State Key Laboratory Of Precision Spectroscopy

Halogen atoms/molecules play an important role in physics,chemistry,and environmental science.Atomic structure of halogen is useful for the study of chemical lasers;halogen molecules may be used for the variation measurement of fundamental physical constants;the fine and hyperfine structure parameters may be used to improve atomic calculation.The hyperfine structure of fluorine atoms and the level splitting of halogen atoms in external magnetic fields are studied in this thesis.The high resolution absorption spectrum of neutral fluorine（F I）was observed around 800 nm using con-centration modulation absorption spectroscopy with a tunable Ti:Sapphire laser.The fluorine atoms were produced by discharging the mixed gases of helium and sulfur hexafluoride（SF₆）in a glass tube（SF₆:He≈1:25）.Thirty four hyperfine structure（hfs）resolved transitions were analyzed to obtain 23 magnetic dipole hfs constants A for 2s²2p⁴（³P）3s,2s²2p⁴（³P）3p and 2s²2p⁴（³P）3d configurations.The hfs constants in 2s²2p⁴（³P）3s and 2s²2p⁴（³P）3p configurations were compared with those obtained from experiments and calculations.Fifteen hfs constants in 2s²2p⁴（³P）3d configuration were reported-to our knowledge-for the first time.The transient neutral iodine atoms were produced by the discharging the iodine vapor（I₂）and helium（He）mixed gases（I₂:He≈1:25）.The Zeeman–hyperfine structure absorption spectrum was obtained in the uniform electric field.The best experimental conditions for the measurement of the Landé-g-factor using spectroscopy were obtained.At the same time,the methods to obtain Landé-g-factor were also explored.