Energy dependence of the proton-induced convoy electron yield

Abstract

In this work the convoy electron yield of protons penetrating a 60 nm carbon foil with energies in the range from 40 keV up to 400 keV was measured. A maximum yield at about 100 keV proton energy was found. The decrease of the yield to higher proton energies follows a power law with an exponent of n = 2.2. The convoy electron yield also decreases, while the fraction of neutralized projectiles increases. The results for energies above the maximum are discussed on the basis of electron capture by the protons on the backside of the foil.