance
Polarization
Magneto-Striction
Magneto-Imaging
TorqueMagneto- Calorimetry
Heat Capacity

60 T
Building C
Room
114-120

Building C
Room 121

magnetic materials. Non-destructive strong pulse magnets
are expected to provide us with reliable and precise solidstate physics measurements. The number of collaborative
groups for the research is almost 50 in the FT of 2019.
A 210 MJ flywheel generator (Fig. 2), which is the world
largest DC power supply (recorded in the Guinness Book ofWorld Records) has been installed in the DC flywheel gener-

40 ms
18 mm

Mid-Pulse Magnet Non-destructive
70 T

40 ms
10 mm

PPMS

Steady State

14 T

ResistanceHeat Capacity

MPMS

Steady State

7T

Magnetization

87 T(2-stage pulse)

5 ms
10 mm

Short-Pulse Magnet Non-destructive
85 T

Building K
Long-Pulse Magnet Non-destructive

43.5 T

ISSP Activity Report 2019

Down to 0.3 K

Magnetization
Magneto-Transport

2K–
Room temperature

210 MJ, 2.7 kVResistance
Magneto-Calorimetry

2K–
Room temperature

Table 1. Available Pulse Magnets, Specifications

54

Lowest temperature
0.1 K

0.5 MJ, 20 kV
5 ms
18 mm
1s
30 mm

Independent
Experiment in 5 siteaccess to the megagauss science and technology, we havethe single-turn coil (STC) system capable of generating
the fields of up to 300 T by a fast-capacitor of 200 kJ. We
have two STC systems, one is a horizontal type (H-type,Fig. 4) and the other is a vertical type (V-type). Various kindsof laser spectroscopy experiments such as the cyclotron
resonance and the Faraday rotation are possible using theH-type STC.

Fig. 3. (Build. C) A view of the electro-magnetic flux compression
1000 T-class megagauss generator set in side of an anti-explosive house.
1000 T project started since 2010, and finally condenser banks of 9 MJ
(5 MJ + 2 MJ +2 MJ) as a main system with the 2 MJ sub bank system
for the seed field have been installed, and settled in the year of 2014.

ator station at our laboratory, and used as an energy sourceof super-long pulse magnets. The magnet technologies areintensively devoted to the quasi-steady long pulse magnet (anorder of 1-10 sec) energized by the giant DC power supply.
The giant DC power source will also be used for the giant
outer-magnet coil to realize a 100 T nondestructive magnet
by inserting a conventional pulse magnet coil in its center
bore.
Magnetic fields exceeding 100 T can only be obtainedwith destruction of a magnet coil, where ultra-high magnetic
fields are obtained in a microsecond time scale. The project,financed by the ministry of education, culture, sports,science and technology aiming to generate 1000 T withthe electromagnetic flux compression (EMFC) system(Fig. 3), has been proceeded. Our experimental techniques
using the destructive magnetic fields have intensively beendeveloped. The system which is unique to ISSP in theworld scale is comprised of a power source of 5 MJ maincondenser bank and 2 MJ condenser bank. Two magnet
stations are constructed and both are energized from eachpower source. Both systems are fed with another 2 MJ
condenser bank used for a seed-field coil, of which magnetic
flux is to be compressed. The 2 MJ EMFC system iscurrently under the process for optimizing several mechanical and electrical parameters such as dimensions of coils
and liners. And so far, generation of 450 T was successfully done using 1.6 MJ energy. The 5 MJ EMFC system
is under conditioning the main gap switches by finely
tuning control parameters. And so far, generation of 1200 T
was successfully done using 3.2 MJ energy. As an easy

Fig. 4. Schematic picture of the H-type single-turn coil equipped with
50 kV, 200 kJ fast operating pulse power system, capable of generating
300 T within 3 mm bore coil.

