Effective atomic numbers of different types of materials for proton interaction in the energy region 1 keV–10 GeV

Abstract

The effective atomic numbers (Zeff) of different types of materials such as tissues, tissue equivalents, organic compounds, glasses and dosimetric materials have been calculated for total proton interactions in the energy region 1keV–10GeV. Also, effective atomic numbers relative to water (ZeffRW) have been presented in the entire energy region for the materials that show better water equivalent properties. Some human tissues such as adipose tissue, bone compact, muscle skeletal and muscle striated have been investigated in terms of tissue equivalency by comparing Zeff values and the better tissue equivalents have been determined for these tissues. With respect to the variation of Zeff with kinetic energy, it has been observed that Zeff seems to be more or less the same in the energy region 400keV–10GeV for the given materials except for the photographic emulsion, calcium fluoride, silicon dioxide, aluminum oxide and Teflon. The values of Zeff have found to be constant for photographic emulsion after 1GeV, for calcium fluoride between 1MeV and 1GeV and for silicon dioxide, aluminum oxide and Teflon between 400keV and 1GeV. This constancy clearly shows the availability of using Zeff in estimating radiation response of the materials at first glance.