STARK ELECTRON-DENSITY MAPPING IN THE HIGH-VOLTAGE SPARK DISCHARGE

The diagnostic utility of spatial and temporal electron density mapping in the analytical high voltage spark discharge using a charge coupled array detector (CCD) is critically evaluated. H(beta) Stark broadening was utilized for electron density measurements where applicable. Quadratic Stark broadening of Ar II was employed in the discharge core, where hydrogen emission is weak. Peak electron density of 10(17) CM-3 was found by both probes. Coupling between electron temperature and computed electron concentration is quantitatively evaluated. Neither independent measurement of electron temperature nor Abel inversion is required for adequate understanding of the plasma dynamics as revealed by spatial electron density distributions. There is weak indication of a shock wave, previously reported only in Schlieren photographs, detaching from the spark channel approximately 37 mus after discharge triggering.