Experimental studies of fast deuterons, impurity- and admixture-ions emitted from a plasma focus

Abstract

The energy and mass analysis of ions emitted from a 50-kJ, 18-kV, plasma focus machine was performed with a Thomson analyzer. Energy distribution functions offast deuterons (E>350 keV) and those of impurity ions have been determined. The energy distributions of the 0, N, and C impurity ions in different ionization states have similar character. They usually increase exponentially and after reaching the maximum at E /Z;:::: 1.0 Me V they decrease exponentially to E /Z;:::: 1.8 MeV. For deuterons at lower operating pressures (Po<2 mbar) the energy distribution measured decreases exponentially from 0.35 to about 3.0 MeV. In some cases, independent of the operating pressure, the maximum energies of the distribution extend to 0.5-1.5 MeV only. With an argon admixture (up to 4.5%) Ar+ -Ar7+ ions of energy from 0.5 to 14 MeV are produced.

Formation and role of filaments in high-current discharges of the pinch type

“…In fact, some portion of the deuterons, which are accelerated by different processes occurring during PF discharges, is lost within the nuclear fusion reactions mainly inside the dense plasma pinch. Another portion of the fast deuterons can, however, escape from the PF pinch region and be recorded within a hemisphere in front of the electrode outlet, as observed in many experiments [5,6,7]. In order to explain angular distributions of the fast deuterons escaping from the pinch, different models of the pinch structure were considered and the computer modelling of deuterons motions was performed.…”

Adaptation of selected diagnostic techniques to magnetic confinement fusion experiments

“…Dimensions of the ion tracks (micro-craters) depend also on etching conditions, i.e. the etching medium, temperature and time [3,4]. NTDs are insensitive to the electromagnetic radiation and electron fluxes up to relatively high doses.…”

Ion Acceleration Independent of the Electric Current Direction in Z-Pinch Plasma

“…The model independent of the current direction should be considered as the main mechanism of ion acceleration in this study. Accelerated ions having energy on the order of MeV have been observed in many studies of high current experiments, particularly in the plasma foci [1,2] and z pinch systems [3,4]. Charged voltages of the main power supplies of these systems are several tens of kV, thus the understanding of any acceleration mechanism is required.…”