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A tracking system for the external target facility of CSR

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Nuclear Science and Techniques 2017年第5期28卷 68-73页

作者： Shu-Wen Tang Shi-Tao Wang Li-Min Duan zhi-yu sun yu-Hong yu Xue-Heng Zhang Ke yue Chen-Gui Lu He-Run Yang Peng Ma Fang Fang Duo Yan yu sun Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000 China University of Chinese Academy of Sciences Beijing 100049China

A tracking system composed of three multiwires proportional chambers(MWPCs) for the external target facility of the Cooler Storage Ring is reported in this paper. The active areas of the MWPCs are 518 mm 9400 mm, 582 mm 9 450 mm, and 710 mm 9 500 mm Each MWPC consists of a series of alternately placed cathode and anode wire planes and can measure position along the directions of-30°, 0°, and 30° relative to horizontal. The construction and operation of the detectors are described, and a method for track reconstruction is introduced. A track-finding efficiency of about 62% and a spatial resolution of 1.21 mm have been achieved. The pion and proton can be identified clearly with the tracking system combined with a time-of-flight system.

关键词： ETF MWPC Track reconstruction Spatial resolution

Main issues in research and practice of environmental protection for water conservancy and hydropower projects in China

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Water Science and Engineering 2016年第4期9卷 312-323页

作者： Ang Chen Miao Wu Kai-qi Chen zhi-yu sun Chen Shen Peng-yuan Wang Institute of Hydropower and Environment Research China Three Gorges Corporation School of Civil Engineering Tsinghua University College of Hydrology and Water Resources Hohai University Appraisal Center for Environment and Engineering Ministry of Environmental Protection

In this paper,we generally summarize the main issues in the operational period of water conservancy and hydropower projects in China over the past several ***,the adverse impacts of these projects since the technical guidelines were proposed in 2006 are ***,combined with projects and experience from 2006 to 2014,the four main issues are summarized:(1) There exist many questions in the design and construction of fishways,which are useful for fish migration,and the migration effects are not as expected.(2) Temperature stratification affecting the downstream fish is the major impact of temperature,and alters fish spawning in the reproduction season.(3)Ecological base flow has been one of the primary questions of the last 30 years in China,the greatest related difficulty being quantification of the amount and flow process necessary to satisfy fish life history.(4) Fish habitat protection and restoration are popular topics in recent years with the development of river ecosystem *** habitat loss due to the impacts of dam construction and habitat fragmentation has become more and more *** four issues are now the main difficulties in water project management,and interact with one another to bear combined effects on river *** issues of eco-hydraulic consideration in the design period are the key ***,future priorities for research and practice of environmental protection for water conservancy and hydropower projects in China are *** main purpose of this paper is to enhance the scientific research,monitoring,and assessment of operating effectiveness.

关键词： Temperature stratification Ecological base flow Fish habitat Environmental protection

Temperature dependence of CsI:Tl coupled to a PIN photodiode and a silicon photomultiplier

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Nuclear Science and Techniques 2019年第2期30卷 81-89页

作者： yu sun zhi-yu sun yu-Hong yu Ruo-Fu Chen Shu-Weng Tang Fang Fang Duo Yan Qiang Hu Ke yue Shi-Tao Wang Xue Heng Zhang Yong-Jie Zhang Jun-Lin Chen Ya-Zhou sun Ze-Hui Cheng Bi-Tao Hu Institute of Modern Physics Chinese Academy of Sciences Lanzhou University University of Chinese Academy of Sciences

With the aim of simulating the harsh temperature condition of space, a thallium-activated cesium iodide crystal(CsI:Tl) detector readout with a PIN photodiode(CsI:Tl(PD)) and with a silicon photomultiplier(CsI:Tl(SiPM)) is investigated over a temperature range from-40 to 40 ℃. With the increase in temperature, the output signal increases by ～ 24% with CsI:Tl(PD) and decreases by ～69% with CsI:Tl(SiPM). To reduce the effect of temperature in outer space, a method of bias voltage compensation is adopted for CsI:Tl(SiPM). Our study demonstrates that after correcting the temperature the variation in the analog-to-digital converter's amplitude is< 3%.

