Overview of SSRF phase-Ⅱ beamlines

The SSRF phase-Ⅱ beamline project was launched in 2016. Its major goal was to establish a systematic state-of-the-art experimental facility for third-generation synchrotron radiation to solve problems in cutting-edge science and technology.Currently, the construction is fully completed. All 16 newly built beamlines with nearly 60 experimental methods passed acceptance testing by the Chinese Academy of Sciences and are in operation.

Beamline design for multipurpose muon beams at CSNS EMuS

A new muon beam facility,called the Experimental Muon Source(EMuS),was proposed for construction at the China Spallation Neutron Source(CSNS).The design of the complex muon beamlines for the EMuS baseline scheme,which is based on superconducting solenoids,superferric dipoles and room-temperature magnets,is presented herein.Various muon beams,including surface muons,decay muons and low energy muons,have been developed for multipurpose applications.The optics design and simulation results of the trunk beamline and branch beamlines are presented.With a proton beam power of 25 kW at a standalone target station that consists of a conical graphite target and high-field superconducting solenoids,the muon beam intensity in the trunk beamline varies from 10^(7)/s for surface muons to 10^(10)/s for high-momentum decay muons.And at the endstations,these values vary from 10^(5)/s for surface muons to 10^(8)/s for decay muons.

BL03HB: a Laue microdiffraction beamline for both protein crystallography and materials science at SSRF

A Laue microdiffraction beamline(BL03HB) was constructed at the Shanghai Synchrotron Radiation Facility(SSRF).This beamline features two consecutive focusing points in two different sectors within its end station, the first dedicated to protein crystallography and the other tailored to materials science applications. Based on a superbend dipole magnet with a magnetic field of 2.29 T, a two-stage focusing design was implemented with two sets of Kirkpatrick-Baez mirrors to achieve a micro white beam as small as 4.2 μ m ×4.3 μ m at the first sector and 0.9 μ m ×1.3 μ m at the second sector in the standard beamline operation mode at SSRF. The X-ray microbeam in the two sectors can be easily switched between monochromatic and white beams by moving a four-bounce monochromator in or out of the light path, respectively. In the protein crystallography sector, white-beam Laue microdiffraction was demonstrated to successfully determine the structure of protein crystals from only a few images of diffraction data collected by a Pilatus 2 M area detector. In the materials science sector,the white-beam Laue diffraction was collected in a reflection geometry using another Pilatus 2 M area detector, which could map the microstructural distribution on the sample surface by scanning the samples. In general, the BL03HB beamline promotes the application of Laue microdiffraction in both protein crystallography and materials science. This paper presents a comprehensive overview of the BL03HB beamline, end station, and the first commission results.

Surface diffraction beamline at the SSRF

BL02U2 of the Shanghai Synchrotron Radiation Facility is a surface diffraction beamline with a photon flux of 5.5×10^(12) photons/s at 10 keV and a beam size of 160µm×80µm at the sample site.It is dedicated to studying surfaces(solid-vacuum,solid-gas)and interfaces(solid-solid,solid-liquid,and liquid-liquid)in nanoscience,condensed matter,and soft matter systems using various surface scattering techniques over an energy range of 4.8-28 keV with transmission and reflection modes.Moreover,BL02U2 has a high energy resolution,high angular resolution,and low beam divergence,which can provide excellent properties for X-ray diffraction experiments,such as grazing incident X-ray diffraction,X-ray reflectivity,crystal truncation rods,and liquid X-ray scattering.Diversity of in situ environments can also be provided for the samples studied.This paper describes the setup of the new beamline and its applications in various fields.

Quick-scanning X-ray absorption fine structure beamline at SSRF

The layout and characteristics of the hard X-ray spectroscopy beamline(BL11B)at the Shanghai synchrotron radiation facility are described herein.BL11B is a bending-magnet beamline dedicated to conventional and millisecond-scale quick-scanning X-ray absorption fine structures.It is equipped with a cylindrical collimating mirror,a double-crystal monochromator comprising Si(111)and Si(311),a channel-cut quick-scanning Si(111)monochromator,a toroidal focusing mirror,and a high harmonics rejection mirror.It can provide 5-30 keV of X-rays with a photon flux of~5×10^(11)photons/s and an energy resolution of~1.31×10^(-4)at 10 keV.The performance of the beamline can satisfy the demands of users in the fields of catalysis,materials,and environmental science.This paper presents an overview of the beamline design and a detailed description of its performance and capabilities.

