Observation of electron capture into continuum states of neutral atoms

Energy spectra of electrons ejected in the forward direction from 75-keV/amu He/sup 0/-He,Ar collisions have been measured in coincidence with the charge-state--selected outgoing projectiles He/sup 0/, He/sup +/, and He/sup 2+/. The appearance of the cusp-shaped peak in the electron spectrum in coincidence with He/sup 0/ gives the first clear experimental evidence that electron capture into the continuum states (ECC) occurs in collisions where the projectile is a neutral atom. The ECC for He/sup 0/ impact is characterized by a considerably smaller width of the cusp peak than for He/sup +/ impact.