Wire-sealed atomic gas cells for noble-gas nuclear magnetic resonance applications

We fabricate a wire-sealed atomic gas cell and evaluate its advantages over a conventional torch-sealed cell for noble-gas nuclear magnetic resonance (NMR) applications. Wire sealing is performed by sweeping a resistively heated wire across a long stem tube at a constant speed. This approach adapts a previously reported technique for dividing a prefilled vapor cell into smaller cells. In our implementation, an XYZ translation stage precisely controls the wire motion. This reliably yields a predefined stem geometry, minimizes variations inherent to manual torch positioning, and thereby enhances geometric reproducibility. To quantitatively verify the geometric enhancements of the cells, we perform free induction decay measurements on both torch-sealed and wire-sealed Rb-Xe cells. Measurements of 129Xe transverse relaxation under applied magnetic field gradients indicate that, for cells with narrow stem apertures, the contribution of stem-induced asymmetry to the relaxation remains comparable despite visibly different stem heights. In contrast, measurements of 131Xe quadrupole splittings as a function of the bias magnetic field direction reveal that the asymmetry parameter of the wire-sealed cell, ηw = 0.13, is markedly smaller than that of the torch-sealed cell, ηt = 0.77. Our results demonstrate that wire sealing enables reproducible production of cells with reduced geometric asymmetry, offering a path toward suppressing asymmetry-induced systematic errors in NMR-based precision measurements.