Energy straggling of hydrogen and helium ions in Al, C, and polystyrene at energies of tens and hundreds keV per nucleon

Abstract

Energy loss and straggling measurements in thin aluminum, carbon, and polystyrene films are performed for H‐ and He‐ions in the energy intervals ≈ 70 to 500 and ≈ 100 to 1200 keV, respectively. It is shown that the observed spread of the specific straggling experimental values for a given material may be significantly reduced by introducing corrections on nonuniformity of target thickness. Analysis of the results based on existing theories indicate that “charge‐exchange” and “correlative” mechanisms of straggling play an important and even dominant (for He‐ions) role at the energies near maximum of stopping power.