Effects of carbon, graphite, and graphene as propellant dopants in a laser-electric hybrid acceleration system

Abstract

With the combination of laser ablation and electromagnetic acceleration, the laser–electric hybrid thruster is now perceived as an advanced propulsion system to support the precise maneuvering of microsatellites. To improve the performance of a laser–electric hybrid acceleration thruster, we used carbon, graphite, and graphene as dopants to modify the polymeric propellant fed into it. The impulse bit, consumed mass, discharge success rate, specific impulse, momentum coupling coefficient, and efficiency were measured and analyzed. Results showed that these three dopants led to higher values of impulse bit, specific impulse, discharge success rate, efficiency, and momentum coupling coefficient. The samples doped with carbon and graphene yielded better performances than those doped with graphite. Furthermore, the propellant sample made of 5% graphene and 95% polytetrafluoroethylene yielded the highest impulse bit of 394.7 μN·s, largest specific impulse of 1012.05 s, highest momentum coupling coefficient of 16.21 N/MW, and maximal efficiency of 8.21%. Furthermore, we compared the performances of the doped samples at different filling ratios and different operations. It was found that 5% was the optimal doping ratio for the dopants of carbon and graphene, and a higher discharge width could effectively improve the performances of the carbon-doped and graphene-doped samples.