Temperature Dependence of Hyperfine Pressure Shifts. II. Nitrogen in Helium, Neon, and Molecular Nitrogen

Spin-exchange optical pumping has been used to measure the hyperfine pressure shift of atomic nitrogen in helium, neon, and molecular nitrogen as a function of temperature. In the range 70-500°C, the change in pressure shift was linear with temperature, and the values were for helium, -(0.1±0.1) ×${10}^{-4\mathrm{}}$; for neon, (0.6±0.1) ×${10}^{-4\mathrm{}}$; and for molecular nitrogen (1.4±0.3)×${10}^{-4\mathrm{}}$ in units of Hz/Torr°C. The measurements also give $A=10\mathrm{}450929.4\pm 1.8$ Hz for the free atom. The quadrupole interaction constant was also measured and found to be independent of temperature and pressure. The value was $B=1.3\mathrm{}\pm 0.5$ Hz.