Appendix 2 - Experimentally determined mass attenuation coefficients

Summary

Data from five tables of experimental values of mass attenuation coefficients are included in the information presented here. The data of Cooke and Stewardson (1964) extend from 730 eV to 1.74 keV and are given in their entirety (table A2.1). Hughes and Woodhouse (1966) reported data in the energy region 1.3–22 keV and made a comparison between their data and theoretical and experimental data reported elsewhere in the literature. A few additional values at low photon energies were included in Hughes et al. (1968). The whole of their data is included here (table A2.2).

Hopkins (1959) has reported data in the energy range 6–40 keV for aluminium and copper, and in the range 6–14 keV for four other elements. This is presented in table A2.3. To fill out the information in the range 10–25 keV we have drawn on the earlier data of Laubert (1941) (table A2.4).

A detailed set of experimental data, with estimated errors, was published by McCrary et al. (1967) extending from 24 to 131 keV, and is reproduced in table A2.5.

The full range of data given in this appendix thus extends from 730 eV to 131 keV. A great deal of additional experimental data, both within and outside this energy range, exists in the literature. A survey of measurements extending from 10 eV to 100 GeV has been given by Hubbell (1971), covering the period 1909 to June 1971, including a complete bibliography.