Introduction
Photonuclear reactions form a unique field of nuclear physics and astrophysics because of their well-known electromagnetic interactions. As early as the 1960s and through the 1980s, the systematic study of the isovector giant-dipole resonance was carried out in photoneutron cross-section measurements with a wide range of nuclei at the Saclay Laboratory, France, and Lawrence Livermore National Laboratory (LLNL), USA, using positron in-flight annihilation technology. However, a large discrepancy between the Saclay and LLNL data regarding the photoneutron cross-sections has persisted [1-5], leading to the creation of the internationnal atomic energy agency (IAEA) photonuclear data library in 2019, which includes new data to resolve the long-standing discrepancy [3].
The laser Compton scattering (LCS) gamma source was developed based on the inverse Compton scattering of laser photons from relativistic electrons in the storage ring. It is currently the most advanced quasi-monoenergetic gamma-ray source and provides a new research opportunity to study photonuclear physics. Since the 1980s, the LCS beamline [6] of the National Institute of Advanced Industrial Science Technology (AIST) and the NewSUBARU BL01 LCS beamline of the University of Hyogo, both in Japan [7], as well as the high-intensity gamma source (HIγS) of the Triangle University Nuclear Laboratory (TUNL) in the USA, have been constructed to study nuclear physics [8]. The high-energy laser electron gamma source (LEGS) at the Stanford Linear Accelerator Center (SLAC) [9] and the laser electron photon beamline (LEPS/LEPS2) at SPring-8 are dedicated to hadron physics [10]. The TERAS LCS beamline was closed in 2013; after the installation of a new injection linac, the operation of the NewSUBARU LCS beamline is currently limited to industrial applications. Currently, only the high-energy LPES/LEPS2 and low-energy HIγS are in operation as major facilities. The laser electron gamma source the variable energy gamma-ray (VEGA) system in extreme light infrastructure-nuclear physics (ELI-NP) was redesigned in 2019, is currently under construction, and is scheduled to begin operation in 2023 [11].
The shanghai laser electron gamma source (SLEGS) was first proposed in 1998 at the Shanghai Synchrotron Radiation Facility (SSRF). Nearly 20 years after the feasibility study and prototype development [12-19], it was approved in 2016 as one of the 16 beamlines in the Phase II project of the SSRF by the National Development and Reform Commission, People's Republic of China. Construction of the SLEGS beamline began in October 2019 and was completed in December 2021. The beamline passed the commissioning test in 2021 and will be open to users by the end of 2022 [20].
Using a CO2 laser with a wavelength of 10.64 μm and a maximum power of 100 W, high-intensity gamma-ray beams are generated in collisions with 3.5 GeV electrons in the SSRF storage ring. The SLEGS is designed to operate in two operating modes: one is the laser Compton back-scattering mode at 180°, which is commonly used around the world to achieve the highest energy and polarization of gamma-ray beams; the other is the laser Compton slant-scattering mode, which enables the energy of gamma-ray beams to be tuned by changing the collision angle between the laser and electron beams in a wide range, from 20° to 160°.
Slant scattering is a key technology for producing energy-tunable gamma-ray beams at synchrotron radiation facilities operating at a fixed electron beam energy. In the past decade, SINAP-II [15-19] and UVSOR-II have played a pioneering role in the technical development of slant scattering. While UVSOR-II has succeeded in producing MeV gamma rays at limited slant-scattering angles ranging from 70° to 110° [21,22], the gamma-ray beam production at SLEGS is systematically carried out in an innovative manner with a dedicated interaction chamber [23] and double collimator system [24,25].
Research at SLEGS
SLEGS is designed to generate gamma-ray beams at energies ranging from 0.25 MeV to 21.1 MeV in slant-scattering at collision angles ranging from 20° to 160° and at a maximum energy of 21.7 MeV in back-scattering at 180°. The full-spectrum flux ranges from ~ 105 photons/s at 20° to ~ 107 at 180°. A 2 % energy resolution is achieved with a 1- to 2-mm collimator, which confines the emission angle of the gamma-ray beam to less than 0.5 mrad.
