次世代放射光施設コアリションビームライン
実施計画に関する国際審査

2021 年 3 ⽉ 15 ⽇
東北⼤学
国際放射光イノベーション・スマート研究センター

⽬次
１）コアリションビームライン実施計画書

3

１．序論
1.1 次世代放射光施設の概要

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1.2 次世代放射光施設とコアリションコンセプト

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1.3 次世代放射光施設におけるビームライン

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1.4 経緯9

1.5 本実施計画書の⽬的

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２．挿⼊光源12

３．ビームライン14

3.1 ビームラインの概要

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3.2 コアリションビームライン

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3.3 ブランチビームライン

47２）国際審査実施概要

51３）国際審査報告書

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エグゼクティブサマリー

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１．コアリションビームラインシステムのメリット

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２．学際的な研究や産学連携の発展に対する本プロジェクトの科学技術的価値

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３．個々のビームラインデザインの⼀般的な科学的/技術的なメリットについてのコメント

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４．ブランチビームライン

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５．その他可能性のある開発領域

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Implementation Plan Reportof Coalition Beamlines
at 3-GeV Next-Generation
Synchrotron Radiation Facility

February 10th, 2021
International Center for Synchrotron Radiation
Innovation Smart (SRIS),
Tohoku University

3

Table of Contents
1. Introduction
1.1 General introduction
1.2 Next-generation synchrotron radiation facility and Coalition concept
1.3 Beamlines at the NGSR facility
1.4 History
1.5 Aim of this report
2. Insertion device
3. Beamline
3.1 Overview of beamlines
3.2 Coalition beamlines
3.2.1 Soft X-ray electronic structure analysis beamline (BL07U)
3.2.1.1 Science
3.2.1.2 Specifications
3.2.1.3 Beamline optics
3.2.1.4 Endstation
3.2.1.4.1 A branch: Nano-photoelectron spectroscopy station
3.2.1.4.2 B branch: Resonant inelastic soft X-ray scattering station
3.2.2 Soft X-ray operando spectroscopy beamline (BL08U)
3.2.2.1 Science
3.2.2.2 Specifications
3.2.2.3 Beamline optics
3.2.2.4 Endstation
3.2.3 Integrated analysis of chemical state and nano/local structure beamline(BL08W)
3.2.3.1 Science
3.2.3.2 Specifications
3.2.3.3 Beamline optics
3.2.3.4 Endstation
3.2.4 X-ray operando spectroscopy beamline (BL09U)
3.2.4.1 Science
3.2.4.2 Specifications
3.2.4.3 Beamline optics

43.2.4.4 Endstation
3.2.5 X-ray multiscale structure-analysis beamline (BL09W)
3.2.5.1 Science
3.2.5.2 Specifications
3.2.5.3 Beamline optics
3.2.5.4 Endstation
3.2.6 X-ray coherent imaging beamline (BL10U)
3.2.6.1. Science
3.2.6.2. Specifications
3.2.6.3. Beamline optics
3.2.6.4 Endstation
3.2.7 Soft X-ray imaging beamline (BL14U)
3.2.7.1 Science
3.2.7.2 Specifications
3.2.7.3 Beamline optics
3.2.7.4 Endstation
3.3 Branch beamlines
3.3.1 Concept of branch beamlines
3.3.2 Methods for beam branching
3.3.3 Branch beamline list5

1. Introduction
1.1 General introduction
Synchrotron radiation (SR) is recognized as an essential research tool for thedevelopment of science and technology as well as for industrial applications. A
number of advanced SR facilities have been constructed world-wide. This mirrors
society's strong demand towards solving energy, environmental, public healthproblems and achieving sustainable development goals (SDGs). SR facilities aroundthe world now work together to study, understand and solve the COVID-19 pandemic,
including new drugs, therapeutic strategies and medical equipment developments,
as declared in AOBA Communique 2 [1].
At SR facilities, powerful X-rays with unprecedented brightness are
increasingly becoming available because of recent technical advances in storagerings; especially, “multi-bend achromat” magnets. New X-ray sources based on thistechnology will revolutionize our ability to investigate materials and devices withnanometer spatial resolution, chemical specificity, and dynamic time resolution,
which will provide unique analytical capability to industry and academic researchers.
Despite its importance, the SR facility with high brightness especially in thesoft X-ray energy region has been lacking in Japan. In 2018, the Ministry of Education,
Culture, Sports, Science and Technology (MEXT) of Japan decided to initiate
construction of the 3 GeV Next-Generation Synchrotron Radiation (NGSR) facility on
the campus of Tohoku University. The construction and operation of the facility will
be carried out by a new organization. It is a combined public-private regional
partnership, in which the partners are the National Institute of Quantum Radiological
Science & Technology (QST), Tohoku University, Miyagi Prefecture, Sendai-City, theTohoku Economic Federation, and the Photon Science Innovation Center (PhoSIC).
Funding comes from private sector investments, local governments, and MEXT
through QST.
1.2 Next-generation synchrotron radiation facility and Coalition concept
The prime objective of the NGSR facility is to drive innovation by visualizationof materials’ function using SR X-rays with unparalleled spatial/temporal resolution
and chemical specificity. To achieve open innovation, the NGSR facility should not belimited to SR specialists, but be open to non-SR specialist with unsolved important
problems. In other words, the NGSR facility is required to be open to both industry
and academia; more importantly, a close collaboration between industry andacademia is necessary. Therefore, a new industry-academic alliance scheme, called“coalition concept”, is developed at NGSR.

6The “coalition concept” is a new research scheme, in which stakeholders fromboth industries and academia form a strong one-on-one team for the purpose ofsolving social challenges (Fig. 1.1). Industrial partners often have unsolved problems
in their R&D, and require a practical and demand-oriented user-support by theexperts. Academic partners often have expertise in measurements and data analysis.
Through an interdisciplinary research collaboration in the “coalition concept”,
academic researchers can expand the applicability of their expertise to new academic
disciplines. This “Coalition Concept” has been attracting industrial users for advanced
utilization of the SR facility, which, we believe, will lead to solving the essential
problems of industries and will promote the diversity of SR research.

Figure 1.1 “Coalition concept”: A new industry-academic alliance scheme
The “coalition concept” is intended to be an engine to drive the businessecosystem for sustainable growth. We anticipate that a positive spiral will be createdin the business ecosystem; excellent strategies and research results are recognizedby society, which then attracts talented researchers to join the NGSR facility. Together
with these new participants, the host community will build an advanced strategy
supported by their knowledge and human resources. Thus, the NGSR facility will becore of the research complex of universities, research institutes, and companies.
Tohoku university plans to build research complex “Science Park” at the Aobayama
campus, in which the NGSR facility will be constructed. The “coalition concept” shallbe the guiding principle of this research complex to create a “research conducting
community for innovation”.

71.3 Beamlines at the NGSR facility
The beamlines at the NGSR facility are designed to satisfy the needs of theusers from both industry and academia in various disciplines. 10 beamlines will be
constructed as the first phase beamlines when the NGSR facility is opened. 7
beamlines will be constructed by the regional partners (Tohoku University, Miyagi
Prefecture, Sendai-City, the Tohoku Economic Federation, and PhoSIC) for the use in
the “coalition concept” (hereafter, called as Coalition beamlines); the remaining 3
beamlines will be built by QST for shared use (hereafter, called as Shared beamlines).
The technological support for the development of the coalition beamlines is givenby the International Center for Synchrotron Radiation Innovation Smart of Tohoku
university. In the present report, we focus on the 7 coalition beamlines.
The cross-sectional use of 7 coalition beamlines offers the users a one-stop
service to collect comprehensive data using a variety of analysis techniques indifferent photon energy ranges. Typically, the users have to visit different SR facilities
to perform experiments using different photon energies. The 7 coalition beamlines
cover the whole photon energy range of extreme ultraviolet (EUV), soft X-ray (SX),
tender X-ray (TX), and hard X-ray (HX). Figure 1.2 shows the concept of crosssectional use of 7 coalition beamlines. There are four important keywords among thecoalition beamlines: multi-dimensional coherent imaging, all-element operando
analysis, mail-in total materials analysis, and plug-and-play technology.

Figure 1.2 Concept of cross-sectional use of the coalition beamlines

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The coalition beamlines will have two types of end-station (ES): automatedmeasurement stations and advanced measurement stations. The automatedmeasurement stations enable high-throughput routine measurements by making fulluse of robot and automation technology along with brilliant X-rays. The advanced
measurement stations enable users to make customized measurements undervarious conditions and environments by installing their own custom-developed
instruments in the end-station using a standardized plug-and-play system.
Furthermore, the plug-and-play system will allow users to perform measurements
utilizing multiple beamlines.

Figure 1.3 Concept of end-stations at the coalition beamlines

In order to take the best advantage of high-brilliance X-rays at the NGSR
facility, X-rays beam is split into one main beamline, and one or two branch beamlines.
The main beamline hosts advanced measurement stations, which make best use ofhigh-brilliance and coherence of X-rays at the NGSR facility. In contrast, the branchbeamline is equipped with automated measurement stations, in which highthroughput routine measurements are performed with help of robotics andautomation technology.

1.4 History
The history and current status of the NGSR facility project is briefly
summarized as follows. The current status of the construction site of the NGSR facility
is shown by the aerial picture in Fig. 1.4.
1) The "SLiT-J International Evaluation Committee" for the Conceptual Design
Report version 2.1. (CDR 2.1) was held in June 2016 (“SLiT-J” is the former project
name of the NGSR).
2) An open design competition for the SLiT-J end-stations was held in July 2017 togather insights from the experts in Japan.

93) A general incorporation foundation, the "Photon Science Innovation Center"(PhoSIC), was established to receive investments from the private industrial
sector for the SLiT-J project in December 21, 2017.
4) The SLiT-J user community was launched in January 7, 2017.
5) PhoSIC requested permission to use a part of Tohoku University's Aobayama
campus for SLiT-J.
6) Deliberation on using synchrotron radiation as a source for soft X-rays and its
usage began in November 2016 at the committee in MEXT.
7) MEXT initiated construction of the new 3 GeV facility on the campus of Tohoku
University in July 2018.
8) The Beamline Review Committee reported the lineup candidates for the first 10
beamlines at the NGSR facility in the "Next Generation Synchrotron Radiation
Facility Beamline Review Committee Report” in 2019.
9) Tohoku university has established International Center for Synchrotron Radiation
Innovation Smart on October 1, 2019.

Figure 1.4 Aerial picture of the construction site of the NGSR facility
as of 28-Jan-2021 (by courtesy of PhoSIC).

101.5 Aim of this report
This report aims to report the implementation plan of coalition beamlines at
the NGSR facility, and have review by international experts. Following the review
process, we hope to initiate the next step of the Engineering Design Process in theearly stage of 2021FY.
This report is organized as follows. In Chapter 1, we introduce the current
situation of synchrotron radiation facilities, and the NGSR facility and its new
industry-academic alliance scheme called “Coalition concept”. In Chapter 2, the brief
explanation of insertion devices is given. In Chapter 3, we describe the details of thefirst-phase 7 coalition beamlines: Science, beamline specifications, beamline optics,
and end-stations.
References[1] http://www.sris.tohoku.ac.jp/covid-19/index.html

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2. Insertion device
At the NGSR facility, 5 types of insertion devices (IDs) will be adopted tocover the whole energy range from EUV to hard X-ray. The specifications of 5
standard IDs are summarized in Table 2.1.
In the region of tender X-ray and hard X-ray (photon energy above 2 keV),
two types of IDs are used: in-vacuum undulator (IVU) and multipole wiggler (MPW).
IVU provides highly-brilliant coherent X-ray in the photon energy range of 2 to 20
keV; MPW gives continuous white beam in the photon energy range of 2 to 30 keV.
In the region of EUV and soft X-ray (photon energy below 2 keV), APPLE-II
undulators [1] and twin helical undulator (THU) are used. The big advantage of the
APPLE-II undulator is the capability of polarization control; it can generate linear
polarization (horizontal/vertical), and circular polarization. Two types of APPLE-II,
APPLE-EUV (periodic length u= 75 mm) and APPLE-SX (u= 56 mm), are built tocover the different photon energy range of EUV and soft X-ray, respectively.
THU consists of two undulator segments which generate circularly-polarized
X-ray with opposite helicity. The photon energy of each ID segment can be
determined independently, and only one of the two segments is tuned to the photon
energy of a monochromator. Therefore, the helicity of X-ray can be switched bychanging the energies (undulator gaps) of two segments. This allows faster helicity
switching compared to APPLE-II undulator, where the helicity is changed by themechanical motion of magnet rows. Note that the magnets of THU are same as thosefor the helical mode of the APPLE-SX undulator.
Brilliances of 5 standard IDs at the NGSR facility are shown in Fig. 2.1. The
brilliance was calculated using a code SPECTRA [2].