Center of Computational
Materials Science
The goal of the computational materials science is tounderstand and predict properties of complicated physicalsystems with a vast number of degrees of freedom and todesign new useful materials before actual experiments. Sincesuch problems cannot be solved with bare hands, it is quite
natural to use computers in computational materials science.
In fact, computer-aided science has been providing answers
to many problems ranging from the most fundamental ones
to the ones with direct industrial applications. In the recent
trends of the hardware developments, however, the growth ofcomputer power is mainly due to the growth in the number ofthe units. This fact poses a very challenging problem in frontof us --- how can we parallelize computing tasks? In orderto solve this problem in an organized way, we coordinate theuse of the computational resources available to our community, and support community members through various
activities such as administrating the website "MateriApps"
for information on application software in computational
science. These activities are supported by funds for various
governmental projects in which CCMS is involved. In
particular, we acted as the headquarters of Priority Area 7 of
MEXT FLAGSHIP2020 Project (so-called "post-K computer
project") in the last project year of 2019. In addition to this,CCMS was involved in Priority Area 5 and Pioneering Area
(CBSM2) of FLAGSHIP2020 project, Element Strategy
Initiative, and Professional Development Consortium for
Computational Materials Scientists (PCoMS).
The following is the selected list of meetings organized
by CCMS in FY2019:• 4/2-4/3 Joint Research Meeting of ISSP Supercomputer
Joint Use and CCMS Annual Activity Report 2019,
ISSP, Kashiwa• 5/17 PCoMS Matching Workshop for industries &
graduate students/postdocs The University of Tokyo,
ISSP, Kashiwa• 7/16-8/8 Computational Approaches to Quantum Manybody Problems 2019 (CAQMP 2019), ISSP, Kashiwa

Fig. 1. Members of CCMS.

ISSP Activity Report 201955

• 8/9 Post-K Project Priority Issue 7, The 5th Annual
Meeting, Ito-Hall, Hongo, Tokyo• 10/8-10/10 The 3rd Innovation Camp for Computational
Materials Science (3rd ICCMS) The Hohoemi-no-Yado,
Yamagata• 12/6 TIA-Kakehashi Poster Workshop 2019, The
University of Tokyo, Kashiwa Campus Station Satellite,
Kashiwa• 2/17-2/18 The 9th Materials Simulation Workshop,
Akihabara• 2/25 PCoMS Skill improvement training for graduate
students & postdocs ISSP, Kashiwa

Laser and Synchrotron Research Center(LASOR Center)
Laser and synchrotron research center (LASOR Center)
was established in October 2012 to push the frontiers of
the photon and materials science. LASOR has 10 groups
in 2019, which is the biggest division in ISSP. Most of theresearch activities on the development of new lasers with anextreme performance and the application to materials science
are studied in specially designed buildings D and E withlarge clean rooms and the isolated floor from the vibrationsin Kashiwa Campus. On the other hand, the experiments
utilizing the synchrotron radiation are performed at beamline
BL07LSU in SPring-8 (Hyogo).
The development of novel laser-based light sourcesin the vacuum-ultraviolet to soft-X-ray regions innovatedmaterials investigations as represented by the highest-energyresolution photoemission, ultrafast time-domain, and ultrafast non-linear spectroscopies. Materials science research
powered by lasers thus has entered a new era. The ultra-shortand high-power lasers are more and more attractive lightsource for both basic science and industry. The state-of-theart laser source and spectroscopy are intensively explored.
Another stream pursued at ISSP is the synchrotron-based
research. The drastic advance in brilliance of the synchrotron
radiation has also opened a new field of its own in photon
science. The soft-X-ray beam-line in SPring-8 (BL07LSU)
was implemented with the longest undulator in the world:
The end stations illuminated by the brilliant soft-X-rays
are used to output innovative achievements based on highresolution spectroscopy data. In 2018, Japanese government
has made a statement to construct a new synchrotron facilityin Tohoku. LASOR has decided to subjectively contribute tothis facility from the design to the operation.

Fig. 1. Optical frequency comb

56

ISSP Activity Report 2019

Fig. 2. Close look of a high-peak-power ultrashort-pulse laser

Lasers and synchrotrons have developed independently;
now both light sources cover a wide photon-energy range
with an overlap in the vacuum-ultraviolet to soft-X-ray
regions. Foreseeing their common interests in research fields
and technologies, ISSP integrated the two streams, namely
the extreme lasers and synchrotron radiations, into thecommon platform. Through the mutual interactions between
the forefronts of lasers and synchrotrons, LASOR will be
the center of innovations in light and materials science, withthe aid of world-wide joint research and close collaborations
with other divisions in ISSP such as New Materials Science,
Nanoscale Science, and Condensed Matter Theory.
The mission of LASOR is to cultivate and propel thefollowing three scientific fields:
1. Laser Science,
2. Synchrotron radiation Science,
3. Extreme Spectroscopy,• Laser science group
We were committed to continuing to developed various
state-of-the-art laser systems such as high-power solid-stateor gas lasers, high-intensity lasers, ultra-short pulse lasers
down to attosecond time scale (Peta Hz linewidth), ultrastable lasers with 1-Hz linewidth, optical frequency combs,
mid-infrared lasers, THz light source, and semiconductor
lasers.
High-power and ultrashort pulse laser technology has
progressed for this 10 years. It opened two directions ofFig. 3. Design of E building for extreme VUV- and SX-lasers and newspectroscopy.

