A novel method for the generation of high Rydberg states of atoms and molecules

High Rydberg states (n∼40–100) of atoms or molecules were successfully generated by impacts of laser induced photoelectrons. The Rydberg states thus produced were separated from ions initially by a 3 V DC electric field and then ionized by a delayed pulsed HV electric field. In this time-of-flight mass spectrometer, a large number of high Rydberg states of atoms (e.g. Ar), molecules (e.g. NO, C2H2, C6H6) and even certain fragments (e.g. C2H, C2 and C6H5) were observed. The yield ratio of Rydberg states to ions was strongly dependent upon the laser power and the energy of the photoemission electrons.