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Radiation dose effects on the morphological development of M_(1) generation pea(Pisum sativum)

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Nuclear Science and Techniques 2021年第11期32卷 63-76页

作者： Da-Peng Xu Hu-Yuan Feng Jian-Bin Pan ze-en yao Jun-Run Wang School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China School of Life Sciences Lanzhou UniversityLanzhou 730000China engineering Research Center for Neutron Application Technology Ministry of EducationLanzhou UniversityLanzhou 730000China

We irradiated pea seeds with neutrons from a ^(252)Cf source and studied the radiation dose effects on various morphological development parameters during the growth of M_(1) generation *** found that in the dose range of 0.51-9.27 Gy,with the increase in neutron-absorbed dose,the morphological development parameters of M_(1) generation peas at the initial seedling stage showed an obvious trend with three *** the development of pea,this trend gradually *** analysis and verification showed that the main trend in the M_(1) generation of pea seeds was an inhibitory effect induced by neutron irradiation and there was a good linear correlation between the inhibitory effect and neutron absorption dose We successfully demonstrated the background removal of mutant plants and defined morphological developmen parameters for peas that match the overall development of *** results will positively impact neutron mutation breeding and automatic agriculture.

关键词： Neutron irradiation Pea(Pisum sativum) ^(252)Cf source Radiation does effects Absorbed dose Morphological development

Transport characteristics of space charge-dominated multi-species deuterium beam in electrostatic low-energy beam line

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Nuclear Science and Techniques 2018年第4期29卷 57-65页

作者： Xiao-Long Lu Yu Zhang Jun-Run Wang Zhi-Wu Huang Zhan-Wen Ma yao Yang ze-en yao School of Nuclear Science and Technology Lanzhou University engineering Research Center for Neutron Application Ministry of Education Lanzhou University Institute of Modern Physics Chinese Academy of Sciences

The transport characteristics of a space chargedominated multi-species deuterium beam consisting of D_1^+,D_2^+, and D_3^+ particles in an electrostatic low-energy beam line are studied. First, the envelope equations of the primary D_1^+ beam are derived considering the space charge effects caused by all particles. Second, the evolution of the envelope of the multi-species deuterium beam is simulated using the PIC code TRACK, with the results showing a significant effect of the unwanted beam on the transport of the primary beam. Finally, different injected beam parameters are used to study beam matching, and a new beam extraction system for the existing duoplasmatron source is designed to obtain the ideal injected beam parameters that allow a D_1^+ beam of up to 50 m A to pass unobstructed through the electrostatic low-energy beam transport line in the presence of an unwanted(D_2^+, D_3^+)beam of 20 m A; at the same time, distortions of the beam emittance and particle distributions are observed.

关键词： envelope equation Space charge effects Multi-species beam Electrostatic LEBT

Study on the multiple characteristics of M3 generation of pea mutants obtained by neutron irradiation

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Nuclear Science and Techniques 2020年第7期31卷 46-54页

作者： Da-Peng Xu ze-en yao Jian-Bin Pan Hu-Yuan Feng Zhi-Qi Guo Xiao-Long Lu School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China School of Life Sciences Lanzhou UniversityLanzhou 730000China engineering Research Center for Neutron Application Technology Ministry of EducationLanzhou UniversityLanzhou 730000China

Irradiation breeding is an important technique in the effort to solve food shortages and improve the quality of agricultural *** this study,a field test was implemented on the M3 generation of two mutant pea plants gained from previous neutron radiation of pea *** relationship between agronomic characteristics and yields of the mutants was ***,differences in physiological and biochemical properties and seed nutrients were *** results demonstrated that the plant height,effective pods per plant,and yield per plant of mutant Leaf-M1 were 45.0%,43.2%,and 50.9%higher than those of the control group,*** analysis attributed the increase in yield per plant to the increased branching *** yield per plant of mutant Leaf-M2 was 7.8%higher than that of the control group,which could be related to the increased chlorophyll content in the *** was a significant difference between the two mutants in the increase in yield per plant owing to morphological variation between the two *** were significant differences in SOD activity and MDA content between the two mutants and the control,indicating that the physiological regulation of the two mutants also *** addition,the iron element content of seeds of the two mutants was about 10.9%lower than in the seeds of the control group,a significant *** findings indicate that the mutants Leaf-M1 and Leaf-M2 have breeding value and material value for molecular biological studies.

