EXPERIMENTAL STUDY ON GRAPHITE-KEEPER HOLLOW CATHODE

Aiming at extending the ion thruster life，Graphite-Keeper hollow cathodes have been developed.The keeper disk are made of high density graphite，which possesses much higher tolerance to ion impingement compared with conventional metal materials.We made a performance test of different structure keeper.At last in order to validate the keeper performance，we started a performance test of a discharge cathode，until May 2016 the cumulative operation time reached 1 000 hours.The hollow cathode anode voltages，keeper voltages have been almost constant and stable，and no severe degradation has been found on the electrodes.