Hyperfine Structure in the Inversion Spectrum ofN14H3by a New High-Resolution Microwave Spectrometer

The hyperfine structure of the inversion spectrum of ${\mathrm{N}}^{14}$ ${\mathrm{H}}_3$ has been reexamined with an ultra-high resolution spectrometer. Lines whose total width at half-maximum is seven kc-sec have been obtained in this spectrometer. Such narrow lines allow resolution of magnetic hyperfine structure caused by reorientation of the spins of the hydrogen nuclei. The new structure has been satisfactorily explained to within the experimental error of about 1 kc/sec by considering the various interactions of the magnetic moments of the hydrogen nuclei with the molecular fields. The interaction energy of the nitrogen nucleus has been remeasured with higher resolution than was possible previously, and indications were found that $\mathrm{}\left|\mathrm{eqQ}\right|\mathrm{}$ for the lower inversion state is larger by about 0.01% than that for the upper state. The sign of $\mathrm{eqQ}$ was directly determined to be negative. A theoretical treatment of the magnetic interactions has been made which is slightly different from that which has previously been used. The method allows some simplification of the form of the magnetic interactions.