Design, Implementation and First Measurements with the Medipix Neutron Camera in CMS

The Medipix detector is the first device dedicated to measuring mixed-field radiation in the CMS cavern and able to distinguish between different particle types. Medipix2-MXR chips bump bonded to silicon sensors with various neutron conversion layers developed by the Czech Technical University in Prague were successfully installed for the 2008 LHC start-up in the CMS experimental and services cavern to measure the flux of various particle types, in particular neutrons. They have operated almost continuously during the 2010 run period, and results are shown here from the proton run between the beginning of July and the end of October 2010. Clear signals are seen and different particle types have been observed during regular LHC luminosity running, and agreement in the measured flux rate is found with the simulations. These initial results are promising, and indicate that these devices have potential for further and future LHC and high energy physics applications as radiation monitoring devices for mixed field environments, including neutron flux monitoring. Further extensions are foreseen in the near future to increase performance and coverage.