关键词： breeding attributed gained

Study on secondary electron suppression in compact D–D neutron generator

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Nuclear Science and Techniques 2019年第5期30卷 139-145页

作者： Zhi-Wu Huang Xiao-Hou Bai Chang-Qi Liu Jun-Run Wang Zhan-Wen Ma Xiao-Long Lu Zheng Wei Zi-Min Zhang Yu Zhang ze-en yao School of Nuclear Science and Technology Lanzhou University engineering Research Center for Neutron Application Technology Ministry of EducationLanzhou University Institute of Modern Physics Chinese Academy of Sciences

A compact D–D neutron generator, with a peak neutron yield of D–D reactions up to 2.48×10~8 n/s is being developed at Lanzhou University in China for application in real-time neutron activation analysis. During tests, the problem of back acceleration of secondary electrons liberated from the neutron production target by deuterium ions bombardment was encountered. In this study,an electric field method and a magnetic field method for suppressing secondary electrons are designed and experimentally investigated. The experimental results show that the electric field method is superior to the magnetic field method. Effective suppression of the secondary electrons can be achieved via electrostatic suppression when the bias voltage between the target and the extraction-accelerating electrode is >204 V. Furthermore, the secondary electron emission coefficient for the mixed deuterium ion(D_1^+,D_2^+, and D_3^+) impacting on molybdenum is estimated. In the deuterium energy range of 80–120 keV, the estimated secondary electron emission coefficients are approximately 5–5.5 for the mixed deuterium ion glancing incidence of 45° and approximately 3.5–3.9 for the mixed deuterium ion normal incidence.

关键词： D–D neutron generator Secondary electron suppression Secondary electron emission coefficient

Bayesian evaluation of energy dependent neutron induced fission yields

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Chinese Physics C 2023年第12期47卷 96-101页

作者：肖名翔包小军韦峥姚泽恩 Department of Physics Hunan Normal UniversityChangsha 410081China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

From both the fundamental and applied perspectives, fragment mass distributions are important observablesof fission. We apply the Bayesian neural network (BNN) approach to learn the existing neutron induced fissionyields and predict unknowns with uncertainty quantification. Comparing the predicted results with experimentaldata, the BNN evaluation results are found to be satisfactory for the distribution positions and energy dependenciesof fission yields. Predictions are made for the fragment mass distributions of several actinides, which may beuseful for future experiments.

关键词： Bayesian evaluation energy dependent neutron induced fission yields

Calculation of the wide-angle neutron spectra from the ~9Be(d,xn) reaction in a thick beryllium target

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Chinese Physics C 2019年第5期43卷 29-34页

作者： Zheng Wei Jun-Run Wang Ya-Ling Zhang Zhi-Wu Huang Zhan-Wen Ma Jie Zhang Yan-Yan Ding Li Xia Jian-Yi Li Xiao-Long Lu Yu Zhang Da-Peng Xu Lei Yang ze-en yao School of Nuclear Science and Technology Lanzhou University engineering Research Center for Neutron Application Ministry of Education Lanzhou University Institute of Modern Physics Chinese Academy of Sciences

The multi-layer computing model is developed to calculate wide-angle neutron spectra, in the range from0° to 180° with a 5° step, produced by bombarding a thick beryllium target with deuterons. The double-differential cross-sections(DDCSs) for the ~9 Be(d, xn) reaction are calculated using the TALYS-1.8 code. They are in agreement with the experimental data, and are much better than the PHITS-JQMD/GEM results at 15°, 30°, 45° and 60° neutron emission angles for deuteron energy of 10.0 MeV. In the TALYS-1.8 code, neutron contributions from direct reactions(break-up, stripping and knock-out reactions) are controlled by adjustable parameters, which describe the basic characteristics of typical direct reactions and control the relative intensity and the position of the ridgy hillock at the tail of DDCSs. It is found that the typical calculated wide-angle neutron spectra for different neutron emission angles and neutron angular distributions agree quite well with the experimental data for 13.5 MeV deuterons. The multi-layer computing model can reproduce the experimental data reasonably well by optimizing the adjustable parameters in the TALYS-1.8 code. Given the good agreement with the experimental data, the multi-layer computing model could provide better predictions of wide-angle neutron energy spectra, neutron angular distributions and neutron yields for the ~9 Be(d, xn) reaction neutron source.

