On the Critical Impact of HF Power Drifts for Miniature Helium-Based NMR Gyroscopes

Nuclear magnetic resonance (NMR) gyroscopes constitute a promising technology for miniaturizing navigation-class gyroscopes. We analyze here a configuration based on a mixture of helium-3 and helium-4. We show that frequency shifts due to the circulation of coherence between helium atoms in metastable and fundamental states have a large impact on the gyroscope drift. In order to reach navigation-class, the high-frequency source used to ignite the plasma is required to have a long-term power stability better than ppm.