EXPERIMENTAL-STUDY OF EXCITATION-FUNCTIONS AND ISOMERIC RATIOS FOR SOME HE-3-INDUCED REACTIONS ON NB-93 NEAR THE COULOMB BARRIER

The excitation functions for the reactions Nb-93(He-3, gamma)Tc-96, Nb -93(He-3, n)(95m), Tc-g, and Nb-93(He-3, xnypz alpha)Mo-93m, Nb-92m, N b-90 have been measured at projectile energies between 5 and 20 MeV by means of the activation technique. The isomeric ratios for Tc-95m,Tc- g have been deduced. Relevant experimental data are presented and int erpreted by using the new code COMPLET, which assumes the multiparticl e preequilibrium emission of photons, nucleons, and gamma particles wi th allowance for angular-momentum effects. The behavior of the measure d excitation functions near the Coulomb barrier is discussed. The esse ntial role of preequilibrium photon emission in the radiative-capture channel is established. The importance of preequilibrium gamma-particl e emission in (He-3, alpha xn) reactions is emphasized.