Evaluation of the Average Weighting Factor in Thin Layer Irradiation by Bremsstrahlung

A.V. Belousov^1, , U.A. Bliznyuk² and A.P. Chernyaev¹

¹Physical department, M.V. Lomonosov Moscow State University, Moscow, Russia

²Nuclear research institute named by D.V. Skobeltcin

Cite this paper:
A.V. Belousov, U.A. Bliznyuk and A.P. Chernyaev. Evaluation of the Average Weighting Factor in Thin Layer Irradiation by Bremsstrahlung. Biomedicine and Biotechnology. 2014; 2(4):80-84. doi: 10.12691/bb-2-4-3

Abstract

Photon radiation passing through biological tissues induces streams of secondary particles. Photonuclear reactions produce radiation with high linear energy transfer values and, consequently, a high value of radiation weighting factor (w_R). When irradiating thin layers, secondary electrons don’t have enough time to transfer all of their energy to the matter of the layer, due to their large range. The heavy particles produced in this process transfer their energy to the matter almost at the location of their production. As a result, the secondary heavy particles may greatly contribute in the equivalent dose, despite the low probability of photonuclear reactions. In this article, the average value of w_R is assessed for all types of radiation induced by bremsstrahlung when thin layers are irradiated.

Keywords:
relative biological effectiveness bremsstrahlung spectra radiation weighting factor photonuclear reaction products

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