Slit emitters had been developed to increase the emitting area of the thruster in order to yield higher thrust levels and to avoid the irregular behaviour observed for single emitters. The substantial advantage of slit emitters over stacked needles is in the self-adjusting mechanism governing the formation and redistribution of emission sites on the liquid metal surface according to the operating parameters; in a stacked-needle array, on the contrary, the Taylor cones can only exist on the fixed tips, which pre-configure a geometrical arrangement that can only be consistent with one particular operating condition.
slit emitters had been developed to increase the emitting area of the thruster in order to yield higher thrust levels and to avoid the irregular behaviour observed for single emitters the substantial advantage of slit emitters over stacked needles is in the self-adjusting mechanism governing the formation and redistribution of emission sites on the liquid metal surface according to the operating parameters; in a stacked-needle array on the contrary the taylor cones can only exist on the fixed tips which pre-configure a geometrical arrangement that can only be consistent with one particular operating condition