氟离子碰撞引起的钽L壳层X射线产生截面测量

Measurement of L-shell X-ray Production Cross Section of Tantalum by 20-55 MeV Fluorine-Ion Bombardment

摘要: 测量了20～55 MeV F⁵⁺离子和Ta原子碰撞中Ta产生的L壳层X射线。计算了Ta的L各支壳层产生截面的比值和总截面的比值。利用L壳层的辐射跃迁几率、Croster-Kroning跃迁几率和L亚壳层的荧光产额，将平面波波恩近似（PWBA）和ECPSSR理论计算的电离截面转换为L层X射线产生截面，并与实验结果进行比较。结果表明，σ（L_l）/σ(L_α)、σ（L_γ）/σ(L_α)和σ（Ltotal）/σ(L_α)与ECPSSR理论预测结果吻合较好，σ（L_β）/σ(L_α)较两种理论预测值均偏小。

Abstract: L-shell X-ray was measured for solid target tantalum by 20-55 MeV F5+ ion. The ratios of tantalum L-subshell production cross sections were calculated according to the experimental data. Radiative transition probability, Croster-Kroning transition probability and fluorescence yield were used to transfer the ionization cross section which was calculated by plane-wave Born approximation (PWBA) theory and the ECPSSR theory to L-shell X-ray production cross section. Then, the results were compared with the experimental results. Reasonable agreement between theory and experiment was observed. However, the ratio of σ（Lβ）/σ(Lα) is smaller than the values calculated by the theories of PWBA and ECPSSR.