ABSORBED DOSE IN ION BEAMS: COMPARISON OF IONISATION- AND FLUENCE-BASED MEASUREMENTS

作者:Osinga Julia Maria*; Brons Stephan; Bartz James A; Akselrod Mark S; Jaekel Oliver; Greilich Steffen
来源:Radiation Protection Dosimetry, 2014, 161(1-4): 387-392.
DOI:10.1093/rpd/ncu004

摘要

A direct comparison measurement of fluorescent nuclear track detectors (FNTDs) and a thimble ionisation chamber is presented. Irradiations were performed using monoenergetic protons (142.66 MeV, phi=3 x 10(6) cm(-2)) and carbon ions (270.55 MeV u(-1), phi=3x10(6) cm(-2)). It was found that absorbed dose to water values as determined by fluence measurements using FNTDs are, in case of protons, in good agreement (2.4 %) with ionisation chamber measurements, if slower protons and Helium secondaries were accounted for by an effective stopping power. For carbon, however, a significant discrepancy of 4.5 % was seen, which could not be explained by fragmentation, uncertainties or experimental design. The results rather suggest aW-value of 32.10 eV +/- 2.6 %. Additionally, the abundance of secondary protons expected from Monte-Carlo transport simulation was not observed.

  • 出版日期2014-10