The 54Fe(3He,t)54Co reaction at 70 MeV, Gamow-Teller strength

The 54Fe(3He,t)54Co reaction has been studied at 70 MeV with an energy resolution around 70keV (FWHM). The triton spectra are characterized by sharp peaks up to 10 MeV excitation energy superimposed on a continuum. Most of the sharp peaks have a forward-peaked angular distribution and 38 peaks or groups of peaks are found to have an angular distribution corresponding to an angular momentum transfer of 2. Model considerations lead to the conclusion that most of these states are 1+ states. A shell-model calculation with parameters that account for the Gamow-Teller strength distribution in 48Ca-48Sc divides the β-strength in 54Co in a ratio 5.7:6.8:1.3 for the T = 0.1 and 2 states. A comparison is made with the 1+ spectrum in 54Mn (T = 2 states) and a tentative assignment of T = 2 states in 54Co is reached. The cross section has been calculated for the 0+, 1+ and 3+ states in 54Co assuming a pure (πf-1sub(7/2)νf-1sub(7/2)) configuration. A second-order finite-range DWBA is used and the conclusions are that the (3He,α,t) and (3He,d,t) processes give significant contributions to the cross sections. (orig.)