Energy distribution of electrons ejected from a thin carbon foil by alpha particles and fission products

Secondary electron spectra up to 3.5 keV electron energy arising from the passage of alpha particles and²⁵²Cf fission products through a 2μg/cm² carbon foil are measured for a forward (42°) and a backward (138°) angle of emission. The forward spectra induced by alpha-particles are compared to binary encounter calculations and to a gas target spectrum. Systematic differences in the shapes of the alpha particle and the fission product induced spectra are discussed. Total yields and mean energies of the secondary electrons are derived from the spectra.