The 13C(3He,n0)15O reaction at 1.4 to 5.8 MeV

Abstract

Excitation functions at 0°, 90° and 150° for the ground state neutron group from 13C(3He, n)15O have been measured for 3He bombarding energies from 1.40 to 5.80 MeV. The 0° yield curve shows a prominent peak of 300 keV width at E3He = 2.0 MeV and more complex structure at higher energies with several maxima. The 90° and 150° excitation functions show three and two broad peaks respectively superimposed on slowly rising cross sections. Twelve angular distributions were measured at 1.70, 1.96, 2.27, 2.66, 2.96, 3.27, 3.44, 3.83, 4.40, 4.67, 5.00 and 5.35 MeV bombarding energy. Below 2.3 MeV bombarding energy, the shape of the angular distribution changes radically with increasing energy. Above 2.7 MeV, the angular distributions all show a strong 0° peak and a second smaller maximum at about 100°. Analysis of the angular distributions into sums of Legendre polynomials indicates resonances in the reaction at about 2.0 and 3.25 MeV bombarding energy. Above 3 MeV, the forward peak of the angular distributions can be well fitted by Newns’ double stripping theory.