A system for microwave — Plasma interaction experiments

In order to investigate physics of nonlinear interaction of high-power microwave (HPM) with an over-dense (f_plasma > f_wave) plasma, an experimental system SYMPLE (System for Microwave and Plasma Experiments), is being developed. The work is taken up in two phases: Phase-1 addressing interaction of plasma with moderate power HPM, ((1/2;εE_μ²) /(nkT_e) ~ 1), and Phase-2 involving extremely intense (eE_μ/mω ~ c) HPM. Here `E<sub>μ</sub>´ is the wave field, `n´ the plasma density, T_e´ the electron temperature, and `m´ the electron mass. The interaction of these intense waves with plasma at the critical density layer (f_plasma=f_wave) is predicted to involve various phenomena, ranging from generation of parametric instabilities to hot electron generation, leading to wave absorption in plasma. Understanding of the underlying physics has implications in inertial fusion. The parametric generation of SYMPLE as well as various aspects of the development of the Phase1 system, with a 3 MW, 3 GHz Magnetron source, a washer gun plasma, and a TE₁₀-TM₀₁ HPM mode converter is discussed here.