The Hyperfine Structure and Nuclear Moments of the Stable Chlorine Isotopes

Abstract

The hyperfine structure of the $^{2}P_{\frac{3}{2}}$ ground states of ${\mathrm{Cl}}^{35}$ and ${\mathrm{Cl}}^{37}$ is investigated by the atomic beam magnetic resonance method. Values of the magnetic dipole interaction constant, $a$, and the electric quadrupole interaction constant $b$ are found to be ${a}_{35}=205.288\ifmmode\pm\else\textpm\fi{}0.010$ Mc/sec., ${a}_{37}=170.686\ifmmode\pm\else\textpm\fi{}0.010$ Mc/sec., ${b}_{35}=55.347\ifmmode\pm\else\textpm\fi{}0.020$ Mc/sec., ${b}_{37}=43.256\ifmmode\pm\else\textpm\fi{}0.020$ Mc/sec.No octupole interaction is required to account for the experimental results. A simple method is introduced for calculating accurate values of the electric quadrupole moments $Q$ from these data and the corresponding values are ${Q}_{35}=\ensuremath{-}(0.0795\ifmmode\pm\else\textpm\fi{}0.0005)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}24}$ ${\mathrm{cm}}^{2}$ and ${Q}_{37}=\ensuremath{-}(0.0621\ifmmode\pm\else\textpm\fi{}0.0005)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}24}$ ${\mathrm{cm}}^{2}$.This method can be extended to many other cases for which the interaction constants $a$ and $b$ and the nuclear gyromagnetic ratio are known. Experimental details are given for the production and detection of beams of atomic chlorine.