关键词： neutron source 9Be(d,xn) reaction thick target wide-angle neutron spectra neutron angular distributions

Evaluation of pre-neutron-emission mass distributions of neutron-induced typical actinide fission using scission point model

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Chinese Physics C 2021年第11期45卷 128-135页

作者： Dong-Ying Huo Xu Yang Chao Han Chang-Qi Liu Kang Wu Xing-Yu Liu Chang Huang Qin Xie Yuan He Xiao-Jun Bao ze-en yao Yu Zhang Jun-Run Wang Xiao-Dong Su Zheng Wei School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China engineering Research Center for Neutron Application Technology Ministry of EducationLanzhou UniversityLanzhou 730000China School of Mathematics and Statistics Lanzhou UniversityLanzhou 730000China Department of Physics Hunan Normal UniversityChangsha 410081China

The scission point model is improved by considering the excitation-dependent liquid drop model to calculate mass distributions for neutron-induced actinide nuclei *** energy effects influence the deformations of light and heavy *** improved scission point model shows a significant advance with regard to accuracy for calculating pre-neutron-emission mass distributions of neutron-induced typical actinide fission with incident-neutron-energies up to 99.5 *** theoretical frame assures that the improved scission point model is suitable for evaluating the fission fragment mass distributions,which will provide guidance for studying fission physics and designing nuclear fission engineering and nuclear transmutation systems.

关键词： mass distributions scission-point model dinuclear system model

Monte Carlo simulation of fast neutron-induced fission of 237Np

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Chinese Physics C 2019年第6期43卷 14-20页

作者： Chang-Qi Liu Zheng Wei Chao Han Chang Huang Zhi-Wu Huang Zhan-Wen Ma Shuang-Jiao Zhang Shao-Hua Peng Wei-Min Li Xiao-Hou Bai Jun-Run Wang Xiao-Long Lu Yu Zhang Da-Peng Xu Xiao-Dong Su ze-en yao School of Nuclear Science and Technology Lanzhou University Lanzhou 730000 China engineering Research Center for Neutron Application Technology Ministry of Education Lanzhou University Lanzhou 730000 China

The potential-driving model is used to describe the driving potential distribution and to calculate the preneutron emission mass distributions for different incident energies in the 237 Np(n, f)reaction. The potential-driving model is implemented in Geant4 and used to calculate the fission-fragment yield distributions, kinetic energy distributions, fission neutron spectrum and the total nubar for the 237 Np(n, f)reaction. Compared with the built-in G4 ParaFissionModel, the calculated results from the potential-driving model are in better agreement with the experimental data and evaluated data. Given the good agreement with the experimental data, the potential-driving model in Geant4 can describe well the neutron-induced fission of actinide nuclei, which is very important for the study of neutron transmutation physics and the design of a transmutation system.

关键词： neutron-induced fission reaction fission process Monte Carlo simulation potential-driving model 237Np

Measurements of neutron energy spectra of 9Be(d,n)10B reaction with a thick beryllium target

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Chinese Physics C 2021年第2期45卷 398-405页

作者： Shuang-Jiao Zhang Zhi-Jie Hu Zhi-Ming Hu Chao Han Xiao-Hou Bai Chang-Qi Liu Chang Huang Qin Xie Dong-Ying Huo Kang Wu Yang-Bo Nie Yan-Yan Ding Kai Zhang Yu Zhang Zhi-Yong Deng Rui Guo Zheng Wei ze-en yao School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China engineering Research Center for Neutron Application Technology Ministry of EducationLanzhou UniversityLanzhou 730000China Key Laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China Nuclear Power Institute of China Chengdu 610000China

Novel measurements of the neutron energy spectra of the 9Be(d,n)10B reaction with a thick beryllium target are performed using a fast neutron time-of-flight(TOF)spectrometer for the neutron emission angles θ=0°and 45°,and the incident deuteron energies are 250 and 300 keV,*** neutron contributions from the 9Be(d,n)10B reaction are distributed relatively independently for the ground state and the first,second,and third excited states of *** branching ratios of the 9Be(d,n)10B reaction for the different excited states of 10B are obtained for the neutron emission angles θ=0°and 45°,and the incident deuteron energies are 250 and 300 keV,*** branching ratio of the 9Be(d,n)10B reaction for the third excited state decreases with increase in the incident deuteron energy,and the branching ratios for the ground state and the second excited state increase with increase in the neutron emission angle.

关键词： neutron energy spectrum branching ratio 9Be(d n)10B reaction neutron time-of-flight spectrometer