Electron beam back-scatter distribution detector for X-ray tube anode

摘要

The electron beam (4) impinges on the elongated anode (2) at a spot (6) from which X-rays (5) are emitted while electrons are backscattered (7) on to a detector (9). The amplitude and/or width of the signal are evaluated by a processor (10) from which inferences can be drawn concerning the distribution of electrons in the spot and its position on the anode. Pref. the electron detector is preceded by a collimator (11) having three offset holes so that detection is confined to a predetermined solid angle of back-scatter, and multiply-scattered electrons are excluded.