ELECTRON CORRELATION-EFFECTS IN THE DISSOCIATIVE IONIZATION OF H2

The dissociative and non-dissociative ionization of H-2 by electron impact has been measured up to 1 keV incident energy using a pulsed electron beam and pulsed ion extraction technique in conjunction with a time-of-flight spectrometer and relative flow technique. These data represent the first accurate measurement on the dissociative ionization of H-2 by electron impact over such a large energy range. It has been shown that the ratio, R*, of the dissociative ionization cross section to non-dissociative ionization cross section in H-2 serves as a useful parameter in probing the electron correlation effects. A comparison of the value of R* obtained by electron impact with those obtained by proton and antiproton impact shows strong dependence on the sign of the projectile charge.