Pulsed-Beam Measurements of the NucleargFactors of the 2+ Rotational States in Neodymium-150, Dysprosium-162 and -164, Erbium-166, -168, and -170, and Tungsten-186

The nuclear $g$ factors and mean lives of the 2+ rotational states of ${\mathrm{Nd}}^{150}$, ${\mathrm{Dy}}^{162}$, ${\mathrm{Dy}}^{164}$, ${\mathrm{Er}}^{166}$, ${\mathrm{Er}}^{168}$, ${\mathrm{Er}}^{170}$, and ${\mathrm{W}}^{186}$ have been measured by the pulsed-beam technique. The time differential precession of the angular distribution of the de-excitation $\gamma$ radiation was measured following Coulomb excitation by a pulsed proton beam. Metallic neodymium targets and dysprosium-copper and erbium-copper eutectic targets were used at about 900°C. Paramagnetic correction factors for free tripositive ions were used in the $g$-factor calculations. Strong perturbations causing an exponential attenuation of the anisotropy of the angular distribution were observed in the liquid targets. These perturbations are interpreted to be magnetic in character, and the $4f$-electron-shell spin-lattice relaxation times are determined. A metallic tungsten target at room temperature was used for the ${\mathrm{W}}^{186}$ experiments. The $g$ factor and mean-life results are: $g=0.310\mathrm{}\pm 0.021$, $\tau =2.191\mathrm{}\pm 0.034$ nsec for the 132-keV state in ${\mathrm{Nd}}^{150}$; $g=0.362\mathrm{}\pm 0.024$, $\tau =3.157\mathrm{}\pm 0.050$ nsec for the 81-keV state in ${\mathrm{Dy}}^{162}$; $g=0.321\mathrm{}\pm 0.025$, $\tau =3.444\mathrm{}\pm 0.054$ nsec for the 73-keV state in ${\mathrm{Dy}}^{164}$; $g=0.329\mathrm{}\pm 0.027$, $\tau =2.696\mathrm{}\pm 0.042$ nsec for the 81-keV state in ${\mathrm{Er}}^{166}$; $g=0.344\mathrm{}\pm 0.028$, $\tau =2.664\mathrm{}\pm 0.042$ nsec for the 80-keV state in ${\mathrm{Er}}^{168}$; $g=0.329\mathrm{}\pm 0.025$, $\tau =2.734\mathrm{}\pm 0.042$ nsec for the 79-keV state in ${\mathrm{Er}}^{170}$; and $g=0.351\mathrm{}\pm 0.030$, $\tau =1.61\mathrm{}\pm 0.03$ nsec for the 122-keV state in ${\mathrm{W}}^{186}$.