References[1] S. Sasaki, Nucl. Instrum. Methods Phys. Res. A 347, 83 (1994).
[2] T. Tanaka and H. Kitamura, J. Synchrotron Radiation 8, 1221 (2001).

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Table 2.1 Specifications of insertion devices at the next-generation synchrotron
radiation facility.
Name

Type of ID

#
(pcs)

BL

Periodic
Length(mm)

NumberofPeriodMax. B (T)Max. K
Value

IVU

In-vacuum
undulator

2

09U
10U

22

190

1.15 (LHP)

2.36 (LHP)

MPW

Multipole
Wiggler

2

08W
09W

120

5

1.91 (LHP)

16.8 (LHP)

APPLEEUVAPPLE-II

1

07U

75

56

APPLESXAPPLE-II

1

08U

56

75

1.08 (LHP)
0.869 (LVP)
0.977 (CP)0.884 (LHP)
0.642 (LVP)
0.521 (CP)7.58 (LHP)
6.09 (LVP)
4.74 (CP)4.62 (LHP)
3.36 (LVP)
2.72 (CP)

THU

Twin
HelicalUndulator

1

14U

56

35x2

0.521 (CP)2.72 (CP)* LHP: Linear Horizontal Polarization, LVP: Linear Vertical Polarization, CP: Circular
Polarization* The parameters in the table might be changed by the detailed design inmanufacturing.

Figure 2.1 Brilliance of insertion devices at the next-generation synchrotron
radiation facility

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3. Beamline
3.1 Overview of beamlines
The storage ring of the NGSR facility consists of 16 unit cells, each of which
has one long straight section and one short straight section. Undulators and MPWs
are installed in long straight sections and short straight sections, respectively. Further
details of the accelerator can be found elsewhere [1]. The maximum of 28 beamlines
can be installed in the storage ring at the NGSR facility. As shown in Fig. 3.1, thebeamlines are numbered in the counterclockwise direction in the storage ring. The
numbering starts with the beamline located east of an injection beam transport linefrom a linear accelerator to the storage ring. The alphabet at the end of the beamline
name (e.g., BL01U and BL02W) stands for the type of ID: U is undulator, and W is
MPW.

Figure 3.1 Beamline map at the NGSR facility
10 beamlines will be constructed as the first phase beamlines when the NGSR
facility is opened: 7 coalition beamlines and 3 shared beamlines. The lineup of thefirst 10 beamline has been suggested by the QST/PhoSIC Beamline Design
Committee to meet the following criteria:1) effective use of the low-emittance light source2) the needs of both academia and industry
3) complementary capabilities with other SR facilities in Japan.

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Table 3.1 shows a list of the first 7 coalition beamlines; the type ofexperiments planned at the main beamlines are shown. The details of the branchbeamlines will be discussed in Section 3.3.
Table3.1 List of the first 7 coalition beamlines (main beamline)
BL No.

Beamline

BL07U

Soft X-ray electronic
structure analysis

BL08U

Soft X-ray operando
spectroscopy

Integrated analysis of
BL08W chemical state andnano/local structure

Type of experiments
A. nano-photoelectron spectroscopy
B. Resonant inelastic scattering
spectroscopy
A. Near-ambient pressure X-ray
photoelectron spectroscopy
B. Near- ambient pressure X-ray absorption
fine structure
A. X-ray absorption fine structure
B. X-ray small angle scattering

BL09U

X-ray operando
spectroscopy

A. Ambient pressure X-ray photoelectron
spectroscopy
B. Ambient pressure Extended X-ray
absorption fine structure

BL09W

X-ray multiscale
structure-analysis

A. Computed tomography
B. Absorption/Phase contrast imaging

BL10U

X-ray coherent imaging

A. Coherent diffraction Imaging
B. Ptychography

BL14U

Soft X-ray imaging

A. Magnetic imaging
B. Soft X-ray Coherent diffraction Imaging

References[1] “Accelerator design report for 3-GeV Next-Generation Synchrotron Radiation
Facility” (September 2020).
https://www.qst.go.jp/uploaded/attachment/18596.pdf

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3.2 Coalition beamlines
3.2.1 Soft X-ray electronic structure analysis beamline (BL07U)
3.2.1.1 Science
In the soft X-ray electronic structure analysis beamline, nano-photoelectron
spectroscopy and resonant inelastic soft X-ray scattering (RIXS) are performed using
high-intensity soft X-rays to visualize the electronic structure of target materials.
In the nano-photoelectron spectroscopy, a monochromatized high-intensity
soft X-ray beam is focused by a focusing mirror to observe photoelectrons emitted
from a target material, which enables us to analyze the valence band andcomposition of the “nano-interface” that determines the properties of catalysts,
battery electrodes, semiconductor devices and so on. In addition, there is a highdemand for the development of a beamline for direct observation of the operatingstate (operando observation), which is close to the actual device operating
environment. As a typical example of research using nano-photoelectron
spectroscopy, we can identify the cause of contact resistance in field-effect transistors(FETs) based on the chemical state change in the charge transfer region extending
from the channel-metal electrode junction to about 500 nm [1]. In the GaN/AlGaN
high-electron-mobility transistor (HEMT), which is expected as a next-generation
high-power, high-frequency device, the cause of the "current collapse phenomenon"
in which the drain current decreases from the original performance due to highvoltage stress was found to be accumulation of electrons trapped at the GaN/AlGaN
interface [2]. Here the operando measurement played an essential role in theobservation. In the near future, in accordance with the rapid downsizing of theelectronic devices, the spatial resolution for the nano-photoelectron spectroscopy
should be in the order of 10 nm, which is one order better than the existing 100 nm
order. It is expected to be a complementary method to surface microscopy probes
such as STM, SEM, and AFM, providing pinpoint element-specific and chemical-statespecific information.
In the RIXS spectroscopy, core electron of a particular element is excited bya monochromatic soft X-ray and subsequent soft X-ray emission occurs by a radiativetransition from a valence state to the excited core state. Using the angle-resolved
high-energy-resolution soft X-ray spectrometer, we can obtain soft X-ray emission
spectra for a series of scattering angles, which can produce an energy dispersion
curve against momentum transfer of elementary excitations. In addition to theconventional use, the angle resolved experiment can provide spatial information likethe size of nanoparticles or fluctuations in a liquid as observed in small angle X-ray
scattering. RIXS is a photon-in and photon-out process and is most compatible with
operando observation, has a high degree of freedom in the environment such as16

solids, liquids, and gases, can accommodate external fields, and has high bulk
sensitivity (>100nm) compared to the photoelectron spectroscopy. It is expected to
be a novel analytical method that strongly supports water-related science, such as
foods, organisms and living organisms that contain water, aqueous solutions, water
bubbles, and aqueous interface for functional materials [3,4]. The advantage of highefficiency measurement makes it possible to perform RIXS measurements undervarious conditions such as concentration, temperature, external field and so on,which was difficult in the present system due to beamtime constraints.
3.2.1.2 Specifications
The performance of the beamline is summarized in Table 3.2. An APPLE-II
EUV undulator will be installed in the long straight section. For the first order light, it
is capable of generating light from 50 to 1000 eV (EUV to soft X-rays) with a sufficient
flux of 1015 photons/sec/0.1% BW. For the use of nano-photoelectron spectroscopy,
an energy resolution better than 50 meV can be achieved at 1000 eV. For RIXS, theenergy resolution on the source side is set to E/ΔE ~10,000-30,000 in order to surpassthe conventional standard resolution E/ΔE ~ 10,000 (the combined energy resolutionof the source and spectrometer). The flux on the sample is estimated to be on theorder of 1013 photons/sec. The beam size on the sample is 50 nm by using a Waltertype focusing mirror, which is characterized by its high transmission efficiency andthe fixed focal position over a wide energy range. Although the flux on the sample isTable 3.2 Beamline specifications

Beamline
Insertion device

Soft X-ray electronic structure analysis
APPLE-II type undulator(APPLE-EUV：75 mm×56 periods)

Photon energy range
Energy resolution（E/ΔE）

50 ~ 1000 eVPolarization

10,000 ~ 30,000
Horizontal linear polarization (100 ~ 1000 eV)
Vertical linear polarization (100 ~ 1000 eV)
Right & left circular polarization(50 ~ 1000 eV)

Photon flux (20 m from the~1015 photons/sec/0.1%BW
light source, 1×1 mm2 slit)
Spot size @ sample
50 nm ~ 10 μm@1000 eV

17

reduced by around half due to the reflection efficiency of the mirror, the obtained
EUV and soft X-ray intensity is sufficient for the measurement.
3.2.1.3 Beamline optics
The configuration of this beamline is shown in Fig. 3.2. After being reflectedhorizontally by the cylindrical mirror M0 to reduce the heat load, the incident light is
led to the entrance slit S1 to determine the virtual source size and improve the energy
resolution. A curved cylindrical mirror M1 converges the light in the vertical direction,
and a plane mirror M2 vertically reflects the light toward the grating, where it ismonochromatized by a variable line spacing diffraction grating, which is often usedin the EUV and soft X-ray region, and the light of the required wavelength is extracted
by the exit slit S2. A soft X-ray chopper, which can extract the necessary bunches fromthe pulse train of the SR beam, is optionally inserted before the exit slit to enable
time-resolved measurements using a single bunch and/or measurements ofbiological samples and catalysts that are susceptible to irradiation damage. The
monochromatic light through the exit slit is directed to the tandemly aligned nanophotoelectron spectroscopy and RIXS endstations. When the RIXS station is used, thesample holder of the upstream nano-photoelectron spectroscopy station is retracted
to pass the beam to the RIXS station. The focusing mirror placed just before each
end-station is planned to be a Walter-type focusing mirror that can be easily adjusted
and can be retracted when it is not in use.

Figure 3.2 Overview of soft X-ray electronic structure analysis beamline (BL07U)

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3.2.1.4 End-station
3.2.1.4.1 A port: Nano-photoelectron spectroscopy station
An overview of the nano-photoelectron spectroscopy system is shown in Fig.
3.3. Monochromatized EUV/soft X-ray beam is focused on a sample at φ50-100 nm,
and the emitted photoelectrons are detected by an energy-dispersive and angledispersive electron analyzer. This enables not only angle-resolved photoemission
spectroscopy of conventional and small-sized (< 1m diameter) single-crystal
samples, but also depth-resolved measurements of devices and buried interfaces
down to around 3 nm. The sample can be scanned by a piezo-driven x-y stage, whichenables two-dimensional mapping of photoelectrons. The system is equipped with asample exchange mechanism and electrodes as well as a multi-probe head for
operando measurements. A spatial resolution of 50 nm both in horizontal and verticaldirection will be achieved by using the Walter-type focusing mirror. Thanks to thehigh photon flux of the incident beam and the high transmission of the focusing
optics, it is possible to conduct both combinatorial mode experiments where
measurements are made under various (operando) conditions, and the other mode
where two-dimensional mapping measurements with high spatial resolution (φ50nm) are made over a large area of the sample. In addition, the high energy resolutionof the incident beam will enable detailed electronic structure analysis.

Figure 3.3 Schematic diagram of the nano-photoelectron spectrometer.

