Interlock system for machine protection at ThomX accelerator

ThomX is a Compton based photons source. It aims to produce a compact and directional X-rays source, with high performance, high brightness and adjustable energy. The principal application fields are medical sciences, social technology and industry. An interlock system has been implemented for machine protection, especially to protect sensitive and essential equipment (magnets, vacuum system, etc.) during machine operation. It will allow taking appropriate actions to minimize recovery time in case of operation problem. ThomX interlock system is based on Programmable Logic Controller (PLC-Siemens S7-1500) distributed over the machine subsystems, it collects default signals from the different equipment of the machine, up to the central PLC which kills the beam, by stopping the RF or the injection, in case of problem (bad vacuum, magnets overheating, etc.). Actually, the interlock system is under implementation in parallel with the assembly of the machine. It will allow accelerator to work safely, and increase the availability of the machine. (author)