Au原子高Rydberg态场致电离的实验研究

EXPERIMENTAL STUDY OF RYDBERG STATES OF AU ATOM

利用电热法将含金物质加热,产生Au原子束,再以两束UV脉冲激光垂直照射,将处于基态的Au原子共振激发至高Rydberg态。滞后于激光脉冲200ns的高压脉冲电场(6500V/cm)加到反应区,使处于Rydberg态的Au原子电离。激光波长在一定范围内扫描,共测出了Au原子的n^2D_(3/2)(n=18—38)和n^2S_(1/2)(n=21—34;36—38)两通道的38条能级的位置。用参数拟合得到~2D_(3/2)和~2S_(1/2)两系列的极限分别为:E_D=74409.8(3)cm^(-1),E_S=74410.0(2)cm^(-1),计算了每条能级的量子亏损。我们的实验还证明了场电离是一种十分有效的电离手段,比用通常的激光光电离效率要高得多。这在共振电离谱学(RIS)的研究中是一种很有效的方法。

A beam of gold atoms was produced by heating the gold containing material by electrothermal method. Two UV laser beams then orthogonally irradiated the atomic beam, exciting the Au atoms to very high Rydberg states from their ground states (6S1/2). A high voltage pulsed electric field was applied to the interaction region approximately 200 ns after the laser pulse, it ionized the Au atoms into Rydberg states. By scanning the wavelength of laser in a certain range, the positions of 38 energy levels of Au atoms in n2D3/2 (n = 18-38) and n2S_(1/2) (n = 21-34; 36-38) series have been determined. the ionization limits of the n2D_(3/2) and n2S1/2 series were found to be ED = 74409.8 (3)cm^(-1) and Es = 74410.0(2) cm-1, respectively, by parametric fitting. The quantum defects of all these levels were also calculated.