Electron backscattering. Implication to electron dosimetry

Plane-parallel electron chambers have structures made of plastic materials of low atomic number which do not provide the same scattering into the sensitive volume as water and suitable correction factors are therefore required to allow for this effect. Hunt et al. (1988) measured electron backscatter in low atomic number materials and this data was, in this work, analyzed together with the experimental data obtained for higher atomic number materials published earlier (Klevenhagen et al., 1982). It was found that both sets of data correlate well and fit to an empirical exponential expression for which the necessary calculation parameters were derived. This expression enables suitable backscatter correction factors to be calculated for materials of atomic numbers between 4 and 82, including plastics, and electron energies between 3 and 35 MeV. The deficiency of backscatter was evaluated for the most popular materials used in the construction of electron chambers and this data may be used for corrections.