Secondary electron emission from a thin carbon foil induced by equi-velocity protons and electrons of 0.5–3.5 MeV/u

The statistical distributions of the number of simultaneously forward-emitted secondary electrons (SEs) from a thin carbon foil have been measured with H0 and H+ projectiles of 0.5–3.5 MeV in coincidence with the foil-transmitted protons, irrespective of projectile incident charge state. From these results, the probabilities of the simultaneous emission of nn electrons and the SE yields by loss electrons have been evaluated. At energies of 2.5–3.5 MeV, the obtained emission probabilities and the SE yields induced by loss electrons are larger than the corresponding ones by protons of the same velocity. Furthermore, the material parameter is found to be almost constant and is slightly larger than that for the protons. On the other hand, the forward SE yields by loss electrons is decreasing to zero with decreasing the incident energy. This behavior is consistent with the range-energy relation of electrons in carbon.