The SLEGS serves as a multi-functional experimental platform for research in nuclear science and technology [20]. The research spectrum in basic research ranges from collective excitation of nuclei, nuclear equations of state, and the origin of elements to ultra-high-energy cosmic rays, while that in application research ranges from atomic energy, nuclear transmutation, and gamma imaging to national security.
SLEGS beamline
The SLEGS beamline is equipped with four main components, as illustrated in Fig. 1. The SLEGS is located in the BL03SSID of the SSRF experimental hall. A 3D drawing is provided in Fig. 2.
(1) 100-W CO2 laser [26] and laser transport.
(2) Interaction chamber for slant-scattering and multi-function chamber for back-scattering.
(3) Two-stage coarse and fine collimators and gamma flux attenuator.
(4) Experimental hutch, experimental detector, gamma absorber, and data acquisition system
Laser transport and gamma production
A continuous-wave 10.64 μm CO2 laser with a laser power of 100 W is located in the laser hutc
Collisions between the 10.64 μm laser photons and 3.5 GeV electrons occurs inside the interaction chamber, as shown in Fig. 3, in two collision modes: laser Compton back-scattering and slant-scattering. The CO2 laser beam passes through the multi-function chamber with a ZnSe window, is bent by 90° through a water-cooled mirror, and undergoes a head-on collision in the back-scattering mode. In contrast, the laser beam vertically enters the interaction chamber, passes through the optical elements (mirrors m4, m3, m2, and m1 and convex lens f1, as shown in Fig. 3), and horizontally collides with the electron beam in the slant-scattering mode. The CO2 laser is finally refocused and led to beam absorber G through mirror m0 and convex lens f0. The optical elements are mounted on a rotating bracket so that the collision angle between the laser and electron beams can be changed from 20° to 160° through a safety stop angle at 90° [23].
Coarse and fine collimators
The energy spread and spot size of the gamma-ray beams at the target position are determined by the two-stage coarse and fine collimator system, as shown in Fig. 4(a) and 4(b). The coarse collimator is a revolver type made of 300-mm-thick Pb, located ~18 m away from the gamma production point inside the interaction chamber and separated from the high-vacuum SSRF with a 150-μmm Be window. It has 10 fixed holes with apertures of 0, 1, 2, 3, 4, 5, 8, 10, 20, and 30 mm. The fine collimator is a camera-shutter type, which is located 36 m away from the gamma production point in the optical hutch and consists of four sets of shielding shutters, each made of 50-mm tungsten-copper alloy (W 80 % + Cu 20 %). The first and second sets of shutters are rotated around the beam axis by 30°, shaping the beam spot into a regular dodecagon [24,25]. The aperture of the fine collimator can be changed continuously from 0 to 40 mm.
Flux attenuator
The flux of gamma-ray beams is regulated by an attenuator consisting of eight pieces of oxygen-free copper blocks with diameters of 50 mm, thicknesses of 15 mm, 25 mm, 50 mm (two pieces), 100 mm (three pieces), and 200 mm, and a total thickness of 640 mm, as shown in Fig. 4(c). Localized shielding around the fine collimator and flux attenuator is shown in Fig. 4(d).
Control system
Figure 5(a) and 5(b) show the interface displays used to remotely control the coarse and fine collimators, respectively. One of the 10 apertures of the coarse collimator is selected, and the aperture of the fine collimator can be continuously changed in the range of 0–40 mm. The horizontal and vertical positions of the coarse and fine collimators can be adjusted with 0.1-mm precision. Fig. 5(c) shows the interface display for selecting any combination of flux attenuator blocks. The movement of the 200-mm and 100-mm blocks of the flux attenuator is monitored with the CCD camera. Fig. 5(d) shows the control display of the laser system to be tuned for the laser Compton back and slant scatterings. The operating conditions of the CO2 laser in the pulse mode are shown in the monitor display, including the pulse interval and width.
