30 Years of Electronics Evolution for CERN Safety Radiation Monitoring

Abstract

Radiation protection at CERN ensures a safe environment for the people working on site and for the general public by protecting against any unjustified exposure to ionizing radiation. One typical detector type used by the radiation monitoring system at CERN are ionization chambers. The ionizing radiation is detected by these sensors which produce a current proportional to the received radiation dose rate. The unavailability of commercial off-the-shelf (COTS) radiation monitoring systems which can fulfill our requirements was the driving force for undertaking in-house development of our own solution. The various systems developed in the Radiation Protection (RP) group of CERN are presented in this paper. The legacy systems and the latest generation of installed radiation monitors are all based on discrete components. The management of such complex systems with thousands of components is a herculean task and there is the unavoidable risk of obsolescence of components. The solution currently applied is the procurement and storage of components that may be required in the foreseeable future. This approach, although temporarily helping to mitigate the obsolescence problem, nonetheless renders any fault repair or upgrade cumbersome. Hence, an application specific integrated circuit (ASIC) development was initiated by the RP group. This paper presents the architecture of the readout section of three systems developed through 30 years of CERN operation before getting into the details of an in-house developed ASIC for radiation monitoring systems that provides state-of-the-art performance, as well as avoids dependency on COTS systems and components.