First Calibration of Alanine and Radio-Photo-Luminescence Dosemeters to a Hadronic Radiation Enviroment

Alanine and Radio-Photo-Luminescence (RPL) dosemeters are used or will be used to monitor the absorbed doses occurring inside the tunnels of all CERN accelerators including the Large Hadron Collider (LHC). They are placed close to radiation sensitive machine components like cables or insulations of magnet coils to predict their remaining lifetime. At these locations the dosemeters are exposed to mixed high-energy radiation fields, but up to now both dosemeter types were only calibrated in the photon field of⁶⁰Co sources. This paper presents the results of a proton calibration campaign applied to Alanine and RPL dosemeters. The dosemeters were irradiated with protons of a momentum of 24 GeV/c at the irradiation facility IRRAD1 at CERN-PS. The energy deposition per impinging protons seen at the location of the dosemeters is calculated with the FLUKA Monte Carlo code. By means of the measured fluence result the achieved number was translated into a finally obtained dose at the dosemeter location. Nine measurements at varying impinging proton intensities were performed. The dose results are related to the readout results obtained by the analysis procedures applied to the various detectors yielding to a proton calibration curve. This new proton based calibration curve is compared to the old one which was obtained by a⁶⁰Co photon irradiation.