Identification of the Metastable Autoionizing States in Potassium with a New rf Spectroscopic Technique

Abstract

A new magnetic resonance method has been developed for studying the metastable autoionizing states previously observed in the alkali elements. With this technique, two distinct but nearly degenerate metastable states were discovered in potassium: a $\left(3\mathrm{}{p}^{5}4s3d\right){}_{}{}^4{}_{}{}^{}F_{\frac{9}{2}}^{}{}_{}{}^{}$ state and a $\left(3\mathrm{}{p}^{5}4s4p\right){}_{}{}^4{}_{}{}^{}D_{\frac{7}{2}}^{}{}_{}{}^{}$ state. In addition, a value of $Q=(5.3\mathrm{}\pm 0.8)\times {10}^{-26\mathrm{}}$ ${\mathrm{cm}}^2$ (uncorrected for the Sternheimer effect) has been obtained for the ${\mathrm{K}}^{39}$ nucleus. The production of polarized electrons and nuclei from these states is also discussed.