Ⅱ

Current Status ofLight Sources andBeamlinesⅡ . Current Status of Light Sources and Beamlines

Light Source in 2020
1. Status of UVSOR Accelerators

is 60 hours. In the single bunch operation weeks, themachine is operated for 12 hours per day from Tuesday
to Friday.

In the fiscal year 2020, we had scheduled to operate
UVSOR-III from May to March, for 36 weeks forusers. Because of the COVID-19 pandemic, some of
the users experiments were canceled. However, weoperated the accelerators as scheduled. We had a few
minor machine troubles, such as a discharge of theelectron gun, malfunction of the cooling water system
for the RF cavity, unstable operation of the klystronpulse modulator of the injection linac and unstable
operation of the timing system. Fortunately, all of them
could be solved quickly and we extended the operation
time and compensated the scheduled users beam time.
We had a scheduled shutdown period in April for 4
weeks. This was for the scheduled maintenance works
as usual. In addition, this year, we replaced the coils of
one third of the multipole magnets as described later.
We had one week shut down period in August andOctober, two week one around the New Year’s Day and
one week one at the end of March. We had 2 weeks formachine and beamline conditioning in May after thespring shut down. We had 4 weeks for machineconditionings and studies. One of them in November
was mainly for the machine conditioning after theannual planned power outage.
We operated the machine for 34 weeks in the multibunch top-up mode at 300 mA, and 2 weeks in the
single-bunch top-up mode at approximately 40 mA.
The monthly statistics of the operation time and theintegrated beam current are shown in Fig. 1.

Fig. 2. Replacing sextupole coil for multipole magnets.
2. Improvements and Developments
The cooling water leakage from the sextupole coils
wound on the pole faces of the multipole (quadrupole/
sextupole) magnets had been getting more frequent. We
confirmed that the hollow conductor walls have beeneroded by the water flow during the fifteen-year
operation. We decided replacing all the coils and, inMarch, 2020, we replaced the one-third of the coils. The
remainder will be replaced in April, 2021.
We started a design study for the future plan of
UVSOR, UVSOR-IV. As its first step, we have analyzed
the present magnetic lattice, seeking a possibility to
reduce the emittance more [1]. Although, we did not
find a drastically low emittance solution, we have founda few interesting solutions which may be useful forsome machine studies which requires lower emittanceas possible.
We continue the efforts to develop novel lightsources technologies and their applications such as
free electron lasers, coherent harmonic generation,
coherent synchrotron radiation, laser Compton
scattering gamma-rays, intense polarized and vortex
UV radiation at the source development station BL1U,
which was constructed under the support of Quantum
Beam Technology Program by MEXT/JST.
In these years, we are focusing on studying the
temporal structure of undulator radiation and exploring
its application. In collaboration with atomic physicists,
we have successfully demonstrated ultrafast spectroscopy
with undulator radiation [2] and polarization utilizationof tandem undulator radiation [3].

Fig. 1. Monthly statistics in FY2020.
The weekly operation schedule is as follows. On
Monday, from 9 am to 9 pm, the machine is operated
for machine conditionings and studies. On Tuesday
and Wednesday, from 9 am to 9 pm, the machine isoperated for users. From Thursday 9 am to Friday 9
pm, the machine is operated for 36 hours continuously
for users. Therefore, the beam time for users in a week

99Ⅱ

Ⅱ . Current Status of Light Sources and Beamlines

Ⅱ

Laser Compton gamma-ray source is anotherresearch subject which we are focusing in these years.
The applications are spreading to a range of research
fields, quantum electrodynamics, imaging technologies,
material sciences and so on [4,5]. The research activity
at the gamma-ray source is now shifting from source
development studies to users experiments.
We have been collaborating with Nagoya University
on the electron source development. In these years, weinvestigated utilizing graphene as a material forphotocathode [6].

[1] E. Salehi and M. Katoh, presented at iPAC2021(2021).
[2] T. Kaneyasu et al., Physical Review Letters 126(11)(2021) 1132202.
[3] T. Kaneyasu et al., New J. Phys. 22(8) (2020) 083062.
[4] K. Ali et al., IEEE Trans. Nucl. Sci. 67(8) (2020) 1976.
[5] K Fujimori et al., Appl. Phys. Express 13(8) (2020)
085505.
[6] L Guo et al., Appl. Phys. Lett. 116(25) (2020)
251903Masahiro KATOH (UVSOR Synchrotron)

1010Ⅱ . Current Status of Light Sources and Beamlines

UVSOR Accelerator Complex
Injection Linear Accelerator

Booster Synchrotron

EnergyLengthFrequency
Accelerating RF Field
Klystron Power
Energy Spread
Repetition Rate

EnergyInjection Energy
Normal Operation Current
Circumference
RF Frequency
Harmonic Number
Bending Radius
Lattice
Betatron Tune
Horizontal
VerticalMomentum Compaction
Repetition Rate

15 MeV
2.5 m
2856 MHz
2π/3 Traveling Wave
1.8 MW~1.6 MeV
2.6 HzUVSOR-III Storage-Ring
Energy750 MeV
Injection Energy
750 MeV
Maximum Storage Current 500 mA (multi bunch)
100 mA (single bunch)Normal operation current 300 mA (multi bunch)(Top-up mode)
50 mA (single bunch)
Natural Emittance
17.5 nm-rad
Circumference
53.2 mRF Frequency
90.1 MHz
Harmonic Number
16
Bending Radius
2.2 m
Lattice
Extended DB×4
Straight Section(4 m×4)+(1.5 m×4)
RF Voltage
120 kV
Betatron Tune
3.75
Horizontal
3.20
VerticalMomentum Compaction 0.030
Natural Chromaticity-8.1
Horizontal-7.3
Vertical
Energy Spread
5.26×10-4
Coupling Ratio
1%
Natural Bunch Length
128 ps

