FMC-based neutron and gamma Radiation Monitoring Module for xTCA applications

The machines used in High Energy Physics (HEP) experiments, such as accelerators or tokamaks, are sources of gamma and neutron radiation fields. The radiation has a negative influence on electronics and can lead to the incorrect functioning of complex control and diagnostic system designed for HEP machines. Therefore, in most cases the electronic equipments is installed in radiation-safe areas, but in some cases this rule is omitted to decrease costs of the project. The European X-ray Free Electron Laser (E-XFEL), being under construction at DESY research center, is a good example. The E-XFEL uses single tunnel and part of the electronic system will be installed next to main beam pipe and exposed to radiation. The modern Advanced/Micro Telecommunications Computing Architecture (ATCA/μTCA) standards are foreseen as a base for control and diagnostic system for this new project. These flexible standard provides high reliability, availability and usability for the system which can be decreased by negative influence of parasitic radiation field. The additional shielding will be introduced to protect racks with electronics, but during commissioning and, in case of control systems errors, the assumed radiation levels can be exceeded. Therefore, it is highly recommended to monitor doses absorbed by electronics. Moreover, it could be helpful for estimating system lifetime, scheduling maintenance periods and protecting machine from unexpended failures. The paper describes a Radiation Monitoring Module (RMM) based on FPGA mezzanine card standard capable of monitoring gamma radiation and neutron fluence in real-time.