The level structure of¹³C around E_x=20 MeV studied by polarised neutron scattering from¹²C

Abstract

Analysing-power for elastic scattering of neutrons from 12C have been obtained at selected angles in small energy steps between incident energies of 15.55 and 17.35 MeV. The excitation energy, spin and parity of levels in 13C have been determined for excitation energies around 20 MeV via a phase-shift analysis of these data and of previously measured n-12C total cross section data. In addition, an auxiliary phase-shift analysis has been performed in the neutron energy range from 12 to 15 MeV. All experimental data are well reproduced by the phase shifts obtained. The need for further experimental data is pointed out.