Branching Ratios and Magnetic Dipole Transition Probabilities in Odd-ARotational Nuclei

Abstract

Branching ratios have been measured for gamma radiations from the second excited level in odd-$A$ rotational nuclei. The magnetic dipole transition probability for the first member of the cascade transition could thus be measured in terms of the known electric quadrupole transition probability for the crossover transition. Results are reported for ${\mathrm{Eu}}^{153}$, ${\mathrm{Gd}}^{155}$, ${\mathrm{Gd}}^{157}$, ${\mathrm{Er}}^{167}$, ${\mathrm{Yb}}^{173}$, ${\mathrm{Lu}}^{175}$, ${\mathrm{Hf}}^{177}$, and ${\mathrm{Ta}}^{181}$. Electric quadrupole transition probabilities could also be determined in some cases where mixing ratios $\frac{E2}{M1}$ were known. The $M1$ and $E2$ transition probabilities are compared with the corresponding quantities for the transition from the first excited state to the ground state. The ratios of $M1$ transition probabilities for the two transitions are in good agreement with the values predicted for collective rotational motion. The gyromagnetic ratios of the collective motion ${g}_{R}$ for odd-$Z$ nuclei are found to be consistently higher than the ${g}_{R}$ for odd-$N$ nuclei.