Observation of Gamow-Teller Strength Distribution in the Reaction 7lGa(p,n)71Ge for Application to Solar-Neutrino Detection

The reaction /sup 71/Ga(p,n) /sup 71/Ge has been studied at E/sub p/ = 35 MeV with a high-resolution time-of-flight system. Individual cross sections to the states at 0.0, 0.175, and 0.500 MeV, which are directly related to solar-neutrino absorption in a proposed /sup 71/Ga detector, have been determined. The cross sections for the 0.0- and 0.175-MeV states are nearly equal, contrary to systematics in this mass region. As a result the absorption of solar neutrinos is estimated to be > or approx. =40% greater than previously calculated.