This paper described new development of the neutron induced prompt gamma-ray analysis(NIPGA) technology in 1988-2003.The pulse fast-thermal neutron activation analysis method,which utilized the inelastic reaction and ...This paper described new development of the neutron induced prompt gamma-ray analysis(NIPGA) technology in 1988-2003.The pulse fast-thermal neutron activation analysis method,which utilized the inelastic reaction and capture reaction jointly,was employed to measure the elemental contents more efficiently.Lifetime of the neutron generator was more than 10000h and the performance of detector and MCA reached a high level.At the same time,Monte Carlo library least-square method was used to solve the nonlinearity problem in the NIPGA.展开更多
Gamma-ray spectrometry and induced polarization (IP) studies were carried out to determine the radioactive anomalous zones and to follow their lateral and vertical extensions in El Atshan-II uranium prospect area, cen...Gamma-ray spectrometry and induced polarization (IP) studies were carried out to determine the radioactive anomalous zones and to follow their lateral and vertical extensions in El Atshan-II uranium prospect area, central Eastern Desert, Egypt. This area and its surroundings are covered by different Precambrian basement rocks, which intruded by younger bostonite rock, andesite dykes and carbonate veins. Data of the gamma-ray spectrometry have been analyzed qualitatively and quantitatively by applying specific interpretation techniques. These data revealed a wide radioactivity range oscillating from 15.0 to 2362.0 Ur, 0.5 to 307.2 ppm, 0.1 to 55.1 ppm and 0.3 to 22.0% for the total count (Tc), equivalent uranium (eU), equivalent thorium (eTh) and potassium (K), respectively. The constructed radioelement concentration maps and eU-composite image of the study area showed that the anomalously high radioactivity levels are mainly associated with outcrops of the bostonite rock. The induced polarization data were mathematically inverted to produce the true resistivity and chargeability values of cross-sections below the surveyed lines traverse in the area. The resistivity values are varied both vertically and horizontally from 7.83 to more than 1042.0 ohm·m, while the chargeability values are ranged from 0.195 to more than 204.0 mV/V, suggesting variation of the rocks facies and mineralizations. Integration of the resistivity and chargeability data indicates the presence of some mineralized zones, mainly associated with the bostonite rock, with depths varied from the near-surface to more than 70 m. Therefore, a core drilling is recommended at some stations along three selected profiles to a depth of 70 - 100 m to test the depth, structural model and grade of mineralization in the area.展开更多
Ⅰ. INTRODUCTIONIt has been established for some time that introduction of nitrogen in the surface and near surface regions of metal alloys can make important modifications in surface properties of the alloys such as ...Ⅰ. INTRODUCTIONIt has been established for some time that introduction of nitrogen in the surface and near surface regions of metal alloys can make important modifications in surface properties of the alloys such as hardness, wear and friction, corrosion resistance and fatigue time. Proton induced gamma-ray emission (PIGE) analysis provides a useful method for direct determination of nitrogen concentration in the surface of nitrided samples and also for its quality test and the investigation of new nitriding technology.The aims of the present work are to study the optimum conditions of展开更多
为实现中子感生瞬发伽马射线方法在线测量煤炭元素含量,采用C#编写了自动测量程序。采用File System Watcher监测谱文件的生成,利用StreamReader读取伽马能谱的数据,用五点二次平滑法平滑计数,利用11道计数和寻找峰位,通过线性回归方程...为实现中子感生瞬发伽马射线方法在线测量煤炭元素含量,采用C#编写了自动测量程序。采用File System Watcher监测谱文件的生成,利用StreamReader读取伽马能谱的数据,用五点二次平滑法平滑计数,利用11道计数和寻找峰位,通过线性回归方程计算碳、氢、氧的含量。自动测量程序不仅可以自动计算元素含量,还能自动控制中子探测器、多道脉冲分析器、伽马射线探测器和D-T中子发生器等硬件。现场测试结果表明,该程序自身问题引起的设备故障率几乎为零,每个伽马能谱的解析时间小于1 s,能满足煤炭元素含量在线测量的要求。展开更多
Calculations of prompt fission neutron spectra （PFNS） from the ^235U（n, f） reaction were performed with a semi-empirical method for En = 7.0 and 14.7 MeV neutron energies. The total PFNS were obtained as a superpo...Calculations of prompt fission neutron spectra （PFNS） from the ^235U（n, f） reaction were performed with a semi-empirical method for En = 7.0 and 14.7 MeV neutron energies. The total PFNS were obtained as a superposition of （n,xnf） pre-fission neutron spectra and post-fission spectra of neutrons which were evaporated from fission fragments, and these two kinds of spectra were taken as an expression of the evaporation spectrum. The contributions of （n,xnf） fission neutron spectra on the calculated PFNS were discussed. The results show that emission of one or two neutrons in the （n,nf） or （n,2nf） reactions influences the PFNS shape, and the neutron spectra of the （n,xnf） fission-channel are soft compared with the neutron spectra of the （n,f） fission channel. In addition, analysis of the multiple-chance fission component showed that second-chance fission dominates the PFNS with an incident neutron energy of 14.7 MeV whereas first-chance fission dominates the 7 MeV case.展开更多
基金Supported by Science Foundation for Young Teachers Normal University
文摘This paper described new development of the neutron induced prompt gamma-ray analysis(NIPGA) technology in 1988-2003.The pulse fast-thermal neutron activation analysis method,which utilized the inelastic reaction and capture reaction jointly,was employed to measure the elemental contents more efficiently.Lifetime of the neutron generator was more than 10000h and the performance of detector and MCA reached a high level.At the same time,Monte Carlo library least-square method was used to solve the nonlinearity problem in the NIPGA.
