Internal Conversion Electrons Following Coulomb Excitation of Highly Deformed Odd-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>A</mml:mi></mml:math>Nuclei

Abstract

The internal conversion electrons emitted following Coulomb excitation of ${\mathrm{Eu}}^{153}$, ${\mathrm{Dy}}^{161}$, ${\mathrm{Dy}}^{163}$, ${\mathrm{Ho}}^{165}$, ${\mathrm{Tm}}^{169}$, ${\mathrm{Lu}}^{175}$, and ${\mathrm{Ta}}^{181}$ have been measured. The relative intensities of the decay transitions from the first two rotational states of these isotopes have been compared with the predictions of the rotational model of Bohr and Mottelson. In general, there is good agreement between the experiment and theory; however, the results for the Dy isotopes indicate some disagreement which is outside the experimental uncertainty. For ${\mathrm{Eu}}^{153}$, ${\mathrm{Dy}}^{163}$, and ${\mathrm{Lu}}^{175}$ transitions involving intrinsic states were observed in addition to the rotational transitions. The reduced $E2$ transition probabilities for these intrinsic transitions are appreciably larger than single-particle estimates. The first rotational state in ${\mathrm{Lu}}^{176}$ was observed with a natural Lu target. The data indicate that this transition is predominantly $M1$.