Two-mode operation of plasma thruster

Much effort is presently devoted to developing stationary plasma thrusters (SPTs) capable of operating at elevated discharge voltages with large specific impulses. Classical SPTs in nominal regimes are characterized by a specific impulse of 1500 s at a thrust of 85 mN. We present experimental data on the characteristics of an SPT of the $\alpha$-100 type capable of operating in two-mode regimes at the same supplied electric power ranging within 1.9–2.5 kW. The first (low-voltage) mode provides a thrust of about 120 mN, while the second (high-voltage) mode ensures a specific impulse of up to $\sim$3000 s.