Fig. 6. Pump-probed photoemission system using 60-eV laser
Fig. 4. Phase-dependence of high harmonic spectra in soft X rays.

research. One is a coherent extreme ultraviolet light source
realized by a high-harmonic generation (HHG) scheme. The
average power of HHG became high enough to use it for a
photoemission spectroscopy. The photon energies of 7 eV
to 60 eV are now available. They can be either very narrow
band width or ultrashort pulse. The other is an industrial
science such as a laser processing. Pulse duration variable,
100-W average power, femtosecond laser is now available in
LASOR for any collaborative research including companies.
We also aim to develop novel laser spectroscopy andcoherent non-linear optical physics, enabled via emerging
lasers and optical science/technology, and extensively study
basic light-matter physics, optical materials science, andapplied photonics. Such researches include ultrafast spectroscopy for excited state dynamics, terahertz magnetic-field
spectroscopy for spin dynamics, quantitative micro-spectroscopy on semiconductor lasers and nano-structure photonics
devices, such as quantum wire lasers, gain-switch semiconductor laser, multi-junction solar cells, and bio-luminescentsystems.
• Synchrotron radiation science group
By inheriting and developing the synchrotron techniques
cultivated for more than 20 years, we continuously develop
world cutting-edge spectroscopies such as time-resolved
photoemission /diffraction, ultrahigh resolution soft X-ray
emission, 3D (depth + 2D microscopy) nano ESCA and
X-ray magneto-optical effect and provide these techniques
both for basic material science and for applied science,
which contributes to the device applications in collaboration

Fig. 5. 10-MHz high harmonic generation in an enhancement cavity.

with outside researchers. In order to pioneer new spectroscopies for the next-generation light sources, we upgrade
fast polarization switching of the undulator light source incooperation with SPring-8. In addition, we promote frontier
works on the use of X-ray free electron lasers, SACLA withhigh spatial and temporal coherence comparable to opticallasers in collaboration with scientists of laser light sources
and spectroscopies.
• Extreme spectroscopy group
The advent of laser-based light sources in the softX-ray region is opening a new stage in the field that has
been cultivated by the synchrotron radiations. One of themilestones is to develop a laser-based light source of ~7 eV
for the sub-meV-resolution photoemission spectroscopy. In
this five years, available photon energy became 11 eV withhelp of Yb-fiber laser technology. It has high photon flux
(1014 photons/sec) with sub picosecond time resolution.
Laser-based spin-resolved ARPES is realizing in LASOR.
This technology would open brand-new spectroscopy. Highharmonic generation based photoemission spectroscopy
in the 20-60 eV region is another direction to be pursued.
Time-domain spectroscopy in the femtosecond region wasachieved. Combined with the picosecond time-domain
spectroscopy utilizing the pulsed light delivered fromsynchrotrons, we investigate the electronic structures anddynamics of matter in bulk, on surface, and into the nanoscale. The ultimate objective is to expand the soft-X-ray
operando methodologies by lasers. Diffractions, magnetooptical effects, and inelastic scatterings now done at synchro-Fig. 7. Photonics devices under study: (left panel) semiconductor
quantum wires and (right panel) firefly-bioluminescence system
consisting of light emitter (oxyluciferin) and enzyme (luciferase)

ISSP Activity Report 201957

trons will be performed by lasers, to access the real-time
dynamics of chemical reactions and phase transitions down
to the femtoseconds.
State-of-the-art laser based organism spectroscopy is
new direction in LASOR. ISSP research area is shifting from
simple material and science to complex one including living
body and functional material with excited state physics.

