RESONANT HOLOGRAPHY TO STUDY PLASMA EROSION OPENING SWITCHES DEVELOPMENT

THE SPATIALLY RESOLVED PLASMA DISTRIBUTION BETWEEN THE ELECTRODES OF A PLASMA EROSION OPENING SWITCH (PEOS) DURING THE CLOSED AND OPENING PHASES OF THE SWITCH IS NEEDED TO UNDERSTAND SWITCH OPERATION. CONVENTIONAL HOLOGRAPHIC TECHNIQUES ARE NOT SUFFICIENTLY SENSITIVE TO STUDY THE 10 TO THE 13TH POWER/3CM PLASMA ENCOUNTERED HERE, AND ARRAYS OF LANGMUIR PROBES ARE REQUIRED TO OBTAIN SPATIALLY RESOLVED MEASUREMENTS. A RESONANT HOLOGRAPHIC TECHNIQUE IS PROPOSED TO MEASURE THE DISTRIBUTION OF IONS WITHIN THE PEOS. IN THIS, TECHNIQUE,THE HOLOGRAPHIC RADIATION SOURCE IS A LASER TUNED TO AN ELECTRONIC TRANSITION FREQUENCY. IN THIS CASE THE PHASE SHIFT PRODUCED BY A PLASMA INTRODUCED INTO ONE ARM OF A MACH ZENDER INTERFEROMETER IS PROPORTIONAL TO THE NUMBER OF ATOMS/IONS IN A LOWER ENERGY STATE OF THE TRANSITION PROBED. ESTIMATES INDICATED THAT POPULATION DENSITIES OF 2 X 10 TO THE 12TH POWER/3CM OF NEUTRAL NEON ATOMS IN THE 1S(2) STATE OR 4 X 10 TO THE 11TH POWER/3CM NEON IONS IN THE 3D 4F LEVEL CAN BE DETECTED IN A ONE CM PATH LENGTH. THIS TECHNIQUE CAN BE USED TO STUDY THE LASING LEVELS IN A GASEOUS LASER, ION DENSITIES IN RELATIVISTIC ELECTRON BEAM PROPAGATION EXPERIMENTS, RELAXATION PROCESSES IN SHOCK WAVES, COMBUSTION PRODUCTS IN FLAMES AND PLASMA DENSITIES IN PEOS IN A NONPERTURBING FASHION.