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Correction factors for parallel-plate chambers used in plastic phantoms in electron dosimetry.

Abstract：

:In electron beam dosimetry using parallel-plate chambers solid phantoms are sometimes necessary. To obtain the dose to water from the ionization obtained in the solid phantom, fluence correction factors and perturbation factors have to be applied. In this study fluence factors in a perturbation free geometry have been determined experimentally for common phantom materials. Wall perturbation factors for simulated Attix, NACP, and Roos chambers have also been determined for the same materials. Comparative Monte Carlo calculations have been performed using the EGS4 Monte Carlo code. Comparison with data in newly published protocols such as IAEA and IPEMB shows an agreement with the results obtained in this paper to within 1%, demonstrating that the data published in these protocols may be used with reasonable accuracy if recommended phantoms are used. The results also show that if unsuitable phantom materials are used, the wall perturbation factors may differ for different chambers and for different phantom materials by more than 3% and perturbation factors have to be considered in order to obtain a high accuracy in the dose determination.

journal_name

Phys Med Biol

journal_title

Physics in medicine and biology

authors

Nilsson B,Montelius A,Andreo P,Johansson J

doi

10.1088/0031-9155/42/11/007

subject

Has Abstract

pub_date

1997-11-01 00:00:00

pages

2101-18

issue

11

eissn

0031-9155

issn

1361-6560

journal_volume

42

pub_type

杂志文章

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