750 MeV
15 MeV
12 mA (uniform filling)
26.6 m90.1 MHz
8
1.8m
FODO×615 MeV
Linear
Accelerator
750 MeV
Booster
Synchrotron

2.25
1.25
0.138
1 Hz (750 MeV)

BL5B

BL5U

BL6U
BL6B

BL1U
BL7U

BL4B

3rd
Harmonic cavity
Main Cavity

BL7B

BL4U

750 MeVElectron
Storage Ring

BL3B

BL3U
BL1U

BL2B

BL1B
BL2A

Electron Beam Optics of UVSOR-III Storage Ring

Horizontal/verticalelectron beam sizeand beam divergences

σx,y [mm]σ'x,y [mrad]ηx√βx,y [√m]

Horizontal/verticalbetatron functions
and dispersion function

Position [m]Position [m]11ⅡⅡ . Current Status of Light Sources and Beamlines

Insertion Device

Ⅱ

Brilliance of radiationfrom the insertion devices(U3, U4, U5, U6 and U7)
and a bending magnet
of UVSOR-III

U5 Apple-II
Variable Polarization Undulator
Number of Periods
38
Period length
60 mm
Pole Length2.28 mPole Gap
24-190 mm
Deflection Parameter
3.4 (Max. Horizontal)
2.1 (Max. Vertical)
1.8 (Max. Helical)

U1 Apple-II Undulator /Optical Klystron
Number of Periods
Period length
Pole Length
Pole Gap
Deflection Parameter

10+10
88 mm
0.968 m + 0.968 m
24-200 mm
7.36 (Max.
Horizontal)
4.93 (Max. Vertical)
4.06 (Max. Herical)

U6 In-vacuum Undulator
Number of Periods
Period length
Pole Length
Pole Gap
Deflection ParameterU3 In-vacuum Undulator
Number of Periods
Period length
Pole Length
Pole Gap
Deflection Parameter

50
38 mm
1.9 m
16.5-40 mm
1.8-0.24

U7 Apple-II
Variable Polarization Undulator
Number of Periods
40
Period length
76 mmPole Length
3.04 mPole Gap
24-200 mm
Deflection Parameter
5.4 (Max. Horizontal)
3.6 (Max. Vertical)
3.0 (Max. Helical)

U4 In-vacuum Undulator
Number of Periods
Period length
Pole Length
Pole Gap
Deflection Parameter

26
36 mm
0.94 m13-40 mm
1.78 - 0.19

26
38 mm
0.99 m13-40 mm2.4-0.19

Bending Magnets
Bending Radius
Critical Energy

12

2.2 m
425 eVⅡ . Current Status of Light Sources and Beamlines

Beamlines in 2020
Yoshitaka TAIRAUVSOR synchrotron Facility, Institute for Molecular ScienceⅡ
UVSOR is one of the highest-brilliance light sourcesin the extreme-ultraviolet region among thesynchrotron radiation facilities with electron energiesof less than 1 GeV. The natural emittance of the
UVSOR-III storage ring is as low as 17.5 nm-rad after
the successful completion of the storage ring upgrade
project (the UVSOR-III project) in 2012.
Eight bending magnets and six insertion devices areavailable as synchrotron light sources at UVSOR. As of
2018 there are a total of fourteen operational beamlines,
which are classified into two categories. Twelve of them
are the so-called “Open beamlines”, which are open toscientists from universities and research institutes
belonging to the government, public organizations,private enterprises and also those from foreign countries.
The remaining two beamlines are the “In-housebeamlines”, and are dedicated to the use of researchgroups within Institute for Molecular Science (IMS).
There is one soft X-ray station equipped with adouble-crystal monochromator, seven extreme
ultraviolet and soft X-ray stations with grazing
incidence monochromators, three vacuum ultraviolet(VUV) stations with normal incidence monochromators,
two infrared (IR) stations equipped with FourierTransform interferometers, and one direct radiation
station located after two tandem undulators, as shown in
the appended table (next page) for all available
beamlines at UVSOR in 2020. The details of the updates
for several beamlines are the followings.
A new associate professor, Yoshitaka Taira, wasappointed in April 2020. He is in charge of BL1U. In
BL1U, the development of a new light source and theutilization of gamma-rays is being carried out. Gammaray induced positron annihilation spectroscopy, which
can analyze nanometer scale defects in bulk materials,
is provided to users. Array detectors using eight BaF2
scintillators were developed to increase the count rate ofannihilation gamma-rays. The measurement can becompleted in a few hours for metals.
BL4U, which is equipped with a scanning transmission
soft X-ray microscope (STXM), is actively used not
only by academic users but also by many industrial
users. In FY2020, it became possible to image thelithium K-edge with a spatial resolution of 72 nm. Final
adjustments for the airtight sample transport system andthe sample transport container are being carried out in
preparation for the organic substance analysis of the
Hayabusa2 returned samples scheduled for the summerof FY2021.
At BL6U, one of the in-house beamlines, photoelectron
momentum microscope (PMM), which is a new highefficiency electronic structure measurement system withhigh resolution in real space and momentum space, hasbeen installed and is in operation. Experiments such as
valence band photoelectron spectroscopy on the
micrometer scale and resonance photoelectron diffraction
by soft X-ray excitation can be performed. In FY2020,
resonant photoelectron spectroscopy of graphenes, hightemperature superconductors, dichalcogenides, andorganic molecular adsorbates were conducted incollaboration with several groups.
Next generation spectro-microscopy and microspectroscopy workshop, involving BL4U and 6U, washeld on October 28-29, 2020
(https://sites.google.com/ims.ac.jp/
uvsor-ws2020/ home?authuser=0).
In BL5U, high energy resolution angle-resolved
photoemission spectroscopy (ARPES) is available.
Users can now use so-called “deflector mapping” for all
kinetic energies and lens modes by using the latest
version of ARPES analyzer. A system that can deposit
alkali metals such as potassium while the sample is still
mounted on the manipulator at low temperatures has
been installed. As part of the development of spinresolved ARPES, a two-dimensional image of the spinresolved spectrum of the Rashba splitting of gold (111)
surface has been successfully obtained.
Those wishing to use the open and in-house beamlines
are recommended to contact the appropriate beamline
master (see next page). Applications can be submitted at
NOUS (https:// nous.nins.jp/user/signin). All users are
required to refer to the beamline manuals and the UVSOR
guidebook, on the occasion of conducting the actual
experimental procedures. For updated information on
UVSOR, please see http://www. uvsor.ims.ac.jp.

