Due to their low cost,big reaction cross-section with neutrons,flexibility,and convenience for long distance data transfer,plastic scintillation fibers(PSF)have been increasingly used as detectors or sensors for high-...Due to their low cost,big reaction cross-section with neutrons,flexibility,and convenience for long distance data transfer,plastic scintillation fibers(PSF)have been increasingly used as detectors or sensors for high-energy neutron radiography.In this paper,Geant4 Monte Carlo simulation tool was used to obtain some characteristics of energy and angular distributions of recoil protons in plastic scintillation fibers irradiated by fast neutrons.The plastic fiber with BCF-20 as the core and an acrylic outer cladding was used in the simulation.The results show that there is a big range of energy and angular distribution of recoil protons in energies varying inversely with the recoil angle.展开更多
<正>A mathematical method was developed to calculate the yield,energy spectrum and angular distribution of neutrons from D(d,n)~3He(D-D)reaction in a thick deuterium-titanium target for incident deuterons in ene...<正>A mathematical method was developed to calculate the yield,energy spectrum and angular distribution of neutrons from D(d,n)~3He(D-D)reaction in a thick deuterium-titanium target for incident deuterons in energies lower than 1.0MeV.The data of energy spectrum and angular distribution were applied to set up the neutron source model for the beam-shaping-assembly(BSA)design of Boron-Neutron-Capture-Therapy(BNCT)using MCNP-4C code. Three cases of D-D neutron source corresponding to incident deuteron energy of 1000,400 and 150 key were inves- tigated.The neutron beam characteristics were compared with the model of a 2.45 MeV mono-energetic and isotropic neutron source using an example BSA designed for BNCT irradiation.The results show significant differences in the neutron beam characteristics,particularly the fast neutron component and fast neutron dose in air,between the non-isotropic neutron source model and the 2.5 MeV mono-euergetic and isotropic neutron source model.展开更多
The microscopic DWBA was used to calculate the inelastic neutron scatteringon <sup>12</sup>C to 4.44 MeV excited state and some energy dependent parameters were used toimprove the calculation.The inelastic...The microscopic DWBA was used to calculate the inelastic neutron scatteringon <sup>12</sup>C to 4.44 MeV excited state and some energy dependent parameters were used toimprove the calculation.The inelastic integrated cross sections and the angular distribu-tions of <sup>12</sup>C（n,n’）<sup>12</sup>C 4.44 MeV excited state were given for the incident neutron whoseenergy varies from 7.0 MeV to 20.0 MeV.Results were also given for the experimentalblank data.展开更多
The microscopic DWBA was used to calculate the inelastic neutron scattering on <sup>11</sup>B to 2.14MeV excited state and some energy dependent parameters were used to improve the calculation.The inte-gra...The microscopic DWBA was used to calculate the inelastic neutron scattering on <sup>11</sup>B to 2.14MeV excited state and some energy dependent parameters were used to improve the calculation.The inte-grated inelastic cross sections and the angular distributions of the <sup>11</sup>B（n,n′）<sup>11</sup>B*（2.14 MeV excitedstate）were given for the incident neutrons whose energy varies from 7.54 MeV to 20.0 MeV.Resultswere also given for the experimental blank data.展开更多
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 doub...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.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.60602065)
文摘Due to their low cost,big reaction cross-section with neutrons,flexibility,and convenience for long distance data transfer,plastic scintillation fibers(PSF)have been increasingly used as detectors or sensors for high-energy neutron radiography.In this paper,Geant4 Monte Carlo simulation tool was used to obtain some characteristics of energy and angular distributions of recoil protons in plastic scintillation fibers irradiated by fast neutrons.The plastic fiber with BCF-20 as the core and an acrylic outer cladding was used in the simulation.The results show that there is a big range of energy and angular distribution of recoil protons in energies varying inversely with the recoil angle.
文摘<正>A mathematical method was developed to calculate the yield,energy spectrum and angular distribution of neutrons from D(d,n)~3He(D-D)reaction in a thick deuterium-titanium target for incident deuterons in energies lower than 1.0MeV.The data of energy spectrum and angular distribution were applied to set up the neutron source model for the beam-shaping-assembly(BSA)design of Boron-Neutron-Capture-Therapy(BNCT)using MCNP-4C code. Three cases of D-D neutron source corresponding to incident deuteron energy of 1000,400 and 150 key were inves- tigated.The neutron beam characteristics were compared with the model of a 2.45 MeV mono-energetic and isotropic neutron source using an example BSA designed for BNCT irradiation.The results show significant differences in the neutron beam characteristics,particularly the fast neutron component and fast neutron dose in air,between the non-isotropic neutron source model and the 2.5 MeV mono-euergetic and isotropic neutron source model.
文摘The microscopic DWBA was used to calculate the inelastic neutron scatteringon <sup>12</sup>C to 4.44 MeV excited state and some energy dependent parameters were used toimprove the calculation.The inelastic integrated cross sections and the angular distribu-tions of <sup>12</sup>C（n,n’）<sup>12</sup>C 4.44 MeV excited state were given for the incident neutron whoseenergy varies from 7.0 MeV to 20.0 MeV.Results were also given for the experimentalblank data.
文摘The microscopic DWBA was used to calculate the inelastic neutron scattering on <sup>11</sup>B to 2.14MeV excited state and some energy dependent parameters were used to improve the calculation.The inte-grated inelastic cross sections and the angular distributions of the <sup>11</sup>B（n,n′）<sup>11</sup>B*（2.14 MeV excitedstate）were given for the incident neutrons whose energy varies from 7.54 MeV to 20.0 MeV.Resultswere also given for the experimental blank data.
基金Supported by the National Magnetic Confinement Fusion Science Program of China(2014GB104002)the National Natural Science Foundation of China(11705071,11875155,11675069,21327801)+2 种基金NSAF(U1830102)the National Key Scientific Instrument and Equipment Development Project(2013YQ40861)the Fundamental Research Funds for the Central Universities(lzujbky-2017-13,lzujbky-2017-kb09)
文摘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.
