Production of v_e∼v_p Electrons from Thin Carbon Foils Bombarded with Hydrogen Molecular Ions (H₂⁺, H₃⁺), H⁺ and ³He⁺

Abstract

Electron spectra have been measured with 0.8 MeV/amu H⁺, ³He⁺, H₂⁺ and H₃⁺ ion bombardments of thin foils (2–20 μg/cm²) at observation angles 15–30°. Large peaks, with speeds v_e close to the projectile speed v_p, have been observed even at these large angles for thinner foils with H₂⁺ and H₃⁺. The molecular enhancement for the yield of v_e∼v_p electrons per proton for H₃⁺ is always larger than that for H₂⁺ and the molecular enhancement for both H₂⁺ and H₃⁺ decreases with increase of foil thickness, disappearing at foil thicknesses \gtrsim15 μg/cm². By comparing data for molecular projectiles (H₂⁺, H₃⁺) with data for atomic projectiles (H⁺, ³H⁺), it is concluded that the molecular enhancement for the yield of v_e∼v_p electrons is consistent with the electron loss model.