Study and development of a multiplexed radiation instrument solution for CERN facilities

CERN designs, builds and operates particle accelerators and experimental areas for scientific research to understand the fundamentals of particle physics. The radiation detectors installed at several places close to the beam lines and target of these areas allows CERN to precisely monitor radiation levels for the purpose of personnel protection. This permits users to know the exact value of the radiation dose rate at any given point for personnel access and ensure they work in a safe condition. In a dedicated CERN target areas, 28 detectors are installed to measure radiation from induced radioactivity. The analog signal coming from each underground detector is sent through a long cable (around 150m) to an Area Controller monitoring system (ARCON) installed on the surface. The existing infrastructure has limitations due to the number of monitoring inputs available, and limited space for the cabling infrastructure. To overcome these constraints an innovative and bespoke circuit has been developed in order to multiplex 28 channels down to 12 channels with a practical and simple programmable interface.