Experimental investigation of a low-power stationary plasma thruster

Integral characteristics of a laboratory model of the new-generation $\alpha$-40 stationary plasma thruster (SPT) designed to operate at a total consumed power of 150 W have been studied. Integral parameters of the SPT prototype, including thrust, discharge current, specific impulse, and efficiency, determined on the test stands of MIREA and Fakel Special Design Bureau proved to be virtually identical. At a deposited power of $\sim$ 150W, discharge voltage of 210 V, and consumption rate of propellant (xenon) of 0.7 mg/s, the thrust reached 9.4 mN, the anodic specific impulse was $\sim$ 1370 s, and the anode thrust efficiency (with allowance for the power consumed by magnetization coils) was about 41%. In a different regime with a greater thrust (9.7 mN) but lower specific impulse (1240 s) at the same deposited power ($\sim$ 150 W), which was observed at a propellant-consumption rate of 0.8 mg/s and a discharge voltage of 190 V, the efficiency was $\sim$ 40%. The jet semidivergence angle was $\pm$ 25$^\circ$. The predicted SPT service life is 2500 h. The obtained data show that the efficiency of $\alpha$-40 SPT is higher than that of the known analogs.