关键词： CsI:Tl SiPM PD Temperature dependence Correction method

Simulation of a soft-gamma-ray polarimeter on board a microsatellite

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Nuclear Science and Techniques 2023年第11期34卷 64-76页

作者： Xiang‑Man Liu Shu‑Wen Tang Wei Wang yu‑Hong yu zhi‑yu sun Yong‑Jie Zhang Fang Fang Duo Yan Shi‑Tao Wang Xue‑Heng Zhang Shu‑Ya Jin Bi‑Tao Hu Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Department of Astronomy School of Physics and TechnologyWuhan UniversityWuhan 430072China Wuhan University‑National Astronomical Observatories Joint Center for Astronomy Wuhan UniversityWuhan 430072China

Gamma-ray polarimetry is a new and prospective tool for studying extremely high-energy celestial objects and is of great significance for the field of *** the rapid development of microsatellite technology,the advantages of space exploration have become increasingly ***,we simulated a soft-gamma-ray polarimeter for a microsatellite based on the Compton scattering *** performed detailed Monte Carlo simulations using monoenergetic gamma-ray linear-polarization sources and Crab-like sources in the energy range of 0.1-10 MeV considering the orbital *** polarimeter exhibited excellent polarization detection *** modulation factor was 0.80±0.01,and the polarization angles were accurate within an error of 0.2°at 200 keV for on-axis *** the Crab-like sources for on-axis incidence,the polarization degrees were consistent with the set values within the error tolerance,the modulation factor was 0.76±0.01,and the minimum detectable polarization reached 2.4%at 3σfor an observation time of10^(6) ***,the polarimeter exhibited recoil electron tracking,imaging,and powerful background suppression in a large field of view(FoV;∼2πsr).The proposed polarimeter meets the requirements of a space soft-gamma-ray polarization detector and has promising research prospects.

关键词： Soft gamma ray Polarization Compton scattering Microsatellite Monte Carlo simulation

A new species of the genus Triplophysa (Cypriniformes： Nemacheilidae), Triplophysa daochengensis, from Sichuan Province, China

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Zoological Research 2016年第5期37卷 290-295页

作者： yu-Yi WU zhi-yu sun Yan-Shu GUO College of Life Sciences China West Normal University Nanchong Sichuan 637009 China Sichuan Academy of Forestry Chengdu Sichuan 610081 China

Triplophysa daochengensis sp. nov. is described from the Daocheng River, a northern tributary of the Jinsha River in Sichuan Province, China. The new species can be distinguished from its congeners by the following characters： body smooth and scales absent; lateral line complete; caudal peduncle compressed, depth unchanging; head length equal to caudal-peduncle length; lower jaw shovel-shaped; dorsal-fin origin anterior to pelvic-fin origin and closer to the tip of the snout than to the caudal-fin base, last unbranched ray hard; pelvic-fin tip not reaching anus; posterior chamber of gas bladder absent; intestine of spiral type with three winding coils.

关键词： Nemacheilidae Triplophysa New species Sichuan

Opportunities for production and property research of neutron-rich nuclei around N=126 at HIAF

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Nuclear Science and Techniques 2024年第6期35卷 101-113页

作者： Shao-Bo Ma Li-Na Sheng Xue-Heng Zhang Shi-Tao Wang Kai-Long Wang Chun-Wang Ma Hool-Jin Ong zhi-yu sun Shu-Wen Tang yu-Hong yu Xin-Tong Du Xiao-Bao Wei Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Advanced Energy Science and Technology Guangdong Laboratory Huizhou 516000China University of Chinese Academy of Sciences Beijing 100049China College of Physics Henan Normal UniversityXinxiang 453007China Institute of Nuclear Science and Technology Henan Academy of ScienceZhengzhou 450046China Joint-Department for Nuclear Physics Lanzhou University and Institute of Modern PhysicsLanzhou 730000China Research Center for Nuclear Physics Osaka UniversityOsaka 567-0047Japan RIKEN Nishina Center Saitama 351-0198Japan Northwest Normal University Lanzhou 730070China

The study of nuclide production and its properties in the N=126 neutron-rich region is prevalent in nuclear physics and astrophysics *** upcoming High-energy FRagment Separator(HFRS)at the High-Intensity heavy-ion Accelerator Facility(HIAF),an in-flight separator at relativistic energies,is characterized by high beam intensity,large ion-optical acceptance,high magnetic rigidity,and high momentum resolution *** provides an opportunity to study the production and properties of neutron-rich nuclei around N=*** this paper,an experimental scheme is proposed to produce neutron-rich nuclei around N=126 and simultaneously measure their mass and lifetime based on the HFRS separator;the feasibility of this scheme is evaluated through *** results show that under the high-resolution optical mode,many new neutron-rich nuclei approaching the r-process abundance peak around A=195 can be produced for the first time,and many nuclei with unknown masses and lifetimes can be produced with high *** the time-of-flight corrected by the measured dispersive position and energy loss information,the cocktails produced from 208 Pb fragmentation can be unambiguously ***,the masses of some neutron-rich nuclei near N=126 can be measured with high precision using the time-of-flight magnetic rigidity *** indicates that the HIAF-HFRS facility has the potential for the production and property research of neutron-rich nuclei around N=126,which is of great significance for expanding the chart of nuclides,developing nuclear theories,and understanding the origin of heavy elements in the universe.

