Energy spectra of secondary electrons induced by fast ions under channeling conditions

We have studied simple aspects of the energy spectra of ion-induced secondary electrons emitted from single crystals under channeling conditions. The energy spectra for Si and GaAs targets, measured at a backward angle of 180° for various incident ions over a 2–8 MeV/amu energy range, showed a constant decrease in the electron yield over certain keV energy regions when channeling occurred. This behavior was interpreted as a decrease in the effective target thickness, resulting from the ion-beam shadowing effect near crystal surfaces