CO2 laser induced gas breakdown in preionized argon

Abstract

CO2 laser induced breakdown of argon is investigated as a function of pressure and preionization. The gas is preionized by uv photons from an electric discharge. By varying the time between the discharge and laser pulses, initial densities in the focal region vary from 109 cm−3 to 1012 cm−3. Numerical calculations of the breakdown process based on a cascade model yield thresholds which are in good agreement with measurements.