LASER SPARK-FREE INITIATION OF A SUBCRITICAL MICROWAVE DISCHARGE

Experimental study has been made of the ignition of a subcritical microwave discharge at pressures in the range 55–79 Torr with the initiation by pulsed laser radiation (58 mJ in a pulse). A rise of 36% in the critical pressure was obtained to form the discharge with the orientation of the laser beam along the vector of the microwave-fi eld strength. Computer modeling has shown that upon the traversal of a focused laser beam, a highly conductive laser trail can be formed with a peak ionization degree as high as 10%, which, for a period of the order of 1 μs, locally enhances the electric microwave fi eld up to supercritical values.
Experimental study has been made of the ignition of a subcritical microwave discharge at pressures in the range 55–79 Torr with the initiation by pulsed laser radiation (58 mJ in a pulse). A rise of 36% in the critical pressure was obtained to form the discharge with the orientation of the laser beam along the vector of the microwave-fi eld strength. Computer modeling has shown that upon the traversal of a focused laser beam, a highly conductive laser trail can be formed with a peak ionization degree as high as 10%, which, for a period of the order of 1 μs, locally enhances the electric microwave fi eld up to supercritical values.
Author:  Yu. V. Dobrov, V. A. Lashkov, I. Ch. Mashek, A. M. Prokshin, M. E. Renev, R. S. Khoronzhuk
Keywords:  microwave discharge, laser radiation, plasma, subcritical discharge, experiment, numerical modeling
Page:  1068 - 1081