Spatial-and spin-resolution ARPES and magnetism beamline at SSRF

The BL07U beamline is a new extreme ultraviolet and soft X-ray beamline housed in the Shanghai Synchrotron Radiation Facility. Beamlines are used in nano-resolved angle-resolved photoemission spectroscopy(nano-ARPES), spin-resolved angle-resolved photoemission spectroscopy(spin-ARPES), X-ray magnetic circular dichroism spectroscopy, and X-ray magnetic linear dichroism spectroscopy for certain scientific research. The BL07U beamline, which is based on a pair of elliptical polarized undulators and a variable-included-angle plane-grating monochromator, delivers circularly or linear polarized X-rays within the energy range of 50–2000 eV. The beamline features two branches: One dedicated to nano-ARPES,which has a minimum spot size of only ~ 200 nm, and another branch comprising spin-ARPES, a vector magnetic field, and superconductive magnetic end-station.

Infrared microspectroscopy beamline BL06B at SSRF

The infrared microspectroscopy beamline(BL06B) is a phase Ⅱ beamline project at the Shanghai Synchrotron Radiation Facility(SSRF). The construction and optical alignment of BL06B were completed by the end of 2020. By 2021, it became accessible to users. The synchrotron radiation infrared(SRIR) source included edge radiation(ER) and bending magnet radiation(BMR). The extracted angles in the horizontal and vertical directions were 40 and 20 mrad, respectively. The photon flux, spectral resolution, and focused spot size were measured at the BL06B endstation, and the experimental results were consistent with theoretical calculations. SRIR light has a small divergence angle, high brightness, and a wide wavelength range. As a source of IR microscopy, it can easily focus on a diffraction-limited spatial resolution with a high signal-to-noise ratio(SNR). The BL06B endstation can be applied in a wide range of research fields, including materials, chemistry, biology, geophysics, and pharmacology.

Design and development of the beamline for a proton therapy system

A proton therapy(PT)facility with multiple treatment rooms based on the superconducting cyclotron scheme is under development at Huazhong University of Science and Technology(HUST).This paper attempts to describe the design considerations and implementation of the PT beamline from a systematic viewpoint.Design considerations covering beam optics and the influence of high-order aberrations,beam energy/intensity modulation,and beam orbit correction are described.In addition to the technical implementation of the main beamline components and subsystems,including the energy degrader,fast kicker,beamline magnets,beam diagnostic system,and beamline control system are introduced.

The biosafety level-2 macromolecular crystallography beamline(BL10U2)at the Shanghai Synchrotron Radiation Facility

BL10U2 is an undulator-based macromolecular crystallography(MX)beamline located at the 3.5-GeV Shanghai Synchrotron Radiation Facility.BL10U2 is specifically designed for conducting routine and biosafety level-2(BSL-2)MX experiments utilizing high-flux tunable X-rays with energies from 7 to 18 keV,providing a beam spot size of 20μm(horizontal)×10μm(vertical)at the sample point.Certification by the Shanghai Pudong Municipal Health Commission confirmed the capability to perform BSL-2 MX experiments.The beamline is currently equipped with an Eiger X 16 M detector and two newly developed in-house high-precision diffractometers that can be switched to perform conventional or in situ crystal diffraction experiments.An automatic sample changer developed in-house allows fast sample exchange in less than 30 s,supporting high-throughput MX experimentation and rapid crystal screening.Data collection from both the diffractometer and detector was controlled by an in-house developed data collection software(Finback)with a user-friendly interface for convenient operation.This study presents a comprehensive overview of the facilities,experimental methods,and performance characteristics of the BL10U2 beamline.

BL02U1:the relocated macromolecular crystallography beamline at the Shanghai Synchrotron Radiation Facility

Macromolecular crystallography beamline BL17U1 at the Shanghai Synchrotron Radiation Facility has been relocated,upgraded,and given a new ID(BL02U1).It now delivers X-rays in the energy range of 6–16 keV,with a focused beam of 11.6μm×4.8μm and photon flux greater than 1012 phs/s.The high credibility and stability of the beam and good timing synchronization of the equipment significantly improve the experimental efficiency.Since June 2021,when it officially opened to users,over 4200 h of beamtime have been provided to over 200 research groups to collect data at the beamline.Its good performance and stable operation have led to the resolution of several structures based on data collected at the beamline.

