Pseudoquadrupole Coupling Constants and Nuclear Moments of Several Promethium Isotopes

Abstract

Nuclei of several isotopes of promethium were aligned at low temperatures by a pseudoquadrupole interaction in cerium magnesium nitrate and by a magnetic hfs interaction in neodymium ethylsulfate. Pseudoquadrupole coupling constants were determined for ${\mathrm{Pm}}^{143}$, ${\mathrm{Pm}}^{144}$, and 5.4-day ${\mathrm{Pm}}^{148}$. Nuclear moments were derived for ${\mathrm{Pm}}^{143}$, 5.4-day ${\mathrm{Pm}}^{148}$, 41-day ${\mathrm{Pm}}^{148}$, and ${\mathrm{Pm}}^{149}$. The spins of 5.4-day ${\mathrm{Pm}}^{148}$ were found to be 1 and 6, respectively. Evidence was obtained for spin assignments of 6 to states in ${\mathrm{Sm}}^{148}$ at 1.90, 2.09, and 2.19 MeV. Measurements on ${\mathrm{Pm}}^{144}$ tend to confirm the validity of the temperature scale for cerium magnesium nitrate.