RESIN AND BARK OF PINE (PINUS-SILVESTRIS) AS NEW OBJECTS FOR RETROSPECTIVE DOSIMETRY BY THE EPR METHOD

The EPR spectra of irradiated and non-irradiated bark and resin of pin e were investigated in order to determine the possibility of using the se objects for retrospective dosimetry. It was shown that yield of gam ma-radiation induced free radicals in bark is to 2-3 times higher than for resin. The stability of these free radicals in conditions of norm al and exceptionally high humidity in resin is higher than for bark. D ose dependencies of radiation-induced free radicals in bark and resin were investigated up to 1 kGy. The minimum dose which we could determi ne from the EPR signal for resin was 10 Gy. Thus pine resin is suitabl e for retrospective dosimetry for a relatively long period after irrad iation, while bark is suitable object for a shorter period. Copyright (C) 1996 Elsevier Science Ltd