Laser‐induced fluorescence measurement of plasma ion temperatures: Corrections for power saturation

TLDR: In this article, the authors used high power pulsed tunable dye laser to measure plasma ion temperatures and found that the fluorescence linewidth of room temperature ions broadens from 1.50 to 2.87 GHz when the homogeneous laser intensity is increased from 50 kW/m2 to 5 MW/m 2.

Abstract: When using high‐power pulsed tunable dye lasers to measure plasma ion temperatures, it is important to attenuate the laser intensity. The temperature is found from the Doppler broadening of a spectral line. This may be obscured by saturation broadening, an instrumental effect encountered when too much laser intensity is used. Three useful experimental methods for determining the optimum pulsed laser intensity are found from a semiclassical atomic physics model. As an example, an Ar II transition pumped by a 1‐GHz bandwidth laser is examined. The fluorescence linewidth of room‐temperature ions broadens from 1.50 to 2.87 GHz when the homogeneous laser intensity is increased from 50 kW/m2 to 5 MW/m2.