  With the increasing interest in using (d,p) transfer reactions to extract
structure and astrophysical information, it is important to evaluate the
accuracy of common approximations in reaction theory. Starting from the
zero-range adiabatic wave model, which takes into account deuteron breakup in
the transfer process, we evaluate the importance of the finite range of the n-p
interaction in calculating the adiabatic deuteron wave (as in Johnson and
Tandy) as well as in evaluating the transfer amplitude. Our study covers a wide
variety of targets, as well as a large range of beam energies. Whereas at low
beam energies finite-range effects are small (below 10%), we find these effects
to become important at intermediate energies (20 MeV/u) calling for an exact
treatment of finite range in the analysis of (d,p) reactions measured at
fragmentation facilities.
