skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Dynamics of hot spots in the DPF-78 plasma focus from x-ray spectra and REB emission

Conference ·
OSTI ID:163145
;  [1]
  1. Univ. Stuttgart (Germany). Inst. fuer Plasmaforschung

The X-ray emission from hot spots in the plasma focus DPF-78 was investigated with the help of two X-ray quartz crystal spectrometers of the Johann type and a 4 fold magnifying X-ray pinhole camera. In the experiments the working gas was chosen to be 300 Pa deuterium with 20 Pa argon admixture. X-ray spectra in the wavelength range from 3.55 {angstrom} to 4.0 {angstrom}, including H-like and He-like Argon lines, were recorded on Kodak DEF-2 film. From the spatially resolved spectra recorded side-on, a relative spectral shift between different hot spots of the same shot was often observed. The shift could be attributed to the Doppler shift. From spectral characteristics such as intensities and FWHM of Ar resonant and intercombination lines electron densities of up to 3 {times} 10{sup 27} m{sup {minus}3} were determined. Radial dimensions of the hot spots ranging from about 140 {micro}m to 300 {micro}m were found from pinhole pictures applying the penumbra method. Usually two pulses of relativistic electron beams were observed using Cherenkov detectors in a magnetic spectrometer. The energy of the first pulse, which was emitted at the time of maximum compression, was higher than that of the second pulse. The measured FWHM of the REB pulses ranges from 3 ns to about 10 ns. The characteristics of the time-integrated X-ray spectra and the time resolved REB spectra and their dependence on the composition of the filling gas are discussed.

OSTI ID:
163145
Report Number(s):
CONF-950612-; ISBN 0-7803-2669-5; TRN: IM9604%%249
Resource Relation:
Conference: 22. international conference on plasma science, Madison, WI (United States), 5-8 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of IEEE conference record -- abstracts: 1995 IEEE international conference on plasma science; PB: 312 p.
Country of Publication:
United States
Language:
English