分析了新型光电器件在常规空间辐射环境下,电子器件所产生的一系列位移型损伤及对应成因。经多次对比实验发现,其位移损伤和器件失效主要由非电离能损(NIEL)所诱发。其根本损耗来源为:在低能空间状态下,库仑间的相互作用力将凸显,并逐...分析了新型光电器件在常规空间辐射环境下,电子器件所产生的一系列位移型损伤及对应成因。经多次对比实验发现,其位移损伤和器件失效主要由非电离能损(NIEL)所诱发。其根本损耗来源为:在低能空间状态下,库仑间的相互作用力将凸显,并逐渐占据主导地位。而当前主要采用的散射微分截面法,如Mott-Rutherford型散射法,均无法有效屏蔽核外电子间存在的库仑作用力影响,从而导致大量非电离能损产生。由此,文中结合非电离能损特性及成因,在解析算法基础上结合Monte-Carlo推衍方法,以SRIM程序模拟并推算出较精确的低能质子在半导体材料(以Si、Ga AS为例)中的NIEL数值量级,同时参照薄靶近似思想改良实验。实验数据规律表明,能量总值为1 ke V的低能质子材料中NIEL评测数值量级大约为Ga As质子材料的1/5、Summers数值量级的1/3,这一结果将为航天材质设计和改良提供重要的参考。展开更多
测量了中低能质子致氘化钛和氘化锆二次电子发射系数。结果表明,20 n A/cm2束流下各二次电子发射系数与其电子能损近似成正比,比例因子Λ较Sternglass理论值偏大约50%,表面吸附层影响二次电子发射系数。束流密度为7μA/cm2的100 ke V质...测量了中低能质子致氘化钛和氘化锆二次电子发射系数。结果表明,20 n A/cm2束流下各二次电子发射系数与其电子能损近似成正比,比例因子Λ较Sternglass理论值偏大约50%,表面吸附层影响二次电子发射系数。束流密度为7μA/cm2的100 ke V质子束长时间测量时,二次电子发射系数γ和正比例因子Λ在前100 s内快速下降并逐渐稳定至理论值。展开更多
Accelerator-based neutron sources could outstandingly compete with the reactor-based ones, which are widely used for research aims and radioisotope production.Spallation neutron sources are used by many research cente...Accelerator-based neutron sources could outstandingly compete with the reactor-based ones, which are widely used for research aims and radioisotope production.Spallation neutron sources are used by many research centers. In this work, the potential of natural uranium spallation target irradiated by low-energy protons for production of an external neutron source was investigated.MCNPX code was used to model the spallation target. The results showed using 30-Me V protons of 100 μA current a neutron flux in order of 10~7n/s cm^2 leaks from an optimized-dimension target. Different physical models available in the computational code do not result in significant relative discrepancies for neutron yield and deposited heat calculations. Water with a velocity of 0.6 m/s can be used as coolant for the spallation target to keep the surface temperature under 100 °C at atmospheric pressure.展开更多
The proton-capture reactions 12C(p,γ)13N and 13C(p,γ)14N have been studied to determine 13C enrichments. The system has been calibrated by measuring the gamma-rays yield from the 12C(p,γ)13N and 13C(p,γ)14N reacti...The proton-capture reactions 12C(p,γ)13N and 13C(p,γ)14N have been studied to determine 13C enrichments. The system has been calibrated by measuring the gamma-rays yield from the 12C(p,γ)13N and 13C(p,γ)14N reactions as a function of known 13C enrichment.This technique is applicable to the analysis of samples with 13C enrichments between 1% and 90%.展开更多
The Coulomb effect in high energy antiproton-nucleus elastic and inelastic scattering from 12C and 16O is studied in the framework of Glauber multiple scattering theory for five kinetic energies ranged from 0.23 to 1....The Coulomb effect in high energy antiproton-nucleus elastic and inelastic scattering from 12C and 16O is studied in the framework of Glauber multiple scattering theory for five kinetic energies ranged from 0.23 to 1.83 GeV.A microscopic shell-model nuclear wave functions, Woods-Saxon single-particle wave functions, and experimental pN amplitudes are used in the calculations. The results show that the Coulomb effect is of paramount importance for filling up the dips of differential cross sections. We claim that the present result for inelastic scattering of antiproton-12C is sufficiently reliable to be a guide for measurements in the very near future. We also believe that antiproton nucleus elastic and inelastic scattering may produce new information on both the nuclear structure and the antinucleon-nucleon interaction, in particular the p-neutron interaction.展开更多
