HYPERFINE-STRUCTURE AND ISOTOPE SHIFT IN THE FAR-INFRARED GROUND-STATE TRANSITIONS OF ATOMIC OXYGEN

We have investigated the P-3(2) --> P-3(1) and P-3(1) --> P-3(0), atomic fine-structure transitions in isotopically enriched samples of oxygen by means of tunable far-infrared spectroscopy. Accurate frequency measurements (a few parts in 10(8)) were made for all three stable isotopes and the O-17 hyperfine structure was resolved. The experimental values for the isotopic shift of O-18 relative to O-16 for the J = 2 --> J = 1 and J = 1 --> J = 0 fine-structure transitions are in agreement with theoretical calculations.