A bearing assembly suitable for use in conjunction with x-ray device having a rotating target anode and electron source disposed in an evacuated enclosure. The bearing assembly includes a shaft having a rotor hub to which the anode is mounted. The shaft cooperates with front and rear bearing rings to define front and rear races, and a spacer facilitates positioning of the bearing rings. Front and rear ball sets are confined in the front and rear races, respectively. A bearing housing receives the bearing rings, spacer, front and rear ball sets, and part of the shaft. Finally, a magnet is disposed near the front bearing ring to prevent escape of foreign matter from the bearings and to prevent ingress of foreign matter to the bearings. Consequently, the magnet serves to extend the life of the bearings and to prevent foreign matter related arcing of the target anode and electron source.