Upgrade of radiation safety interlock system for accelerator complexes and access control system for controlled areas at Research Center For Electron Photon Science, Tohoku University

Research center for electron photon science, Tohoku university conducted a wide variety of research with four electron accelerators and many radioisotopes, including beam dynamics, Quark Nuclear Physics, and radiation chemistry. Accelerators and radioisotopes are located and used in radiation controlled areas. Access to radiation controlled area is recorded by an access control system. However, the old access control system has some issue to be solved, which is less maintainability and stability. In addition, the access control system sometimes shut down for unknown reason. To improve the safety during accelerator operation, the modification of radiation safety interlock system was required. We report the newly developed access control system, and modified radiation safety interlock system. (author)