Ion thruster with a combination keeper electrode and electron baffle

An ion thruster is described in which the cathode front end, surrounded by our insulator, is mounted flush with the front end of the flanged portion of the cathode pole piece. The thruster's baffle positioned in front of the cathode's front end supports the thruster's keeper electrode which is space apart and directed to the cathode's open end. The baffle is at the keeper's electrode potential.