传统X射线数字成像方法通常固定X光机参数，但是受工件结构及材料衰减系数和光电器件物理动态范围的制约，当同一场景中透射X射线通量的最大值和最小值超出成像器件动态范围时，会出现通量大的区域高于成像器件的电荷容纳能力而达到饱...传统X射线数字成像方法通常固定X光机参数，但是受工件结构及材料衰减系数和光电器件物理动态范围的制约，当同一场景中透射X射线通量的最大值和最小值超出成像器件动态范围时，会出现通量大的区域高于成像器件的电荷容纳能力而达到饱和状态，当通量低的区域产生的光电荷低于设备热噪声水平时，该区域信息将淹没在噪声中而无法正常成像。为有效解决传统X射线数字成像技术在获取宽动态范围透射X光通量内容时的局限性，提出一种管电压递变高动态成像方法。首先分析了光电探测器电荷容量对有效透照厚度范围的影响；结合标准样块试验及相关数据分析，得到任意厚度特定材质试块达到最佳灵敏度时对应的透照X光管电压范围的关系函数，在此基础上提出管电压递变控制策略和有效子图提取方法。最终对0～20 m m厚度范围工件进行管电压递变高动态成像，结果表明：管电压递变高动态成像能够有效地实现透照厚度差异大的工件的高动态范围成像，最终融合结果能够保留较宽范围厚度上的细节信息。展开更多
The effective atomic numbers （Zeff ） and effective electron density （Ne ） for Fe-Mn alloy with different Mn contents are calculated using the mass attenuation coefficients μ/p obtained via XCOM in the photon ener...The effective atomic numbers （Zeff ） and effective electron density （Ne ） for Fe-Mn alloy with different Mn contents are calculated using the mass attenuation coefficients μ/p obtained via XCOM in the photon energy range of i keV-1 GeV. The results are compared with the values measured at the photon energy of 662, 1170 and 1332keV.展开更多
The mass attenuation coefficients of indium are systematically measured byusing the characteristic X-rays from elemental or compound targets excited by energeticproton in the X-ray energy range 2.6 to 29.1 keV.The acc...The mass attenuation coefficients of indium are systematically measured byusing the characteristic X-rays from elemental or compound targets excited by energeticproton in the X-ray energy range 2.6 to 29.1 keV.The accuracy of experimental data isimproved to be±1%.The photoeletric cross sections are obtained by subtracting thescattering cross section from the measured total cross sections.Comparisons of our ex-perimental results with the available data of earlier investigations as well as with thetheoretical calculations are presented and discussed.展开更多
Mass attenuation coefficients,effective atomic numbers,and electron densities for semiconductor and scintillation detectors have been calculated in the photon energy range 1 keV-100 GeV.These interaction parameters ha...Mass attenuation coefficients,effective atomic numbers,and electron densities for semiconductor and scintillation detectors have been calculated in the photon energy range 1 keV-100 GeV.These interaction parameters have been found to vary with detector composition and the photon energy.The variation in the parameters with energy is shown graphically for all the partial photon interaction processes.The effective atomic numbers of the detector were compared with the ZXCOM program,and the results were found to be comparable.Efficiencies of semiconductor and scintillation detectors are presented in terms of effective atomic numbers.The study should be useful for comparing the detector performance in terms of gamma spectroscopy,radiation sensitivity,radiation measurement,and radiation damage.The results of the present investigation should stimulate research work for gamma spectroscopy and radiation measuring materials.展开更多
Iron-ore-imbedded silicone rubber materials were produced for radiation shielding. Samples were tested against a Co-60 gamma source, which is widely used in nuclear technology and medicine. Decreasing the particle siz...Iron-ore-imbedded silicone rubber materials were produced for radiation shielding. Samples were tested against a Co-60 gamma source, which is widely used in nuclear technology and medicine. Decreasing the particle size of iron ore resulted in better gamma radiation protection owing to more homogenous distribution. In addition, the materials had flexible properties up to the addition of 60 wt% iron ore content. Further, 0.5 mm Pb E gamma protection was provided by using 2.06-mm-thick SDT-60 as the Co-60 source. Iron ore–silicone rubber composites are candidate materials for lead-free flexible radiation protection systems owing to their relatively inexpensive and easy production.展开更多
文摘传统X射线数字成像方法通常固定X光机参数，但是受工件结构及材料衰减系数和光电器件物理动态范围的制约，当同一场景中透射X射线通量的最大值和最小值超出成像器件动态范围时，会出现通量大的区域高于成像器件的电荷容纳能力而达到饱和状态，当通量低的区域产生的光电荷低于设备热噪声水平时，该区域信息将淹没在噪声中而无法正常成像。为有效解决传统X射线数字成像技术在获取宽动态范围透射X光通量内容时的局限性，提出一种管电压递变高动态成像方法。首先分析了光电探测器电荷容量对有效透照厚度范围的影响；结合标准样块试验及相关数据分析，得到任意厚度特定材质试块达到最佳灵敏度时对应的透照X光管电压范围的关系函数，在此基础上提出管电压递变控制策略和有效子图提取方法。最终对0～20 m m厚度范围工件进行管电压递变高动态成像，结果表明：管电压递变高动态成像能够有效地实现透照厚度差异大的工件的高动态范围成像，最终融合结果能够保留较宽范围厚度上的细节信息。
文摘The effective atomic numbers （Zeff ） and effective electron density （Ne ） for Fe-Mn alloy with different Mn contents are calculated using the mass attenuation coefficients μ/p obtained via XCOM in the photon energy range of i keV-1 GeV. The results are compared with the values measured at the photon energy of 662, 1170 and 1332keV.
文摘The mass attenuation coefficients of indium are systematically measured byusing the characteristic X-rays from elemental or compound targets excited by energeticproton in the X-ray energy range 2.6 to 29.1 keV.The accuracy of experimental data isimproved to be±1%.The photoeletric cross sections are obtained by subtracting thescattering cross section from the measured total cross sections.Comparisons of our ex-perimental results with the available data of earlier investigations as well as with thetheoretical calculations are presented and discussed.
文摘Mass attenuation coefficients,effective atomic numbers,and electron densities for semiconductor and scintillation detectors have been calculated in the photon energy range 1 keV-100 GeV.These interaction parameters have been found to vary with detector composition and the photon energy.The variation in the parameters with energy is shown graphically for all the partial photon interaction processes.The effective atomic numbers of the detector were compared with the ZXCOM program,and the results were found to be comparable.Efficiencies of semiconductor and scintillation detectors are presented in terms of effective atomic numbers.The study should be useful for comparing the detector performance in terms of gamma spectroscopy,radiation sensitivity,radiation measurement,and radiation damage.The results of the present investigation should stimulate research work for gamma spectroscopy and radiation measuring materials.
文摘Iron-ore-imbedded silicone rubber materials were produced for radiation shielding. Samples were tested against a Co-60 gamma source, which is widely used in nuclear technology and medicine. Decreasing the particle size of iron ore resulted in better gamma radiation protection owing to more homogenous distribution. In addition, the materials had flexible properties up to the addition of 60 wt% iron ore content. Further, 0.5 mm Pb E gamma protection was provided by using 2.06-mm-thick SDT-60 as the Co-60 source. Iron ore–silicone rubber composites are candidate materials for lead-free flexible radiation protection systems owing to their relatively inexpensive and easy production.
