Abstract: An improved metal center rotating anode x-ray tube is shown. The improved x-ray tube includes means for preventing the build-up of charge on the anode glass portion of the tube envelope where the glass flares by constraining the equipotential lines of the electric field in the vicinity of th eflare to parallel the flare surface. Parallelism may be achieved by (1) controlling the angle of the flare and sealing the flare directly to the metal section, (2) modifying the anode rotor to include a flare conforming to the glass flare, and (3) including a ground plane screen in the tube housing.