In article are described questions of hollow cathode parameters influence on plasma thruster characteristics. It is validated a necessity to reducing of hollow cathode mass flow rate and power consumption. Physical aspects of development and results of cathode construction thermal modeling are describes. Test results of micro flow rate (mcg/s) heaterless cathode-neutralizer for electric propulsion with working current up to 300 mA are presented. It is shown that manufactured cathode model provides neutralized current from 0 to 300 mA with plume potential 10- 45 V, power consumption 5,5-12,5 W and xenon mass flow rate 10-30 microgram/sec. Application of this model with low power electric propulsion system will allow to increase on 13-21 % specific impulse of thruster module and to reduce necessary mass of propellant on spacecraft board.