γ-Ray dose intercomparison in the absorbed dose range, 5–50 kGy, using dichromate and alanine dosimeters

A γ-ray absorbed dose intercomparison study was carried out in high-dose range of 5–50 kGy, employing two kinds of aqueous silver-dichromate dosimeters and alanine-polystyrene (PS) dosimeters between IC-VINATOM and JAERI. The dichromate dosimeters with different useful dose ranges, prepared by IC-VINATOM, were irradiated by 60Co γ-rays at JAERI and analyzed at IC-VINATOM by spectrophotometry. The alanine-PS dosimeters provided by JAERI were irradiated by 60Co γ-rays at IC-VINATOM and analyzed at JAERI by electron spin resonance (ESR) spectroscopy. Quoted dose values at irradiation laboratories and correspondent dose values estimated at analysis laboratories were in good agreement within ±4% over the dose range 1–50 kGy for the two-way blind dose intercomparisons using different dosimeters. It is expected that this kind of dose intercomparison study will lead us to a regional dose standardization network through dose intercomparison studies among reference-level laboratories using mailing dosimeters.