N14S324gJFactor Measured by an Atomic-Beam Universal-Detector Technique

The atomic-beam magnetic-resonance technique has been used to measure the $g$-factor ratio of the ground state of nitrogen to the ground state of potassium. The result is $\frac{g_J({\mathrm{N}}^{14}, {}_{}{}^4{}_{}{}^{}S_{\frac{3}{2}}^{}{}_{}{}^{})}{g_J({\mathrm{K}}^{39}, {}_{}{}^2{}_{}{}^{}S_{\frac{1}{2}}^{}{}_{}{}^{})}=0.999\mathrm{}9196\left(20\right)\mathrm{}$, where the quoted error represents the 90% confidence level. Combining this result with that of other researchers, we find the absolute $g_J$ factor for nitrogen to be $g_J({\mathrm{N}}^{14}, {}_{}{}^4{}_{}{}^{}S_{\frac{3}{2}}^{}{}_{}{}^{})=2.002\mathrm{}134\left(5\right)\mathrm{}$. This value is in much better agreement with the result of a recent calculation carried out according to the theory of Kambe and Van Vleck than is the earlier measured value, which was obtained by electron paramagnetic resonance. The discrepancy between experiment and theory is reduced from 13.5 ± 2 to 4 ± 2.5 ppm. The atomic nitrogen was generated in an electrodeless discharge and detected with a new mass-spectrometer universal detector; this latter instrument is described in some detail.