Synchrotron Radiation Laboratory
The Synchrotron Radiation Laboratory (SRL) was established in 1975 as a research division dedicated to solid statephysics using synchrotron radiation (SR). Currently, SRL is
composed of two research sites, the Harima branch and theE-building of the Institute for Solid State Physics.
• Brilliant soft X-ray beamline at Harima branch
In 2006, the SRL staffs have joined the Materials
Research Division of the Synchrotron Radiation Research
Organization (SRRO) of the University of Tokyo and they
have played an essential role in constructing a new highbrilliant soft X-ray beamline, BL07LSU, in SPring-8. The
light source is the polarization-controlled 25-m long soft
X-ray undulator with electromagnetic phase shifters thatallow fast switching of the circularly (left, right) and linearly(vertical, horizontal) polarized photons.
The monochromator is equipped with a varied linespacing plain grating, which covers the photon energy range
from 250 eV to 2 keV. At the downstream of the beamline,
a lot of experimental stations have been developed forfrontier spectroscopy researches: five endstations, i.e. timeresolved soft X-ray spectroscopy (TR-SX) equipped witha two-dimensional angle-resolved time-of-flight (ARTOF)
analyzer (Fig. 1), three-dimensional (3D) nano-ESCA
station equipped with the Scienta R-3000 analyzer (Fig. 2),high resolution soft X-ray emission spectroscopy (XES)
stations (Fig. 3) are regularly maintained by the SRL staffs
and open for public use, and at free-port station many novel
spectroscopic tools have been developed and installed
such as ambient pressure photoemission (Fig. 4) and soft
X-ray diffraction (Fig. 5) which are also open for public
use from 2018, and soft X-ray resonant magneto-optical
Kerr effect (MOKE) and so on. The beamline construction

Fig. 1. TR-SX station

58

Fig. 2. 3D-nano ESCA station

ISSP Activity Report 2019

Fig. 3. Soft X-ray emission station

was completed in 2009 and SRL established the Harimabranch laboratory in SPring-8. At SPring-8 BL07LSU, each
end-station has achieved high performance: the TR-SX
station have established the laser-pump and SR-probe
method with the time-resolution of 50 ps which corresponds
to the SR pulse-width; the 3D nano-ESCA station reaches
the spatial resolution of 70 nm; the XES station provides
spectra with the energy resolution around 70 meV at 400 eVand enabled real ambient pressure experiments. Soft X-ray
resonant MOKE station has been developed to make novel
magneto-optical experiment using fast-switching of thepolarization-controlled 25-m long soft X-ray undulator. The
soft X-ray diffraction station has been fully constructed andthe time-resolved measurement is available by using lasers
at the TR-SX station. In 2019, 240 researchers made theirexperiments during the SPring-8 operation time of 4584
hours.
• High-resolution Laser SARPES at E-building
Spin- and angle-resolved photoelectron spectroscopy(SARPES) is a powerful technique to investigate the spindependent electronic states in solids. In FY 2014, LASOR
and SRL staffs constructed a new SARPES apparatus(Fig. 6), which was designed to provide high-energy and-angular resolutions and high efficiency of spin detection
using a laser light at E-building. The achieved energy resolution of 1.7 meV in SARPES spectra is the highest in theworld at present. From FY 2015, the new SARPES system
has been opened to outside users.

Fig. 4. Ambient pressure photoemis- Fig. 5. Soft X-ray diffraction
sion
stationFig. 6. Laser-SARPES system at E-building

The Laser-SARPES system consists of an analysis
chamber, a carousel chamber connected to a load-lockchamber, and a molecular beam epitaxy chamber, which
are kept ultra-high vacuum (UHV) environment and areconnected each other via UHV gate valves. The electrons are
excited with 6.994-eV photons, yielded by 6th harmonic of a
Nd:YVO4 quasi-continuous wave laser with repetition rate of
120 MHz and 10.7 eV photons, driven by the third harmonic
radiation at 347 nm of an Yb:fiber chirped pulse amplifierlaser, which was developed by Kobayashi's lab in LASOR.
The hemispherical electron analyzer is a custom-made ScientaOmicron DA30-L, modified for installing the spin detectors. The spectrometer is equipped with two high-efficient
spin detectors associating very low energy electron diffraction are orthogonally placed each other, which allows us toanalyze the three-dimensional spin polarization of electrons.
At the exit of the hemispherical analyzer, a multi-channel
plate and a CCD camera are also installed, which enables us
to perform the angle-resolved photoelectron spectroscopy
with two-dimensional (energy-momentum) detection. The
laser-SARPES machine can provide both high-resolution
spin-integrated and spin-resolved photoemission spectra invarious types of solids, such as spin-orbit coupled materials
and ferromagnetic materials.

ISSP Activity Report 201959