Radiation field induced perturbations in CO2laser plasmas. I. Current and pressure fluctuations

Changes in the 10.6 mu m CO 2 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 collision 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.