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Production of high-energy neutron beam from deuteron breakup

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Nuclear Science and Techniques 2022年第7期33卷 125-132页

作者： Ren-Sheng Wang Li Ou zhi-gang xiao School of Radiation Medicine and Protection Medical College of Soochow UniversitySuzhou215123China Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions Suzhou215123China College of Physics and Technology Guangxi Key Laboratory of Nuclear Physics and TechnologyGuangxi Normal UniversityGuilin541004China Department of Physics Tsinghua UniversityBeijing100084China

The deuteron breakup on heavy targets has been investigated in the framework of an improved quantum molecular dynamics model,focusing on the production of neutrons near zero degrees.The experimental differential cross sections of neutron production in the 102 MeV d+C reactions were reproduced by simulations.Based on the consistency between the model prediction and experiment,the feasibility of producing a neutron beam through the breakup of deuteron on a carbon target was demonstrated.Because of the nucleon Fermi motion inside the deuteron,the energy spectrum of the inclusive neutron near 0°in the laboratory exhibits considerable energy broadening in the main peak,whereas the long tail on the low-energy side is suppressed.By coincidentally measuring the accompanying deuteron breakup proton,the energy of the neutron can be tagged with an intrinsic uncertainty of approximately 5%(1σ).The tagging efficiency of the accompanying proton on the forward-emitted neutron can reach 90%,which ensures that the differential cross section in the(d,np)channel remains two orders higher than that in(p,n)after considering the measurement of accompanying protons.This enables the application of a well-defined energy neutron beam in an event-by-event scheme.

关键词： Deuteron breakup Monochromatic neutron High energy Quantum molecular dynamics

Probing nucleon effective mass splitting with light particle emission

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Nuclear Science and Techniques 2023年第6期34卷 135-146页

作者： Fang-Yuan Wang Jun-Ping Yang Xiang Chen Ying Cui Yong-Jia Wang zhi-gang xiao Zhu-Xia Li Ying-Xun Zhang China Institute of Atomic Energy Beijing102413China School of Science Huzhou UniversityHuzhou313000China Department of Physics Tsinghua UniversityBeijing100084China Guangxi Key Laboratory of Nuclear Physics and Technology Guangxi Normal UniversityGuilin541004China

The main objective of this study was to investigate the impact of effective mass splitting on heavy-ion-collision observables.We first analyzed correlations between different nuclear matter parameters obtained from 119 effective Skyrme interaction sets.The values of the correlation coefficients illustrate that the magnitude of effective mass splitting is crucial for tight constraints on the symmetry energy via heavy-ion collisions.The^(86)Kr+^(208)Pb system at beam energies ranging from 25 to 200A MeV was simulated within the framework of the improved quantum molecular dynamics model(ImQMD-Sky).Our calculations show that the slopes of the spectra of ln[Y(n)/Y(p)]and ln[Y(t)/Y(^(3)He)],which are the logarithms of the neutron to proton and triton to helium-3 yield ratios,are directly related to effective mass splitting and can be used to probe the effective mass splitting.

关键词： Effective mass splitting Symmetry energy Heavy-ion collisions Skyrme interaction

An FPGA‑based trigger system for CSHINE

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Nuclear Science and Techniques 2022年第12期33卷 138-146页

作者： Dong Guo Yu‑Hao Qin Sheng xiao zhi Qin Yi‑Jie Wang Fen‑Hai Guan Xin‑Yue Diao Bo‑Yuan Zhang Yao‑Peng Zhang Da‑Wei Si Shi‑Wei Xu Xiang‑Lun Wei He‑Run Yang Peng Ma Tian‑Li Qiu Hai‑Chuan Zou Li‑Min Duan zhi‑gang xiao Department of Physics Tsinghua UniversityBeijing 100084China Institute of Modern Physics Chinese Academy of ScienceLanzhou 730000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

A trigger system of the general function was designed using the commercial module of CAEN V2495 for heavy-ion nuclear reaction experiments at Fermi energies.The system was applied and verified on the compact spectrometer for heavy IoN experiment(CSHINE).Based on the field-programmable logic gate array technology of the command register access and remote computer control operation,trigger functions can be flexibly configured according to experimental physical goals.Using the trigger system on CSHINE,we conducted a beam experiment at 25 MeV/u^(86)Kr+^(124)Sn on the Radioactive Ion Beam Line 1 in Lanzhou,China.The online results demonstrated that the trigger system worked normally and correctly.This system can be extended to other experiments as well.

