SOFT-X-RAY HOT-SPOTS OBSERVATION IN AN ARGON ADMIXED PLASMA-FOCUS EXPERIMENT

Hot spots in a dense plasma focus are investigated with a time-resolved and filtered pinhole camera system through Ar K-lines emission. A Moire Schlieren technique is used to observe the macroscopic plasma behavior conjunctly. The hot spots are generated at the disruption of the plasma column with growth of macroscopic instabilities. At the disrupted regions, the hot spots appear and emit intense K-lines of argon approximately for 15 ns. A spatial distribution of Ar K-line emission is quantitatively obtained using the pinhole camera system. The maximum intensity, approximately 9.8 x 10(11) +170%(-50%) (photons/(s.mm2.(mrad)2.0.01%BW)) is observed when 6% of argon is added to the 4 Torr hydrogen.