Propulsion research on the variable tandem mirror plasma rocket

This report describes the progress made in the past two years as well as the overall picture of this research. In the past years, several-milestones have been achieved towards the realization of a practical space plasma thruster from the tandem mirror rocket experiment, i.e. the specific impulse, thrust, energy conversion efficiency, and mass flow-rate have been determined. The experiment operates at 9.4 kW of input power at an rf-to-plasma efficiency of 68%; The ion temperature is 172 eV (2,000,000 K) which gives an I sub sp of 12, 852 s. The thrust is 76 mN (milli Newton) which is a high value for a low input power (9.4 kW) and very high I sub sp, (12,852 s). The radiation loss was found to be very low. Most important, these results fall within our prediction.