Measurement of air kerma rates for 6- to 7-MeV high-energy gamma-ray field by ionisation chamber and build-up plate

• Published in: Radiation protection dosimetry Vol. 162; no. 4; p. 446
• Main Authors: Kowatari, Munehiko, Tanimura, Yoshihiko, Tsutsumi, Masahiro
• Format: Journal Article
• Language: English
• Published: England 01.12.2014
• Subjects: Air; Calibration; Gamma Rays - adverse effects; Humans; Japan; Monte Carlo Method; Radiation Monitoring - statistics & numerical data; Radiometry - instrumentation; Radiometry - statistics & numerical data; Scintillation Counting; Japan
• ISSN: 1742-3406
• DOI: 10.1093/rpd/nct366

The 6- to 7-MeV high-energy gamma-ray calibration field by the (19)F(p, αγ)(16)O reaction is to be served at the Japan Atomic Energy Agency. For the determination of air kerma rates using an ionisation chamber in the 6- to 7-MeV high-energy gamma-ray field, the establishment of the charged particle equilibrium must be achieved during measurement. In addition to measurement of air kerma rates by the ionisation chamber with a thick build-up cap, measurement using the ionisation chamber and a build-up plate (BUP) was attempted, in order to directly determine air kerma rates under the condition of regular calibration for ordinary survey meters and personal dosemeters. Before measurements, Monte Carlo calculations were made to find the optimum arrangement of BUP in front of the ionisation chamber so that the charged particle equilibrium could be well established. Measured results imply that air kerma rates for the 6- to 7-MeV high-energy gamma-ray field could be directly determined under the appropriate condition using an ionisation chamber coupled with build-up materials.