The cross sections for the double ionization, ionization plus excitation, and double excitation of H2 by electrons and protons in the range of 350 to 3500 keV/amu have been measured. In all cases, the cross section for electron bombardment was greater than that for equivelocity proton bombardment. The results are discussed in terms of first and second Born processes and interferences between the two.

No abstract

No abstract

No abstract

We performed a fully differential experimental and theoretical study on ionization of He in intermediate-energy collisions with protons for a small projectile coherence length. Data were taken for an ejected electron energy corresponding to a speed close to the projectile speed (velocity matching). In the fully differential angular electron distributions, a pronounced double-peak structure, observed previously for a coherence length much larger than the atomic size, is much less pronounced in the current data. This observation is interpreted in terms of interference between first-and higher-order transition amplitudes. Although there is large quantitative disagreement between experiment and theory, the qualitative agreement supports this interpretation.