Resonances in the 15N(α,γ)19F Reaction Between Eα = 1.68 and 2.72 MeV

Abstract

Using the 15N(α,γ)19F reaction, the properties of 6 levels between 5.3 and 6.2 MeV in 19F have been studied. In conjunction with previously reported restrictions on spins for these levels, measurements of branching ratios, radiative widths, and angular distributions have been used to make the following spin–parity assignments; 5618 keV, 3/2−; 5938 keV, 1/2+; 6070 keV, 7/2+; 6088 keV, 3/2−; 6160 keV, 7/2−. The properties of these levels and that at 5336 keV have been compared in detail to the various shell model calculations done for 19F. The properties of the third Jπ = 7/2+ level at 6.07 MeV can be used to clear up some of the confusion caused by the first two Jπ = 7/2+ levels in 19F and the properties of the Jπ = 3/2− levels confirm the fact that the weak coupling model does not explain the negative parity states outside the K = 1/2− band.