193.2.1.4.2 B port: Resonant inelastic soft X-ray scattering station
An overview of the resonant inelastic soft X-ray scattering measurement
system is shown in Table 3.3 and Fig. 3.4. The system is equipped with an angleresolved soft X-ray emission spectrometer with a 2.5 m arm from the sample to thedetector that includes three valid-line-spacing gratings with an improved slope-error
for broadband spectroscopy in the range of 50-1000 eV and high spatial resolution
soft X-ray CCD detector with its resolution better than 5 m. Combining the soft Xray spectrometer with the state-of-the-art Walter-type mirror that can focus theincident beam smaller than φ 0.5 m on the sample, the total energy resolution willbe E/E~20,000 (26 meV @ O 1s edge). Depending on the irradiation damage thefocus size can be tuned from 0.5 m to 5 m. RIXS is one of the spectroscopic
methods that requires the highest incident photon flux. To avoid the irradiation
damage of fragile samples, we will develop and introduce an operando spectroscopy
system (temperature, humidity, electric field, magnetic field, etc.) that enables fastsample position scanning and/or liquid jet system with total sample recovery.
According to requests from users and by scientific needs, the system will be upgradedto accommodate real ambient pressure measurement without window materials butwith differential pumping.

Table 3.3 Specifications of Resonant inelastic soft X-ray scattering equipment
Photon energy range

50〜1000 eV

Total Energy resolution（E/ΔE）

10,000〜20,000

Spot size @ sample

500 nm〜5 μm

Temperature range

6〜500 K

Scattering angle range

45〜135° & 0.1°

& angular resolution

20

Figure 3.4 Schematic diagram of a high-efficiency, high-resolution RIXS station.

References[1] N. Nagamura, K. Horiba, S. Toyoda, S. Kurosumi, T. Shinohara, M. Oshima, H.
Fukidome, M. Suemitsu, K. Nagashio, A. Toriumi, Appl. Phys. Lett. 102, 241604(2013).
[2] K. Omika, Y. Tateno, T. Kouchi, T. Komatani, S. Yaegassi, K. Yui, K. Nakata, N.
Nagamura, M. Kotsugi, K. Horiba, M. Oshima, M. Suemitsu, H. Fukidome, Sci. Rep.
8, 13268 (2018).
[3] K. Yamazoe, Y. Higaki, Y. Inutsuka, J. Miyawaki, Y.-T. Cui, A. Takahara, Y. Harada,
Langmuir 33, 3954-3959 (2017).
[4] R. Watanabe, T. Sakamoto, K. Yamazoe, J. Miyawaki, T. Kato, Y. Harada, Angew.
Chem. Int. Ed. 59, 23461-23465 (2020).

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3.2.2 Soft X-ray operando spectroscopy beamline (BL08U)
3.2.2.1 Science
Soft X-ray spectroscopies, such as photoemission or absorption, have been used
to investigate electronic states in matters. Recently, there have been needs to directly
trace them in materials during operation and to unveil their functionalities. Suchexperiments, so-called “operando observation”, have been developed vigorously inboth academic and industrial fields. Giving an example of catalytic reaction, operando
observation with soft X-ray beam has an advantage to probe in situ chemical statesof both heavy metal atoms in catalysts and light elements, such as C, N. and O, inreacting molecules. The technique allows us to understand the whole picture of thereaction.

Figure 3.5 AP-XPS system and science at soft X-ray operando spectroscopy[1,2]
The soft X-ray operando beamline, BL08U, offers advanced instrumentation ofAmbient Pressure X-ray Photoelectron Spectroscopy, AP-XPS. The beamline isdesigned primarily for operando chemical analysis of interfaces/surfaces underreaction or working conditions and it is aimed to reveal the detailed mechanisms.
Research at the beamline covers catalysts, battery, and bio-materials, for examples.
Measurements of AP-XPS allow users to examine chemical states of their samples withelement selectivity, with precise quantitative evaluation, and under the actual
environments. Gas pressure in AP-XPS will reach 1 atm (760 Torr), which is large
enough to link gas pressure of reaction experiments in users’ laboratories. These
instruments at the beamline make it possible to track varieties of catalytic reactions,such as methanol synthesis on CuZn, that have not been realized in conventional
systems of near-ambient pressures XPS (NAP-XPS), typically at 1-20 Torr. In addition,
the beamline will be also equipped with nano-beam optics to spatially visualize
chemical states or to track local functions in non-uniform samples. The beamline
BL08U will be a research base to examine energy materials to sustain our societies
and also to be a platform to study cutting-edge nanomaterials, such as nanopatterned
catalysts.

22

3.2.2.2 Specifications
Table 3.4 Beamline specifications
Beamline
Insertion device

Soft X-ray Operando Spectroscopy
APPLE-II undulator（APPLE-SX：56 mm×75 periods）

Photon energy range

130〜2,000 eVEnergy resolution（E/ΔE）> 10,000
Horizontal linear polarization（130〜2000 eV）

Polarization

Vertical linear polarization（230〜2000 eV）
Right & left circular polarization（180〜1400 eV）

Photon flux @ sample
Spot size @ sample>1×1012 photons/sec/0.01%BW
50 nm〜3 μm

Figure 3.6 Overview of soft X-ray operando spectroscopy beamline (BL08U). M
and G stands for a mirror and a grating, respectively, while S represents a slit.
The main and branch beamlines are individually installed with end stations (ES’s).

23

3.2.2.3 Beamline optics
The beamline BL08U employs an entrance-slitless variable-included-angle
Monk–Gillieson mounting monochromator with a varied-line-spacing plane grating(G), as shown in Fig. 3.6. Two types of the diffraction gratings, graving densities of
600 lines/mm and 1200 line/mm, will be installed. The entrance-slitless layout
effectively restricts the magnification of the monochromator and facilitates hightransmission. Beam focusing will be operated with a combination of a KB mirror anda Wolter mirror. A soft X-ray beam will be divided into the main and branch beamlines
by a mirror (Ms) at the downstream of the grating.
3.2.2.4 Endstation
A soft X-ray AP-XPS system will be installed at the main beamline. The
instrument is equipped with a mass spectrometer and with an electron analyzer thathas a multi-differential pumping unit in the electrostatic lens. The system will allow
users to make measurement of AP-XPS as well as AP-NEXAFS (Near-edge X-ray
absorption fine structure) in the gas pressure, tuned up to 1 atm. Nanobeam with abeam size of 50 nm will also be ready at the station.
In the branch beamline, we plan to install a measurement system of XPS andNEXAFS that makes remote experiments by users or automatic measurements ofmail-in samples.
References[1] T. Koitaya, S. Yamamoto, Y. Shiozawa, Y. Yoshikura, M. Hasegawa, J. Tang, K.
Takeuchi, K. Mukai, S. Yoshimoto, I. Matsuda, and J. Yoshinobu, ACS catalysis 9,4539 (2019).
[2] T. Koitaya, S. Yamamoto, I. Matsuda, J. Yoshinobu, e-J. Surf. Sci. Nanotechnol., 17,
169 (2019).

24

3.2.3 Integrated analysis of chemical state and nano/local structure beamline(BL08W)
3.2.3.1 Science
Integrated analysis of chemical state and nano/local structure beamline(BL08W) can obtain information on the chemical state and the structure using X-raysof 2.1 to 17.4 keV. The main beamline aims for X-ray absorption fine structure (XAFS)
and Small-Angle X-ray Scattering (SAXS) measurements using X-rays from 2.1 to 13
keV. In XAFS measurement, the electronic structure (valence, chemical species) andcoordination structure of the specific element can be analyzed from the spectrum
near the absorption edge (X-ray absorption near-edge structure: XANES).
Furthermore, information on the local structure (interatomic distance, coordination
number) around a specific element can be analyzed from the region away from theabsorption edge (extended X-ray absorption fine structure: EXAFS). On the other hand,
SAXS measurement can obtain information on nanoscale density difference in asample, which means the structure of scatters (size, shape, distribution, higher-order
structure, surface structure) from several nm to several hundred nm. This beamline
uses complementarily these measurement methods to evaluate the correlation
between changes in the electronic structure of specific atoms and macroscopic
structural changes under dynamic conditions in polymers, metals, battery materials,
etc. (Figure 3.7).
In this beamline, since continuous energy scanning can be easily performed
with energies lower than 3.5 keV, the K-edges of phosphorus and sulfur and the Ledge of palladium, which play important roles in functional materials and biomaterials,
are the objects of measurements. Furthermore, dynamic anomalous small-angle Xray scattering (ASAXS) using the anomalous effect in near absorption edge canvisualize the time-space distribution of specific atoms.
The use of this beamline in combination with the X-ray operando
spectroscopic beamline (BL09U), X-ray multiscale structure-analysis beamline(BL09W), and X-ray coherent imaging beamline (BL10U) advance hierarchicalstructure analysis, which is important for materials science and engineering. Besides,
two branch beamlines for multipurpose X-ray diffraction and general-purpose SAXS
measurement will be prepared by taking advantage of the wide beam in thehorizontal direction from MPW. The flux of the branch beamlines is larger than thatof the SPring-8 bending magnet beamline. Furthermore, we are planning to introduce
soft X-rays from the adjacent soft X-ray operando spectroscopic beamline (BL08U)

25

into this beamline and build a system that irradiates the sample with both soft X-rays
and hard X-rays as the next phase development in the future.

[1]
[2]

[3]

Figure 3.7 Measurement methods for the beamline and applications [1-3].

26

3.2.3.2 Specifications
Table 3.5 Beamline specifications
Beamline
Insertion device
Photon energy range

Integrated analysis of chemical
nano/local structure
MPW (120 mm×5 periods)
Master beamline: 2.1〜13 keV

state

and

Branch beamline: 8〜17.4 keV
Energy resolution（E/ΔE）

1,600~13,000

Polarization
Photon flux (20 m from the lightsource, 1×1 mm2 aperture)
Spot size @ sample

Horizontal linear polarization
2×1011〜2×1012 photons/sec/0.1% b.w.
150 m×50 m

3.2.3.3 Beamline optics
Figure 3.8 shows the bird's eye and top views of the Integrated analysis ofchemical state and nano/local structure beamline. The beam emitted from the MPW
is incident on the Si (111) double crystal monochromator (DCM), and an X-ray beamof arbitrary energy reflected from the energy range of 2.1 to 13 keV is emitted at a
fixed position. The chamber of the DCM will be miniaturized by setting the offset
distance between the optical axes of the incident X-ray beam and the outgoing X-ray
beam to 50 mm and limiting the upper limit of the energy used to 13 keV. A toroidal
mirror coated with Pt is installed downstream of DCM so that two-dimensional
focusing of 150 µm in horizontal and 50 µm in vertical can be achieved at the focal
point at 45 m from the light source. In the upstream area of the experimental hatch,boron carbide (B4C), Ni-coated, and Pt-coated plane mirrors are installed and can beused to remove higher harmonics.
3.2.3.4 Endstation
The size of the experimental hatch of the master beamline is 4 m in width ×
12.5 m in length × 4 m in height. An optical bench (1.5 m in width and 3 m in length)
for installing a sample stage, detector, exposure shutter, absorbers will be installed in
the middle area of the experimental hatch. Besides, slits for reducing parasitic
scattering can be installed where needed. When conducting SAXS measurements, thesample is placed in a vacuum chamber and the chamber is connected to the detector
by a vacuum path.

27

Figure 3.8 Overview of integrated analysis of chemical state and nano/local
structure beamline (BL08W)
SAXS measurements up to a camera length of 13 m can be performed in themain beamline. The light path from the sample to the detector positions is connectedwith a vacuum pipe. Assuming that the energy used is 6 keV, the q range that can becovered is 10-3 nm-1 at the camera length of 13 m. Furthermore, the main beamline issupposed in situ SAXS measurement using a large apparatus provided by the user.
XAFS measurements can be conducted by the conversion electron yield
method, fluorescent X-ray yield method, and transmission method. The time
resolution during XAFS measurement is 10 s. Furthermore, the measurement
arrangement for transmission mode allows simultaneous measurements of XAFS andSAXS on the same sample. When conducting XAFS and SAXS measurements at theenergy of less than 4 keV or less, it is necessary to replace the sample surroundings
with a vacuum (for solids) or He atmosphere (for solutions) to suppress the effect of
decreased transmissivity of X-rays due to the atmosphere.

