Direct absorption measurement of the spin–orbit splitting and 2P1/2 radiative lifetime in atomic fluorine (2p5)

Abstract

We report the first direct measurement of the fluorine atom ground state fine structure transition. The transition was measured by diode laser absorption spectroscopy. The position of the (J=3/2, F=2)→(J=1/2, F=1) absorption line was measured with high precision relative to a pure rotational transition in H2O, establishing the fine structure energy splitting as 404.082 cm−1 ±0.025. The measured transition probability for the hyperfine component is 1.26×10−3 s−1 (±25%), yielding a radiative lifetime of 660 s for the 2P1/2 fine structure level.