Abstract
This paper discribes the xenon gas effect on the high pressure sodium arc. The previous paper reported that with increasing xenon gas pressure, the spectral broadening of the D-lines increases. In this paper, the arc temperature profiles of 20 Torr filling gas pressure and 300 Torr filling gas pressure of the HPS lamps were measured and the following profiles were estimated
Xe 20 Torr T=4120- (4120-1370) (r/R)2·3
Xe 300 Torr T=4290- (4290-1350) (r/R)1·6
Using these profiles, the spectral distributions were calculated by the radiation transfer equation and the calculated results showed the spectral broadening of the D-lines of the Xe 300 Torr arc was a little greater than that of Xe 20 Torr. From this result, it is considered that with increasing xenon pressure, the arc “shrinks” and the thickness of the dark annular space increases so that the broadening of the spectral lines increases.
