Design of an experiment to optimize plasma energization by beating electrostatic waves

The design and implementation of an experiment dedicated to testing the wave frequency and amplitude dependence of the heating of a magnetized plasma with beating electrostatic waves is discussed. This non-resonant heating process has the potential to be more efficient than current radio frequency plasma heating methods and thus is particularly promising for electrothermal plasma propulsion. Recent theoretical work on beating electrostatic wave heating is reviewed with an emphasis on the existence of an optimal frequency for maximum heating as well as a scaling relation for the magnitude of heating. While the possibility of optimizing the process thus is demonstrated theoretically, systematic experimental verification remains to be conducted. The implementation of a cylindrical, magnetized plasma generated with an inductive source is discussed as a testbed for the predicted theoretical trends. The diagnostics for observing the amplitude and frequency dependence are also presented as well as a derivation of the experimental parameters necessary for the tests to accurately investigate the theoretical predictions.