Commissioning of the SLEGS beamline
Measurements of the gamma-ray beams during the commissioning of the SLEGS beamline were performed in an experimental hutch. At the end of the beamline, unreacted gamma rays entered the gamma absorber, which is made of thick concrete, Pb, and high-density polyethylene, as shown in Fig. 1.
Collimator alignment
The collimators must be aligned with respect to the gamma ray beam axis. The collimator alignment was performed horizontally and vertically by maximizing the intensity of the gamma rays passing through the collimator. Figure 6(a) and (b) show the gamma ray intensity as a function of the vertical and horizontal positions of the coarse collimator, respectively. In this collimator position scan, a coarse collimator with an aperture of 2 mm was used along with a 20-mm fine collimator and a 100-mm flux attenuator. A Φ3” x 4”(Φ76.2 mm x 101.6 mm) LaBr3(Ce) detector [27] was used to measure the gamma rays. The optimized position of the coarse collimator was found to be 51.97 (± 0.04) mm vertically and 34.54 (± 0.03) mm horizontally. The laser - electron collision position and fine collimator underwent the same adjustment process.
Gamma-ray beam spot
The SLEGS beamline is equipped with two beam spot monitors in the experimental hutch (Fig. 7): an X-ray camera called MiniPIX [28], shown in Fig. 7(b), and a gamma spot monitor (GSM), shown in Fig. 7(d). The MiniPIX consists of 256 × 256 silicon pixels with a pixel size of 55 μm × 55 μm and a silicon wafer thickness of 500 μm. The GSM involves a LYSO scintillator that is 70 mm in diameter and has a thickness of 2.5 mm, which collects the scintillation light generated by X- and gamma rays with a CCD/CMOS camera through a 45° plane mirror, with a 135° optical path as a reserved monitoring channel.
Figure 7(a) shows an example of a beam spot with a Bremsstrahlung background measured using MiniPIX. Figure 7(c) shows an example of the gamma beam spot measured with the GSM after subtracting the Bremsstrahlung background along with the horizontal (X) and vertical (Y) distributions. The gamma beam spot size in the full width at the tenth maximum (FWTM) is horizontally 17.31 mm and vertically 8.91 mm. Because the GSM is placed approximately 38 m from the gamma production point, the calculated gamma-ray emission angles are 0.46 mrad in the X direction and 0.25 mrad in the Y direction.
Energy profile and flux of gamma-ray beams
A Saint-Gobain lanthanum bromide (LaBr3(Ce)) detector 3” (76.2 mm) in diameter and 4” (101.6 mm) in length with an energy resolution of approximately ~3 % at 661 keV [27] was used as the energy profile and flux monitor detector in the commissioning run. A BGO detector 76.2 mm in diameter with a length of 200 mm from SICCAS [29], located in the gamma absorber, was used to monitor the gamma flux. The flux value was fed back to the control system of the collimator and laser for online recording and display and will be used for automatic correction of laser power output in the future. Figure 8(a) shows a typical response function of the LaBr3(Ce) detector with respect to the gamma-ray beam, where a 3-mm coarse collimator, 3-mm fine collimator, and 1-mm additional lead external collimator were used, but without the flux attenuator. The background gamma spectrum is shown by the green line, where the lower-energy synchrotron radiation and higher-energy Bremsstrahlung are seen, as well as internal radiation from 138La in the LaBr3(Ce) detector. Figure 8(b) shows the background-subtracted spectra measured at 20°, 90°, and 180°.
We systematically measured the response functions of the LaBr3(Ce) detector to gamma-ray beams produced by slant-scattering. The background-subtracted spectra are shown in Fig. 9. The gamma-ray energy follows the kinematics of laser Compton slant scattering. The production of gamma-ray beams was confirmed in the energy range of 0.25 - 21.1 MeV in slant-scattering mode from 20° to 160° and at 21.7 MeV in back-scattering at 180°.