28

A high-temperature furnace and a cooling/heating stage can be attached tothe sample stage on the optical bench placed in the experimental hatch, andoperando/in situ observation can be conducted both XAFS and SAXS under variabletemperature conditions. Gas supply equipment will be installed to enablemeasurements under reaction conditions. In addition, the downstream of theexperimental hatch can be equipped with a user-carrying device up to 1.5 m in widthand 2 m in length.
References[1] T. Hirai, Y. Nagae, K. L. White, K. Kamitani, M. Kido, T. Uchiyama, M. Nishibori, Y.
Konishi, K. Yokomachi, R. Sugimoto, K. Saigo, T. Ohishi, Y. Higaki, K. Kojio, A.
Takahara, J. Polym. Sci., Part A: Polym. Chem. 53, 2075-2078 (2015).
[2] K. Kamitani, A. Hamada, K. Yokomachi, K. Ninomiya, K. Uno, M. Mukai, Y. Konishi,
N. Ohta, M. Nishibori, T. Hirai, A. Takahara, , Langmuir 34, 8516-8521 (2018).
[3] Y. Higaki, K. Suzuki, Y. Kiyoshima, T. Toda, M. Nishiura, N. Ohta, H. Masunaga, Z.
Hou, A. Takahara, Macromolecules 50, 6184–6191 (2017).

29

3.2.4 X-ray operando spectroscopy beamline (BL09U)
3.2.4.1 Science
X-ray operando spectroscopy beamline (BL09U) is a beamline in which thebulk electronic structure and geometric structure of materials can be studied byhard X-rays with a bulk sensitivity. More specifically, hard X-ray Photoemission
Spectroscopy (HAXPES) and X-ray absorption fine structure (XAFS) spectroscopy
will be used to investigate the bulk electronic structures and geometric structureof materials under operando conditions.
Utilizing the high brilliance of IVU undulator, the XAFS system will allow
measuring trace elements, 2D scanning microscopy XAFS with a spatial resolutionof 100 nm, and quick XAFS (QXAFS). The HAXPES system will start withmeasurements in high vacuum, and will be upgraded to measurements underatmospheric pressure (Ambient pressure HAXPES, AP-HAXPES). This beamline will
be able to visualize reactions in a wide range of materials, which include catalysts,
batteries, power devices, steels, and biomaterials.
By the complementary use of soft X-ray operando spectroscopy beamline(BL08U), one can obtain information on the electronic structure and structure fromthe surface to the bulk.
3.2.4.2 Specifications
Table 3.6 Beamline specifications
Beamline
Insertion device
Photon energy
Energy resolution（E/ΔE）
Polarization

Photon flux @ sample

Spot size @ sample

X-ray operando spectroscopy
IVU（22 mm×190 periods）
6 keV（HAXPES, AP-HAXPES）
2.1 ~ 15 keV（XAFS）> 20,000 @6 keV（HAXPES、AP-HAXPES）>5,000（XAFS）
Horizontal linear polarization（2.1 ~ 15 keV）
~7x1012 photons/sec (E/ΔE > 20,000, spot size 6.0 μm(H) × 0.2 μm (V), 6 keV)
~1.5x1011 photons/sec (E/ΔE > 20,000, spot size 0.16μm (H) × 0.2 μm (V), 6 keV)
100 nm ~ 10 μm @ 6 keV（HAXPES, AP-HAXPES）
100 nm @ 8 keV（XAFS）

30

3.2.4.3 Beamline optics
Figure 3.9 shows an overview of this beamline. Brilliant hard X-rays from the
IVU are first monochromatized by the Si(111) double crystal monochromator (DCM)
in the optical hutch. A high-precision 4-way slit (4WS), placed at the downstream ofthe optical hutch, controls the size of the X-ray beam, which works as a virtual sourceof X-ray nano-focusing optics. In the experimental hutch, high-reflection mirrors(HRM), channel-cut monochromator (CCM), and X-ray nano-focusing optics are
installed. High-order X-rays can be cut off by choosing the coating materials of HRM.
The CCM is used for HAXPES experiments that require higher energy resolution; for
XAFS experiments, the CCM is not used and retracted from the beam path. Theenergy resolving power E/ΔE of > 20,000 can be achieved by using DCM (Si(111)) andCCM (Si(311)). The X-ray nano-focusing optics consists of KB mirrors. In order toachieve the beam size of 100 nm at a sample position, the size of the virtual source
needs to be reduced to ~10 m by the 4WS at the sacrifice of photon flux.

Figure 3.9 Overview of X-ray operando spectroscopy beamline (BL09U)

31

3.2.4.4 Endstation
There are two endstations in the experimental hutch: HAXPES and XAFS
endstations. At the HAXPES endstation, the HAXPES measurements in high vacuum
are allowed at the start-up phase; the upgrade of the system by introducing a
differentially-pumped electron analyzer will enable the HAXPES measurements in a
gas atmosphere above atmospheric pressure. The HAXPES system is designed to be
movable with respect to a focal point of KB mirrors so that the beam size can be
adjusted, and the beam size can be optimized for each sample to avoid beam
damage. At the XAFS endstation, one can perform 2D scanning microscopy XAFS
using the focused X-ray beam with a spatial resolution of 100 nm. In addition, thetemporal resolution of s~ms in EAXAFS measurements will be achieved by QXAFS.
Note that these two endstations can be switched against the same focal point of Xrays.

32

3.2.5 X-ray multiscale structure-analysis beamline (BL09W)
3.2.5.1 Science
The MPW source of the NGSR facility can provide an X-ray beam havingfeatures that cannot be attained at existing SR facilities in Japan, which have potential
to develop a new science frontier in the scheme of coalition concept. The beam hasa large area, a wide bandwidth, and a flux that cannot be achieved with a bending
magnet source at SPring-8 for X-ray energies less than 30 keV. The X-ray multiscale
structure-analysis beamline (BL09W) takes advantage of these features to realize sub
μs temporal-resolution X-ray imaging, sub ms temporal-resolution X-ray
tomography (high-speed-rotation [1] and multi-beam X-ray tomographies [2]), ms
temporal-resolution dispersive XAFS (DXAFS), and dispersive surface X-ray diffraction

Figure 3.10 Measurement methods and their prospective applications.

33

Table 3.7 Specifications of measurement methods and perspective applications.
Methods
X-ray imaging

Max. time
resolution
0.1 μsSpatialResolution

Application examples(μm)
0.2～20Material & bonding failures
Biomimetics

X-ray
tomography

0.1 msDispersive
XAFS

1 ms

10

Catalytic reaction

Dispersive
SXRD

1 ms

10

Surface reaction

0.2～20Phase separation

Inorganic materials

X-ray
diffraction
Residualstressmeasurement
Fluorescent
X-ray imaging

Microfluidics

Organic materials
Practical materials
50

50

Practical materials
Agricultural
products&

marinePractical materials
cultural properties

X-ray
fluorescenceholography

50

Single crystalline (shortand
middle-range-order
structure)(DSXRD [3]) that can make it possible to realize in-vivo, in-situ, and operando
observation of dynamic phenomena with high temporal resolutions and highthroughputs. By complementarily using other BLs such as the integrated analysis ofchemical state and nano/local structure beamline (BL08W) and the X-ray coherent
imaging beamline (BL10U), it will unveil unprecedented spatiotemporal region inmaterials and life sciences.
In addition, the wide beam in the horizontal direction enables us to install
two other branch beamlines, where general-purpose X-ray diffraction experiments(powder, single-crystalline, thin-film, multilayer-film structure analysis, and residual
stress measurement) can be performed with a larger flux than that of the bending
magnet beamlines in SPring-8. Furthermore, in the future, an optionally insertable34

two-dimensional focusing mirror will make it possible to realize scanning residual
stress measurement, scanning fluorescent X-ray imaging, and X-ray fluorescenceholography, which are important for industrial applications. Figure 3.10 and Table 3.7
summarize the measurement methods (specs) and their perspective applications
realized at BL09W.
3.2.5.2 Specifications
Table 3.8 Beamline specifications
Beamline

X-ray multiscale structure analysis

Insertion device

MPW (120 mm×5 periods)

Photon energy range

5 ~ 30 keVEnergy resolution（E/ΔE）~ 1 (white beam)

Polarization

Horizontal polarization

Photon flux @ sample

2×1011 ~ 2×1012 photons/sec/0.1%BW
Non-focusing ： 50 mm (horizontal)×5 mm

Spot size @ sample(vertical) (50 m position from the source)
Focusing：50 μm×50 μm (55 m position fromthe source)

3.2.5.3 Beamline optics
Figure 3.11 shows an overview of this beamline. A large area beam from
MPW is reflected by a water-cooled planar mirror HRM-B (low energy-pass filter) forthe main endstation. The planar mirror is Pt-coated and used at glancing angles
ranging from 3 to 8 mrad, corresponding to maximum energies of the reflected Xray beam, approximately, from 10 to 30 keV. A vertical offset of 15 mm for thereflected beam is kept for a gamma stopper (GS) located downstream of the mirror.
The mirror enables us not only to control of the spectrum of the reflected beam forthe white X-ray imaging experiments but also to effectively suppress higher
harmonics in the experiments of monochromatic X-ray imaging and DXAFS. The
lower limit of the X-ray energy (5 keV) is determined by the absorption by the watercooled beryllium windows for the vacuum beam path to the main endstation. Notethat the L absorption edges of Pt makes it difficult to perform DXAFS experimentsfrom 10 to 15 keV. It is therefore desired that the mirror has Pt and Rh-coated areas
with a stripe shape and they are switchable by a translational stage. In addition, it will

35

Figure 3.11 Overview of X-ray multiscale structure-analysis beamline (BL09W)
be possible in the future to optionally replace the mirror with a Pt-coated toroidal
focusing mirror which provides a two-dimensionally focused beam with a size of 50
μm (1: 1 focusing) at a position 55 m from the source.
3.2.5.4 Endstation
In the main endstation, experiments of monochromatic and white X-ray
imaging, DXAFS, and DSXRD will be implemented for increasing demand of highspeed and/or high-throughput measurements. Monochromatic X-ray imaging canbe performed using a channel-cut crystal, while DXAFS and DSXRD can be done usinga polychrometer. Both the channel-cut crystal and polychrometer will be installed on
an optical table in the upstream side of the endstation. In its downstream side, a large
area space (space A) is kept for user’s apparatuses with a size up to a 3 m x 3 m area
and a 3.5 m height to perform these measurements. A high-speed rotation of asample in the user’s apparatus allows for up to sub ms temporal-resolution X-ray
tomography. A multi-beam imaging system [2] can also be installed in this space. The
latter will make it possible to realize sub ms temporal-resolution 4D X-ray
tomography without rotation of a sample, and therefore enables us not only toobserve living creatures and deformable materials (e.g., liquid, viscoelastic materials)

36but also to introduce a complicated environment around a sample. Because such a
4D X-ray tomography measurement is normally completed in a few seconds, it isdesired that an automatic sample changer is installed in the endstation, which cancontribute to effective manpower management and high-throughput measurements.
The shutter and absorber at the entrance of the endstation should have a sufficiently
high response speed to reduce radiation damage of the samples in the high-speed
and/or high-throughput measurements. Note that highly sensitive and quantitative
X-ray phase-contrast imaging is also possible by an X-ray grating interferometer,
which can be easily installed in both upstream and downstream sides of theendstation. The multimodality of this X-ray grating interferometry is also worth being
noted. It provides three independent images: absorption, phase-contrast, and smallangle-X-ray-scattering (SAXS)-contrast images. The former two can makes it possible
to realize element-selective X-ray tomography, while the latter can provide
information on unresolvable microstructures.
After installing the toroidal focusing mirror, scanning residual stressmeasurement, fluorescent X-ray imaging, and X-ray fluorescence holography will bepossible with the two-dimensionally focused beam with a size of 50 μm at theposition 55 m from the source. In these measurements, samples are located on adiffractometer in the space A.
References[1] R. Mashita, W. Yashiro, D. Kaneko, Y. Bito, and H. Kishimoto, J. Synchrotron Rad.
28, 322-326 (2021).
[2] W. Voegeli, K. Kajiwara, H. Kudo, T. Shirasawa, X. Liang, and W. Yashiro, Optica 7,
514-517 (2020).
[3] W. Voegeli, K. Kajiwara, H. Kudo, T. Shirasawa, X. Liang, and W. Yashiro, J. Appl.
Phys. 110, 102209 (2011).
[4] http://www.spring8.or.jp/wkg/BL28B2/solution/lang/SOL-0000001524[5] https://www.srigroup.co.jp/data/open/cnt/3/6433/1/2015_137.pdf.
[6] K. Kikuchi, M. A. Stremler, S. Chatterjee, W.-K. Lee, O. Mochizuki, and J. J. Socha,
Sci. Rep. 8, 4885 (2018).
[7] https://www.itmedia.co.jp/news/articles/1705/16/news097.html.

