SPIN-ISOSPIN STRENGTH DISTRIBUTIONS IN F-P SHELL NUCLEI - A STUDY OF THE V-51(N,P) AND CO-59(N,P) REACTIONS AT 198 MEV

The (n,p) reaction has been studied on the nuclei V-51 and Co-59 at an energy of 198 MeV. Spectra were measured at laboratory angles of 0-degrees, 4-degrees, 8-degrees, 12-degrees, 16-degrees, and 20-degrees up to an excitation energy of 35 MeV in the final nuclei Ti-51 and Fe-59. A multipole analysis of the data up to 30 MeV was carried out to identify Gamow-Teller (GT) (DELTAL = 0, DELTAJ(pi) = 1+) and spin-dipole (DELTAL = 1, DELTAJ(pi) = 0-, 1-, 2-) strengths. GT strength is concentrated in a resonance with centroid energy of 5.2 MeV in Ti-51 and 4.1 MeV in Fe-59. The spin-dipole strength appears as a broad resonance with centroid energy about 16 MeV in both nuclei. Shell model calculations of the GT strength reproduce the energy distribution reasonably well, but the calculated strength exceeds the measurement by a factor of about 4.