The total gamma-ray flux is an important parameter in the commissioning of the SLEGS beamline. The gamma flux required to be approved is the total flux at the gamma production point integrated over the entire gamma energy spectrum for the electron beam current Ie = 300 mA (design value). The background-free gamma-ray flux φ was measured using a LaBr3(Ce) detector at Ie = 200 mA (test value). After normalizing the measured flux φ by F=φ/［ηD×ηA×ηC］×［300 mA/200 mA］ with the detection efficiency ηD of the LaBr3(Ce) detector, transmission rate ηA of the attenuator, and transmission rate ηC of the collimator hole, the total flux is shown in Fig. 10. The maximum flux at an electron current of 300 mA and a laser power of 100 W can reach approximately 105 photons/s at 20° and 108 photons/s at 180°.
Energy distribution of gamma-ray beams
The electron beam energy of the SSRF storage ring is 3.5 GeV. Because of this high electron beam energy, the energy of the gamma-ray beams produced in the laser Compton scattering strongly depends on the emission angle. Thus, the energy spread (resolution) of the gamma ray beam is highly sensitive to the angular acceptance, defined by the collimator aperture. The black line in Fig. 11 shows the experimental response function of the LaBr3(Ce) detector to gamma rays produced in backscattering at 180°. Assuming that the energy distribution of the gamma-ray beam incident on the detector is given by a truncated Breit-Wigner function, which is indicated by the blue line, we performed a Geant4 simulation of the response function of the LaBr3(Ce) detector to the gamma-ray beam. The results are indicated by the red line in Fig. 11. It is clear that the Geant4 simulation reproduces the experimental response function well (black line). Phenomenologically, as the scattering angle decreases in slant-scattering mode, the incident gamma-ray spectra of the Gaussian function better fit the experimental response function in the Geant4 [30] simulation. In this phenomenological study, it was found that an energy resolution of 2 – 15 % could be obtained with a collimator aperture of 1 – 3 mm.
A thorough study of the energy resolution of the gamma-ray beam requires more realistic Geant4 simulations, in which gamma-ray beams are kinematically produced in laser Compton scattering, transported through the collimator system, and incident on the LaBr3(Ce) detector. The energy distribution of the gamma-ray beam produced in laser Compton scattering depends on the electron beam emittance, which is an important parameter for reproducing the experimental response function. A thorough analysis using more realistic Geant4 simulations will be conducted in the near future.
Experimental spectrometers
We have developed four types of experimental spectrometers (sometimes called detector arrays), as shown in Fig. 12: a gamma nuclear resonance fluorescence (NRF) spectrometer, neutron flat-efficiency detector (FED) spectrometer, neutron time-of-flight (TOF) spectrometer, and light charged-particles (LCP) spectrometer. The four experimental spectrometers are used for the photon elastic/inelastic scattering reaction, photo-neutron reaction, and photo-light charged particle reaction, respectively. The spectrometer for the photofission reaction is not involved in the current construction stage. The photonuclear reaction experiment can also employ a combination of two spectrometers, such as FED combined with an NRF spectrometer, which will be used in the (γ,nγ) experiment [31].
The NRF gamma spectrometer consists of two large-volume coaxial HPGe detectors, two clover HPGe detectors [32], and eight 3” (76.2 mm) x 4” (101.6 mm) LaBr3(Ce) detectors [28]. The neutron FED consists of twenty-six 3He counters [33] embedded in a polyethylene moderator [34]. The TOF neutron spectrometer consists of twenty Φ5” (127 mm) x 2” (50.8 mm) EJ301 [35] liquid scintillation detectors. The LCP (p,d,t,αa) spectrometer consists of 4-6 groups ΔDE-E telescope detectors comprising a grid ionization chamber (GIC) [36], silicon strip detector (SSD) [37], and CsI (Tl) crystal [36] mounted in a large high-vacuum experimental chamber, as shown in Fig. 12 (d).
