HPM development at IPR for plasma physics applications

Recent years, the studies of High power electromagnetic wave particularly microwave or laser propagation in plasma has attracted much attention because of its importance in many practical areas. At IPR, an experimental system "SYMPLE" is recently conceived to investigate the physics of interaction of extremely intense e.m. waves (eE_em/mωem ∼ c) with an over dense (ω_p > ω_em) plasma. The study of such experiments remained constrained for a long time due to limited availability of high power required resources as well as limitation of diagnostic access but the advent of high power microwave (HPM) sources have opened a new arena of investigations. VIRCATOR and Relativistic magnetron are two real contenders for the required HPM source both works on fast high voltage electrical discharge system. Virtual cathode is a nonlinear state, which develops when the electron beam injection current exceeds the space charge limiting current (defined by beam energy and wave guide geometry) and whose oscillations can generate high power microwaves. Whereas Relativistic magnetron works on the principle of gyration of electron in presence of high magnetic and electrical field produced by connected pulsed power. A compact and repetitive generator based on Tesla transformer for application in plasma opening switch has been developed. This system is designed to operate with up to 300 kV on water pulsed forming line to generate 40 kA (in short circuit condition), 50 ns pulse, which is further compressed in time with the help of plasma opening switch. Operation of this generator with VIRCATOR (virtual cathode oscillator) as a load will be presented here