Measurement of the neutron-induced total cross sections of ^(nat)Pb from 0.3 eV to 20 MeV on the Back-n at CSNS

The neutron-induced total cross sections of natural lead have been measured in a wide energy range(0.3 eV-20 MeV)on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source.Neutron energy was determined by the neutron total cross-section spectrometer using the time-of-flight technique.A fast multi-cell fission chamber was used as the neutron detector,and a 10-mm-thick high-purity natural lead sample was employed for the neutron transmission measurements.The on-beam background was determined using Co,In,Ag,and Cd filters.The excitation function of ^(nat)Pb(n,tot)reaction below 20 MeV was calculated using the TALYS-1.96 nuclear-reaction modeling program.The present results were compared with previous results,the evaluated data available in the five major evaluated nuclear data libraries(i.e.,ENDF/B-VIII.0,JEFF-3.3,JENDL-5,CENDL-3.2,and BROND-3.1),and the theoretical calculation curve.Good agreement was found between the new results and those of previous experiments and with the theoretical curves in the corresponding region.This measurement obtained the neutron total cross section of natural lead with good accuracy over a wide energy range and added experimental data in the resonance energy range.This provides more reliable experimental data for nuclear engineering design and nuclear data evaluation of lead.

The protein complex crystallography beamline(BL19U1)at the Shanghai Synchrotron Radiation Facility

The protein complex crystallographic beamline BL19U1 at the Shanghai Synchrotron Radiation Facility is one of the five beamlines dedicated to protein sciences operated by National Facility for Protein Science(Shanghai,China).The beamline,which features a small-gap invacuum undulator,has been officially open to users since March 2015.This beamline delivers X-ray in the energy range 7–15 keV.With its high flux,low divergence beam and a large active area detector,BL19U1 is designed for proteins with large molecular weight and large crystallographic unit cell dimensions.Good performance and stable operation of the beamline have allowed the number of Protein Data Bank(PDB)depositions and the number of articles published based on data collected at this beamline to increase steadily.To date,over 300 research groups have collected data at the beamline.More than 600 PDB entries have been deposited at the PDB(www.pdb.org).More than 300 papers have been published that include data collected at the beamline,including 21 research articles published in the top-level journals Cell,Nature,and Science.

Overview of Development Status for EAST-NBI System

The neutral beam injection （NBI） system was developed on the Experimental Ad- vanced Superconducting Tokamak （EAST） for plasma heating and current driving. This paper presents the brief history, design, development, and the main experimental results of the R＆D of neutral beam injector on the test bed and on EAST. In particular, it will describe： （1） how the two beamlines with a total beam power of 8 MW were developed; （2） the design of the EAST-NBI system including the high power ion source, main vacuum chamber, inner components, beam diag- nostic system and sub-system; （3） the experimental results of beamline-1 on the summer campaign of EAST in 2014 and, （4） the status of beamline-2 and the future plan of EAST-NBIs.

Design of wide-range energy material beamline at the Shanghai Synchrotron Radiation Facility

We report the design of a wide-range energy material beamline(E-line) with multiple experimental techniques at the Shanghai Synchrotron Radiation Facility.The undulators consisted of an elliptically polarizing undulator and in-vacuum undulator that generate the soft and hard X-rays, respectively. The beamline covered a wide energy range from 130 to 18 ke V with both a high photon flux([ 10^(12) phs/s with exit silt 30 lm in soft X-ray and [ 5 9 10^(12) phs/s in hard X-ray within 0.1%BW bandwidth) and promising resolving power(maximum E/DE [ 15,000 in soft X-ray with exit silt 30 lm and [6000 in hard X-ray). Moreover, the beam spots from the soft and hard X-rays were focused to the same sample position with a high overlap ratio, so that the surfaces, interfaces, and bulk properties were characterized in situ by changing the probing depth.