1313

Ⅱ . Current Status of Light Sources and Beamlines

Beamlines at UVSOR
Ⅱ

Beamline
BL1U

Monochromator /SpectrometerFree electron laser,
Tandem undulator,
LSC Gamma-rays

BL1B

Martin-Puplett FT-FIR

BL2A

Double crystal

BL2B

18-m spherical grating(Dragon)

BL3U

Varied-line-spacing
plane grating(Monk-Gillieson)

BL3B

2.5-m off-plane Eagle
Varied-line-spacing
plane grating(Monk-Gillieson)
Varied-line-spacing
plane grating(Monk-Gillieson)

BL4U
BL4B
BL5U

Spherical grating(SGM-TRAIN†)

BL5B

Plane grating

BL6U*

Variable-included-angle
varied-line-spacing
plane grating

BL6B

Michelson FT-IR

BL7U

10-m normal incidence(modified Wadsworth)BL7B

3-m normal incidence

Energy Range

Targets

585 – 4 keV
24 – 205 eV
60 – 800 eV
1.7 – 30 eV
50 – 770 eV
25 eV – 1 keV
5 – 250 eV
6 – 600 eV
30 – 500 eV
3 meV – 2.5 eV
6 – 40 eV
1.2 – 25 eV

Yellow columns represent undulator beamlines.
In-house beamline.

*

14
14

Contact(Irradiation)

Y. Taira

Solid

Reflection
Absorption

K. Tanaka

Solid

Reflection
Absorption

K. Tanaka

Solid

Photoemission

S. KeraGas
LiquidSolid

Absorption
Photoemission
Photon-emission
Reflection
Absorption
Photon-emission

1.6 – 13.9 eV, 1-10MeV
0.5 – 30 meVTechniquesSolidyostaira@ims.ac.jp

k-tanaka@ims.ac.jp

k-tanaka@ims.ac.jp

kera@ims.ac.jp

M. Nagasaka

nagasaka@ims.ac.jp

K. Tanaka

k-tanaka@ims.ac.jp

Gas
LiquidSolid

Absorption(Microscopy)

T. Ohigashi

Gas
Solid

Photoionization
Photodissociation
Photoemission

H. Iwayama

Solid

Photoemission

K. Tanaka

Solid

Calibration
Absorption

K. Tanaka

Gas
Solid
Solid

Photoionization
Photodissociation
Photoemission
Reflection
Absorption
IR microscopeohigashi@ims.ac.jp

iwayama@ims.ac.jp

k-tanaka@ims.ac.jp

k-tanaka@ims.ac.jp

F. Matsui

matui@ims.ac.jp

K. Tanaka

k-tanaka@ims.ac.jp

Solid

Photoemission

S. Ideta

Solid

Reflection
Absorption
Photon-emission

K. Tanaka

idetas@ims.ac.jp

k-tanaka@ims.ac.jp

Ⅱ . Current Status of Light Sources and Beamlines

Countermeasures against COVID-19
Yoshitaka TAIRAUVSOR synchrotron Facility, Institute for Molecular Science
In Japan, the first wave of covid-19 began at the endof March 2020, followed by the second wave in August
and the third wave in January 2021. As a result, a stateof emergency was declared twice, from April 7 to May
25, 2020, and from January 8 to March 21, 2021.
To avoid stagnation of research activities, UVSOR
accepted users at all times after taking countermeasures
to prevent the spread of infection. Users were asked totake and record their temperature two weeks before thestart of the experiment. A non-contact thermometer wasplaced at the entrance of the user waiting room, as
shown in the photo below, and users were asked to takeand record their temperature and wear a mask every day.
Chairs in the user waiting room were placed at intervals
to ensure social distance (see photo below). By March
2021, no one has been infected from UVSOR.
In FY2020, all the first half-year proposals were
copied and pasted into the second half-year proposals.
The beam time allocated in the first half-year was stillvalid, and if uses were able to come to UVSOR
according to the regulations of their institutions, users
could carry out their experiments. New applications forbeam time in the second half-year were suspended, andthe remaining beam time was allocated to special calls
for proposals as needed. UVSOR was able to accept
users, but some proposals were canceled because theusers could not travel due to the regulations of their
institutions. The implementation rate of the proposals
was 63 % in the first half-year and 86 % in the second
half-year. There were five proposals that could not be
implemented. Substitute measurements were conducted
in 20 cases. The total number of visitors decreased by
23 % from the previous year to 2,806, due to a significant
decrease in the number of domestic students andinternational visitors. We have started to examine
technologies for automation, remoteness, AI analysis
processing, and standardization.

