Line-Profiles and Translational Temperatures of Pb Atoms in Multi-Micro Hollow Cathode Lamp Measured by Diode Laser Absorption Spectroscopy

Abstract

The behaviors of Pb and metastable He atoms in the multi-micro hollow cathode lamp (multi-MHCL) at pressures of the order of kPa have been investigated by diode laser absorption spectroscopy. The pressure broadening effect for absorption line-profile was overlapped to Doppler profile and was estimated to be 0.26 MHz/Pa from line-profiles of metastable He atoms in the range from 5 to 10 kPa. The translational temperatures of metastable He atoms decreased from 830 to 410 K with increasing the pressure from 5 to 10 kPa. From line-profiles of Pb atoms, the temperatures and densities of Pb in the multi-MHCL were evaluated to decrease from 820 to 610 K and 9.0×1011 to 4.6×1011 cm-3 with increasing He pressure from 4.9 to 7.4 kPa, respectively. The Lorentz broadenings was larger than those of He atom and the pressure dependence were estimated to be 0.22 MHz/Pa. The behaviors of emission intensities corresponded with those of atomic densities due to enhancement of sputtering. From these results, the multi-MHCL with line-profile guaranteed has been realized for measuring multi-metallic atom densities precisely.