Isomeric Cross Sections and Yield Ratios of (d,p) Reactions below 15 MeV

Absolute cross sections and isomeric yield ratios of ($d,p$) reactions in ${\mathrm{Co}}^{59}$, ${\mathrm{Y}}^{89}$, ${\mathrm{Rh}}^{103}$, ${\mathrm{Pd}}^{110}$, ${\mathrm{Cd}}^{114}$, ${\mathrm{Cs}}^{133}$, ${\mathrm{Ta}}^{181}$, ${\mathrm{Re}}^{187}$, and ${\mathrm{Pt}}^{196}$ have been determined between ∼4 and ∼15 MeV. The isomer ratios are found to increase gradually with bombarding energy from values at lower energies which are only slightly greater than the ratios for the production of the same isomeric pairs by the ($n,\gamma$) reaction. The qualitative features of ($d,p$) isomer ratios are discussed. Isomer ratios have been calculated at 15 MeV for seven ($d,p$) reactions in even-even targets by using distorted-wave Born approximation to obtain the initial angular-momentum distributions and computing the effects of subsequent gamma-ray cascades leading to the observed isomeric states. Agreement with experiment of the order of 15-20% is achieved. The effects of various cascade treatments on the agreement of the calculated isomer ratios with experiment are discussed.