37

3.2.6 X-ray coherent imaging beamline (BL10U)
3.2.6.1. Science
Coherent X-ray imaging, such as coherent diffraction imaging andptychography, can provide imaging with high spatial resolution at the nanoscale.
These methods allow us to quantitatively visualize the spatial distribution of electron
density and lattice distortion of a sample by capturing them as phase shift of X-rays.
In other words, coherent X-ray imaging is an extremely useful imaging technique forvisualizing the spatial distribution of microstructures at the mesoscale, which lies
between the atomic and macroscopic scales. In this beamline (BL10U), meso-scale
structure visualization by coherent X-ray imaging [1] is the cornerstone, and local
atomic imaging by X-ray fluorescence holography [2], holotomography [3], and fullfield imaging by imaging microscopy [4] are used in a complementary manner toseamlessly visualize structures from atoms to sub-millimeters. In addition, a variety of
information on elements and chemical states is obtained by combining scanning Xray fluorescence microscopy for mapping trace elements [5] and X-ray absorption
spectroscopy [6, 7] (Fig 3.12).
Many functional materials have spatial hierarchical structures ranging fromatomic to macro scales, and the mesoscale microstructures formed by various
processing techniques are heterogeneous and are the source of functional expression.
On the other hand, in living organisms, the mesoscale is also a spatial scale dominatedby higher-order structures of biological macromolecules and cellular organelles, andits visualization is essential for understanding cellular functions [8]. The use of thisbeamline will enable us to pioneer materials science and biology at the mesoscale. In
addition, the imaging technology provided by this beamline is expected to be applied
not only to academia but also to industry. For example, solving various manufacturing
problems in industry, such as the cross-linked heterogeneous structure of tire rubber,the elution and decomposition process of platinum catalysts in fuel cells, and the
diffusion path of lithium ions in the cathode active material of storage batteries, isFigure 3.12 Three-dimensional valence imaging by ptychography-XAFS

38

expected to lead to the optimization of processing technology and the creation of
new functional materials.
3.2.6.2. Specifications

Table 3.9 Beamline specifications
Beamline

X-ray coherent imaging

Insertion device

IVU (22 mm×190 periods)

Photon energy range

2.1~15 keVEnergy resolution（E/ΔE）

7,000

Polarization

Horizontal linear polarization（2.1 ~ 15 keV）

Photon flux @ sample~ 1013 photons/sec (@5keV）~ 1011 photons/sec (@5keV, coherent illumination)~ 1 μm (@5keV, Experimental hatch 1 @focusing)

Spot size @ sample~ 50 μm (@5keV, Experimental hatch1 @nonfocusing)~ 200 nm (@5keV, Experimental hatch2 @focusing)

3.2.6.3. Beamline optics
In this beamline, as shown in Fig. 3.13, high-brightness SR emitted from theundulator is monochromatized by a liquid nitrogen-cooled Si double-crystal
monochromator and mirror optics, and 2.1 keV to 15 keV X-rays are supplied to a
fixed position at the end station. The mirror optics consists of three planar mirrors,
and by adjusting the grazing incidence angle of each mirror, the height of the opticalaxis just after the mirror optics is kept constant during insertion and retraction. The
plane mirror has three surfaces on a single-crystal silicon substrate: silicon mirror
surface, Ni-coated mirror surface, and Rh-coated mirror surface, and the surface canbe selected according to the energy used. In addition, a high-precision four-quadrant
slit is placed downstream of the optical hutch and its aperture size is adjusted tocontrol the spatial coherence and flux of X-rays required for each measurement.

39

3.2.6.4 Endstation
The end station consists of two experimental hutches arranged in tandem:
experimental hutch 1, 29 m away from the source, and experimental hutch 2, 47 maway from the source. The size of the experimental hutch 1 is 6 (optical axis direction)× 4 (W) × 3.3 (H) m3. On the other hand, the size of the experimental hutch 2 is 10(optical axis direction) × 4 (W) × 3.3 (H) m3. Total-reflection focusing mirrors (focusing
size ~1 μm @ 5 keV) are installed upstream of the experimental hutch 1, and various
imaging experiments (e.g., coherent diffraction imaging, ptychography, X-ray
fluorescence holography, Bragg coherent diffraction imaging [9], cryogenic coherent
diffraction imaging [10], and full-field imaging with total reflection imaging mirrors.
In the experimental hutch 2, total reflection focusing mirrors (focusing size ~200 nm@ 5 keV) and a multimodal imaging system are installed for high-resolution imaging
by ptychography, wide-field imaging by holotomography, and imaging XAFS
measurements. In the user space upstream of the experimental hutch 2, for example,
trace element mapping and XAFS measurements are performed using a scanning Xray fluorescence microscope. Coherent diffraction imaging and X-ray photon
correlation spectroscopy experiments requiring a camera length of more than 10 m
can also be performed by placing samples in experimental hutch 1 and image
detectors in experimental hutch 2. As the image detectors, high-count rate image
detectors such as CITIUS being developed at RIKEN, and visible light conversion
image detectors with a high resolution of several microns will be available.

40

Figure 3.13 Overview of X-ray coherent imaging beamline (BL10U)
 Experimental hatch 1
Permanent installation

Total-reflection focusing mirrors

Examples of user equipment


Cryogenic coherent X-ray diffraction imaging system

X-ray fluorescence holography systemCoherent X-ray diffraction imaging system with Bragg geometry

Full-field Transmission X-ray microscope Experimental hatch 2
Permanent installation

Total reflection focusing mirrors



X-ray ptychography apparatus

Examples of user equipment


Scanning X-ray fluorescence microscope

41

References[1]

H. N. Chapman & K. A. Nugent, Nature Photonics 4, 833-839 (2010).

[2]

K. Hayashi et al., J. Phys.: Condens. Matter 24, 093201 (2012).

[3]

M. Hubert et al., Appl. Phys. Lett. 112, 203704 (2018).

[4]

S. Matsuyama et al., Sci. Rep. 7, 46358 (2017).

[5]

M. Shimura et al., Cancer Research 65, 4998-5002 (2005).

[6]

N. Ishiguro et al., ChemPhysChem 15, 1563-1568 (2014).

[7]

M. Hirose et al., Communications Chemistry 2, 50 (2019).

[8]

Y. Nishino et al., Phys. Rev. Lett. 102, 018101 (2009).

[9]

T. Kawaguchi et al., Phys. Rev. Lett. 123, 246001 (2019).

[10] M. Nakasako et al., Rev. Sci. Instrum. 84, 093705 (2013).

42

3.2.7 Soft X-ray imaging beamline (BL14U)
3.2.7.1 Science
Soft X-ray absorption spectroscopy (SXAS) provides element-specificinformation about the electronic and magnetic states of materials through coreelectron excitation at the absorption edge of each element. In modern materials
science, it is widely known that inhomogeneities in the microstructure on the nm toμm scale greatly affects the function of the materials. This fact implies that material
properties can be improved through appropriately controlling the microstructure.
However, until very recently it has been difficult to visualize the chemically andmagnetically inhomogeneous distributions superimposed on the microstructureusing conventional observation techniques. Fortunately, with the advent of SXAS
microscopy techniques, quantitative visualizations of the inhomogeneous
distributions have been realized, which has facilitated analysis of the local electronic
and magnetic properties in materials with nm-scale microstructures. The acquired“large-scale-data” describing the locally varying properties contains information
which could ultimately lead to discoveries of hidden and essential properties of thesematerials by making full use of modern data science techniques.
The SXAS microscope has a variety of applications. Electrode materials inenergy devices are using transition metal compounds, carbon materials, and oxidematerials, in which the nm-scale structures relate to the chemical states that affectthe performance of the devices. Furthermore, chemical and electronic states at the
nm-scale need to be understood in many complex materials of interest to both
fundamental science and advanced material technologies: for example, the bioelements and other trace elements in biological samples, microscopic samples
derived from asteroids, environmental materials such as microplastics, and organic
materials used in many products such as rubber, plastics, and polymers. Magnetic
circular dichroism (MCD) of SXAS, in which circularly polarized soft X-rays are used,is the most popular way to evaluate the element-specific magnetic properties ofmaterials. The SX-MCD measurement technique has found applications in studies ofpermanent magnets, spintronics materials, and other novel magnetic materials, which
are the key materials for energy products and information technologies. As with SXAS,SX-MCD microscopy observations are crucial for understanding the local magnetic
interactions between magnetic grains and will be an important tool for elucidating
the microstructure-dependent coercivity mechanism. The BL14U beamline is mainly
dedicated to the SXAS and the MCD microscopies and will be constructed at the
BL14U port in which soft X-ray radiation is generated using a twin helical undulator.
In the twin helical undulator, the upstream and downstream helical undulators arearranged in tandem and generate left- and right-circularly polarized soft X-rays,

43

respectively. The helicity of the soft X-ray is switched by only changing the undulator
gaps to minimize the effect of polarization changes on the electron orbits of thestorage ring without modulation of the electron orbits.
From a technical point of view, various types of SX microscopy techniques
have been developed in many synchrotron facilities all over the world, so far,including scanning, imaging, and coherent diffraction. A great advantage of the
NGSR facility, which is a low emittance light source of 1.1 nm·rad, is to use the highcoherent flux which makes it possible to record coherent diffraction images withhigh-speed and high-quality. Besides, the small electron beam size increases
practically the intensity of the focused X-ray beam illuminating the sample surface.
The BL14U beamline has advantage of the nm scale information of materials andcontributes to the development of “nm scale science and technologies”.
3.2.7.2 Specifications
Table 3.10 Beamline specifications

Beamline
Insertion device
Photon energy range
Energy resolution（E/ΔE）
Polarization
Photon flux
(exit slit = 25μm )Spot size @ sample

Soft X-ray Imaging
Twin helical undulator (THU)(56 mm×35 periods×2 sets)
Right circular polarization 1 set
Left circular polarization 1 set
250 ~ 1400 eV
3000 ~10000
Right & Left circular polarization (250 ~ 1400 eV)
5.0×1012 ~ 3.9×1013 photons/sec
50 nm〜10 μm

3.2.7.3 Beamline optics
Figure 3.14 shows the optical layout of the BL14U. The soft X-rays emitted
from THU are introduced into the entrance slit of the monochromator through theM0 mirror, the beam splitter, and the M1 mirror. The monochromator is a constantangle-of-deviation type using a varied-line-spacing plane grating. Two diffraction
gratings are set in the monochromator; the line densities of the diffraction grating
are 600 and 1200 lines/mm. A high-precision 4-way slit is placed in front of the
focusing mirror system to control the spatial coherence and flux of X-rays required
for each measurement. The focusing mirror system is a combination of a KB mirror

44and a rotational Walter mirror, which is currently under development to make thebeam size variable from 50 nm to 10 μm. The optical layout by applying a variableangle-of-deviation type monochromator is also discussed as an alternative design.