15
15

Ⅱ

BL1U

Light Source Development Station
Ⅱ▼Description
BL1U is dedicated for developments and applications of novel light sources. This beamline is equipped with adedicated tandem undulator for variable polarization with a buncher section, which can be used for free electron
laser in the range from visible to deep UV, VUV coherent harmonic generation (CHG), and generation of
spatiotemporal structured light such as an optical vortex beam, a vector beam and double-pulse wave packets. It
is also equipped with a femto-second laser system synchronized with the accelerator, which is used for thegeneration of CHG, laser Compton scattered gamma-rays, and coherent THz radiation. Nowadays, material
analysis by positron annihilation spectroscopy using laser Compton scattered gamma rays is actively used.

Fig. 1. Configuration of the free electron laser

VerticalCircular

Horizontal

Fig. 2. Brilliance of BL1U Apple-II Undulator

Fig. 3. Accelerator synchronized Laser System▼Technical Data of FEL▼Technical Data of Ti:Sa Laser

Wave Length

199-800 nm

Wave Length

800 nmSpectral Band Width~10

Pulse Length

130 fsec

Polarization

Circular/Linear

Oscillator

90.1 MHz

Pulse Rate

11.26 MHz

Pulse Energy

2.5 mJ

10 mJ

50 mJ

Max. Ave. Power~1 W

Repetition Rate

1 kHz

1 kHz

10 Hz

-4

16
16

BL1B

Terahertz Spectroscopy Using Coherent Synchrotron Radiation
Ⅱ▼Description
Coherent synchrotron radiation (CSR) is a powerful light source in the terahertz (THz) region. This beamline
has been constructed for basic studies on the properties of THz-CSR. However, it can be also used formeasurements of reflectivity and transmission spectra of solids using conventional synchrotron radiation.
The emitted THz light is collected by a three-dimensional magic mirror (3D-MM, M0) of the same type as thosealready successfully installed at BL43IR in SPring-8 and BL6B in UVSOR-II. The 3D-MM was installed inbending-magnet chamber #1 and is controlled by a 5-axis pulse motor stage (x, z translation; x, y, z rotation).
The acceptance angle was set at 17.5-34 degrees (total 288 mrad) in the horizontal direction. The vertical angle
was set at 40 mrad to collect the widely expanded THz-CSR.
The beamline is equipped with a Martin-Puplett type interferometer (JASCO FARIS-1) to cover the THz spectral
region from 4 to 240 cm-1 (h = 500 eV-30 meV). There is a reflection/absorption spectroscopy (RAS) endstation for large samples ( several mm). At the RAS end-station, a liquid-helium-flow type cryostat with aminimum temperature of 4 K is installed.

Fig. 1. Schematic top view of the beam extraction part of
the THz-CSR beamline, BL1B. The three-dimensional
magic mirror (3D-MM, M0) and a plane mirror (M1) arelocated in the bending-magnet chamber. A parabolic
mirror (M2) is installed to form a parallel beam. The
straight section (BL1U) is used for coherent harmonic
generation (CHG) in the VUV region.

Fig. 2. Obtained intensity spectra with the
combination of a light source (UVSOR),
interferometer (FARIS-1), and detectors (Sibolometer and InSb hot-electron bolometer).

▼Technical Data
Interferometer

Martin-Puplett (JASCO FARIS-1)

Wavenumber range(Energy range)

4-240 cm-1
(500 eV-30 meV)

Resolution in cm-1

0.25 cm-1

Experiments

Reflection/transmission spectroscopy

Miscellaneous

Users can use their experimental system in this beamline.

17

17

BL2A

Soft X-Ray Beamline for Photoabsorption Spectroscopy

Ⅱ▼Description
BL2A is a soft X-ray beamline for photoabsorption spectroscopy. The beamline is equipped with a pre-focusing
mirror and a double-crystal monochromator [1]. The monochromator serves soft X-rays in the energy region from
585 to 4000 eV using several types of single crystals, such as beryl, KTP (KTiOPO4), and InSb. The throughput
spectra measured using a Si photodiode (AXUV-100, IRD Inc.) are shown in Fig. 1. The typical energy resolution(E / ΔE) of the monochromator is approximately 1500 for beryl and InSb.
There is a small vacuum chamber equipped with an electron multiplier (EM) detector. Photoabsorption spectra
for powdery samples are usually measured in total electron yield mode, with the use of the EM detector. In addition,a hemispherical electron analyzer for photoelectron spectroscopy is equipped.
Recently, a new omnidirectional photoelectron acceptance lens (OPAL) has been developed aiming to realize
2π-steradian photoelectron spectroscopy and photoelectron holography [2]. By combining OPAL and the existing
hemispherical electron analyzer, a photoelectron spectrometer with high energy resolution can be realized, and afull range (90) 1D angular distribution can be measured at once. This upgrade is currently in the commissioning
phase.
[1] Hiraya et al., Rev. Sci. Instrum. 63 (1992) 1264.
[2] H. Matsuda and F. Matsui, Jpn. J. Appl. Phys. 59 (2020) 046503.

Fig. 1. Throughput spectra of the double-crystal monochromator at BL2A.

