The distribution of magnetic dipole transition strength in ${}_{}{}^{120}{}_{}{}^{}\mathrm{Sn}$ has been measured at excitations between 7.3 and 9.3 MeV using highly polarized tagged photons. A total M1 strength of Σ eV corresponding to B(M1↑)=8.$8_{-0.9}^{+1.1\mathrm{}}$${\mu }_0^2$ was found to be more or less uniformly distributed throughout the region. This result and previous polarized photon measurements in ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ and the Pb nuclei present a consistent picture of M1 strengths in closed-shell nuclei in terms of the required normalization for the spin nucleon g factors. Normalizations with respect to the bare nucleon values are 0.68±0.02 and 0.64±0.03 for the proton and neutron spin g factors, respectively.

• Received 6 July 1989

DOI:https://doi.org/10.1103/PhysRevC.40.R1097