NEON GAS PUFF IMPLOSIONS ON A HIGH-CURRENT MICROSECOND GENERATOR WITH AND WITHOUT A PLASMA OPENING SWITCH

Implosions of 2.5-cm-diam neon gas shells on a 1.2-mu-s quarter-period, 3 MA driver, FALCON, have produced no more than 7.6 kJ of kilovolt neon K-shell radiation. The incorporation of a plasma opening switch produces faster current pulses: up to 1.8 MA in 190 ns. With the higher rate of rise of current, neon gas puffs have produced up to 13.5 kJ of kilovolt K-shell radiation. Numerical calculations indicate that this increase in radiation is due to the achievement of a higher kinetic energy per ion at higher current levels. Spectroscopic measurements confirm that a significant fraction of the plasma is heated into the K-shell ionization states and that the faster current pulses increase this fraction up to 40%.