▼Technical Data

Monochromator
Monochromator crystals:(2d value, energy range)
Resolution
Experiments

Double crystal monochromatorberyl (15.965 Å, 826–2271 eV), KTP (10.95 Å, 1205–3310 eV),InSb (7.481 Å, 1764–4000 eV), Ge (6.532 Å, 2094–4000 eV)
E/ΔE = 1500 for beryl and InSb
Photoabsorption spectroscopy (total electron yield using EM and partial
fluorescence yield using SDD)

18

18

BL2B

Photoelectron spectroscopy of molecular solids
Ⅱ▼Description
This beamline previously dedicated for experiments in the field of gas phase photoionization and reaction
dynamics. Then, the beamline has been reconstructed for photoelectron spectroscopy of molecular solids with a
new end station, and experiments can be performed from May 2014. The monochromator is a spherical grating
Dragon type with 18-m focal length. High throughput (1  1010 photons s-1) and high resolution (E/E = 2000 8000) are achieved simultaneously under the condition of the ring current of 100 mA [1]. The optical system
consists of two pre-focusing mirrors, an entrance slit, three spherical gratings (G1 - G3), two folding mirrors, amovable exit slit, and a refocusing mirror [2]. The monochromator is designed to cover the energy range of 23–
205 eV with the three gratings: G1 (2400 lines mm-1, R = 18 m) at 80–205 eV; G2 (1200 lines mm-1, R = 18 m) at
40–100 eV; G3 (2400 lines mm-1, R = 9.25 m) at 23–50 eV. The percentage of the second-order light contamination
at h = 45.6 eV is 23 % for G2 or 7 % for G3.
A UHV chamber is placed downstream of the refocusing mirror chamber and equipped silicon photodiode,sapphire plate Au mesh and filters for absolute photon flux measurement, monitor the photon-beam position,
relative photon flux measurements and attenuate higher order light, respectively.
The new end station consists of a main chamber with a hemispherical analyzer (SCIENTA R3000) and a liquidHe-cooled cryostat (temperature range of 15-400 K) with 5-axis stage, a sample preparation chamber with a fastentry load-lock chamber and a cleaning chamber with LEED, ion gun for sputtering and IR heating unit.
[1] M. Ono, H. Yoshida, H. Hattori and K. Mitsuke, Nucl. Instrum. Meth. Phys. Res. A 467-468 (2001) 577.
[2] H. Yoshida and K. Mitsuke, J. Synchrotron Radiation 5 (1998) 774.

Fig. 2. End station of BL2B for photoelectron
spectroscopy of molecular solids.

Fig. 1. Throughput from Dragon monochromator.

▼Technical Data
Monochromator

18 m spherical grating Dragon-type

Wavelength Range

23-205 eVResolution

2000–8000 depending on the gratings

Experiments

Angle-resolved ultraviolet photoelectron spectroscopy

19
19

BL3U
Ⅱ

Varied-Line-Spacing Plane Grating Monochromatorfor Molecular Soft X-Ray Spectroscopy▼Description
The beamline BL3U is equipped with an in-vacuum undulator composed of 50 periods of 3.8 cm period length.
The emitted photons are monochromatized by the varied-line-spacing plane grating monochromator (VLS-PGM)
designed for various spectroscopic investigations in the soft X-ray range. Three holographically ruled laminar
profile plane gratings are designed to cover the photon energy range from 40 to 800 eV. The beamline has liquidcells for soft X-ray absorption spectroscopy (XAS) in transmission mode as shown in Fig. 1. The liquid cell is in
the atmospheric helium condition, which is separated by a 100 nm thick Si3N4 membrane with the window size of
0.2 × 0.2 mm2 from the beamline in an ultrahigh vacuum condition. The thin liquid layer is assembled by using
two 100 nm thick Si3N4 membranes. The thickness of the liquid layer is controllable from 20 to 2000 nm byadjusting the helium pressures around the liquid cell in order to transmit soft X-rays. Liquid samples areexchangeable in situ by using a tubing pump. The liquid cell has two types of windows: one is the liquid part toobtain the soft X-ray transmission of liquid (I), and the other is the blank part to obtain the transmission withoutliquid (I0). We can obtain the reliable XAS spectra based on the Lambert-Beer law ln(I0/I). Since the liquid cell isin the atmospheric condition, we can measure XAS of liquid samples in the real environment. Operando XAS
observation of several chemical reactions such as catalytic, electrochemical reactions are also possible by using
our liquid cells developed for these purposes.

Fig. 1. (a) Schematics of a liquid cell for XAS in transmission mode settled in BL3U. The blowup shows a thinliquid layer assembled by two Si3N4 membranes with the thickness of 100 nm. (b) Flux at the sample position
with the resolving power of λ/Δλ=104.

▼Technical Data
Monochromator
Energy Range
Resolution
Experiments

Varied-line-spacing plane grating monochromator
40-800 eV
E / ΔE > 10 000
Soft X-ray absorption spectroscopy of liquid in transmission mode

20
20

BL3B (HOTRLU)

VIS-VUV Photoluminescence and Reflection/Absorption
Spectroscopy▼Description
BL3B has been constructed to study photoluminescence (PL) in the visible (VIS) to vacuum ultraviolet (VUV)
region. This beamline consists of a 2.5 m off-plane Eagle type normal-incidence monochromator, which covers
the VUV, UV, and VIS regions, i.e., the energy (wavelength) region of 1.7-31 eV (40-730 nm), with three sphericalgratings having constant grooving densities of 1200, 600, and 300 l/mm optimized at the photon energies of ~20,
~16, and ~6 eV, respectively. The schematic side view and top view layouts are shown in Figs. 1(a) and 1(b),respectively. The FWHM of the beam spot at the sample position is 0.25 mm (V) × 0.75 mm (H). Low energy passfilters (LiF, quartz, WG32, OG53) can be inserted automatically to maintain the optical purity in the G3 (300 l/mm)
grating region (1.7~11.8 eV). Figure 2 shows the throughput spectra (photon numbers at a beam current of 300mA) for each grating with entrance and exit slit openings of 0.1 mm (resolving power E / E of ~2000 (G3, ~6.8eV)). Since both slits can be opened up to 0.5 mm, a monochromatized photon flux of 1010 photons/s or higher isavailable for PL measurements in the whole energy region.
The end station is equipped with a liquid-helium-flow type cryostat for sample cooling and two detectors; oneof which is a photomultiplier with sodium salicylate and the other a Si photodiode for reflection/absorption
measurement. For the PL measurements in the wide energy region from VIS to VUV, two PL monochromators,
comprising not only a conventional VIS monochromator but also a VUV monochromator with a CCD detector,
are installed at the end station.

