THE RESPONSE OF THE NEW HYPERSENSITIVE THERMOLUMINESCENCE MATERIALS TO HIGH-ENERGY PHOTONS (0.6-6.0 MEV)

The energy dependence of two types of LiF:Mg,Cu,P (GR-200A from China, MCP-N from Poland) and one type of alpha-Al2O3:C from Russia has been studied in the range 0.6-6.0 MeV. For completion, standard LiF:Mg,Ti (TLD-100 from USA) was also tested with the same methods. All the irra diations were carried out in Metrological Facilities in Spain (CIEMAT) and Germany (PTB). A build-up experiment was performed using differen t thicknesses of PMMA placed at the front and back of detectors. Corre ctions from photon attenuation, build-up factor and dose enhancement h ave been calculated and compared for further discussion. The results f or the hypersensitive phosphors show an agreement within 5% when the 6 -7 MeV photon response is compared with the standard Cs-137 calibratio n, while an under-response of 10% is observed or TLD-100.