Results of the commissioning of the SLEGS beamline
The SLEGS beamline started the first test run at a small electron-beam current of 10 mA in July 2021 and finished the debugging of the gamma beam generation in the back- and slant-scattering modes at 200 mA. The performance of the SLEGS beamline in generating gamma-ray beams and the experimental spectrometer was approved by the Chinese Academy of Sciences (CAS) [38] in December 2021, completing the construction of the SLEGS beamline station. The results obtained during the commissioning run are summarized in Table 1.
| Commissioning item | Final measured results |
|---|---|
| Beamline | |
| Energy | 0.25 - 21.7 MeV |
| Resolution | ~ 2-15 % (with collimator) |
| Full-spectrum integrated gamma flux | ~ 2.1 x 104 photons/s at 20° |
| Angular divergence | < 0.45 mrad |
| Experimental Station | |
| Charged particle Detector | Energy resolution < 0.5 % at 5.5 MeV |
| High efficiency gamma detector | Energy resolution < 0.3 % at 662 keV Relative efficiency > 94 % |
Table 2 shows the situation of several LCS facilities worldwide and a comparison of the main gamma parameters. Currently, only HIγS and SLEGS can provide MeV gamma rays for nuclear-physics research.
| Facility/LCS Name | Collision Mode | Energy Range | Gamma Flux | Energy Resolution | Current Operating Status |
|---|---|---|---|---|---|
| TUNL/HIγS (USA) | BCS | 1-100MeV | 106-9 phs/s | (0.8-10)% | 1996 -, open |
| SSRF/SLEGS (China) | BCS/SCS | 0.25-21.7MeV | 105-8 phs/s | < 5%@2mm | 2022 -, open |
| ELI-NP/VEGA (Europe) | BCS | 0.2-19.5MeV | ~ 2.5x108 phs/s@10MeV | ≤ 0.5@2mm | under construction |
| NewSUBARU/BL01 (Japan) | BCS | 1-76MeV | ~ 107 phs/s | ~10%@3mm | 2007 -，LCS, limited operation |
| UVSOR-III/BL01 (Japan) | BCS/SCS | 1-5.4MeV | ~ 107 phs/s | ~2.9%@2mm | 2015 -, open |
| SPRing-8 /LEPS&LEPS2 (Japan) | BCS | 1300-2900MeV | 106-7 phs/s | < 15%@tagging | 1999 -, open |
Summary and prospects
The completion of the SLEGS beamline station was approved by the Chinese Academy of Sciences (CAS) in December 2021 after the successful commissioning run. Gamma-ray beams are produced in the energy range from 0.25 to 21.1 MeV in the laser Compton slant-scattering mode with 10.64 μmm CO2 laser photons at scattering angles from 20° to 160°, and at a maximum energy of 21.7 MeV in laser Compton back-scattering mode at 180°. The slant-scattering mode is employed in the SLEGS beamline to systematically produce gamma-ray beams.
Two-stage coarse and fine collimators are used to produce fine pencil-like quasi-monochromatic gamma ray beams. The gamma-ray integrated flux is 2.1 x 104 photons/s at 20°, 2.5 x 106 photons/s at 90°, and 1.2 x 107 photons/s at 180°. The energy spread of the gamma-ray beam is 2 -15 % when the gamma-ray emission angle is confined to less than 0.45 mrad at 38 m using the collimator system. Four types of spectrometers, which may reflect the versatility of nuclear physics experiments [39-44], are available at the SLEGS experimental station. The SLEGS beamline will be open to users by the end of 2022. In recent years, some large nuclear scientific facilities have started construction and been put into operation, including the back-streaming neutron (Back-n) source [45,46] at the China Spallation Neutron Source (CSNS), the High-Intensity Heavy-ion Accelerator Facility (HIAF) [47-49] and CSR External-target Experiment (CEE) [50], Collinear Laser Spectroscopy (CLS)[51,52], and the new Beijing Radioactive Ion-beam Facility (BRIF) [53]. The completion of these facilities or devices will surely push China's nuclear physics basic and applied research to the next level.
