Beam transport system for a hadron therapy facility

摘要

A beam transport system for a hadron therapy facility comprises: a main beam transport line (16); secondary beam transport lines (18 i ) branching off from the main beam transport line (16) for delivering the hadron beam into the patient treatment stations (12 i ); and switching electromagnets (20 i ) for deviating the hadron beam from the main beam transport line (16) into the secondary beam transport line (18 i ). A discharge circuit associated with each switching electromagnet (20 i ) comprises a discharge accelerating circuit capable of generating a voltage opposing the counter electromotive force induced in the electromagnet coil of the switching electromagnet (20 i ) when the energisation of the electromagnet coil producing the hadron beam deviation is interrupted, wherein this voltage stays substantially constant or increases as the current induced in the electromagnet coil decreases.