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The lifetime spectroscopy of slow positron accelerated with linear accelerator and pulse punch system was first used to analyze the vacancies in the thin surface layer of silicon heavily doped with arsenic. The results demonstrated that no mono-vacancy was detected to support the arsenic-vacancy complex models for explaining the electrical deactivation mechanism of arsenic-heavily-doped silicon. 相似文献
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本文在E_d=0.1—2.5MeV能量范围内,研究了Be~9(d,p_0)Be~(10)(0),Be~9(d,p_1)Be~(10)(3.368MeV),Be~9(d,t_0)Be~8(0),Be~9(d,α_0)Li~7(0)及Be~9(d,α_1)Li~7(0.478MeV)诸反应。在E_d=0.150,0.220,0.401,0.706,1.005,1.301,1.484,1.750,2.000,2.250和2.500MeV共十一个能量上分别测量了这五群出射粒子在θ_L=10—155°区间的角分布。在θ_L=135°,E_d=0.1—2.5MeV,在θ_L=95°,E_d=0.1—2.2MeV,和在θ_L=112.5°,E_d=0.5—2.5MeV测量了Be~9(d,p_0)Be~(10)的激发函数。在θ_L=135°和112.5°,E_d=1.2MeV,用较厚靶(100—300μg/cm~2)测量了Be~9(d,p_0)Be~(10)(0)反应的截面绝对值,结果为σ_p_0(θ_L=135°)=1.60mb/sr,σ_p_0(θ_L=112.5°)=1.55mb/sr。这样就得到了在此能区内,这五群出射粒子的截面情况。对所得结果进行了一些讨论。 相似文献
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X射线质量衰减截面和光电截面的高精度测量 总被引:1,自引:0,他引:1
利用特征X射线源系统地测量了Si、Fe、Cu、Y、In、Sn等六种元素及SiH4的X射线质量衰减系数,实验误差为±1%. By using the characteristic X ray sources and the Si( Li) detector system, the X ray mass attenuation coefficients for Si,Fe,Cu,Y,In,Sn and SiH 4 have been systematically measured in the energy range of 1.486~29.109 keV. The accuracy of experimental data has been reduced to ±1% . 相似文献
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利用2.5MeV的质子束激发单质金属元素靶或化合物靶产生的K线或L线特征x射线作为x光源,用Si(Li)谱仪系统测得了3.3KeV—27.8keV能区Cu的x射线质量衰减系数,对于较强而孤立的特征x射线峰,衰减系数的实验误差≤1%。在本能区里,由于瑞利散射和康普顿散射的截面很小,因此,由总衰减截面扣除散射截面便得到了光电截面的实验值,与一些早期的实验结果及理论值进行了比较,并作了讨论。 相似文献
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MASS ATTENUATION COEFFICIENTS FOR ELEMENTS MEASURED WITH CHARACTERISTIC X-RAYS FROM TARGETS EXCITED BY ENERGETIC PROTON 下载免费PDF全文
The characteristic X-rays from elemental or compound targets excited by energetic proton are quasi-monochromatic X-ray sources. The advantages of high line/ background ratio, controllable intensity as well as many available energies, make them suitable for applications in many important fields. The total mass attenuation cross sections of yttrium have been systematically measured by using this kind of X-ray source. The accuracy of experimental data has been improved to ±1%, which is much better than that of earlier results. The contributions of the coherent and incoherent scattering crees sections have been calcu-lated in accordance with the present experimental condition. And the total photoelectric cross sections have been obtained by subtracting the scattering cross section from the measured total cross sections. The com-parisons of our experimental results with the available data of earlier investigations as well as with the theo-retical calculations have been presented and discussed. 相似文献