Plume characteristics of polymeric material doped with different metal particles under pulsed laser irradiation

The polymer emerges as a promising propellant for laser propulsion, which is expected to achieve high specific impulse and momentum coupling coefficient. However, the low laser absorptivity of polymer deteriorates its further application. Metals can improve the laser absorption of laser energy, contributing to better propulsion performance. This paper investigated the influence of different alloy particles (Cu-Zn, Al-Si, Ni-Ti, Co-Cr) on the plume characteristics of polymeric material under laser irradiation. The plume images, length, area, and relative intensity distribution of the doped sample were analyzed and compared. It is found that each alloy particle could contribute to the stable and massive formation of the ablation plume. When laser irradiates these doped samples, an obvious jet was generated from the ablation surface, and there was an additional expansion cluster at the end of the jet. Compared to other samples, the target filled with Al-Si witnessed the maximal plume length of 13 cm, expansion velocity of 26 m/s, and plume area of 33 cm2. Besides, the higher doping ratio contributed to the larger plume length while the smaller plume area in general, but the doping ratio had little effect on the plume length and area for the short laser-material interaction process.