Method and apparatus for prolonging the life of an x-ray target

摘要

An x-ray generator (1) comprises an electron gun (3), an electron focusing lens (15) and an x-ray target (4). The x-ray generator (1) has electronic control means which controls the electron focusing lens (15) to move the electron beam (28,38) to a fresh area (23) of the target (4) when the previous area (22) of the target (4) becomes degraded through use. In this way the life of the target (4) is increased.