Abstract: Researches show that the gas distributor of Hall thrusters with manufacture and installation error, or the vent holes plugged up by the sputtered particles would result in azimuthal non-uniformity of neutrals. The influences of the degree of azimuthal non-uniformity of neutrals on the discharge characteristic and performance of Hall thrusters were studied by plugging up the vent hole of gas distributor. Current characteristic,  ion current density distribution and overall performance were obtained by experiments. Results show that azimuthal non-uniformity of neutrals results in higher discharge current with the maximum of increments of 25 %, lower thruster efficiency, lower special impulse, and bigger oscillation.

Key words: Hallthrusters, gasdistributor, azimuthalnonuniformity, dischargecharacteristic, plume