Supplementary comparison CCRI(I)-S3 of standards for absorbed dose to water in 60Co gamma radiation at radiation processing dose levels

Main text A supplementary comparison of standards for absorbed dose to water in 60Co fields used for calibrations at radiation processing dose levels has been completed. Alanine dosimeters from the NIST and the NPL were used as transfer dosimeters and all participant irradiations were carried out in self-shielded irradiators. Irradiations were also carried out at the BIPM to allow direct comparison of dose ratios with the Key Comparison BIPM.RI(I)-K4. No significant difference was seen between the dose ratios obtained using the NPL and NIST alanine systems, no significant impact of mailing on dosimeter response was noted, and the adopted protocol limited any dose rate effects to the level of Type A uncertainties. The national standards of the participants are in agreement within the standard uncertainties, which are in the range from 1 to 2 parts in 102. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA). © 2022 BIPM & IOP Publishing Ltd.