X-RAY TUBE WITH SWITCHABLE GRID FOR GATING OF ELECTRON BEAM CURRENT DURING VOLTAGE BREAKDOWN

摘要

The invention relates to a medical imaging system (100) comprising an X- ray tube (120) having a cathode (210) and the anode (230). There is arranged a grid (200) between the cathode (210) and the anode (230). The grid is switchable by a switch (260) to block a beam of electrons between the cathode (210) and the anode (230) in the event a sensor (240) senses a critical condition in the medical imaging system (100). The critical condition may be indicative to damaging effects such as an electric arc in the X- ray tube (120). The switch (260) is arranged as a high-speed switch to better prevent the X-ray tube (120) from damage.