LOCAL SADDLES AND MAXIMA IN DOUBLE DIFFERENTIAL CROSS
       SECTIONS IN ION-ATOM/MOLECULE COLLISIONS

       B.S. Nesbitt, M.B. Shah, S.F.C. O'Rourke, D.S.F. Crothers
       and J. Geddes

             The School of Mathematics & Physics
              The Queen's University of Belfast 
                 Belfast BT7 1NN, N.Ireland  

 A recently constructed apparatus to permit measurements with
 a range of different targets including He and H$_{2}$ has been 
 used to study emissions at zero degrees. We have adopted the
 continuum-distorted-wave eikonal-initial-state (CDW-EIS) model
 to compare our theoretical calculations with our new observations.