关键词： CSHINE Trigger system FPGA Heavy ion experiment

Reconstruction of fission events in heavy ion reactions with the compact spectrometer for heavy ion experiment

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Nuclear Science and Techniques 2022年第4期33卷 1-9页

作者： Xin-Yue Diao Fen-Hai Guan Yi-Jie Wang Yu-Hao Qin zhi Qin Dong Guo Qiang-Hua Wu Da-Wei Si Xuan Zhao Sheng xiao Yao-Peng Zhang Xiang-Lun Wei Hai-Chuan Zou He-Run Yang Peng Ma Rong-Jiang Hu Li-Min Duan Artur Dobrowolski Krzysztof Pomorski zhi-gang xiao Department of Physics Tsinghua UniversityBeijing 100084China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Institute of Physics Maria Curie Skłodowska UniversityLublin 20031Poland

We report a reconstruction method for fast-fission events in 25 MeV/u^(86)Kr +^(208)Pb reactions at the Compact Spectrometer for Heavy Ion Experiment(CSHINE). The fission fragments(FFs) are measured using three large-area parallel-plate avalanche counters, which can deliver the position and arrival timing information of the fragments. The start timing information is provided by the radio frequency of the cyclotron. Fission events were reconstructed using the velocities of the two FFs. The broadening of both the velocity distribution and azimuthal difference of the FFs decreases with the folding angle, in accordance with the picture that fast fission occurs. The anisotropic angular distribution of the fission axis also consistently reveals the dynamic features of fission events.

关键词： Fast fission Heavy ion reactions Parallelplate avalanche counter CSHINE

Simulation and prototype testing of multi-wire drift chamber arrays for the CEE

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Nuclear Science and Techniques 2020年第1期31卷 102-111页

作者： Li-Ming Lyu Han Yi Li-Min Duan Zhao Zhang zhi-gang xiao Department of Physics Tsinghua UniversityBeijing 100084China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

The building of a large-scale external-target experiment, abbreviated as CEE, in the cooling storage ring at the Heavy Ion Research Facility in Lanzhou has been planned. The CEE is a multi-purpose spectrometer that will be used for various studies on heavy-ion collisions. A multi-wire drift chamber(MWDC) array is the forward tracking detector of the CEE. In this work, GEANT4 simulations were performed for the MWDC forward tracking array with a focus on the track reconstruction algorithm. Combined with the time of flight information,particle identification is achieved. The residue is about 30 μm, while the tracking efficiency is higher than 90%with the current redundancy. In addition, a prototype of the forward tracking system using three MWDCs was assembled and tested using a high-energy proton beam. The firing efficiency of the detector and the reconstruction accuracy of the prototype were derived. The track residue for the protons at about 400 MeV/c is better than 300 μm, meeting the requirements of the CEE. Suggestions for improving the performance of the forward tracking system are given.

关键词： CEE Multi-wire drift chamber array Track finding and reconstruction

CSHINE for studies of HBT correlation in heavy ion reactions

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Nuclear Science and Techniques 2021年第1期32卷 27-34页

作者： Yi-Jie Wang Fen-Hai Guan Xin-Yue Diao Qiang-Hua Wu Xiang-Lun Wei He-Run Yang Peng Ma zhi Qin Yu-Hao Qin Dong Guo Rong-Jiang Hu Li-Min Duan zhi-gang xiao Department of Physics Tsinghua UniversityBeijing 100084China Institute of Modern Physics Lanzhou 730000China

The compact spectrometer for heavy ion experiment(CSHINE)is under construction for the study of isospin chronology via the Hanbury Brown–Twiss(HBT)particle correlation function and the nuclear equation of state of asymmetrical nuclear matter.The CSHINE consists of silicon strip detector(SSD)telescopes and large-area parallel-plate avalanche counters,which measure the light charged particles and fission fragments,respectively.In phase I,two SSD telescopes were used to observe 30 MeV/u 40Ar?197Au reactions.The results presented here demonstrate that hydrogen and helium were observed with high isotopic resolution,and the HBT correlation functions of light charged particles could be constructed from the obtained data.

