  We study the ionization process involving antiproton and hydrogen in the
energy range between 0.1 keV to 500 keV, using single center close coupling
approximation. We construct the scattering wave function using B-spline bases.
The results obtained for ionization of atomic hydrogen are compared with other
existing theoretical calculations as well as with the available experimental
data. The present results are found to be encouraging. We also employed this
method to study the ionization of ionized helium in the energy range between 1
and 500 keV. On comparision, the present results are found to interpret well
the cross section values calculated using other theories.
