NUKLEONIKA 2009;54(1):39−43 ORIGINAL PAPER Introduction The interactions of photons (γ and X rays) and high en- ergy electrons produce with glass mainly ionization and excitation, but also cause a certain amount of atomic displacement depending on the energy of the radiation. The displacement of lattice atoms and/or electron de- fects and production of electron-hole pairs, which may be individually trapped at various defect sites in the glass structure, imply changes in the valence state of lattice atoms or inclusion of impurity atoms in glass. Some of the modified electronic configurations or defects cause preferential light absorption; the glass thus becomes coloured, and hence these defects are called “colour centres”. These centres are of many types and depend on the glass components and have associated charac- teristic optical absorption bands and ESR spectra. The radiation-induced colour centres in some commercial glasses have been found suitable for radiation dosim- etry [2, 9, 13]. The use of glass samples as radiation dosimeters presents some advantages that make them attractive for the scope: they are recyclable (a thermal treatment at 300°C for time > 20 min is enough for Dosimetric properties of gamma- and electron-irradiated commercial window glasses Piergiorgio Fuochi, Ugo Corda, Marco Lavalle, András Kovács, Marika Baranyai, Arbi Mejri, Khaled Farah P. Fuochi  , U. Corda, M. Lavalle ISOF-CNR, 101 P. Gobetti Str., 40129 Bologna, Italy, Tel.: +39 051 6399786, Fax: +39 051 6399844, E-mail: fuochi@isof.cnr.it A. Kovács, M. Baranyai Institute of Isotopes, HAS, P. O. Box 77, H-1525 Budapest, Hungary A. Mejri, K. Farah Laboratoire de Radiotraitement, CNSTN, 2020 Sidi-Thabet, Tunisia Received: 19 August 2008 Accepted: 19 December 2008 Abstract. Two different types of window glasses have been investigated as possible routine dosimeters in the range of 1–50 kGy. Glass samples were irradiated with 3.4 MeV and 8.4 MeV electron beams and the results compared with those obtained by 60 Co γ irradiation. Due to the strong optical absorption at wavelengths < 310 nm, even at low doses, optical measurements were limited to the range 320–700 nm. In both types of glasses, irradiation induced two absorption bands around 410 and 600 nm the intensities of which are proportional to dose; the 600 nm band being less sensitive to radiation. These bands have been attributed to non bridging oxygen hole centres existing in two different configura- tions. Because of the rapid fading of the optical absorbance observed at room temperature immediately after irradiation (> 15% in two days), the samples underwent a post-irradiation thermal treatment (150°C for 20 min) to improve the stability of absorbance. The fading characteristics of the irradiated and thermally treated glasses, kept in the dark at room temperature, were studied for several weeks. A fast decay, whose intensity depends on the type and energy of the ionizing radiation, was observed for few days after irradiation and thermal treatment, followed by a much slower decay. The results show that this kind of material could be used as routine dosimeters within a certain dose range, as long as proper calibrations are made for each batch of glass and the appropriate precautions are taken when doing calibration and performing routine dosimetry. Key words: silicate glass • gamma rays • electron beam • optical absorption • dosimeter • fading behaviour