Magnesium monofluoride(MgF)is proposed as an ideal candidate radical for direct laser cooling.Here,the rotationally resolved laser spectra of MgF for the A^(2)Π-X^(2)∑^(+) electronic transition system were recorded ...Magnesium monofluoride(MgF)is proposed as an ideal candidate radical for direct laser cooling.Here,the rotationally resolved laser spectra of MgF for the A^(2)Π-X^(2)∑^(+) electronic transition system were recorded by using laser induced fluorescence technique.The MgF radicals were produced by discharging SF_(6)/Ar gas mixtures between the tips of two magnesium needles in a supersonic jet expansion.We recorded a total of 19 vibrational bands belonging to three sequences of Δv=0,±1 in the region of 348-370 nm.Accurate spectroscopic constants for both X^(2)∑^(+) and A^(2)Π states are determined from rotational analysis of the experimental spectra.Spectroscopic parameters,including the Franck-Condon factors(FCFs),are determined from the experimental results and the Rydberg-Klein-Rees(RKR)calculations.Significant discrepancies between the experimentally measured and RKR-calculated FCFs are found,indicating that the FCFs are nearly independent of the spin-orbit coupling in the A^(2)Π state.Potential energy curves(PECs)and FCFs determined here provide necessary data for the theoretical simulation of the laser-cooling scheme of MgF.展开更多
基金supports from the National Natural Science Foundation of China(No.21773221 and No.21827804)the National Key R&D Program of China(No.2017YFA0303502)the Fundamental Research Funds for the Central Universities of China(No.WK2340000078)。
文摘Magnesium monofluoride(MgF)is proposed as an ideal candidate radical for direct laser cooling.Here,the rotationally resolved laser spectra of MgF for the A^(2)Π-X^(2)∑^(+) electronic transition system were recorded by using laser induced fluorescence technique.The MgF radicals were produced by discharging SF_(6)/Ar gas mixtures between the tips of two magnesium needles in a supersonic jet expansion.We recorded a total of 19 vibrational bands belonging to three sequences of Δv=0,±1 in the region of 348-370 nm.Accurate spectroscopic constants for both X^(2)∑^(+) and A^(2)Π states are determined from rotational analysis of the experimental spectra.Spectroscopic parameters,including the Franck-Condon factors(FCFs),are determined from the experimental results and the Rydberg-Klein-Rees(RKR)calculations.Significant discrepancies between the experimentally measured and RKR-calculated FCFs are found,indicating that the FCFs are nearly independent of the spin-orbit coupling in the A^(2)Π state.Potential energy curves(PECs)and FCFs determined here provide necessary data for the theoretical simulation of the laser-cooling scheme of MgF.
