Ⅱ

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

Light Source in 2021
Yoshitaka TairaUVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, JapanⅡIn FY2021, UVSOR-III was scheduled to operate
for 36 weeks from end of May 2021 to March 2022 forusers. However, the user operation time was cut by two
weeks due to a vacuum leak incident and its restoration
work. Finally, the 300 mA multi-bunch top-up mode
was operated for 32 weeks and the 35 mA single-bunch
top-up mode for 2 weeks. Monthly statistics ofoperation time and integrated beam current are shownin Figure 1.
From April 1 to May 7 was a shutdown period,
during which periodic inspections and replacement of
sextupole coils were conducted. The details of thereplacement of sextupole coils are described in last
year's activity report [1]. The replacement of the
sextupole coils was conducted over a multi-year period,
and all replacements were completed during thisperiod. The two weeks following the shutdown wereallocated to the adjustment of the accelerator andbeamlines.
The vacuum leak accident over the entire circumferenceof the storage ring was occurred in July 2021 and wascaused by water leaking from the cooling water pipe ofthe four-quadrant slit used to cut out the synchrotron
radiation, which is located between the manual valve
and the fast-acting valve immediately after the bending
magnet. It took a total of five weeks for baking,photobaking, and adjustment of the accelerator andbeamlines before user operation resumed.
Minor machine problems including the failure of thebeam position monitor module due to an instantaneousvoltage drop and the failure of the RF-frequency signal
oscillator, both of which were addressed by replacing
them with alternatives or repairing them.
The weekly operation schedule is as follows. Mondays
are assigned to machine studies from 9:00 AM to 9:00
PM. User operation is assigned Tuesday through Friday,with Tuesday and Wednesday operating from 9:00 AM
to 9:00 PM, and Thursday from 9:00 AM to 9:00 PM on
Friday for 36 continuous hours. Thus, the user's beamtime per week is 60 hours.
We started a design study for the future plan of
UVSOR-IV. As a first step, we have analyzed thepresent magnetic lattice, seeking a possibility to reduce
the emittance more [2]. Although, we did not find asolution to drastically reduce emittance, we have founda few interesting solutions that achieved lower
emittance than the current situation. As the second step,
we have started designing a totally new storage ring,which is close to the diffraction limit in the VUV range.
The light source development and utilization
beamline BL1U, constructed under the support ofQuantum Beam Technology Program by MEXT/JST,

continue to develop new light source technologies andtheir applications such as free electron laser, coherent
harmonic generation, coherent synchrotron radiation,
coherent control [3], laser Compton scattered gamma
rays [4], and optical vortices.
In particular, in April 2021, a new vacuum duct for
laser injection was installed in the storage ring, shownin Figure 2. To solve the space constraint, a manualvalve and injection windows were integrated. By using
this injection windows, the gamma ray intensity wasincreased by a factor of 10 or more.

Ⅱ

Current Status ofLight Sources andBeamlines

Fig. 1. Monthly statistics in FY2021.

Fig. 2. Laser injection vacuum duct installed in April
2021.
[1] M. Katoh, UVSOR Activity Report (2021).
[2] E. Salehi and M. Katoh, Proceedings of IPAC2021(2021) 3970.
[3] T. Kaneyasu et al., Phys. Rev. Lett. 126 (2021)
113202.
[4] K. Ali et al., Appl. Sci. 11 (2021) 3415.

9

Ⅱ . Current Status of Light Sources and Beamlines

Ⅱ

10

2

Ⅱ . Current Status of Light Sources and Beamlines

Ⅱ

3
11

Ⅱ . Current Status of Light Sources and Beamlines

Beamlines in 2021
Fumihiko Matsui
UVSOR synchrotron Facility, Institute for Molecular ScienceⅡ
BL4U, which is equipped with a scanningtransmission 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 the lithium K-edge with aspatial resolution of 72 nm. Final adjustments forthe airtight sample transport system and thesample transport container were carried out forthe organic substance analysis of the Hayabusa2
returned samples for the summer of FY2021.
 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. An alkalimetal deposition system has been installed.
Potassium for example can be deposited while thesample is still mounted on the manipulator at low
temperatures. As part of the development of spinresolved ARPES, a two-dimensional image of thespin-resolved spectrum of the Rashba splitting of
Au(111) surface has been successfully obtained.
 At BL6U, one of the In-house beamlines,
photoelectron momentum microscope (PMM),
which is a new-concept multi-modal electronic
structure analysis system with high resolution inreal space and momentum space, has been
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 are performed.
In FY2021, valence band study on graphenes,
high-temperature superconductors, dichalcogenides,
and organic molecular adsorbates were conductedin collaboration with several groups. In FY2022,
we plan to further expand PMM's capabilities byintroducing an additional 2D spin filter.
 At BL7U, high-energy resolution ARPES isavailable with extremely low energy of photons (6eV~) using the low-temperature 6-axis manipulator
with a sample temperature 4.5-350 K. In FY2022,
the deflector-type detector for the hemisphericalanalyzer was installed to realize an effective 2D
measurement with the automated manipulator
control. Users can perform the measurement of thebulk sensitive electronic structure of solids and thehigh-throughput measurement for molecularmaterials using high-photoionization cross-section
using low-excitation photon energy.
Those wishing to use the open and in-housebeamlines are recommended to contact the appropriate
beamline contact persons (see next page). Applications
can be submitted at NOUS (https:// nous.nins.jp/user/
signin). All users are required to refer to the beamline

