open access

https://hdl.handle.net/2115/54776

Angular distributions of absorbed dose of Bremsstrahlung and secondary electrons induced by 18-, 28- and 38-MeV electron beams in thick targets

英語

2013-03

Oxford University Press

Radiation Protection Dosimetry

153(3)

369-383

Angular distributions of absorbed dose of Bremsstrahlung photons and secondary electrons at a wide range of emission angles from 0 to 135, were experimentally obtained using an ion chamber with a 0.6 cm(3) air volume covered with or without a build-up cap. The Bremsstrahlung photons and electrons were produced by 18-, 28- and 38-MeV electron beams bombarding tungsten, copper, aluminium and carbon targets. The absorbed doses were also calculated from simulated photon and electron energy spectra by multiplying simulated response functions of the ion chambers, simulated with the MCNPX code. Calculated-to-experimental (C/E) dose ratios obtained are from 0.70 to 1.57 for high-Z targets of W and Cu, from 15 to 135 and the C/E range from 0.6 to 1.4 at 0; however, the values of C/E for low-Z targets of Al and C are from 0.5 to 1.8 from 0 to 135. Angular distributions at the forward angles decrease with increasing angles; on the other hand, the angular distributions at the backward angles depend on the target species. The dependences of absorbed doses on electron energy and target thickness were compared between the measured and simulated results. The attenuation profiles of absorbed doses of Bremsstrahlung beams at 0, 30 and 135 were also measured.

学術雑誌論文

Accepted Manuscript

This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Radiation Protection Dosimetry following peer review. The definitive publisher-authenticated version Angular distributions of absorbed dose of Bremsstrahlung and secondary electrons induced by 18-, 28- and 38-MeV electron beams in thick targets is available online at: http://rpd.oxfordjournals.org/content/153/3/369.full.

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