Fig. 1. Schematic layout of the BL3B (a) side view and(b) top view.

Fig. 2. Throughput spectra for each grating(G1:1200 l/mm, G2:600 l/mm and G3:300l/mm) with S1 = S2 = 0.1 mm.

▼Technical Data
Monochromator-2.5 m normal-incidence monochromator

Energy range

1.7-31 eV (40~730 nm)

Resolution (h/ h) 12000 (at ~ 6.9 eV, 0.02 mm slits, G1 (1200 l/mm)

Experiments

Photoluminescence, reflection, and absorption spectroscopy, mainly for solids

21
21

Ⅱ

BL4U

Scanning Transmission X-ray Microscopy in the Soft X-ray Region
Ⅱ▼Description
In the soft x-ray region, there are several absorption edges of light elements and transition metals. The near edge
X-ray absorption fine structure (NEXAFS) brings detailed information about the chemical state of target elements.
A scanning transmission X-ray microscope (STXM) in the soft X-ray region is a kind of extended technique of the
NEXAFS with high spatial resolution. The STXM has a capability of several additional options, for example, insitu observations, 3-dimensional observation by computed tomography and ptychography, by utilizing thecharacteristics of the X-rays. The STXM can be applied to several sciences, such as polymer science, materialscience, cell biology, environmental science, and so on.
This beamline equips an in-vacuum undulator, a varied-line-spacing plane grating monochromator and a fixed exit
slit. The soft X-ray energy range from 50 to 770 eV with the resolving power (E/E) of 6,000 is available. The aperturesize of the fixed exit slit determines not only the resolving power but also the size of a microprobe. A Fresnel zone plateis used as a focusing optical device through an order select aperture and its focal spot size of ~30 nm is available atminimum. An image is acquired by detecting intensities of the transmitted X-rays by a photomultiplier tube with
scintillator with scanning a sample 2-dimensionally. By changing the energy of the incident beam, each 2-dimensional
NEXAFS image is stacked. A main chamber of STXM is separated from the beamline optics by a silicon nitride
membrane of 50-nm thickness; therefore, sample folders can be handled in vacuum or in helium.

PinholeSlit

M0 mirror

M1 mirror andGrating

M2 mirror

Fixed exit slit

STXM

Fig. 1. Schematic image of BL4U

Monochromatized X-rays

Fresnel zone plate
Order Sorting Aperture
SamplePhoto multiplier tube
with scintillator P-43

Central stopper
Fig. 2. Schematic image of STXM

▼Technical Data
Energy range (E)50 -770 eVResolving power (E/E)~6,000

Photon flux on a sample (photons/s)~2107 @400 eV

Focusing optical element

Fresnel zone plate

Spatial resolution~30 nmExperiments

2-dimensional absorption spectroscopy
standard sample folder in vacuum or in helium,
specially designed sample cell in ambient condition

Measurement environment

22

22

BL4B

Varied-Line-Spacing Plane Grating Monochromatorfor Molecular Soft X-Ray Spectroscopy▼Description
The beamline BL4B equipped with a varied-line-spacing plane grating monochromator (VLS-PGM) wasconstructed for various spectroscopic investigations in a gas phase and/or on solids in the soft X-ray range. Threeholographically ruled laminar profile plane gratings with SiO2 substrates are designed to cover the photon energy
range from 25 to 800 eV. The gratings with groove densities of 100, 267, and 800 l/mm cover the spectral rangesof 25–100, 60–300, and 200-1000 eV, respectively, and are interchangeable without breaking the vacuum. Figure
1 shows the absolute photon flux for each grating measured using a Si photodiode (IRD Inc.), with the entranceand exit-slit openings set at 50 and 50 μm, respectively. The maximum resolving power (E/ΔE) achieved foreach grating exceeds 5000.
There is no fixed endstation on this beamline. A small vacuum chamber equipped with an electron multiplier(EM) detector is available. Soft X-ray absorption spectra of solid samples are usually measured by means of thetotal electron yield method using EM, and the partial fluorescence yield method using a silicon drift detector (SDD).

1E12

Intensity (photons/s)

G3
1E11

Slit: 50m-50m

G2

1E10

G1
1E9

1E8
0

200

400

600

800

1000

1200

Photon Energy (eV)Fig. 1. Throughput from the VLS-PGM monochromatoron BL4B.

Fig. 2. Photo of BL4B.

▼Technical Data
Monochromator

Varied-line-spacing Plane Grating Monochromator

Energy range

25-1000 eVResolution

E / ΔE > 5000 (at maximum)

Experiments

Soft X-ray spectroscopy (mainly, photoabsorption spectroscopy for solid targets
by means of total electron yield method using EM and partial fluorescence yield
method using SDD)

23
23

Ⅱ

BL5U

Photoemission Spectroscopy of Solids and Surfaces
Ⅱ▼Description
Since the monochromator of BL5U was an old-style spherical grating type SGMTRAIN constructed in 1990s
and the throughput intensity and energy resolution were poor, the whole beamline has been replaced to state-ofthe-art monochromator and end station. The new beamline has been opened to users from FY2016 as high-energy
resolution ARPES beamline. Samples can be cooled down to 3.8 K with newly developed 5-axis manipulator toperform high energy resolution measurements. Users can also obtain spatial-dependence of the electronic structureof solids using micro-focused beam (~ 50 μm). The new electron lens system makes it possible to obtain ARPES
spectra without moving samples. This beamline will also have new capability to perform high-efficient spinresolved ARPES in the future.

