Magnetic-Resonance Studies of Gaseous Atomic Hydrogen Confined at 1 K and Zero Magnetic Field

Abstract

High-resolution magnetic-resonance studies are reported for an atomic hydrogen gas confined in a closed glass bulb with superfluid-$^{4}\mathrm{He}$-coated walls in zero magnetic field and for $1.0<T<1.3$ K. H atoms at low density, ${10}^{11}<{n}_{\mathrm{H}}<5\ifmmode\times\else\texttimes\fi{}{10}^{12}$/${\mathrm{cm}}^{3}$, in the equilibrium helium vapor, are found to recombine into molecules in times or order ${10}^{3}$ s. Results are presented for the rate constant for recombination, the diffusion constant and pressure shift for H in $^{4}\mathrm{He}$, and for ${T}_{1}$ due to H-H spin exchange.