Abstract
Resonant spin conversion on the ordered sites has been observed in CH 4 through the time dependence of T1 at 0.18 K. The increase in the A-F level splitting at low F-species concentration P F has been confirmed. Resonant E → F conversion has given a direct measurement of the E → F level splitting. T1 at fixed PF has been measured as a function of temperature to 80 mK for 9 x 10-4 < PF < 2 × 10-2