COMPRESSION OF HOLLOW GASEOUS ENVELOPES I N THE MICROSECOND GPX INSTALLATION

Electric discharges across hollow gaseous envelopes were experimentall y investigated in a microsecond plasma generator (200 kA, 40kV, 1. 5 m us, Ne - Ar mixture). A diagnostic complex was used to carry out time- and spatial-resolved observations in the visible range using the stre ak and framing camera techniques. A transmission grating spectrograph and an X-ray vacuum-tube diode were used in the VUV; the soft X-ray ra nge was covered by a crystal spectrograph utilizing a convex and a sph erically bent crystals, a crystal X-ray microscope, a camera obscura, and p - i - n diodes. The recording range 0.3 - 1.5 nm included the li nes of He- and H-like neon and He-like argon which were used to obtain X-ray-spectral estimates of electronic temperature and density of hot -spot plasma. These estimates fall within the ranges 1 - 1.3 keV and ( 0.5 - 1) . 10(22) cm-3. When the nozzle diameter was optimal in terms of X-ray radiation yield, the snake-like instability was observed simu ltaneously with the hot spot formation. Stabilization of the ''snake'' resulted in a higher radiation output. The emission from a plasma col umn showed in K(alpha) lines of argon.