The Nuclear Mechanical Moment of Lanthanum from Hyperfine Structure

Abstract

The hyperfine structure of the lines $\lambda \lambda 5212$, 5234 and 6250 of ${\mathrm{La}}_{\mathrm{I}}$ has been observed with a flint glass spectrograph crossed with Fabry-Perot etalons. A liquid-air cooled Schüler tube was used as a source. The number of components, the intensity ratios and the interval spacing are all in good agreement with the value $I=\left(\frac{7}{2}\right)\left(\frac{h}{2\pi }\right)$ for the nuclear mechanical moment.