The influence of the cathode array and the pressure variations on the current sheath dynamics of a small plasma focus device in the presence of an axial magnetic probe

Autor: H. R. Yousefi, A. Salar Elahi, T. D. Mahabadi, Mahmood Ghoranneviss, S. Javadi, D. Piriaei
Rok vydání: 2017
Předmět:
Zdroj: Physics of Plasmas. 24:043504
ISSN: 1089-7674
1070-664X
DOI: 10.1063/1.4979275
Popis: In this research, the influence of the cathode array and the pressure variations on the current sheath dynamics of a small plasma focus device (450 J) was investigated. For this purpose, the signals of an axial magnetic probe for two different gases (argon and nitrogen) were studied. The magnetic probe signals showed the slower movement of the current sheath layer when the number of cathode rods decreased. This was related to the increase in the circuit inductance, which caused the longer discharge time of the capacitor bank followed by the creation of runaway electrons. These electrons in turn produced the impurities that led to the appearance of the instabilities inside the plasma. On the other hand, in order to investigate the effect of the cathode array variation on the instabilities produced inside the plasma, the wavelet technique was used. With the aid of frequency analysis, this technique showed the increase in these instabilities, which was due to the non-uniform formation of the current sheath l...
Databáze: OpenAIRE