A blind test of the alanine dosimetry secondary standard of the PTB conducted by the BIPM
Abstract
In order to verify the reliability of the PTB's secondary standard measurement system for the absorbed dose to water, DW, based on alanine with readout by electron spin resonance (ESR), a blind test was conducted. Nine detectors consisting of four alanine pellets each were irradiated in the 60Co reference field of the BIPM. The doses were restricted to the range between 10 Gy and 20 Gy in order to minimize the influence of noise. The values of the delivered doses were not communicated until after the measurement results were reported back to the BIPM. The absorbed dose to water DW was measured using a slightly simplified procedure, compared to previous publications, i.e. without construction of a calibration curve.
On average, the measurement results are 0.12% higher than expected from the known difference between the primary standards for DW of the BIPM and the PTB. Compared to the combined measurement uncertainty of the ratio of determined and delivered dose of approximately 0.45%, the agreement is good. Main text. 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 kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by EURAMET, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).- Publication:
-
Metrologia
- Pub Date:
- January 2014
- DOI:
- 10.1088/0026-1394/51/1A/06001
- Bibcode:
- 2014Metro..51.6001A