文摘Gamma-ray spectrometry and induced polarization (IP) studies were carried out to determine the radioactive anomalous zones and to follow their lateral and vertical extensions in El Atshan-II uranium prospect area, central Eastern Desert, Egypt. This area and its surroundings are covered by different Precambrian basement rocks, which intruded by younger bostonite rock, andesite dykes and carbonate veins. Data of the gamma-ray spectrometry have been analyzed qualitatively and quantitatively by applying specific interpretation techniques. These data revealed a wide radioactivity range oscillating from 15.0 to 2362.0 Ur, 0.5 to 307.2 ppm, 0.1 to 55.1 ppm and 0.3 to 22.0% for the total count (Tc), equivalent uranium (eU), equivalent thorium (eTh) and potassium (K), respectively. The constructed radioelement concentration maps and eU-composite image of the study area showed that the anomalously high radioactivity levels are mainly associated with outcrops of the bostonite rock. The induced polarization data were mathematically inverted to produce the true resistivity and chargeability values of cross-sections below the surveyed lines traverse in the area. The resistivity values are varied both vertically and horizontally from 7.83 to more than 1042.0 ohm·m, while the chargeability values are ranged from 0.195 to more than 204.0 mV/V, suggesting variation of the rocks facies and mineralizations. Integration of the resistivity and chargeability data indicates the presence of some mineralized zones, mainly associated with the bostonite rock, with depths varied from the near-surface to more than 70 m. Therefore, a core drilling is recommended at some stations along three selected profiles to a depth of 70 - 100 m to test the depth, structural model and grade of mineralization in the area.
文摘Ⅰ. INTRODUCTIONIt has been established for some time that introduction of nitrogen in the surface and near surface regions of metal alloys can make important modifications in surface properties of the alloys such as hardness, wear and friction, corrosion resistance and fatigue time. Proton induced gamma-ray emission (PIGE) analysis provides a useful method for direct determination of nitrogen concentration in the surface of nitrided samples and also for its quality test and the investigation of new nitriding technology.The aims of the present work are to study the optimum conditions of
文摘为实现中子感生瞬发伽马射线方法在线测量煤炭元素含量,采用C#编写了自动测量程序。采用File System Watcher监测谱文件的生成,利用StreamReader读取伽马能谱的数据,用五点二次平滑法平滑计数,利用11道计数和寻找峰位,通过线性回归方程计算碳、氢、氧的含量。自动测量程序不仅可以自动计算元素含量,还能自动控制中子探测器、多道脉冲分析器、伽马射线探测器和D-T中子发生器等硬件。现场测试结果表明,该程序自身问题引起的设备故障率几乎为零,每个伽马能谱的解析时间小于1 s,能满足煤炭元素含量在线测量的要求。
基金Supported by National Natural Science Foundation of China(11205246,91126010,U1230127,91226102)AEA CRP(15905)Defense Industrial Technology Development Program(B0120110034)
文摘Calculations of prompt fission neutron spectra （PFNS） from the ^235U（n, f） reaction were performed with a semi-empirical method for En = 7.0 and 14.7 MeV neutron energies. The total PFNS were obtained as a superposition of （n,xnf） pre-fission neutron spectra and post-fission spectra of neutrons which were evaporated from fission fragments, and these two kinds of spectra were taken as an expression of the evaporation spectrum. The contributions of （n,xnf） fission neutron spectra on the calculated PFNS were discussed. The results show that emission of one or two neutrons in the （n,nf） or （n,2nf） reactions influences the PFNS shape, and the neutron spectra of the （n,xnf） fission-channel are soft compared with the neutron spectra of the （n,f） fission channel. In addition, analysis of the multiple-chance fission component showed that second-chance fission dominates the PFNS with an incident neutron energy of 14.7 MeV whereas first-chance fission dominates the 7 MeV case.
