Hyperfine Structure of the 24-kev Transition inSn119

Abstract

The Zeeman splittings of the two lower levels of ${\mathrm{Sn}}^{119}$ were measured by the method of recoilless emission and resonant absorption of the 24-kev $\ensuremath{\gamma}$ radiation emitted in the decay of ${\mathrm{Sn}}^{119m}$. The source consisted of ${\mathrm{Sn}}^{119m}$ diffused into 0.002-in. iron foil. Grey tin metal at a temperature of \ensuremath{\sim}10\ifmmode^\circ\else\textdegree\fi{}C was used as the absorber. The magnitude of the internal magnetic field at the source nuclei was sufficient to allow resolution of the six absorption peaks resulting from the ${\frac{3}{2}}^{+}\ensuremath{\rightarrow}{\frac{1}{2}}^{+}$ $M1$ transition. Measurements were made with the internal fields aligned by application of a small external magnetic field; in this manner the central line of each triplet could be enhanced or suppressed by observing the radiation emitted either perpendicular or parallel to the external field. The splitting parameters obtained from the measurements yield a value of 0.672\ifmmode\pm\else\textpm\fi{}0.025 nm for the magnetic moment of the first excited state of ${\mathrm{Sn}}^{119}$, and an effective magnetic field at the tin nuclei in the iron environment of 78.5\ifmmode\pm\else\textpm\fi{}2.0 koe. The chemical shift is such that the transition energy in the source is less than that in the absorber by (4.24\ifmmode\pm\else\textpm\fi{}0.04)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}8}$ ev. Within the limits of measurement, no quadrupole coupling was observed.