Experimental Nuclear Reaction Data (EXFOR)
, https://www-nds.iaea.org/exfor/exfor.htmIAEA TECDOC-1178, Handbook on Photonuclear Data for Applications Cross -sections and Spectra. Final report of a co-ordinated research project
(2000). https://www.iaea.org/publications/6043/handbook-on-photonuclear-data-for-applications-cross-sections-and-spectraIAEA Photonuclear Data Library 2019
, Nuclear Data Sheets, 163, 109-162 (2020). doi: 10.1016/j.nds.2019.12.002Reliability of Photonuclear Data: Various Experiments and Evaluations
. Phys. Part. Nuclei 50, 637-643 (2019). doi: 10.1134/S1063779619050241Physical Reliability Criteria and Special Features of Data on the Photodisintegration of 75As, 127I, 181Ta, and 208Pb
, Nuclei. Phys. Atom. Nuclei 84, 603-614 (2021). doi: 10.1134/S1063778821050148γEnchancement of Laser Compton gamma-ray beam with F-P cavity in storage ring TERAS, Free Electron Lasers 2003
,NewSUBARU BL01, Laser Compton Gamma Source
, https://www.lasti.u-hyogo.ac.jp/NS-en/facility/bl01/High Intensity Gamma-Ray Source (HIGS)
. https://tunl.duke.edu/research/our-facilitiesHigh energy gamma ray beams from Compton backscattered laser light
. IEEE Transactions on Nuclear Science 30, 3083-3087 (1983). doi: 10.1109/TNS.1983.4336577.LEPS-Laser Electron Photon Experiment at SPring-8
. https://www.rcnp.osaka-u.ac.jp/Divisions/np1-bExtreme Light Infrastructure - Nuclear Physics (ELI-NP)
. www.eli-np.roResearch on properties and application of Compton backscattered gamma light source based on synchrotron radiation accelerator
. Progress in Physics 23, 389 (2003). doi: 10.3321/j.issn:1000-0542.2003.04.001(in Chinese)A high intensity beam line of γ-rays up to 22 MeV energy based on Compton backscattering
. Nucl. Instr. and Meth. A 578, 457 (2007). doi: 10.1016/j.nima.2007.05.322An X-ray source based on Compton backscattering of CO2 laser and 100 MeV electrons
. Nucl. Instr. and Meth. A 580, 1184-1190 (2007), doi: 10.1016/j.nima.2007.07.007Laser Compton scattering experiments and the latest developments in construction of experimental facilities at SINAP
. Proc. SPIE, V 7385, 73852D (2009), doi: 10.1117/12.835572A laser-Compton scattering (LCS) prototype experiment at 100MeV Linac of Shanghai Institute of Applied Physics
. Rev. of Sci. Instr. 81, 013304 (2010). doi: 10.1063/1.3282445.An X-ray spectroscopy system and its application to the Laser-Compton scattering experiments
. Nucl. Instr. and Meth. A 624, 141-147 (2010), doi: 10.1016/j.nima.2010.09.045A 4D Monte Carlo laser-Compton scattering simulation code for the characterization of the future energy-tunable SLEGS
. Nucl. Instr. and Meth. A 660, 108-115 (2011). doi: 10.1016/j.nima.2011.09.035X-ray generation from slanting laser-Compton scattering for future energy-tunable Shanghai Laser Electron Gamma Source
. Applied Physics B 101, 761-771 (2010). doi: 10.1007/s00340-010-4100-0Development and prospect of Shanghai Laser Compton Scattering Gamma Source
. Nucl. Phys. Rev. 37(1), 53-63 (2020). doi: 10.11804/NuclPhysRev.37.2019043(in Chinese)Generation of ultra-short gamma ray pulses via laser Compton scattering in UVSOR-II electron storage ring
, inGeneration of energy-tunable and ultra-short-pulse gamma rays via inverse Compton scattering in an electron storage ring
