Extrapolated ranges and stopping cross-sections for alpha particles (0.4-5.5 MeV) in normal and cyclo-hydrocarbons. I. Gases and vapours

The stopping power and ranges of methane, ethane, ethene, n-propane, cyclopropane, n-butane, n-pentane, cyclopentane, n-hexane and benzene for ²⁴¹Am alpha particles have been measured by the indirect method in which the residual energy is measured as a function of thickness of absorber traversed. Analytical expressions to allow numerical calculations of extrapolated ranges and the stopping cross-sections of the materials investigated are presented and the results are compared where possible with other published results. The standard error of presented range values is 1-2% and that of stopping cross-sections is 2-4%. This work supports the application of the Bragg rule for single and double bonded hydrocarbons.