X-ray tube with cold cathode

摘要

The X-ray tube comprises a cold field emission cathode (6) and a scanning unit (9) arranged between the cathode and an anode (2). The scanning unit diverts and bundles the electrons (8) on a focus (10) of the anode in such way, that emitted ions (12) proceed on different paths through the scanning unit than the electrons. The fall-in point of the ions at the casing comprises preferably an ion interceptor (17), and the cathode is formed from individual, individually activated areas for the control of the focus point size. The scanning unit may be arranged inside the casing or outside, at the casing.