Pinched Plasma Study in a Filippov-Type Plasma Focus "Dena"

• Published in: IEEE transactions on plasma science 2008-06, Vol.36 (3), p.794-801
• Main Authors: Talaei, A., Kiai, S.M.S., Adlparvar, S.
• Format: Article
• Language: English
• Subjects: Approximation; Character generation; Distribution functions; Electronics; Electrons; Elementary processes in plasma; Exact sciences and technology; Filippov-type plasma focus; fringe shift density; Gas lasers; Integral equations; Interferometry; laser interferometry; neutron production mechanisms; Neutrons; Particle measurements; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; pinched plasma; Plasma; Plasma density; Plasma diagnostic techniques and instrumentation; Plasma properties; Radioactive decay; Studies; Thermal expansion
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/TPS.2008.922498

A characteristic feature of physical processes occurring in pinched plasma is their tendency to generate thermal and nonthermal emissions. In this case, the roles played by plasma compression dynamics such as pinch formation, pinch disruption, expansion, etc., are predominant. In this paper, first, we present some of the experimental results concerning the thermal and nonthermal neutron emissions. Then, a new approach based on some theoretical assumptions and the experimental data for which the pinched plasma density evolution was studied are introduced. In the new approach, the compression dynamics are divided into two phases: plasma compression (thermal) and plasma expansion (nonthermal). For each phase, electron distribution functions such as a parabolic and a hyperbolic are attributed, respectively. Assuming a maximum electron density for each phase and an Abel integral equation (used in laser interferometry method), the fringe density maps in a new Filippov-type plasma focus ldquoDenardquo (25 kV, 288 muF , and 90 kJ) operating in deuterium gas were obtained in the approximation of low collision frequencies.