LOW-ENERGY POLARIZED-PROTON CAPTURE ON LI-6

We have measured the thick-target yield and analyzing power for the Li -6((p) over right arrow, gamma) reaction to the ground and first excit ed state of Be-7 below E(p)=80 keV. High-purity-germanium detectors we re used to acquire data at five angles from theta=0 degrees to 124 deg rees. For both states the yield, integrated from the beam energy of 80 keV down to 0 keV, is nearly isotropic and the integrated analyzing p ower shows only small deviations from zero. This is taken as an indica tion that, unlike the case of the Li-7((p) over right arrow,gamma(0))B e-8 reaction, the p-wave-capture process is unimportant compared to th e s-wave process. Transition-matrix-element analyses of the ground-sta te data yield p wave contributions of a few percent. Under the assumpt ion of a constant astrophysical S factor, consistent with direct s-wav e capture, a value of S=(2.69+/-0.54)x10(-5) MeV b has been deduced.