α粒子轰击钍和铀引起的M亚壳层电离

M-SUBSHELL IONIZATION OF Th AND U BY ALPHA PARTICLE BOMBARDMENT

本文研究2.5—4.5MeVα粒子轰击Th和U引起的M亚壳层电离。采用最小二乘法拟合实验谱求得N_(6,7)→M_5(M_α线),N_6→M_4(M_β线),N_5→M_3(M_γ线),N_4→M_2和N_2→M_1线的x射线产生截面。利用M壳层的辐射跃迁率,Coster—Kronig跃迁率和M亚壳层的荧光产额将x射线产生截面转换为M亚壳层电离截面。将实验所得的M亚壳层电离截面与PWBA和ECPSSR理论预言值进行比较,本文讨论了理论值与实验结果之间的偏差来源。

The M X-rays-of Th and U were produced by alpha particle bombardment in the energy range of 2.5-4.5 MeV, N6.7→M5 (Mα) , M5→M4(Mβ), N5→M3 (Mγ),N4→M2- and N2→M1 lines were selected to deduce M-subshell X-ray production cross sections. The radiative transition rates and the Coster-kronig yields and M-subshell fluorescence yields were used to convert the X-ray production cross sections into M-subshell ionization cross sections. The deduced M-subshell ionisation cross sections were compared with PWBA predictions and ECPSSR theory. The discrepancies of our experimental results from the theoretical calculations were discussed.