文摘分析了新型光电器件在常规空间辐射环境下,电子器件所产生的一系列位移型损伤及对应成因。经多次对比实验发现,其位移损伤和器件失效主要由非电离能损(NIEL)所诱发。其根本损耗来源为:在低能空间状态下,库仑间的相互作用力将凸显,并逐渐占据主导地位。而当前主要采用的散射微分截面法,如Mott-Rutherford型散射法,均无法有效屏蔽核外电子间存在的库仑作用力影响,从而导致大量非电离能损产生。由此,文中结合非电离能损特性及成因,在解析算法基础上结合Monte-Carlo推衍方法,以SRIM程序模拟并推算出较精确的低能质子在半导体材料(以Si、Ga AS为例)中的NIEL数值量级,同时参照薄靶近似思想改良实验。实验数据规律表明,能量总值为1 ke V的低能质子材料中NIEL评测数值量级大约为Ga As质子材料的1/5、Summers数值量级的1/3,这一结果将为航天材质设计和改良提供重要的参考。
文摘测量了中低能质子致氘化钛和氘化锆二次电子发射系数。结果表明,20 n A/cm2束流下各二次电子发射系数与其电子能损近似成正比,比例因子Λ较Sternglass理论值偏大约50%,表面吸附层影响二次电子发射系数。束流密度为7μA/cm2的100 ke V质子束长时间测量时,二次电子发射系数γ和正比例因子Λ在前100 s内快速下降并逐渐稳定至理论值。
文摘Accelerator-based neutron sources could outstandingly compete with the reactor-based ones, which are widely used for research aims and radioisotope production.Spallation neutron sources are used by many research centers. In this work, the potential of natural uranium spallation target irradiated by low-energy protons for production of an external neutron source was investigated.MCNPX code was used to model the spallation target. The results showed using 30-Me V protons of 100 μA current a neutron flux in order of 10~7n/s cm^2 leaks from an optimized-dimension target. Different physical models available in the computational code do not result in significant relative discrepancies for neutron yield and deposited heat calculations. Water with a velocity of 0.6 m/s can be used as coolant for the spallation target to keep the surface temperature under 100 °C at atmospheric pressure.
文摘The proton-capture reactions 12C(p,γ)13N and 13C(p,γ)14N have been studied to determine 13C enrichments. The system has been calibrated by measuring the gamma-rays yield from the 12C(p,γ)13N and 13C(p,γ)14N reactions as a function of known 13C enrichment.This technique is applicable to the analysis of samples with 13C enrichments between 1% and 90%.
文摘The Coulomb effect in high energy antiproton-nucleus elastic and inelastic scattering from 12C and 16O is studied in the framework of Glauber multiple scattering theory for five kinetic energies ranged from 0.23 to 1.83 GeV.A microscopic shell-model nuclear wave functions, Woods-Saxon single-particle wave functions, and experimental pN amplitudes are used in the calculations. The results show that the Coulomb effect is of paramount importance for filling up the dips of differential cross sections. We claim that the present result for inelastic scattering of antiproton-12C is sufficiently reliable to be a guide for measurements in the very near future. We also believe that antiproton nucleus elastic and inelastic scattering may produce new information on both the nuclear structure and the antinucleon-nucleon interaction, in particular the p-neutron interaction.
