Electron Heating due toS-Polarized Microwave (Laser) Driven Parametric Instabilities

Microwave experiments and simulation calculations for laser parameters are reported of electron heating and microwave (laser) absorption due to parametric instabilities excited in the strongly steepened density profile near the critical surface. An approximate theory is developed that shows that $\frac{T_H}{T_e}$ should be a function of only the variable $\frac{f_{H}I{{\lambda }_0}^2}{T_e}$. The microwave measurements and simulation calculation results agree (±20%) with this theory.