Performance of a 4 cm iodine-fueled radio frequency ion thruster

The performance of an iodine radio ion thruster with a 4 cm diameter (IRIT4) was studied experimentally in this paper. Regulation of the mass flow rates of the iodine propellant is achieved by using a temperature control method of the iodine reservoir. Performance of the thruster using iodine as propellants is obtained at different total thruster powers of 40.6–128.8 W, different grid voltages of 1000–1800 V and the iodine flow rate of 100 μg s⁻¹. Results show that thrust and specific impulse increase approximately linearly with the increasing total thruster power and the screen grid voltage. The thrust of 2.32 mN and the specific impulse of 2361 s are obtained at the nominal total thruster power of 95.8 W and the screen grid voltage of 1800 V. It is also indicated that performance of the iodine propellant is comparable to that of the xenon propellant; and a difference between them is that the iodine thrust is slightly higher than xenon when the total thruster power is more than 62 W. At the nominal 95.8 W total thruster power, the thrust values of them are 2.32 mN and 2.15 mN respectively, and the thrust-to-power ratios of them are 24.2 mN kW⁻¹ and 23.5 mN kW⁻¹, respectively.