Cathode used as electron source of X-ray tube for therapeutic application, has emitter that is provided in form of spiral band comprised with outwardly directed emitter region and inwardly directed emitter region

摘要

The cathode has an emitter (1) that is arranged on a cathode head to emit electrons on application of a heating voltage. The emitter is provided in the form of spiral band (2) comprised with outwardly directed emitter region (3) and inwardly directed emitter region (4). The emitter is formed with trapezoidal, rectangular, rhomboid or square-shaped cross-section. The spiral band is formed with constant thickness.