Energy loss of monoenergetic positrons passing through a thin carbon foil

In this paper, the measurements of energy loss and energy loss straggling for 1–10keV monoenergetic positrons passing through thin carbon foils of different thicknesses ranging from 1.0 to 5.0μg/cm2 are presented. The stopping power dE/dx and positron transmission coefficient as a function of incident positron energy and foil thickness have also been investigated. Particularly, the experimental results obtained are compared with those from Monte Carlo simulation and theory with a view to providing a way to determine the actual thickness of a carbon foil. The ratio of the energy straggling to the foil thickness seems to have a linear relation with the beam energy.