An X-ray tube assembly includes an electron beam transport tube, a beam tube protection assembly, and a control module. The electron beam transport tube includes an opening configured for passage of an electron beam, and includes an inner surface bounding the opening along a length of the electron beam transport tube. The beam tube protection assembly includes a plurality of beam protection electrode segments disposed within the opening of the electron beam transport tube and configured to protect the inner surface of the electron beam transport tube from contact with the electron beam. The control module is configured to determine a direction of the electron beam responsive to information received from the beam tube protection assembly.