Radioactive nuclide production and isomeric state branching ratios in P + W reactions to 200 mev

摘要

Calculations of nuclide yields from spallation reactions usually assume that the products are formed in their ground states. We are performing calculations of product yields from proton reactions on tungsten isotopes that explicitly account for formation of the residual nuclei in excited states. The Hauser-Feshbach statistical/preequilibrium code GNASH, with full accounting for angular momentum conservation and electromagnetic transitions, is utilized in the calculations. We present preliminary results for isomer branching ratios for proton reactions to 200 MeV for several products including the 31(minus)y, 16+ state in (sup l78)Hf and the 25-d, 25/2(minus) state in (sup 179)Hf. Knowledge of such branching ratios, might be important for concepts such as accelerator production of tritium that utilize intermediate-energy proton reactions on tungsten.