SPECTROSCOPIC INVESTIGATION OF PF-1000 DISCHARGES UNDER DIFFERENT EXPERIMENTAL CONDITIONS

The emission from free-propagating plasma streams was studied in experiments with a 1-MJ plasma-focus PF-1000 facility operated at the IPPLM in Warsaw, Poland. The machine was filled up with a pure deuterium or a mixture of deuterium and argon. Optical spectra were recorded at a distance of 30 cm from the electrodes, at different experimental conditions, i.e. initial pressures, charging voltages and acquisition times, in the wavelength range of 350 ... 1000 nm. The most intense lines originated from the applied working gases. In some cases distinct CuI and FeI lines resulted from the electrodes and the insulator were observed. From the Balmer lines, D-beta and D-gamma, an electron density as a function of time was estimated. The application of this finding made it possible to perform some experiments concerning spectroscopic research on the interaction of free-propagating plasma streams with tungsten targets. In the recorded spectra some WI and WII lines were identified, but the resolution of the spectrometer was not good enough for their quantitative analysis.