Thrust Performance Test of a Micro Multi-Plasmajet-Array Thruster

Microfabrication of a 3x3 micro-plasmajet array with ultra-violet lasers and its thrust performance tests were conducted for nozzle elements with exit height of 0.5 mm and length of 0.5 mm. Stable discharge and operational conditions were confirmed for the 3x3 micro-plasmajet array thruster. To evaluate thrust characteristics of the arrayed plasmajet, thrust characteristics of the thruster were compared with those of the micro-single-nozzle plasmajet. It was shown that the thrust and specific impulse of the micro-plasmajet array were higher than those of the micro-single-nozzle plasmajet due to the multi-jet effect. The typical values of the thrust, specific impulse and thrust efficiency averaged per nozzle element of the micro-plasmajet array thruster operated at 6.2 W with 1.46 mg/sec of propellant mass flow per nozzle element were 1.13 mN, 79 sec, and 24%, respectively.