Investigation of ion charge composition and energy distribution of laser ablation plasma from liquid metal

The use of recoil momentum from a laser ablation flare is found to be one of promising way for development of low-propulsion thrusters (LPT) for launching of micro and nano-satellites. The present work suggests using the liquid Ga-In alloy as the ablated body instead of a solid-state one. A Nd:YAG laser with output of 0.25 mJ and pulse duration of 2.5 ns (FWHM) was used for ablation. Charge-resolved ion energy distributions of the laser-ablation plasma were studied by means of an energy-mass analyzer EQP Hiden Analytical. Angular distribution of laser plasma density and plasma flow velocity were retrieved from measurement of ion saturation currents on a set of collectors placed at different axial and azimuthal angles relative to the target surface normal. It was found that the thrust from the liquid-metal target remains very stable during a long operation time while life-time of the target is limited only by the working body supply.