Energy loss, angular distributions and charge fractions of low energy hydrogen transmitted through thin carbon foils

Abstract

Abstract The energy loss, angular distributions and charge fractions of hydrogen transmitted through thin carbon foils in the energy range 200 ≤ E ≤ 3000 eV have been measured. The values of the stopping power constant equal 4.18 ± 0.30 and 4.38 ± 0.34 (eV)1/2 cm2/μg, where the two values are the result of using the most probable final energy and the average final energy, respectively. These values agree well with the theoretical value of 4.09 (eV)1/2 cm2/μg. The measured angular distributions were narrower than those predicted by the theory of Meyer except at the highest energies and thinnest foils. The fractions of particles emerging from the foil as positive ions, f+ , and negative ions, f −, as a function of the exit energy are given by f+ (%) = 3.0 E and f− (%) = 2.3 E, where E is in keV.