The ablation characteristics of laser-assisted pulsed plasma thruster with metal propellant

In this study, a laser-assisted pulsed plasma thruster (LA-PPT) with a novel configuration is proposed as an electric propulsion thruster which separates laser ablation and electromagnetic acceleration. Owing to the unique structure of the thruster, metals can also be used as propellants, and a higher specific impulse is expected. The ablation quality, morphology, and plume distribution of various metals (aluminium alloy, red copper, and carbon steel) with different laser energies were studied experimentally. The ablation morphology and plume distribution of red copper were more uniform, as compared to those of other metals, and the ablation quality was higher, indicating its greater suitability for LA-PPT. The plume generated by nanosecond laser ablation of aluminium alloy expanded faster, which indicated that the response time of the thruster with aluminium alloy as the propellant was shorter. In addition, when the background pressure was 0.005 Pa, an obvious plume splitting phenomenon was observed in the ablation plume of the pulsed laser irradiating aluminium alloy, which may significantly reduce the utilisation rate of the propellant.