Hybrid plasma source based simultaneously on laser ablation and vacuum arc discharge for plasma propulsion

A concept of a hybrid plasma source with a liquid gallium-indium propellant as a thruster for micro-satellites is proposed. Plasma source operates in two regimes: generating the laser ablation plasma and generating the plasma of low voltage vacuum arc discharge with a laser triggering. In the discharge cell of the source, the cathode is a stainless steel capillary tube filled with working liquid. The meniscus of working liquid is the target for an intense laser beam. At the absence of voltage in the discharge cell, only the laser ablation plasma is generated. When even a relatively low voltage (<;1 kV) is applied, the ablation initiates high-current vacuum arc discharge. In the experiment, waveforms of current and voltage of the discharge are recorded, high-speed images of a plasma glow are registered. Regularities and peculiarities of vacuum arc discharge triggered by the laser ablation of the cathode are studied and discussed.