Our lab focuses on “Accurate measurement of dynamic parameters of atoms and molecules”. By bringing forward new experimental method and reforming the experimental setup, we improved the accuracy of experimental results. A set of benchmark data of atomic and molecular dynamic parameters were determined, and excitation mechanism in valence shell excitation process of noble atoms were elucidated. It is also observed that new correlation quantum numbers have important influences on transition characteristics in doubly excited process of the helium atom.
    We mainly use two kinds of experimental method in our research.
    1. High-Resolution Fast-Electron Energy Loss Spectroscopy
    In this method, monoenergetic electron beam of 1-5 keV is produced and collides atoms and molecules. The excitation energy of atom or molecule can be determined by measuring the difference of energies of the incident and scattered electrons. Then the differential cross section of a definite state can be determined by the angular distribution of its intensity. The decay information from the ionization continuum or definite superexcited states to different channels of ion fragments can be determined by measuring the scattered electrons and ions coincidently. The ions were identified by measuring the time interval from its producing to its being detected by the time of flight mass spectrometer.
    2. High-Resolution Inelastic X-ray Scatting Spectroscopy
    In this method, we use hard X-ray of 10keV to collide atoms and molecules. Similarly, the excitation energy of atom or molecule can be determined by measuring the difference of energies of the incident and scattered photons. The differential cross section of a definite state can be determined by the angular distribution of scattered photon’s intensity. Then the squared form factor of a definite transition can be converted from the measured differential cross sections.

    Since the establishment of our lab, we have already determined the accurate data of the dynamic parameters of some noble atoms, diatomic molecules and triatomic molecules. Furthermore, we have observed and assigned some new dipole-forbidden transitions. Our accurate dynamic parameters have been served as experimental benchmark data to test theoretical models and calculational codes strictly. We have published more than 50 SCI papers in Phys. Rev. Lett., Phys. Rev. A, J. Chem. Phys, J. Phys. B and etc and given the invited talks on international conferences on atomic and molecular physics for many times.