- It is well established that e.m wave propagation is not supported by an unmagnetized, over-dense plasma. However, depending on the intensity of the incoming wave, several interesting linear and nonlinear interactions occur between the wave and plasma at the critical layer (ω=ωp), leading to the absorption of the wave.
- In the range where the wave pressure is of the order of plasma particle pressure, energy transfer to plasma occurs through phenomena involving caviton formation, wave trapping etc.
- Interactions at very high intensities where the quiver velocity to which plasma electrons are driven is of the order of “c”, absorption occurs fast electron formation in the plasma.
- Investigation of the wave-plasma interaction assumes great importance not only in understanding various related physics issues, also in the context of its implications in inertial fusion and laser plasma accelerators.
SYMPLE, being developed, aims at investigating the e.m. wave plasma interaction, in two phases, covering
- weakly nonlinear effects by studying interaction of high power microwaves of ~a few MW with plasma and
- relativistic effects by studying interaction of 1 GW HPM with plasma.
The developmental work of SYMPLE calls for parallel R & D works and technical advancements in the following areas : Plasma source, HPM source, HPM coupling to Plasma, High frequency (a few Gega Hertz) diagnostics.
The developments under way:
- Plasma source (1-10)12/cm3, 1m axial and ~10 cm radial uniformity, sharp gradient at the regime of wave interaction.
- HPM sources for phase 1 (magnetron based) and phase 2 (VIRCATOR) studies.
- HPM plasma coupling hardware
- High frequency ~5 GHz) diagnostics.
1. High density 100 ms plasma.
2. HPM of ~ a few Mega Watts, (~3 GHz)
3. Know how on VIRCATOR simulation.
SYMPLE Plasma and HPM
Plasma discharge current