Citation
Abstract
A low-pressure mercury-argon discharge, similar to the type existing in the mercury lamp for the trapped-ion standard, ts probed with a new technique of laser spectroscopy to determine the influence of the I[g(6 °P2) population on discharge emission. The discharge is excited with inductively coupled rf power. Variations in the intensity of emission lines in the discharge were examined as = 546.1-nm light from a continuous-wave (CW) laser excited the Ig (6 3P2) to (7 7S,) transition. The spectrum of the discharge viewed in the region of laser irradiation showed increased emission in A = 546.1, 435.8, 404.7, 253.7, and 194.2 nm lines. Other lines in Ifg I exhibited a decrease in emission. When the discharge was viewed outside the region of laser irradiation, all lines exhibited an increased emission. Based on these results, 1t 1s concluded that the dominant mechanism for the excitation of higher lying levels of mercury is the electron-impact excitation via the 3P»2 level. The depopulation of this metastable level is also responsible for the observed increase in the electron temperature when the laser irradiates the discharge. It is also concluded that the 3P, metastable level of mercury does not play a significant role in the excitation of the 2Priy level of mercury ton.
Details
- Volume
- 42-101
- Published
- May 15, 1990
- Pages
- 61–72
- File Size
- 547.2 KB