Hot Spot Formation In The Plasma Focus Antsiferov, P.; Franz, D.; Jonas, A. ...
IEEE Conference Record - Abstracts. 1991 IEEE International Conference on Plasma Science,
1991
Conference Proceeding
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.
An analogy is suggested between the emission of radiation from a solid- state laser and the frictional motion of a particle in a potential well. This analogy is used to demonstrate analytically that ...a system of rate equations which allows only for the spatial inhomogeneity of the population inversion fails to describe the undamped pulsation regime. It is shown that this inhomogeneity makes the emission much more sensitive to perturbations in a real resonator. A comparison of the theoretical and experimental results is used to demonstrate the existence of a mechanism which generates undamped pulsations but is not related to laser instabilites.
