Beta-NMR of short lived nuclei in liquid media for g-factor measurement

For the study of nuclear electromagnetic moments of unstable nuclei, the technique of the beta-ray detected nuclear magnetic resonance (beta-NMR) has been applied for many years. So far, in the beta-NMR measurement, solid materials have been used as a catcher in which objective unstable nuclei are stopped for NMR detection. One of the most important characteristics required for the catcher materials is that they maintain spin polarization for longer than the nuclear lifetime, which however depends on the combination of the material and the species of atomic nucleus. This sometimes makes it difficult to measure the nuclear moments even though the nuclear spin polarization is generated. We expect that the NMR detection in liquid samples is easier than in solid ones even with the beta-NMR as in the case of the conventional NMR, since the fast motion of molecules in solution averages the internal field distribution and reduces nuclear spin relaxation. Here, we demonstrate that the beta-NMR in liquid media is quite useful for the precise g-factor measurement from our recent results on ¹²B, ¹²N and ¹⁷N.