Magnetic dipole and quadrupole transitions in self-conjugate S-D shell nuclei

Electron scattering has been used to study the structure of the nuclei of 32S and 40Ca. The data for 32S were taken at ten incident electron energies and at scattering angles of 1800 and 162.40, yielding a range for the momentum transfer of 0.34 to 0.75 fm-1. The data for 40Ca were taken at six incident electron energies and scattering angles of 162.40 and 127.80, yielding a range of momentum transfer from 0.31 to 0.60 fm-1. Form factors for seven inelastic levels in 32S and two inelastic levels in 40Ca were extracted and compared to a harmonic oscillator shell model calculation to determine the multipolarities and radiative widths of the levels. The distribution of magnetic dipole and quadrupole strength in 32S is considerably fragmented compared to the lighter self-conjugate s-d shell nuclei. The presence of a magnetic dipole transition at 10.31 MeV in 40Ca is a clear indication of configuration mixing in the 40Ca ground state