抄録
For Hg I λ2537 Å (63P→61S) line emitted from a low-pressure mercury lamp, we have determined the relative population in the upper level as a function of discharge current and mercury density. From the radial profile of the emission-line intensity, the spatial distribution function of the upper-revel population has been determined to be the zero-th order decay mode for the trapped radiation. Line absorption has been measured by a mercury vapor in a cell with various mercury densities and Lorentzian widths. The results are consistent with the upper-levl-population distribution as determined above. On the basis of these findings we calculate the emission-line profile and its change in the absorption cell. The amount of absorption at an arbitrary depth of the absorption cell is calculated, and the optium cold-spot temperature of the lamp of 40-50°C is suggested for the maximum absorption under the typical condition of the photo-CVD experiment.
