The Rovibronic Spectrum Study Of The PbF And Pb₂ Molecular

Precision measurement physics is an important research direction of modern basic physics.It is the product of the combination of precision measurement technology and scientific exploration,and also the basis of solving the national relevant major precision measurement needs.Precision spectroscopy is a very important research method in precision measurement physics.The precise information of the upper and lower energy levels of molecules can be obtained by precise measurement of molecular spectrum,and the precise values of molecular constants can be obtained.Electron electric dipole moment(eEDM)is an important physical quantity in new physics,and it is of great significance to measure it accurately.PbF,a valuable candidate for the measurement of the eEDM,there is still a lack of relevant studies on the ground state X1 and excited state B of PbF molecules,so it is of great significance to collect their spectra and deduce the corresponding molecular constants through experiments.In this paper,the PbF molecular has been studied in the following aspects:1)Build and optimize the PbF molecular B2?+-X12?1/2 fluorescence spectrum detection experiment equipment,design and build zeeman spectrum detection device;2)Pb plasma is generated in the vacuum chamber by laser ablation technology,and the PbF molecule is prepared by reaction with the CF4 gas ejected from the pulse valve;3)The fluorescence spectra of the B2?+-X12?1/2 transition(0,0)and(1,0)bands of PbF molecule were excited by laser-induced fluorescence technique and zeeman spectra under external magnetic field condition.The fluorescence signal was collected by fluorescence collection system,and the fluorescence decay lifetime of excited state B was measured;4)Calibrate and fit the spectral lines of(0,0)and(1,0)bands of fluorescence spectrum obtained in the experiment,and obtain the molecular constants of ground state X12?1/2(v"=0)and the excited state B2?+(v'=0,1).The potential curves of B2?+ and X12?1/2 states and the Franck-Condon factor(FCFs)of their transitions have been calculated using the RKR/LEVEL and Morse potential methods,respectively;5)By analyzing zeeman splitting spectrum of(0,0)band of PbF molecule B2?+-X12?1/2 transition,the isotope belonging of the spectrum line was determined,and the g factor of excited state B was obtained by preliminary fitting of zeeman splitting spectrum of 208PbF molecule,providing theoretical and experimental support for eEDM measurement.In the end,the vibration spectra of the F-X transition of Pb2 were studied,and the spectral constants of the F-X bands were calibrated and calculated.The vibrational spectra of the F-X transition of Pb2 molecule were measured,and each band was assigned in this paper.The FranckCondon factors of the F-Xtransitions were also calculated using the RKR/LEVEL methods.Among them,the signal which does not belong to Pb2 polymer was preliminarily analyzed and discussed.