关键词： Silicon strip detector Telescope HBT correlation function Nuclear equation of state

Revolution in thermoelectric cooling using PbSe thermoelectrics by grid plainification

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Science China Materials 2024年第5期67卷 1672-1673页

作者： xiao-Lei Shi Qingfeng Liu zhi-gang Chen School of Chemistry and Physics ARC Research Hub in Zero-emission Power Generation for Carbon Neutralityand Centre for Materials ScienceQueensland University of TechnologyBrisbaneQueensland4000Australia State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing211816China

Thermoelectric materials and devices enable direct conversion between heat and electricity,holding potential applications in thermoelectric power generation,localized cooling,and electronic thermal management[1].Howev... 详细信息

关键词： enable thermoelectric constrained

Classification of knowledge graph completeness measurement techniques

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Journal of Systems Engineering and Electronics 2024年第1期35卷 154-162页

作者： ZHANG Ying xiao gang Institute of Systems Engineering Academy of Military SciencesBeijing 100107China

At present,although knowledge graphs have been widely used in various fields such as recommendation systems,question and answer systems,and intelligent search,there are always quality problems such as knowledge omissions and errors.Quality assessment and control,as an important means to ensure the quality of knowledge,can make the applications based on knowledge graphs more complete and more accurate by reasonably assessing the knowledge graphs and fixing and improving the quality problems at the same time.Therefore,as an indispensable part of the knowledge graph construction process,the results of quality assessment and control determine the usefulness of the knowledge graph.Among them,the assessment and enhancement of completeness,as an important part of the assessment and control phase,determine whether the knowledge graph can fully reflect objective phenomena and reveal potential connections among entities.In this paper,we review specific techniques of completeness assessment and classify completeness assessment techniques in terms of closed world assumptions,open world assumptions,and partial completeness assumptions.The purpose of this paper is to further promote the development of knowledge graph quality control and to lay the foundation for subsequent research on the completeness assessment of knowledge graphs by reviewing and classifying completeness assessment techniques.

关键词： quality assessment completeness assessment closed world assumptions open world assumption partial completeness assumption

Casual associations between blood metabolites and colon cancer

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 1995-2005页

作者： Ke-Yue Hu Yi-Quan Cheng zhi-Long Shi Fu-Peng Ren gang-Feng xiao Department of Hematology and Oncology Ningbo No.2 HospitalNingbo 315000Zhejiang ProvinceChina

BACKGROUND Limited knowledge exists regarding the casual associations linking blood metabolites and the risk of developing colorectal cancer.AIM To investigate causal associations between blood metabolites and colon cancer.METHODS The study utilized a two-sample Mendelian randomization(MR)analysis to investigate the causal impact of 486 blood metabolites on colorectal cancer.The primary method of analysis used was the inverse variance weighted model.To further validate the results several sensitivity analyses were performed,including Cochran's Q test,MR-Egger intercept test,and MR robust adjusted profile score.These additional analyses were conducted to ensure the reliability and robustness of the findings.RESULTS After rigorous selection for genetic variation,486 blood metabolites were included in the MR analysis.We found Mannose[odds ratio(OR)=2.09(1.10-3.97),P=0.024],N-acetylglycine[OR=3.14(1.78-5.53),P=7.54×10^(-8)],X-11593-O-methylascorbate[OR=1.68(1.04-2.72),P=0.034],1-arachidonoylglycerophosphocholine[OR=4.23(2.51-7.12),P=6.35×10^(-8)]and 1-arachidonoylglycerophosphoethanolamine 4[OR=3.99(1.17-13.54),P=0.027]were positively causally associated with colorectal cancer,and we also found a negative causal relationship between Tyrosine[OR=0.08(0.01-0.63),P=0.014],Urate[OR=0.25(0.10-0.62),P=0.003],N-acetylglycine[0.73(0.54-0.98),P=0.033],X-12092[OR=0.89(0.81-0.99),P=0.028],Succinylcarnitine[OR=0.48(0.27-0.84),P=0.09]with colorectal cancer.A series of sensitivity analyses were performed to confirm the rigidity of the results.CONCLUSION This study showed a causal relationship between 10 blood metabolites and colorectal cancer,of which 5 blood metabolites were found to be causal for the development of colorectal cancer and were confirmed as risk factors.The other five blood metabolites are protective factors.

关键词： Metabolites Colon cancer Mendelian randomization Genome-wide association studies Casual