Interaction potential energies and quasi-continuum vacuum UV emission of rare-gas-alkali ionic eximers

摘要

An ab initio calculation of the potential energies was made forthe electronic states of ionic excimer molecules consisting of raregases (Rg=Ne,Ar,Kr and Xe) and alkali metals (A=K AND Rb). Thecalculation included the ground 1~1∑＋, which correspond to theRg(~S)＋A(~1S) and Rg＋(~2P)＋A(~2S) separate limits, respectively.The calculated results predict that the emission based on transitionsfrom the 2~1∑＋(υ'=0) states to the higherυ" levels of the 1~1∑＋ states is characterised by the highest relative transitionprobabilities, which are promising for lasing in the vacuum andextreme ultraviolet (VUV/XUV) SPECTRAL RANGES. Moreover, bound-freeVUV emission bands were observed for electron-beampumped gas mixturesof Xe or Kr with a hot Rb or Cs alkali vapour. The observed fouremission bands were assigned to the 2~1∑＋ transitions in therare-gas-alkali ionic excimers Xe＋Rb, Kr＋Rb, Xe＋Cs, and kr＋ Cs,respectively.