关键词： HFRS Fragmentation Neutron-rich nuclei around N=126 Mass measurement Lifetime

A method for aligning the plastic scintillator detector on DAMPE

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Research in Astronomy and Astrophysics 2019年第6期19卷 63-70页

作者： Peng-Xiong Ma Yong-Jie Zhang Ya-Peng Zhang Yao Li Jing-Jing Zang Xiang Li Tie-Kuang Dong Yi-Zhong Fan Shi-Jun Lei Jian Wu yu-Hong yu Qiang yuan Chuan yue zhi-yu sun Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China School of Astronomy and Space Science University of Science and Technology of China Hefei 230026 China Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China School of Nuclear Science and Technology Lanzhou University Lanzhou 730000 China University of Chinese Academy of Sciences Beijing 100049 China

The Plastic Scintillator Detector(PSD) onboard the DArk Matter Particle Explorer(DAMPE)is designed to measure cosmic ray charge(Z) and to act as a veto detector for gamma ray *** fully exploit the charge identification potential of PSD and to enhance its capability to identify gamma ray events, we develop an alignment method for the PSD. The path length of a given track in the volume of a PSD bar is derived taking into account the shift and rotation alignment corrections. By examining energy spectra of corner-passing events and fully contained events, position shifts and rotations of all PSD bars are obtained, and are found to be on average about 1 mm and 0.0015 radian respectively. To validate the alignment method, we introduce artificial shifts and rotations of PSD bars into the detector *** shift and rotation parameters can be recovered successfully by the alignment procedure. As a result of the PSD alignment procedure, the charge resolution of the PSD is improved from 4% to 8%, depending on the nuclei.

关键词： instrumentation detectors-methods data analysis

Fragmentation of stable and neutron-rich ^(12-16)C into boron fragments at approximately 240 MeV/nucleon

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Chinese Physics C 2022年第1期46卷 118-123页

作者： Shu-Ya Jin Ya-Zhou sun Shi-Tao Wang zhi-yu sun Xue-Heng Zhang zhi-Qiang Chen Bo Mei Yi-Xuan Zhao Shu-Wen Tang yu-Hong yu Duo Yan Fang Fang Yong-Jie Zhang Shao-bo Ma Xiang-Man Liu Rui Han CAS Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100080China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China School of Physics and Electrical Engineering Anyang Normal UniversityAnyang 455000China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

The elemental fragmentation cross sections of boron fragments produced by stable and neutron-rich^(12-16)C beams with a carbon target were systematically measured at an incident beam energy of approximately 240 MeV/*** measured cross sections were found to increase as the projectile mass number *** observed feature is explained qualitatively based on the abrasion-ablation two-stage reaction model and is compared quantitatively with predictions from various reaction models,including empirical and statistical *** models agree with the measured cross sections within a factor of 2.

关键词： elemental fragmentation cross sections neutron-rich carbon isotopes abrasion-ablation model

Toward real-time digital pulse process algorithms for CsI(Tl)detector array at external target facility in HIRFL-CSR

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Nuclear Science and Techniques 2023年第9期34卷 8-20页

作者： Tao Liu Hai-Sheng Song yu-Hong yu Duo Yan zhi-yu sun Shu-Wen Tang Fen-Hua Lu Shi-Tao Wang Xue-Heng Zhang Xian-Qin Li Hai-Bo Yang Fang Fang Yong-Jie Zhang Shao-Bo Ma Hooi-Jin Ong Cheng-Xin Zhao Northwest Normal University Lanzhou 730070China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

A fully digital data acquisition system based on a field-programmable gate array(FPGA) was developed for a CsI(Tl) array at the external target facility(ETF) in the Heavy Ion Research Facility in Lanzhou(HIRFL). To process the CsI(Tl) signals generated by γ-rays and light-charged ions, a scheme for digital pulse processing algorithms is proposed. Every step in the algorithms was benchmarked using standard γ and α sources. The scheme, which included a moving average filter, baseline restoration, leading-edge discrimination, moving window deconvolution, and digital charge comparison, was subsequently implemented on the FPGA. A good energy resolution of 5.7% for 1.33-MeV γ-rays and excellent α-γ identification using the digital charge comparison method were achieved, which satisfies CsI(Tl) array performance requirements.

关键词： CsI(Tl)array On-line digital algorithms Moving average filter Moving window deconvolution On-line particle identification algorithms