Figure 3.14 Overview of soft X-ray imaging beamline (BL14U)
3.2.7.4 Endstation
At the end stations of the BL14U, two types of imaging systems will be
installed. One is a ptychographic spectro-microscopy based on the coherent
diffraction technique with a spatial resolution of less than 10 nm. The other is ascanning microscope with a focusing optical system that produces a several 10nmscale beam spot, where both transmission and electron/fluorescence yield detection
are planned. The two imaging systems will be switched by moving the wholeapparatus using guide rails installed on the floor. A preferable application in the
branch beamline that is under consideration is a scanning transmission microscope
because the high beam intensity is unnecessary when using a photon-counting
detector to record the transmitted soft X-ray. As an attractive usage of the beamlines,
simultaneous measurements at both the main and branch beamlines with different
energy regions could possibly be performed by setting the relevant undulator gaps

45

accordingly for each measurement. Of course, interference and/or contamination
between two distinct color soft X-rays should be investigated in advance.

46

3.3 Branch beamlines
3.3.1 Concept of branch beamlines
A beamline at the NGSR facility consists of a main beamline and branchbeamlines. At SR facilities, it is common to have multiple branch beamlines toaccommodate different endstations to meet the demands by the users for various
measurements. However, X-ray beam is usually delivered to only one of themain/branch beamlines and the users can perform experiments at only one
endstation at the same time. The users’ beamtime is limited by the operation hoursof the storage ring.
In order to maximize the users’ opportunity to use the high-brilliance X-rays
at the NGSR facility, X-rays beam is split into main beamline and branch beamlines.
The users can operate multiple systems working in parallel. This is called as asimultaneous branching method. The main beamline hosts advanced measurement
stations, which make best use of high-brilliance and coherence of X-rays at the NGSR
facility. In contrast, the branch beamline is equipped with automated measurement
stations, in which high throughput routine measurements are performed with help ofrobotics and automation technology. In addition, the research and developments forthe future measurement methods and optics will be performed at the branchbeamlines. This allows the NGSR facility to increase the productivity and thecompetitiveness in the cutting-edge SR science.
3.3.2 Methods for beam branching
The simultaneous branching methods at the NGSR facility are summarized
in a matrix format in Fig. 3.15. We consider the wavefront splitting by an edge mirror
for soft X-rays, and the amplitude/wavefront splitting by crystal (Si and diamond) for
tender/hard X-rays. The applicability of the methods for each X-ray energy range isshown in the matrix. For the soft X-ray region, sufficient reflectance is available with
sufficiently large angle of reflection to separate the branched beams. The wavefront
splitting by edge mirror will be used for the branching of the soft x-ray beamlines.
For the hard X-ray region, both Si crystal and diamond crystal provide suitable Braggreflections for the branching. We plan to adopt the amplitude splitting by the thin
diamond crystal for the narrow beam from the hard x-ray undulator (IVU), while
adopt the wavefront splitting by the Si crystal for the relatively wide beam from MPW,
as shown in Fig. 3.16.

47

3.3.3 Branch beamline list
The branch beamlines at the first phase are summarized in Table 3.11. With
the simultaneous branching methods, there will be 15 beamlines in total at the first
7 coalition beamlines that can be operated in parallel.
As shown in Fig. 3.16, MPW beamlines (BL08W and BL09W) will be branched into
three beamlines using the wavefront splitting by two Si crystals. BL09U (IVU
beamline) will be branched into main beamline and one branch beamline using theamplitude splitting (transmitted beam and reflection beam) by thin diamond crystal.
Since a large coherent flux is required for coherent diffraction imaging, BL10U (IVU
beamline) will not be branched.
In the case of the SX beamline, a part of the X-ray beam will be reflected by
the edge mirror into the branch beamline with a reflection angle of about 4°. Notethat measurements at the branched beamline are restricted by the undulator gap
determined by the main beamline. Therefore, the operation column of the undulator
beamline is described as "semi-simultaneous" in the table. This problem can be
mitigated by pre-adjusting the allocation of the users’ beamtime.

48

Figure 3.15 Beam splitting methods.

Figure 3.16 Schematic views of the beam splitting by thin diamond crystal(upper) and by Si crystals (lower).

49

Table 3.11 Branch beamlines in the first stage
BL No.

(ID)
Range

BL nameBranchmethodBL07U(APPLEEUV)EUV,SXSoft X-ray
Electronic
Structure
Analysis

underconsideration

BL08U

BL08W

BL09U

Soft X-ray(APPLEoperando
SX)
spectroscopy
SX

(MPW)
TX, HX(IVU)
TX

Wavefront
splitting byedge mirror

Branches
Main
Branch#1
Main
Branch#1
Main

Integrated
analysis ofchemicalstate andnano/local
structure

Wavefront
splitting by
Si crystal

X-ray
operando
spectroscopy

Amplitude
splitting by
thin diamond

Branch#1
Branch#2

B09W

X-ray
multiscale
structural
analysis

Wavefront
splitting by
Si crystal

BL14U

(IVU)
TX

(THU)
SX

X-ray
coherent
imaging-

Soft X-ray
Imaging

Wavefront
splitting byedge mirror

High-speed SX
imaging (Tentative）
Near Ambient
Pressure XPS,
and XAFS
MM-PES (Tentative)
XAFS, SAXS
Smart-SAXS(Tentative)
8.0 / 13.1 keV
XRF (Tentative)
17.5 / 28.5 keVprimary
semisimultaneous
primary
semisimultaneous
primary
simultaneous
simultaneous

Ambient Pressure
HAXPES, EXAFS

primary

Branch#1

HAXPES, XRD

semisimultaneous

Branch#1

Branch#2

BL10U

RIXS, nano-PES

operation

Main

Main
(MPW)
TX, HXEnd stations

XCT,
Absorption/Phase
contrast imaging
Smart-XRD(Tentative)
17.5 keV / 28.5 keV
Smart-XRD(Tentative)
22.7 keV

primary
simultaneous

simultaneous

Main

CDI, Ptychography

primaryMain

SX-CDI, Magnetic
Imaging,

primary

Branch#1

50

STXM, PEEM
(Tentative)

semisimultaneousFeb. 10, 2021

International Review of Coalition Beamlines Implementation
International Center for Synchrotron Radiation Innovation Smart
Tohoku University
Director, Prof. Atsushi Muramatsu
Tohoku University launched the International Center for Synchrotron Radiation Innovation Smart (SRIS)on Oct. 2019 to lead the Next Generation 3GeV Synchrotron Radiation Facility project as one of the
project partners which include QST, MEXT, Miyagi Prefecture, Sendai City, Tohoku Economic
Federation, Tohoku University and the Photon Science Innovation Center. SRIS is in charge of the
Science and Technology of the 7 beamlines organized by industry and academia coalitions, referred toas Coalition beamlines.
SRIS is organizing a review of the 7 Coalition beamlines in order to obtain an independent scientificevaluation of the plan for their implementation. In addition, we would like to solicit suggestions for futurescientific and technical developments of the beamlines. The panel will be composed of experts in SR
beamline science and technology from leading international facilities.

Review Panel

Dr. Jerome Hastings
Professor of SLAC
Stanford University(US)(Chair)Dr. Andreas Scholl
Deputy for Science
ALS(US)

Dr. Shunji Goto
Division Director ofLight Source
JASRI/SPring-8

Dr.Thomas Schmidt
Group Leader
PSI/SLS (Swiss)

Schedule(Important date) 2021
Technical ReportFeb. 15

Terms of Reference

Feb. 16

Mail Review

Feb. 16-Mar. 1

Review Report (draft)

Mar. 8

Final ReportMar. 1551

Dr. Steven Hulbert
R&D Manager
NSLS-IIBNL(US)

March 15th 2021

Executive summary
The NGSR is a state‐of‐the‐art near diffraction limited storage ring that will provide a broad photon
energy range and provide user access in a unique and innovative way: the “Coalition Concept”. The
ring design is aimed at robust operation from the beginning and is based on the experience atSPring‐8. The innovative “Coalition Concept” aims to create an environment that is most conducive
to a collaborative approach to addressing scientific and technical challenges that benefit society. It
goes beyond access to a single beamline but rather to a suite of capabilities using the latest x‐raytechniques. Not only has industry joined the coalition but universities and national research
institutes as well.
The potential for the “coalition concept” to contribute to the most challenging problems facing
society today is clear. The scientific environment that the NGSR will create will bring together
industry and academia in a way that the breadth of the scientific and technical questions that areinvestigated broadly with x‐rays in both industrial and basic research environments can beadvanced.
The designs of the x‐ray sources, the undulators and wigglers, are based on experience from SPring‐
8. In some aspects the undulator design is ambitious and may only be fully realised when the NGSR
is in mature operation. It is noted that in the very unlikely event that there are challenges to meet
the beamline needs there are solutions that can be implemented.
The suite of the initial 7 beamlines addresses a broad range of capabilities that are matched to thescientific needs today. There are of course opportunities beyond those discussed in the report, forexample aspects of energy science and environmental science. It is noted that as the facility comeson‐line there is room for growth and further development of new x‐ray capabilities to address both
existing areas of research as well as emerging scientific and technical challenges. The initial suite isalready impressive and future development should be based on the evaluation of the operation of
the first 7 beamlines.
In summary the proposed development of the NGSR is well founded on known technologies andprovides an environment, the “coalition concept”, that will stimulate the development of solutions
to important questions that will benefit society.
Shunji Goto, Japan Synchrotron Radiation Research Institute
Jerome Hastings, SLAC National Accelerator Laboratory, Chair
Steven Hulbert, Brookhaven National Laboratory
Thomas Schmidt, Paul Scherrer Institute
Andreas Scholl, Lawrence Berkeley Laboratory

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I.

Benefits of the Coalition BL system

X‐rays are a unique analytical tool. The advent of accelerator based x‐ray sources has pushed
the capabilities to the point where spatial resolution on 3d objects can reach voxel sizes of
10x10x10 nm3 over mm scale objects, imaging structure and elemental maps. Protein
crystallography has become routine. Diffraction techniques have advanced our understandingof a breadth of materials. The majority of this development has been driven by basic
researchers found predominantly in academic institutions. The challenge has always been how
to provide these unique capabilities to the breadth of the R&D community with special
emphasis on industry with the specific aim to drive innovative solutions to the ongoing societal
challenges. Ultimately, for this to be successful there is a need for an environment that
promotes collaboration between industry and academia bringing the strengths of both to bear.
To address this need NGSR has developed the “coalition concept”, a new research scheme inwhich stakeholders from both industry and academia form a strong one‐on‐one team for the
purpose of solving societal challenges). Industrial partners have unsolved problems that could
benefit from access to state of the art tools and demand‐oriented user‐support by the experts.
Academic partners often have the expertise in measurement and data analysis. Through aninterdisciplinary research collaboration in the “coalition concept” academic researchers can
expand the applicability of their expertise to new disciplines.
The “Coalition Concept” is a natural extension of the participating research team system (PRT)
developed at NSLS now more than 40 years ago. But it goes qualitatively beyond that first step.
It is a format that on the one hand gives access not just to one x‐ray technique but rather tomany specialized capabilities and on the other forms a natural environment to create
partnerships between industry and academia. It does even more. It creates the opportunity
for collaboration amongst the science communities at the academic partners as well. There aremany academic research efforts within university communities that would directly benefit fromcollaboration between x‐ray specialists and subject matter specialists. These collaborations areenabled by the coalition concept.
This “Coalition Concept” has been attracting industrial users interested in utilizing the latest x‐
ray techniques made possible by the NGSR facility. This approach will almost certainly lead tosolutions for challenges that are critical to society that are being attacked by industry today.
One can think of the “coalition concept” in terms of an ecosystem for sustainable growth. The
hope and expectation are that a positive spiral will be created in the business ecosystem;
strategies and research results are recognized by society, which then attracts talented
researchers to join the NGSR facility. Together with these new participants, the host53

community will build an advanced strategy supported by their knowledge and humanresources. The NGSR facility will be the core of a research complex of universities, research
institutes, and companies. It should be noted Tohoku university plans to build a “Science Park”
at the Aobayama campus, the site of the NGSR facility. The “coalition concept” shall be theguiding principle of this research complex to create a “community for innovation”.

NGSR should be applauded for launching the “Coalition Concept” and its importance isdemonstrated by the strong commitments from industry and academia.

54

II.

Scientific and technological value of the project fordevelopment of interdisciplinary research and industry‐
academia collaboration.