Fig. 1. Picture and photon flux of BL5U.

▼Technical Data (Expected Performance)
Light source

APPLE-II type undulator (λu = 60 mm, N = 38)
vertical/horizontal, right/left circular (depending on hv)

Monochromator

Monk-Gillieson VLS-PGM

Energy Range

20-200 eVResolution

hv/ ΔE > 10,000 for < 10 μm slits

Experiment

ARPES, Space-resolved ARPES, Spin-resolved ARPES

Flux<1012 photons/s for <10 μm slits (at the sample position)

Beam spot size

23 (H) x 40 (V) µm

Main Instruments

Hemispherical photoelectron analyzer with deflector scan (MBS A-1
Lens#4),
Liq-He flow cryostat with 5-axis manipulator (3.8 K-350 K)

24

24

BL5B

Calibration Apparatus for Optical Elements and Detectors
Ⅱ▼Description
BL5B has been constructed to perform calibration measurements for optical elements and detectors. This
beamline is composed of a plane grating monochromator (PGM) and three endstations in tandem. The most
upstream station is used for the calibration measurements of optical elements, the middle one for opticalmeasurements for solids, and the last for photo-stimulated desorption experiments. The experimental chamber at
the most downstream station is sometimes changed to a chamber for photoemission spectroscopy. The calibrationchamber shown in Fig. 2 is equipped with a goniometer for the characterization of optical elements, which has six
degrees of freedom, X-Y translation of a sample, and interchanging of samples and filters. These are driven bypulse motors in vacuum. Because the polarization of synchrotron radiation is essential for such measurements, therotation axis can be made in either the horizontal or vertical direction (s- or p-polarization).

Fig. 1. Throughput spectra for possible combinations ofgratings and mirrors at BL5B measured by a gold mesh.

Fig. 2. A side view of the experimental chamber
for calibration measurements.

▼Technical Data
Monochromator

Plane Grating Monochromator

Energy range

6-600 eV (2-200 nm)

Resolution

E / ΔE ~500

Experiments

Calibration of optical elements, reflection and absorption spectroscopy mainly
for solids

25
25

BL6U
▼Description

The beamline BL6U equipped with a variable-included-angle Monk-Gillieson mounting monochromator witha varied-line-spacing plane grating was constructed for various spectroscopic investigations requiring highbrilliance soft X-rays on solid surfaces. Through a combination of undulator radiation and sophisticatedmonochromator design (entrance slit-less configuration and variable-included-angle mechanism), using a single
grating, the monochromator can cover the photon energy ranging from 40 to 500 eV, with resolving power ofgreater than 10000 and photon flux of more than 1010 photons/s. Figure 1 shows an example of themonochromator throughput spectra measured using a Si photodiode, with the exit-slit opening set at 30 μm, whichcorresponds to the theoretical resolving power of 10000 at 80 eV.
A new Momentum Microscope experimental station for photoelectron spectroscopy resolved in 3D
momentum space with a microscopic field of view has been built at BL6U (SPECS KREIOS 150 MM). A
momentum resolution of 0.01 Å-1 in kx/ky as well as kz is achieved. A spatial resolution of 50 nm, an energy
resolution of 20 meV at 9 K, and a field of view of 2 μm for ARPES are successfully demonstrated. This
experimental station specializes in characterizing the electronic structure of surface atomic sites, thin films,
molecular adsorbates, and bulk crystals. This method opens the door to direct observation of the Fermi
surface of μm-sized crystals, which was difficult with conventional ARPES-type hemispherical analyzers.

Throughput spectra of the BL6U (Gap=13 mm, Slit=30m)

1E13

Flux(Photons/s/100mA:PD-AXUV100G)

Ⅱ

Variable-Included-Angle / Variable-Line-Spacing Plane Grating
Monochromator for Soft X-Ray photoelectron Spectroscopy

3rd

1E12

5th

1st

1E11

168170
172174

1E10
1E9
1E8
1E7

30

100

Photon energy(eV)Fig. 2. Photograph of BL6U end station

Fig. 1. Throughput spectra of the BL6U
monochromator at various included angles.

▼Technical Data
Monochromator

Variable-included-angle Varied-line-spacing Plane Grating Monochromator

Energy range

45-600 eV(practical)

Resolution

E / ΔE > 10000 (at maximum)

Experiments

High-resolution soft X-ray spectroscopy (photoelectron spectroscopy for solid
surfaces)

26
26

BL6B

Infrared and Terahertz Spectroscopy of Solids
Ⅱ▼Description
Synchrotron radiation (SR) has good performance (high brilliance and high flux) not only in the VUV and soft
X-ray (SX) regions but also in the infrared (IR) and THz regions. BL6B covers the IR and THz regions. The
previous beamline, BL6A1, which was constructed in 1985, was the pioneer in IRSR research. The beamline wasdeactivated at the end of FY2003 and a new IR/THz beamline, BL6B (IR), was constructed in FY2004. The frontend part including bending duct #6 was replaced with a new part having a higher acceptance angle (215 (H) × 80(V) mrad2) using a magic mirror, as shown in Fig. 1.
There are two Michelson type interferometers in this endstation; with first one (Bruker Vertex70v), which covers
a wide spectral region from 30 to 20,000 cm-1 (hν = 4 meV-2.5 eV), reflection/absorption spectroscopy measurementsof large samples (up to several mm) and IR/THz microscopy measurements of tiny samples (up to several tens ofµm) can be performed. For reflection/absorption spectroscopy measurements, a liquid-helium- flow type cryostat
with a minimum temperature of 4 K is installed. The other interferometer (Jasco FT/IR-6100), which covers 350 to
15,000 cm-1 (hν = 45 meV-1.8 eV), has been available for IR microscopy imaging measurements from FY2014. One
can also perform ATR measurements using diamond ATR prism.

