Circular Polarization Measurements inEu154

Abstract

The circular polarization of the 1.28-MeV gamma ray following the beta decay in ${\mathrm{Eu}}^{154}$ was measured by means of the transmission method. The anisotropy coefficient $A$ was found to be $A=-0.21\mathrm{}\pm 0.07$ which gives the $M2\mathrm{}$ to $E1\mathrm{}$ multipolarity admixture as $\delta =-0.07\mathrm{}\pm 0.08$ (standard deviations). This together with other information implies the $K$ value for the 1.4-MeV level in ${\mathrm{Gd}}^{154}$ is $K=1\mathrm{}$.