X‐ray techniques are unique analytical tools. They provide direct information about thestructure of matter whether crystalline, liquid, even amorphous as well as information on
heterogeneity on length scales from sub‐nanometer to microns to millimeters and even larger
distances. The information one gleans informs basic questions in materials, chemical andbiological sciences as well answers to questions that help industrial progress and thedevelopment of solutions to important problems that impact society. The challenge that is
faced by the facilities that provide these unique tools is how to couple problem solvers to
problems. That is, there are experts, found mostly in academia, who develop methods andinstrumentation while in both the academic world as well as industry there are problems
begging for results. The “Coalition Concept” is an outgrowth of the very successful soft matter‘alliance’ that was established at SPring‐8. It is the next step at a much larger scale and withboth academic institutional members as well as industrial members it has the potential to
overcome the ‘divide’ between x‐ray science experts and the broader research community.
With access not just to one ‘technique’ but a breadth of experimental tools the “coalition
Concept” has the right combination of partners and methods. The challenge will be stimulating
this research ecosystem. The direct involvement of Tohoku University is a key step. The
construction of an office/lab complex on the NGSR facility site is also an important aspect thatshould be considered. Physical proximity of researchers has always driven collaboration and it
would almost certainly do so at the NGSR facility.
Noteworthy is the academic institution membership. Cross disciplinary studies at these
institutions almost certainly will be nurtured through the “Coalition Concept”. The community
at large will be looking carefully at the development of the “Coalition Concept” eager for its
success.

55

III. Comment on the general scientific/technical merits of thedesign for the individual beamlines.
a. Undulator development
Using variable polarization APPLE‐II undulators for the soft x‐ray beamlines and in‐vacuum
undulators for the hard x‐ray beamlines follows the design strategies of the establishedmedium energy storage rings. In addition, the hard x‐ray undulators shall also serve the tender
x‐ray regime.
Combining tender x‐rays with hard x‐rays out of one source requires a rather high K‐value tohave an overlap between the first and third harmonics. In order to accomplish this the
proposed U22 undulator needs to reach a minimum gap of 5mm to provide the K‐value of 2.36
with the latest grade of NdFeB magnets to guarantee the needed overlap. The gap is a result of
the scaling of SPring‐8 in‐vacuum undulator operation to the NGSR parameters. However,compared to the existing mid‐range storage ring facilities this is very ambitious. For example,
SLS2.0 aims to achieve a 4.2mm gap with 3m long U18 undulators with the same small
acceptance A = (gap/2)2/βL/2 = 1.45 with βL/2 = β0 + (L/2)2/β0 as the U22. We note the user
specifications in terms of photon energy range can be met already at a larger gap with either a
U18: 5.2mm or a CPMU16: 4.5mm. Thus, the U22 can be exchanged for a CPMU or longer
period undulator at a later date, if required.
For the soft x‐ray undulators the APPLE II undulators are used due to the adopted off‐axis
injection. The chosen parameters for the VUV seem to be a reasonable compromise between
lowest photon energies and power load, which is already close to 11kW and with the soft x‐ray
UE56 undulators the Carbon edge can be covered in all polarizations states.
Fast helicity switching with the twin helical undulator (THU) concept and the monochromatorwith small gap changes results in small orbit distortions and in addition to much fasterswitching compared to shifting of the magnet arrays. The parameters for the THU given intable 2.1 suggest that only helical light will be used. However, in the beamline description it isstated that BL14U is mainly dedicated to SAXS and MCD microscopies. Just in case it is notplanned, adding a simple phase‐matcher between the two APPLE X undulators could expand
the capabilities of the beamline to the other polarization states and higher energies. In
addition,the flux can be increased by using both undulators even with circular light. With thehigh stability of modern synchrotrons MCD spectra can be taken also by successive scans of thetwo56helicities. Finally using the third harmonic with elliptical light the energy range above 1400 eV
could be addressed.

b. Soft X‐ray electronic structure analysis beamline (BL07U)
Science target and appropriateness of the technical approach:The beamline is designed to use the high brightness of the source to study the nanoscalechemistry and electronic structure of electronic materials and devices and relies on
sophisticated Wolter focusing optics. Core‐level PES will be used to interrogate local band‐
bending effects in devices, and the complementary RIXS technique will be used to study bulk
electronic effects. This is an interesting combination of techniques that should find usage in theelectronic characterization of quantum materials, novel storage media, and electronics. Core‐level PES will make excellent use of the nano focus and is less demanding than RIXS. RIXS
studieswill be challenging using a nano focus because of the low data rates and the risk ofsample degradation and heating. It is not clear whether ARPES is available at the beamline. If
available, academic and industrial users might be interested in studying the electronic band
structure of novel topological materials and devices under operando conditions.

Source:The APPLE‐II EPU75 is a good choice to cover the 50 ‐ 1000 eV photon energy range. Since
polarization control is an important parameter for this beamline, a polarization analyzer
diagnostic should be included downstream of the exit slit.

Optics:Consider using the focusing VLS‐PGM beamline design from Reininger and de Castro (2005), ifthat isn’t the current plan. The advantages of this design include a simple method of focusing
the beam at the exit slit and being able to correct for first order (“spherical”) deformations ofresolution‐determining optical elements such as M2 and the grating. Furthermore, the variablefocusing capability could permit independent vertical sources for the refocusing Wolter‐typemirrors for the two endstations by being able to focus at either of two exit slits with locations
chosen to optimize the focusing performance at the two endstation positions.

57

We endorse the following optics design aspects: (1) provision of a pulse chopper for time‐
resolved studies, and (2) use of sophisticated Wolter‐type refocusing mirrors, which provide thepossibility of providing superior focusing performance compared to standard solutions such as
Kirkpatrick‐Baez mirror pairs.
We provide two warnings regarding the optics design: (1) focusing to < 100 nm at EUV photon
energies (< 100 eV) can be limited by diffraction properties, and (2) focusing high‐flux EUV/SX
photon beams to < 100 nm spot sizes can result in undesirable heating of the sample.

Endstations:
NanoARPES and nanoRIXS techniques are both state‐of‐the‐art. Combining those with
operando sample conditions and identified scanning/imaging modes will provide uniqueexperimental capabilities.

Comments:● Navigating on the sample and finding a region of interest will be challenging when using
inefficient probes like XPS and especially RIXS. Methods should be developed tofiducialize regions of interest using optical microscopy or SEM and then transfer thecoordinate system to the x‐ray endstation.
● Manipulation of the sample with nanometer precision and stability will be challenging,
especially for angle‐dependent RIXS when the sample and spectrometer need to berotated synchronously while maintaining a common focus on the sample.
● Diffraction‐limited focusing at the lower energies will require a very large numericalaperture. Reaching the required optical specifications will be challenging.
● Focusing the projected beamline flux to a sub 100 nm scale focus will likely cause
heating and sample damage issues that will be difficult to mitigate since each individual
x‐ray pulse deposits a large amount of energy, causing instant heating of the sample
that can’t be outrun by translation.

c. Soft X‐ray operando spectroscopy beamline (BL08U)
Source:The APPLE‐II EPU56 is a good choice to cover the 130 ‐ 2000 eV photon energy range. Since
polarization control is an important parameter for this beamline, a polarization analyzer

58diagnostic should be included downstream of the exit slit. The photon flux value at the sample(1012 ph/sec/0.01% bw = 1013 ph/sec/0.1% bw) looks reasonable.

Optics:If you are not planning to do so already, consider using the focusing VLS‐PGM beamline designfrom Reininger and de Castro (2005). The advantages of this design include a simple method of
focusing the beam at the exit slit and being able to correct for first order (“spherical”)
deformations of resolution‐determining optical elements such as M2 and the grating.
Furthermore, the variable focusing capability would permit independent vertical sources for the
refocusing Wolter‐type mirrors for the two endstations by being able to focus at either of two
exit slits with locations chosen to optimize the focusing performance at the two endstation
positions.
Endorsement of refocusing optics design: while very few details are provided regarding
refocusing, the use of sophisticated Wolter‐type refocusing mirrors, apparently in conjunction
with KB mirror pairs, will offer the possibility of providing superior focusing performance.
Sample heating by highly focused soft X‐ray beams: focusing a high‐flux soft X‐ray photon beam
to ~50 nm spot size can result in undesirable heating of the sample, certainly under vacuum
conditions. Modeling of the convective cooling provided by the atmospheric sample condition
would be important in addressing the sample heating issue for this beamline.

Endstations:
Nano AP‐XPS and nano AP‐NEXAFS techniques operated at up to 1 atmosphere gas pressure
will be state‐of‐the‐art. Good experience in both techniques exists in Japan, which forms a solid
basis for proceeding with this beamline.
Suggestion regarding scanning capability: We wonder if it is intended to include sample (orbeam) scanning capability to provide spatial XPS and NEXAFS maps under ambient pressure
conditions. Adding scanning capability would make this beamline and endstations even moreunique in the world.

d. Integrated analysis of chemical state and nano/local
structure beamline (BL08W)

59

The beamline capabilities to combine spectroscopy and scattering to obtain information on thechemical state and the structure using X‐rays of 2.1 to 17.4 keV gives access to elements in the
periodic table from the K edge of phosphorus to the LIII edge of uranium. The use of X‐ray
absorption fine structure (XAFS) will give simultaneous information about the electronic
structure (valence, chemical species) and coordination of the specific element and informationon the local structure (interatomic distance, coordination number) around a specific element.
The SAXS measurements provide information on the nanoscale inhomogeneity in a sample,
size, shape, distribution, higher‐order structure, surface structure on lengths scales fromseveral nm to several hundred nm. This beamline uses these measurement methods toevaluate the correlation between changes in the electronic structure of specific atoms andmacroscopic structural changes under dynamic conditions in polymers, metals, battery
materials, etc. The access to photon energies from 2.1 keV from a wiggler source permits
straight forward energy scanning easily reaching the K‐edges of phosphorus and sulfur and theL‐edge of palladium as well as the LIII edge of uranium. These elements, phosphorus and sulfur,
play important roles in functional materials and biomaterials. Furthermore, dynamic anomalous
small‐angle X‐ray scattering (ASAXS) can visualize the time‐space distribution of specific atoms
on the second time scale.

Source:A wiggler meets the needs defined for this beamline and the ‘wide’ horizontal fan intrinsic towiggler sources enables branch line capabilities which are proposed for future development.
Because the focal spot size is modest the use of an undulator source is not required.

Optics:Here it is important to ensure that the energy resolution of the monochromator is better thanthe core‐hole lifetime for the full range of x‐ray edges that can be accessed. Best would be tohave the ability to switch between the Si(220) reflection and the Si(111) reflections in the DCM.
The increased resolution (x2 approximately) will not result in a significant loss in intensity.
When reaching the lower end of the spectral range the Si(111) is required.

Experimental equipment:
The 13 m maximum camera distance for SAXS is important for many systems with nm scaledensity fluctuations and is noted. As well, the capability for simultaneous SAXS and XAFS is an
important attribute.

60

e. X‐ray operando spectroscopy beamline (BL09U)
Science target and appropriateness of the technical approach:
X‐ray spectroscopies are unique in their ability to be elementally specific. The most widely usedof these spectroscopies X‐ray Absorption Spectroscopy (XAS) in it’s two forms, X‐ray absorption
near‐edge structure (XANES) and extended (EXAFS) access both the electronic structure(XANES) and the atomic structure (EXAFS). When combined with hard x‐ray photoemission
spectroscopy (HAXPES) with nanometer scale beams these spectroscopies are important tools
for the investigation of materials ranging from catalysts to batteries, from steel to biomaterials.
BL09U aims to provide these spectroscopic capabilities. It will almost certainly have extremely
high demand.

Source:
The aim of this beamline is tunable x‐rays beams with scale 100 nm foci. The nano‐focus‘demands’ an undulator source to maximize the flux which translates directly to the minimum
concentration of minor constituents that can be studied in ‘bulk’ materials. Thus, theproposedsource is well matched to the experimental techniques that will be available on thisbeam line.

