Multistep charge-exchange reactions at energies up to 120 MeV Original Research Article

Multistep direct (MSD) cross sections are calculated according to the theory of Feshbach, Kerman and Koonin for charge-exchange reactions to the continuum. The theory is modified to include the non-DWBA matrix elements as well as both the coherent vibrations and the incoherent particle–hole excitations. A complete analysis of the charge-exchange (p,xn) reaction in zirconium at energies from 25 MeV to 120 MeV is presented. It is shown that distinction between one-step cross sections to unbound and to bound final particle–hole states is important. Only the latter are folded into the MSD cross sections.