An online radiation monitoring system for CMS

The Large proton-proton cross-section at 14 TeV and the high luminosity of the LHC will expose CMS to a very complex radiation environment which consists of many different particles. Some electronic components and materials will be exposed to doses of radiation never faced before. CMS must operate reliably for many years in this high-intensity, mixed radiation field. Early warning of problems caused by these high doses is provided by regular and quantitative monitoring of the radiation absorbed at key points by a carefully designed array of remote-reading dosimeters, centred largely on CMS subdetectors. In this note the suitable, existing dosimetric technologies are evaluated. To be suitable the system must perform online monitoring of the radiation environment and have an extremely high dynamic range. The testing of three dosimetric principles is described.