Optics:There are two important requirements that drive the optical solutions: (1) focal spot size, here
aimed at 100 nm and (2) energy resolution here defined as resolving power (R=E/ΔE). For
HAXPES the stated requirement is R=20,000 and for XAFS R=5000. The focal spot size
requirement is good. However, the 5000 resolving power is a bit low for XAFS. Here you want
to be sure that the instrumental resolution is better than the core‐hole lifetime and as a rule ofthumb better would be to have R⪚10,000. This is easily achieved by, for example, using theSi(220) reflection rather than Si(111) in the DCM.
The other concern is throughput for the nano‐focus. Here the 100 nm beam size is achieved byimaging the slit placed just after the upstream DCM. To maximize the flux the ‘standard’approach is a 1:1 mirror system that focuses the source onto the beam defining slit. Thisapproach should be considered for this beamline.

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There is also the desire to be able to ‘tune’ the spot size for HAXPES and almost certainly as
well, for XAFS. The proposal is to operate downstream of the focus. There should beconsideration of developing bendable KB mirrors and/or studying the impact focal spot sizewith a large upstream slit opening.

Comments:
It is strongly suggested to implement the capability to do ‘simultaneous’ HAXPES and XAFS. By
simultaneous what is meant on the same sample position keeping in mind the 100 nm focal
spot size. Also, sample environment and sample positioning at the sub 100 nm level is criticalto reach the full potential of the beamline capabilities.

f. X‐ray multiscale structure‐analysis beamline (BL09W)
Energy dispersive XAFS, surface XRD, and multi‐beam x‐ray tomography will provide uniquesolutions of the high‐throughput measurements for the coalition users, particularly users fromindustry. The wiggler source, providing sufficient photon flux of broadband x‐rays, is suitable forthe purposes. The energy dispersive optics will enable reasonable measurements with proper
spatial‐temporal resolution. Beam splitting is a very effective way at this beamline to obtainsufficient beam‐time for coalition users, starting with a limited number of coalition beamlines.
Branch lines will be designed and used mostly for the general purpose high‐throughput
measurements.
Beam splitting using the single‐bounce Si monochromator seems to be feasible. Fixed photon
energy use is very helpful for the simple design of the monochromator under stable operation.
Heat load at the optics will be up to 100 W for the main line, and several tens of watts at thebranch lines. They should move to critical engineering consideration/design for the beam
splitting system with proper water cooling soon. Spatial interference between the main beamand branch beams must be carefully avoided. High‐heat‐load energy dispersive optics should
also be into a technical design phase soon.
They propose several different techniques at the beamline. End stations should becommissioned and opened, based on the priority determined by availability of equipment andalso by user demands.

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g. X‐ray coherent imaging beamline (BL10U)
Tender to hard x‐ray coherent imaging beamline is one of the state‐of‐the‐art beamlines of the
NGSR. It will be a very attractive one for coalition users, who need the meso‐scale material
information using various imaging techniques.

Source:An IVU is the best choice for this beamline covering the energy from tender to hard x‐ray
region.

Optics:Stable operation of the optics is very crucial for a coherent imaging beamline. There are somany optical components including a DCM, harmonic rejection mirrors, and focusing K‐B
mirrors. Each must be carefully designed for the beam stability. Experience at SPring‐8, forexample, will be helpful. Cryogenic cooling of the Si(111) DCM is essential for the beamline. Theenergy range limited up to 15 keV seems to be reasonable. Again, for imaging, stable operationof the DCM is critical. This is best achieved by limiting the number of stages required for fixed
exit operation. Also, if possible, minimize the range of motion for the stages. In order to insure
a high quality coherent beam for the main line a branch line has quite low priority. However,studying wavefront preservation with a single crystal diamond Bragg reflector to send radiation
to a side branch is encouraged. The in‐line three‐mirror higher‐order rejection system is a good
choice for the operation of the tandem end stations. The mirror surface finish must be
specified carefully, avoiding unwanted speckle and wave‐front distortion for coherent imaging.

Endstations
Aside from the main CDI and Ptychography station, other imaging techniques: x‐ray
fluorescence holography, holotomography and full‐field microscopy will also play importantroles for the various user demands. Several imaging techniques coexist at the beamline withtime‐sharing operation. End stations should be commissioned and opened, based on thepriority determined by availability of equipment and also by user demands.

h. Soft X‐ray imaging beamline (BL14U)

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Science target and appropriateness of the technical approach:
Scanning probes will be of significant interest to a range of industry and academic communities,e.g., studying battery materials, porous materials for capture and catalysis or filtration,
quantummaterials for computing and data storage purposes, structural materials such asconcrete, biological and bioinspired materials, soil samples from industrial clean‐ups.
The two endstations appear to be differentiated by the data acquisition process, ptychographic
in one case, point detector in the other. Running a diverse set of experiments will require very
different sample environments, e.g., cooling, high fields, possibly vacuum for quantum andmagnetic materials; operando cells for energy materials; introduction of frozen samples for cellstudies. Consider offering point detection and ptychography on both endstations anddifferentiate by the sample environment they offer.

Source:
The choice of Twin Helical Undulators (THU56) is appropriate to cover the 250 ‐ 1400 eV range
with fast‐switching circular polarization accomplished by varying the THU gaps as described in
the insertion device section (section 2 of the Coalition BL Report). Even though the sources
have fixed polarization, the beamline optics will alter it, so including a polarization analyzer
diagnostic downstream of the exit slit is recommended.
The tandem undulators can also be set to the same gap and polarization values and used as asingle, intense source for fixed‐polarization techniques. In such cases, the brightness andcoherence of the combined insertion device can be optimized by introducing a phasing magnet
between the two undulators, as pointed out in the undulator section of this report.
The photon flux range at the sample (presumably at that location, not stated) of 5 x 1012 to 4 x
1013 photons/sec for 25 microns exit slit appears reasonable, but it would be easier forcomparison to other beamlines to state this flux in units of ph/sec/% bw.

Optics:We suggest adoption of the variable‐included‐angle VLS PGM optics design proposed by
Reininger and de Castro (2005). The advantages of this design include a simple method of64

focusing the beam at the exit slit and being able to correct for first order (“spherical”)
deformations of resolution‐determining optical elements such as M2 and the grating.
Furthermore, the variable focusing capability would permit simple optimization of the focus of
the two endstation branches. In addition, the focusing capabilities of this design could easily
adapt to multiple endstation positions on each branch, although separate exit slits andrefocusing optics would be needed for each endstation.
We endorse the planned use of a combination of KB and Wolter‐type refocusing mirrors toprovide a variable focal spot size at the sample which will be, if successful, an innovative
solution to providing a desired “zoom” capability for the endstation techniques. We offer awarning about potential sample heating: focusing high‐flux soft X‐ray photon beams to ~50 nm
spot size can result in undesirable heating of the sample, certainly under vacuum conditions.
If the method of splitting the beam for the branch line away from the main beamline is, as
described in the branch beamlines section (section 3.3 of the Coalition BL Report), by a planar
diverting mirror located between the M0 mirror and the two M1 mirrors, various problems areenvisaged: (i) optimized alignment of the branch line optics must depend to some extent on theamount of beam that is intercepted by the diverting mirror; if this amount is not fixed,
realignment would be desirable any time the fraction changes; (ii) even tiny lateral instabilities
in the position of the diverting mirror will change the amount of flux going to each beamline(branch and main); techniques such as MCD are quite sensitive to changes in flux as the photon
energy is scanned, for example. If such issues were to lead, eventually, to a reversion to the
traditional mode of operating (one beamline branch at a time), it would have been more
efficient (in both photons and cost) to simply insert the M1 mirror for the branch line when it isused and retract it for main branch use.
Simultaneous usage of two branches: The stated goal of using both branches of this beamline
simultaneously (via usage of different gaps for the two helical undulators), while risky
technically, will (if successful) be highly demanded because it will double the output of thisbeamline per unit time. This success would necessarily interfere, schedule‐wise, with the MCD
program, which depends inherently on usage of both helical undulators, set to the same gap
value, at the same time. In addition, any changes in the gap setting of one helical undulator
would almost surely lead to noticeable changes in the flux measured at the sample of the otherbranch (the one with its monochromator set to a different photon energy), owing to tails in the
angular distribution of undulator radiation. This risk is noted in the Coalition Beamline Report.
We suggest to optimize the design of each branch of this beamline independently, which will
most likely lead to separate (in time) operation of the two branches. This strategy will support
state‐of‐the‐art performance of the beamline and endstations, which in turn will extend the65useful long‐term lifetime of this beamline and both of its branches compared to compromised
performance of a simultaneous‐usage design.

Endstation techniques:
The coherence‐hungry ptychographic and scanning microscope techniques will be well‐matched to the beamline properties and represent state‐of‐the‐art SR techniques.

Comments:● Fast switching is conceptually very nice but in practice not that often used or needed.
● Care has to be taken that x‐ray flux and illumination don’t change and that there is nocross talk when beam is split between the branches, e.g., when changing theenergy/gapin one branch

IV. Branch lines ‐ especially wiggler lines, possible soft x‐ray
beamlines
To provide the coalition with the experimental capabilities needed the use of branch lines is an
important option. The specific choice of branch lines can only be made after the initial
operation of the NGSR and the 7 coalition beamlines have been commissioned. Based on the
demand from the coalition members the specific branch lines can be defined. It is
recommended however to install the initial hardware to accommodate the splitting optics so as
not to adversely impact the operations of the main lines as the branch lines are developed.
Wiggler beamlines at many existing SR sources have a main branch using the central
milliradians of the ‘wiggler’ fan and side or branch lines using the outer portions of the fan.
There are wiggler lines at the NGSR source and of course branch lines should be considered.
These are developed using crystal optics in either Bragg or Laue geometry depending on the
wavelength range. The coalition beamlines should consider this approach carefully, noting that66

the use of the sides of the fan introduces a larger effective source size. It may also be useful toconsider a Laue geometry crystal in the ‘central’ portion of the fan if source size is an importantconsideration. Of course, ‘splitting’ undulator lines in the x‐ray regime, by necessity, uses Lauecase reflections from ‘transparent’ crystals, most often diamond. As photon energy is set by
the main branch and thus the side branch needs to be flexible in the photon energy to makemaximal use of the radiation or the choice of ‘technique’ to be developed with the side
branches that would depend on the source, wiggler versus undulator. The thinking behind thisis simple, the undulator beamline will have the photon energy chosen by the main branch.
Developing side branches in the soft x‐ray spectral range is much more challenging and since inthis energy range the majority of the techniques are ‘spectroscopic’ the main branch‐side
branch photon energy issue is much more crucial. For soft x‐rays the proposed ‘division of
wavefront’ using a sharp edge of a splitting mirror must be very carefully evaluated in particularwith regard to vibrations of the splitting mirror to avoid the introduction of unwanted
fluctuations in intensity of the main branch.

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V. Possible other areas for development
1. Bio/medical research
Synchrotron x‐rays are heavily used in medical and biological research and by
the pharmaceutical industry. Bio‐SAXS, XRD, micro and nano‐CT, full‐field andscanning x‐ray imaging, synchrotron IR nanoimaging could be of interest to thebio/medical research community and the high brightness of the ring would likely
enable strong academic and industrial research programs. Beamlines could have
impact in the areas of solving protein structures, cell imaging, 3D and surface
chemical imaging of tissues, plants, bio‐minerals, etc.

2. Environmental sciences
X‐rays are an important tool to identify contaminants in soils, to image andchemically identify organic, inorganic and biological components across lengthscales in minerals, soils, sediments, water. High‐brightness x‐rays from a state‐of‐the‐art ring would enable high‐throughput, high‐resolution imaging
techniques, such as soft x‐ray STXM and ptychography under operando
conditions (e.g., flow cells) or at cryogenic temperatures (especially of
biologicalsystems), and micro and nanoprobes using tender and hard x‐rays.

3. Energy sciences
The program in energy sciences, e.g., related to industrially important materials
and systems such as membranes for water purification, electrochemicalsystems, batteries, fuel cells, carbon capture technology, structural materials,
could benefit from a broadened suite of tools including SAXS/WAXS, soft x‐ray
scattering, chemical crystallography, tomography and operando imaging andspectroscopy techniques.

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