铝原子激发态近阈限光电离截面测量
Photoionization cross section measurements of the excited states of aluminum in the above-threshold region

本文利用激光烧蚀、激光泵浦-探测、共振增强多光子电离和飞行时间质谱相结合的实验技术，根据离子产额和电离激光能量的关系，获取铝原子激发态的光电离截面；并研究了光电离截面与电离富余能的依赖关系.电离富余能0-2.98 eV内光电离截面值范围为15.6±1.7 Mb-2.3±0.9 Mb，激发态的寿命为17.6±1.8，16.9±1.7ns.在光电离截面的测量中，总的均方根误差上限约为17%.
In this paper, we present the photoionization cross sections of the excited states of aluminum by using the technique of the laser pump-probe and resonance ionization in conjunction with a molecular beam and time of flight (TOF) mass spectrometer. The photoionization cross sections are deduced from the dependence of ion yields on the laser intensity of the probe laser. The ionizing energy dependent behavior of the measured photoionization cross sections from the 3s23d 2D3/2 and 3s23d 2D5/2 states of aluminum is reported. The photoionization cross-sections at threshold and above threshold regions （0-2.98ev）are measured. The measured values are in the range from15.6±1.7 Mb to 2.3±0.9 Mb. The measured lifetimes of the 3s23d（2D3/2）and 3s23d（2D5/2） states are 17.6±1.8 ns and16.9±1.7 ns, respectively. The upper limit of the overall root-mean-square error in the absolute photoionization cross-section measurements is 17%.