New status of the infrared beamlines at SSRF

There are two infrared beamlines at the Shanghai synchrotron radiation facility(SSRF)-BL01B and BL06B.BL01B was the first infrared beamline of the National Facility for Protein Science in Shanghai at SSRF,which is dedicated to synchrotron infrared microspectroscopy.It utilizes bending magnet radiation and edge radiation as light sources.Diffraction-limited spatial resolution is reached in the infrared microspectroscopy experiment.BL01B has been in operation for approximately five years since it opened in January 2015.In the past few years,many meaningful results have been published by user groups from various disciplines,such as biomacromolecule materials and pharmaceutical,environmental,and biomedical sciences.In addition,a new infrared beamline station BL06B is under construction,which is optimized for the mid-infrared and far-infrared band.BL06B is equipped with a vacuum-type Fourier transform infrared spectrometer,infrared microscope,custom longworking-distance infrared microscope,infrared scanning near-field optical microscope,and mid-infrared Mueller ellipsometer.The purpose is to serve experiments with high vacuum requirements and spatial resolution experiments,as well as those that are in situ and time-sensitive,such as high-pressure and atomic force microscopy infrared experiments.The station can be used for research in biomaterials,pharmacy,geophysics,nanotechnology,and semiconductor materials.

A possible scheme for the surface muon beamline at CSNS

An experimental muon source is planned for the China Spallation Neutron Source.A simplified beamline with a limited number of magnets is achieved using a FODO lattice for implementation in a future preliminary stage.The yield of the muon delivered to the experimental sample is slightly larger than 10^5 μ^+/s within the FWHM beam spot(-φ30 mm)from a thick muon target.In addition,the beam polarization is 92%and the contamination that is mainly formed by positrons is approximately a fraction of 1%.

Performance of an electron linear accelerator for the first photoneutron source in China

A compact 15.0-MeV, 1.5-kW electron linear accelerator(LINAC) was successfully constructed to provide an electron beam for the first photoneutron source at the Shanghai Institute of Applied Physics, Shanghai,China. This LINAC consists of five main parts: a thermal cathode grid-controlled electron gun, a pre-buncher, a variable-phase-velocity buncher, a light-speed accelerating structure, and a high-power transportation beamline. A digital feedforward radio frequency compensator is adopted to reduce the energy spread caused by the transient beam loading effect. Furthermore, a real-time electron gun emission feedback algorithm is used to keep the beam stable. After months of efforts, all the beam parameters successfully met the requirements of the facility. In this paper, the beam commissioning process and performance of the LINAC are presented.

New measurement of the neutron-induced total cross-sections of^(nat)Cr in a wide energy range on the Back-n at CSNS

The neutron total cross-section of ^(nat)Cr plays a crucial role in new nuclear engineering design and fundamental science.A new measurement of the neutron-induced total cross-sections of ^(nat)Cr was performed using the transmission method on the back-streaming white neutron beamline(Back-n)at the China Spallation Neutron Source(CSNS).The neutron energy was determined using the time-of-flight technique.The neutron total cross-sections of ^(nat)Cr were obtained across a broad energy range(0.3 eV−20 MeV)in one experiment for the first time.The resulting effective total cross-sections were compared with the existing experimental data in different energy ranges,which revealed good agreement with the evaluated libraries.Theoretical calculation of the total cross-section in the energy range of 1.5 to 20 MeV was then conducted using TALYS-1.96 and compared with the present results.The measurement provides a high-quality total cross-section of ^(nat)Cr,including detailed uncertainty data across a wide energy range,offering a valuable reference for nuclear data re-evaluation and nuclear engineering design.

Imaging beamline for high energy proton radiography

Proton radiography is a new tool for advanced hydrotesting. This article will discuss the basic concept of proton radiography first, especially the magnetic lens system. Then a scenario of 50 GeV imaging beamline will be described in every particular, including the matching section, Zumbro lens system and imaging system. The simulation result shows that the scenario of imaging beamline performs well, and the influence of secondary particles can be neglected.

Radiation shielding for the first optics enclosure at the High Energy Photon Source beamlines

Purpose The High Energy Photon Source(HEPS)is currently under construction in China and will be the brightest synchrotron radiation facility in the world.To solve the gas bremsstrahlung and synchrotron radiation hazard at HEPS beamlines,a comprehensive radiation study is performed.Method The Monte Carlo method is used to analyze the radiation field in the first optics enclosure at HEPS beamlines.First,the radiation sources including gas bremsstrahlung and synchrotron radiation are estimated.Then,the distribution of the radiation field in the hutch is calculated.Conservative parameters and a typical beamline geometry are used in the calculations.Finally,the shielding recommendations are summarized.Results and Conclusion In this paper,the considerations and bulk shielding design of the first optics enclosure at HEPS beamlines are described.The design satisfies the requirements of the radiation safety principles.