Reflection/absorption
end station

Michelson FT-IR(Jasco FT/IR-6100)

IR microscopy imaging(Jasco IRT-7100)

Michelson FT-IR(Jasco FT/IR-6100)

Fig. 2. Obtained intensity spectrawith thecombination of a light source (UVSOR), detector (Sibolometer), and interferometer (Bruker Vertex70v) withdifferent beamsplitters (6 µm Mylar and KBr) . (Onlylow energy side is shown).

Fig. 1. Schematic top view of BL6B.

▼Technical Data
Interferometer

Michelson (Bruker Vertex70v)

Michelson (Jasco FT/IR-6100)

Wavenumber Range(Energy range)

30-20,000 cm(4 meV-2.5 eV)

350-15,000 cm-1
(45 meV-1.8 eV)Resolution in cm-1

0.1 cm-1

0.5 cm-1

Experiments

Reflectivity and transmission
spectroscopy
THz Microspectroscopy

IR microscopy imaging (JASCO IRT-7000)
ATR spectroscopy

-1

27
27

BL7U (SAMRAI)

Angle-Resolved Photoemission of Solids in the VUV Region
Ⅱ▼Description
Beamline 7U, named the Symmetry- And Momentum-Resolved electronic structure Analysis Instrument(SAMRAI) for functional materials, was constructed to provide a photon flux with high energy resolution and highflux mainly for high-resolution angle-resolved photoemission spectroscopy, so-called “ARPES”, of solids [1]. An
APPLE-II-type variable-polarization undulator is installed as the light source. The undulator can produce intense
VUV light with horizontal/vertical linear and right/left circular polarization. The undulator light ismonochromatized by a modified Wadsworth type monochromator with three gratings (10 m radius; 1200, 2400,
and 3600 lines/mm optimized at hv = 10, 20, and 33 eV). The energy resolution of the light (hv/Δhv) is more than
104 with a photon flux of 1011-1012 ph/s or higher on samples in the entire energy region. The beamline has aphotoemission end-station equipped with a 200 mm-radius hemispherical photoelectron analyzer (MB Scientific
AB, A-l analyzer) with a wide-angle electron lens and a liquid-helium-cooled cryostat with 6-axis pulse motor
control. The main function of the beamline is to determine the electronic structure of solids and its temperaturedependence in order to reveal the origin of their physical properties.
[1] S. Kimura, T. Ito, M. Sakai, E. Nakamura, N. Kondo, K. Hayashi, T. Horigome, M. Hosaka, M. Katoh, T. Goto,
T. Ejima and K. Soda, Rev. Sci. Instrum. 81 (2010) 053104.

Fig. 1. SAMRAI beamline [(a), (b)]consisting of an APPLE-II typeundulator (U7), a modified Wadsworth
type monochromator (M0-S), and ahigh-resolution photoemission analyzer
at the focal point. The monochromator
has five major optical components: twoplane mirrors (M0 and M1) with watercooling, one set of three sphericalgratings (G), an exit slit (S), and one
toroidal refocusing mirror (M3). (c)Example of flux intensity versus
photon energy [1]▼Technical Data
Light source

APPLE-II type undulator (λu = 76 mm, N = 36)vertical/horizontal, right/left circular (depending on hv)

Monochromator

10 m normal-incidence monochromator (modified Wadsworth type)

Photon energy range

6 – 40 eV (λ = 30 – 200 nm)

Resolution (hv/Δhv)

E / ΔE > 10000-50000

Photon flux on sample

 1011-1012 ph/s (depending on hv)

Beam size on sample

200 (H) × 50 (V) μm2

Experiments

Angle-resolved photoemission of solids(MV Scientific A-1 analyzer, acceptance angle: ± 18 deg)

28
28

BL7B

3 m Normal-Incidence Monochromator for Solid-State Spectroscopy
Ⅱ▼Description
BL7B has been constructed to provide sufficiently high resolution for conventional solid-state spectroscopy,
sufficient intensity for luminescence measurements, wide wavelength coverage for Kramers–Kronig analyses, andminimum deformation to the polarization characteristic of incident synchrotron radiation. This beamline consistsof a 3-m normal incidence monochromator, which covers the vacuum ultraviolet, ultraviolet, visible, and infrared,i.e., the wavelength region of 50–1000 nm, with three gratings (1200, 600, and 300 l/mm). Two interchangeablerefocusing mirrors provide two different focusing positions. For the mirror with the longer focal length, an LiF or
a MgF2 window valve can be installed between the end valve of the beamline and the focusing position. Figure 1
shows the absolute photon intensity for each grating with the entrance and exit slit openings of 0.5 mm. A silicon
photodiode (AXUV-100, IRD Inc.) was utilized to measure the photon intensity and the absolute photon flux was
estimated, taking the quantum efficiency of the photodiode into account.
The cooling system for the pre-focusing mirror has been removed, resulting in longer beam
settling times. Currently, BL7B is opened during single bunch mode, but limited use is possible
during multi bunch mode.

Fig. 1. Throughput spectra of BL7B measured using
a silicon photodiode.

Fig. 2. Photo of BL7B.

▼Technical Data
Monochromator

3 m Normal-Incidence Monochromator

Wavelength Range

50-1000 nm (1.2-25 eV)Resolution

E / E = 4000-8000 for 0.01 mm slits

Experiments

Absorption, reflection, and fluorescence spectroscopy, mainly for solids

2929