Polarization measurements of the 5.83→5.10 MeV gamma transition in N 14

Abstract

An experiment has been made to obtain information about the relative parity of the 5.83 MeV and 5.10 MeV states in N 14. Using the reaction C 13(p,γ)N 14 at the 1.47 MeV resonance, measurements have been made to determine the plane polarization of the 0.73 MeV gamma ray due to the transition from the J = 3,5.83 MeV state to the J = 2, 5.10 MeV state. If the transition is mainly dipole in character, as has been concluded by Warburton, Rose and Hatch from a Doppler shift measurement on the 0.73 MeV gamma ray, the results of the present measurements give conclusive evidence that it must be Ml (with possible small admixtures of E2) and, hence, that the 5.83 MeV and the 5.10 MeV state have the same parity. In as much as a preference for an odd-parity assignment of the 5.83 MeV state is indicated by previous work, this preference, then, is also for the 5.10 MeV, J = 2 state. Further polarization measurements on the Ni 60 1.17 MeV gamma radiation and the 0.42 MeV radiation following the Coulomb excitation of Ag 107/109 have been made in order to calibrate the polarimeter.