Study of the Energy Levels ofCd112Using Nuclear Photoexcitation

Abstract

Elastic and inelastic scattering of monochromatic photons were used for studying nuclear energy levels in ${}_{}{}^{112}{}_{}{}^{}\mathrm{Cd}$; the photons were produced by thermal-neutron capture in iron. The energy of the resonance level was 7632 keV; it was found to decay to 19 known low-lying energy levels in ${}_{}{}^{112}{}_{}{}^{}\mathrm{Cd}$. The angular distributions of the elastic and inelastic lines were measured and the following spin-parity determinations were made (energy in keV, $J^{\pi }$): 617, $2^{+}$; 1223, $0^{+}$; 1429, $0^{+}$; 1468, $2^{+}$; 1869, $0^{+}$; 2832, $0^{+}$; 2850, $2^{+}$; 3110, 2; 3193, 2; 3247, 0; and 7632, $1^{-}$. The parity of the last level was directly determined by polarization measurements, while the parities of the other levels were inferred from the radiation strength of the corresponding high-energy transitions. The $\frac{M2\mathrm{}}{E1\mathrm{}}$ mixing ratio for one primary transition was found to be about 3 orders of magnitude higher than that predicted by the simple theory. The results of statistical analysis of the data are given.