Time and space resolved observation of hot spots in a plasma focus

Summary form only given. The time and space evolution of hot spots on the DPF-78 plasma focus at the University of Stuttgart was investigated. The experiments were carried out in mixtures of deuterium and krypton at a bank voltage of 60 kV and a stored energy of 28 kJ. A modification of the ADRRM streak technique carried out in the soft X-ray region made it possible to examine some characteristics of the hot spots directly. Simultaneous measurements were carried out on the hard X-ray radiation (80 keV), the spatially resolved optical emissions, the neutron yield rate with TOF (time-of-flight) information, and the plasma and bank currents. The stability of the plasma column is important; streak photographs show no gross disturbances in the geometrical shape of the plasma column during the presence of the hot spots. The hot spots observed in this experiment are not created as a result of large scale m=0 instabilities and would support a radiative-collapse-type mechanism, for hot spot formation