An x-ray tube includes a frame forming a first portion of a vacuum enclosure, a rotating subsystem shaft positioned within the vacuum enclosure and having a first end and a second end, wherein the first end of the rotating subsystem shaft is attached to a first portion of the frame, a target positioned within the vacuum enclosure and attached to the rotating subsystem shaft between the first end and the second end, the target positioned to receive electrons from an electron source positioned within the vacuum enclosure, and a thermal compensator mechanically coupled to the second end of the rotating subsystem shaft and to a second portion of the frame, the thermal compensator forming a second portion of the vacuum enclosure.