THEORETICAL FIVE-FOLD DIFFERENTIAL CROSS SECTION FOR THE IONIZATION OF H2 AND D2 BY FAST ELECTRON IMPACT P. Weck, B. Joulakian and P. A. Hervieux Laboratoire de Physique Moleculaire et des Collisions, Universite de Metz,1 rue Arago, 57078 Metz, France The five-fold differential cross section (5DCS) of the ionization of H2 and D2 by fast electron (4168 eV) impact is determined theoretically for a 100 eV ejected electron. Transitions between the lowest vibrational level of the 1 sigma g ground state of H2 and those of the fundamental 2 sigma g state of H2+ are considered.