Hyperfine Separation of Tritium

The hyperfine separation of tritium has been measured with respect to the hyperfine separation of hydrogen by comparing the frequency of the tritium maser with that of a hydrogen maser. The result is $\Delta \nu \left(\mathrm{T}\right)=1\mathrm{}516701470.8087\pm 0.0071$ Hz, where it is assumed that $\Delta \nu \left(\mathrm{H}\right)=1\mathrm{}420405751.8$ Hz. Wall shifts were measured for tritium and hydrogen for FEP Teflon at 35°C. For a spherical bulb, $d$ cm in diameter, the fractional wall shift for hydrogen is $-(3.61\mathrm{}\pm 0.54)\times \frac{{10}^{-10\mathrm{}}}{d}$, and for tritium it is $-(3.14\mathrm{}\pm 0.47)\times \frac{{10}^{-10\mathrm{}}}{d}$.