Resonances in the ¹⁵N(α,γ)¹⁹F Reaction Between <i>E</i>_α = 1.68 and 2.72 MeV

Abstract

Using the 15 N(α,γ) 19 F reaction, the properties of 6 levels between 5.3 and 6.2 MeV in 19 F 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 19 F. The properties of the third J π = 7/2 + level at 6.07 MeV can be used to clear up some of the confusion caused by the first two J π = 7/2 + levels in 19 F and the properties of the J π = 3/2 − levels confirm the fact that the weak coupling model does not explain the negative parity states outside the K = 1/2 − band.