Abstract: In view of the fact that the free radicals formed after irradiation of alanine were cousiderably stable and their total number, in the dose range commonly used for food irradiation (10²~10⁴Gy), was proportional to the irradiation dose, the alanine/ESR system was selected as the transfer dosimeter for measuring high-level doses of γ-rays in China, related studies were made and normal conditions for ESR measurement was established.Especially, the linear relations between gain settings of the spectrometer were amended and the effect of rotation of the specimen tube on the signal amplitude was quantified.The lower limit for detecting the absorbed dose was found to be 5 Gy. In the range of 0.05~17kGy, for alanine specimens irradiated with ten different doses, the linear correlation coefficient between the main peak amplitude h of the ESR spectrum and the corresponding dose D was greater than 0.999.

Key words: γ-ray dosimptry, alanine/ESR dosimeter, transfer dosimeter, high-level dosimetric assurance system