Personal Safety Interlock System Based on Siemens Safety PLC

Abstract

The proton therapy system is currently one of the internationally recognized high-performance cutting-edge radiotherapy equipment. When the proton therapy system is running, secondary radiation and induced radiation such as gamma rays and neutron radiation will be generated during various stages such as beam generation, injection, acceleration, extraction, and transmission. Even after a period of time after shutdown, there will still be residual radiation fields, which pose a threat to the personal safety of on-site personnel. Therefore, it is crucial to design an effective personal safety chain system. This article designs and develops a personal safety interlock system for the cyclotron production and debugging room of the proton medical system production base of CGN Medical Technology (Mianyang) Co., Ltd. The personal safety interlock system uses Siemens safety PLC and safety programs to embed safety procedures into the operation and maintenance process of the cyclotron, achieving functions such as master key switch control, accelerator gate beam flow interlock, ventilation delay door opening interlock, site clearance patrol system interlock, and personal dose system interlock, to protect the personal safety of on-site personnel. The system has been put into operation and passed the on-site inspection of environmental protection supervisors