. Nucl. Instr. And Meth. A 652, 696-700 (2011). doi: 10.1016/j.nima.2010.08.036Interaction chamber for laser Compton slant scattering in SLEGS beamline at Shanghai Light Source
. Nucl. Instr. and Meth, Phys. A 1033, 166742 (2022); published online (doi: 10.1016/j.nima.2022.166742).Collimator system of SLEGS beamline at SSRF
. Nucl. Instr. Meth. A 1013, 165638 (2021). doi: 10.1016/j.nima.2021.165638A new annular collimator system of SLEGS beamline at SSRF
. Nucl. Instr. and Meth. B 519, 9-14 (2022). doi: 10.1016/j.nimb.2022.02.010p-process chaser detector in – coincidences
. Nucl. Instrum. Methods Phys. Res. A 1034, 166819 (2022). doi: 10.1016/j.nima.2022.166819.Canberra
, https://www.mirion.com/Design and simulation of 4π flat-efficiency 3He neutron detector array
. Nuclear Techniques 43, 57-65(2020). doi: 10.11889/j.0253-3219.2020.hjs.43.110501(in Chinese)Energy calibration of the NewSUBARU storage ring for laser Compton-scattering gamma rays and applications
. IEEE Trans. Nucl. Sci. 61, 1252-1258 (2014). doi: 10.1109/TNS.2014.2312323Determination of the stellar reaction rate for 12C(α,γ) 16O:Using a new expression with the reaction mechanism
. Chin. Phys. B 18, 1421-1407 (2009). doi: 10.1088/1674-1056/18/4/023.Measurement of PV asymmetry in n + p→d + γ and γ+ d→n + p
. Chin. Phys. C 34, 1465 (2010). doi: 10.1088/1674-1137/34/9/073.New astrophysical Reaction Rate for the 12C(α,γ)16O reaction
. Astr. J. Lett. 817, L5 (2016), doi: 10.3847/2041-8205/817/1/L5.Design and simulation of 4π flat-efficiency 3He neutron detector array
. Nuclear Techniques 43, 110501(2019), doi: 10.11889/j.0253-3219.2020.hjs.43.110501(in Chinese)Study on polarized γ beam properties of a new LCS light source based on SXFEL
. Nuclear Techniques 42,120201(2019). doi: 10.11889/j.0253-3219.2019.hjs.42.120201(in Chinese)Back-n white neutron source at CSNS and its applications
. Nucl. Sci. Tech. 32, 11 (2021). doi: 10.1007/s41365-021-00846-6Measurements of the 197Au(n, γ) cross section up to 100 keV at the CSNS Back-n facility
. Nucl. Sci. Tech. 32, 101 (2021). doi: 10.1007/s41365-021-00931-wCryogenic system design for HIAF iLinac
. Nucl. Sci. Tech. 30, 178 (2019). doi: 10.1007/s41365-019-0700-5Electrostatic-lenses position-sensitive TOF MCP detector for beam diagnostics and new scheme for mass measurements at HIAF
. Nucl. Sci. Tech. 30, 152 (2019). doi: 10.1007/s41365-019-0676-1Design of an efficient collector for the HIAF electron cooling system
. Nucl. Sci. Tech. 32, 116 (2021). doi: 10.1007/s41365-021-00949-0Simulation and prototype testing of multi-wire drift chamber arrays for the CEE
. Nucl. Sci. Tech 31, 11 (2020). doi: 10.1007/s41365-019-0716-xCommissioning of a high-resolution collinear laser spectroscopy apparatus with a laser ablation ion source
. Nucl. Sci. Tech. 33, 9 (2022). doi: 10.1007/s41365-022-00992-5Construction and commissioning of the collinear laser spectroscopy system at BRIF
. Nucl. Instrum. Meth. Phys. A 1032, 166622 (2022), doi: 10.1016/j.nima.2022.166622First proof-of-principle experiment with the post-accelerated isotope separator on-line beam at BRIF: measurement of the angular distribution of 23Na + 40Ca elastic scattering
. Nucl. Sci. Tech. 32, 53 (2021). doi: 10.1007/s41365-021-00889-9