High Energy Photon Response of Different Environmental TLDs

• Published in: Radiation protection dosimetry 1993-05, Vol.47 (1-4), p.327-330, Article 327
• Main Authors: Sáez-Vergara, J.C., Gómez-Ros, J.M., Delgado, A.
• Format: Article
• Language: English
• ISSN: 0144-8420; 1742-3406
• DOI: 10.1093/oxfordjournals.rpd.a081761

The presence of high energy photons (4-7 MeV) around nuclear power plants and high energy accelerators is important during operation. Environmental monitoring frequently uses passive TL measurements for the assessment of the radiological impact of these facilities. However, due to the presence of this energetic photon radiation component, the design of environmental TLDs must be reconsidered, in order to provide charged particle equilibrium. The energy dependence of phosphors (LiF:Mg,Ti, Li2B4O7:Cu, CaSO4:Tm) in different irradiation conditions has been measured in the range 0.6-6.5 MeV. Irradiations using 6 MeV photons were performed in the calibration facility recently established at PTB (Germany). These data also seem to indicate that it could be necessary to apply specific corrections to the TLD readouts to account for these high energies and the convenience of the use of a discriminant TL dosemeter with special dose calculation algorithms for this radiation. These algorithms are usually based on element ratios and can be impractical in field readouts. However, this is not a serious limitation since the maximum error should not exceed ±10%.