Hot Spot Formation In The Plasma Focus

At the plasma focus DPF78 (60 kV, 28 kJ) conditions for the formation of hot spots, their properties and the influence on electron, microwave, and X-ray as well as neutron emission in the PF operation regime with heavy gas admixtures to deuterium were investigated. From X-ray spectra taken from Argon and Xenon doped deuterium fill discharges, electron and ion temperatures around 1 keV were determined. In the micropinch regime T is smaller than in the plasma column regime. Time resolved electron beam emission was investigated in axial direction with a magnetic spectrometer. No temporal correlation of the electron beam pulses to the hot spot formation could be found so far. There seems to be some anticorrelation, however, between the occurence of hot spots and high energy (≫ 400 keV) electron beams, which is consistent with results of X-ray spectroscopy. Preliminary results from measurements of microwave emission and their correlation to hot spots will also be discussed.