Study on the laser propulsion performance of carbon–boron filled aluminum-matrix composite targets based on microcavity confinement

Abstract This study investigates the effects of a microcavity confinement structure and aluminum-matrix composite target containing propellants, namely containing carbon and boron powder propellants at different doping ratios, on propulsion efficiency. After laser focusing, high-temperature and high-pressure plasma is generated, thereby inducing a shock wave. The microcavity restricts the outward expansion of the shock wave, thereby enhancing its interaction with the target. To further characterize the shock wave behavior, the propagation process of the shock wave inside the microcavity is simulated using COMSOL. The results show that the microcavity confinement structure can effectively reduce energy dissipation into free space and promote directional plasma ejection. The study further indicates that a doping ratio of 70% yields the best propulsion performance among the tested compositions. Under this optimal composition, the hemispherical microcavity further increases the impulse coupling coefficient ( C m ) by 97.7% compared with the planar target. In addition, preliminary laser-induced ignition observations and a conceptual laser-cleaning scheme are also presented as possible extensions of the observed plasma and shock-wave effects. The results indicate that both the microcavity confinement structure and the propellant ratio have significant effects on propulsion efficiency.