Radiation field induced perturbations in CO2 laser plasmas

Changes in the 10.6 μm CO2 laser resonant radiation field cause gas number density changes in the irradiated volume by V-T energy exchange and gas heating. This primary pressure fluctuation (approximately 0.5%) causes a change in the mean energy exchange per electron-molecule collisions dX/X and a change in the electron mean free path lambda and hence the discharge current. The current fluctuation di/i (approximately 1 to > 10%) can be eliminated with a constant-current power supply with a sufficiently rapid response feedback circuit. (author)