Measurement of the hydrogen-tritium gJ-factor ratio

A hydrogen maser operating at fields of up to 16 G has been used as a spin-exchange detector of Zeeman transitions in the hyperfine spectra of hydrogen and tritium. The maser oscillates on the field-dependent π transition which is sensitive to the state of colliding atoms. Atomic magnetic moment or gJ-factor ratios were obtained from the measured Zeeman frequencies with the aid of the Breit-Rabi formula. Measurements were made at different values of magnetic field and an extrapolation was done to eliminate the effects of spin-exchange frequency shifts. The result is gJ (H)gJ (T)=1+(10.7±1.5)×10-9, in agreement with the theoretical predictions.