UVSOR is one of the highest-brilliance light sourcesin the extreme-ultraviolet region among the synchrotron
radiation facilities with electron energies of less than 1
GeV. The low natural emittance of the UVSOR-III
storage ring, 17.5 nm-rad, was accomplished after the
successful completion of the storage ring upgrade
project (the UVSOR-III project) in 2012. Eight bending
magnets and six insertion devices are available assynchrotron light sources at UVSOR. There are a totalof fourteen operational beamlines. Twelve of them are
the so-called “Public 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 beamline BL6U is the “In-house beamlines”, andare dedicated to the use of research groups within
Institute for Molecular Science (IMS). The beamline
BL1U is a partially "Public" and partially "In-house"beamline. There is one tender X-ray (TX) stationequipped with a double-crystal monochromator, seven
extreme ultraviolet (EUV) and soft X-ray (SX) stations
with grazing incidence monochromators, three vacuum
ultraviolet (VUV) stations with normal incidence
monochromators, two infrared (IR) stations equippedwith Fourier Transform 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 2021. The details of the updates
for undulator beamlines are the followings.
 In BL1U, the development of a new light source
and the utilization of gamma-rays are being
carried out. Users are provided with gamma-ray
induced positron annihilation spectroscopy that
can analyze nanometer-order defects in bulk
materials. To increase the counting rate ofannihilation gamma rays, an array detector witheight BaF2 scintillators was developed. The
measurement can be completed in a few hours formetal samples.
 In BL3U, the ultrathin-liquid cell for low-energy
XAS has been developed. The studies of local
structures of several aqueous solutions andvarious chemical processes in solution such as
catalytic and electrochemical reactions, andlaminar flows in microfluidics by using operando
XAS in C, N, and O K-edges were demonstrated.
Moreover, we have established an argon gas
window that is effective from 60 to 240 eV withthe removal of high-order X-rays, which willdevelop chemical research since it includes Kedges of Li and B and L-edges of Si, P, S, and Cl.
Resonant soft X-ray scattering for soft materials
is also applicable.



4
12

Ⅱ . Current Status of Light Sources and Beamlines

manuals and the UVSOR guidebook, on the occasionof conducting the actual experimental procedures. For

updated information on UVSOR, please see http://
www. uvsor.ims.ac.jp.

Ⅱ

5
13

Ⅱ . Current Status of Light Sources and Beamlines

Beamlines at UVSOR
Ⅱ

Beamline

Monochromator /Spectrometer

BL1U

Free electron laser

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
23 – 205 eV
40 – 800 eV
1.7 – 31 eV
50 – 770 eV
25 eV – 1 keV
20 – 200 eV
6 – 600 eV
40 – 500 eV
4 meV – 2.5 eV
6 – 40 eV
1.2 – 25 eV

Yellow columns represent undulator beamlines.
In-house beamline.

*

6
14

Contact(Irradiation)

Y. Taira

Solid

Reflection
Absorption

K. Tanaka

Solid

Reflection
Absorption

F. Matsui

Solid

Photoemission

S. KeraGas
LiquidSolid

Absorption
Photoemission
Photon-emission
Reflection
Absorption
Photon-emission

1.6 – 13.9 eV
0.5 – 30 meVTechniquesSolidyostaira@ims.ac.jp

k-tanaka@ims.ac.jp

matui@ims.ac.jp

kera@ims.ac.jp

H. Iwayama

iwayama@ims.ac.jp

F. Matsui

matui@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

K. Tanaka

Solid

Reflection
Absorption
Photon-emission

F. Matsui

k-tanaka@ims.ac.jp

matui@ims.ac.jp

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

7
15

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; θx, θy, θz 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 (hν = 500 μeV-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 μeV-30 meV)

Resolution in cm-1

0.25 cm-1

Experiments

Reflection/transmission spectroscopy

Miscellaneous

Users can use their experimental system in this beamline.

8

16

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)

9

17

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/ΔE = 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 hν = 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

10
18

BL3U

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

11
19

Ⅱ

BL3B (HOTRLU)Ⅱ

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 / ΔE 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 (Δhν/ hν)≥ 12000 (at ~ 6.9 eV, 0.02 mm slits, G1 (1200 l/mm)

Experiments

Photoluminescence, reflection, and absorption spectroscopy, mainly for solids

12
20

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/ΔE) 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.

Slit

PinholeM0 mirror

M1 mirror andGrating

M2 mirror

Fixed exit slit

Fig. 1. Schematic image of BL4U
X-raysFresnel zone plate

Order Sorting
Aperture
SampleCentralstopper

Photo multiplier tube
with scintillator P-43

Fig. 2. Schematic image of STXM

Fig. 3. Photon flux at the sample▼Technical Data
Energy range (E)50 -770 eVResolving power (E/ΔE)~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

13

21

STXM

BL4B

▼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

G3
Intensity (photons/s)

Ⅱ

Varied-Line-Spacing Plane Grating Monochromatorfor Molecular Soft X-Ray Spectroscopy

1E11

Slit: 50μm-50μm

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)

14
22

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)

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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

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BL6U

Variable-Included-Angle / Variable-Line-Spacing Plane Grating
Monochromator for Soft X-Ray photoelectron Spectroscopy▼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=30μm)

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

1E13

3rd

1E12

5th

1st

1E11

α+β=168°α+β=170°α+β=172°α+β=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

40-500 eV(practical)

Resolution

E / ΔE > 10000 (at maximum)

Experiments

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

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Ⅱ

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 spectra with the combinationof a light source (UVSOR), detector (Si bolometer), andinterferometer (Bruker Vertex70v) with different
beamsplitters (6 μm Mylar and KBr) . (Only low 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

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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)

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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 / ΔE = 4000-8000 for 0.01 mm slits

Experiments

Absorption, reflection, and fluorescence spectroscopy, mainly for solids

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UVSOR User 1

UVSOR User 2