Collisional Excitation Transfer and Radiative Decay of Ne 2p Levels in Capillary Discharge

The rate coefficients of the atomic-collision excitation transfer between 2p levels of Ne (Paschen notation) have been determined by an excitation experiment with a dye laser. The N 2 pumped dye laser was tuned to excite Ne atoms from 1s 3 or 1s 5 metastable level to 2p levels in a steady capillary discharge, and enhanced intensities of emission lines, i.e. , direct and transfer fluorescences, from 2p levels were observed with a boxcar averager connected to a spectrophotometer. The filling gas pressure and discharge current were varied from 0.5 to 10 Torr and from 10 to 130 mA, respectively. The analysis of fluorescence signals has shown a linear dependence of the transfer rates on gas pressure, which leads to the following values of the rate coefficients Q i , j a for the atomic-collision transfer between i and j levels in 2p; Q 2p 4 ,2p 3 a =8.8×10 -11 , Q 2p 4 ,2p 5 a =2.4×10 -11 , Q 2p 5 ,2p 4 a =1.1×10 -11 and Q 2p 6 ,2p 7 a =9.2×10 -12 s -1 cm 3 . Furthermore, the population densities of 1s 2–5 levels were measured by the hook method, and the radiative and collisional decay from 2p levels are discussed in relation to the radiation trapping of the fluorescences.