Inner conversion process of electric dipole transitions in180Hf and182W

The conversion electron process of the retarded electric dipole transitions of 58keV in¹⁸⁰Hf and 67, 116, 152, 156 and 222 keV in¹⁸²W have been studied by means of high resolution double focusing beta-ray spectrometers. No penetration effects were found in the conversion process of the retarded 58 keV and 67, 116 and 222 keV E1 transitions. While the retarded 152 and 156 keV transitions in¹⁸²W show an anomalous internal conversion ratios compared with theoretical values. Implications of the results for current nuclear theories are discussed.