Molecular Beam Electric Resonance Spectroscopy

Abstract

Beam spectroscopy has provided much of what is known about the fine structure of atoms, the hyperfine structures and g values of atoms and molecules, and the values of nuclear spins and moments. This chapter summarizes what has been achieved with molecular beam electric resonance (MBER) spectroscopy. The operation of a molecular beam resonance spectrometer is shown. The field (say, A field) of the spectrometer selects molecules in the desired quantum state; the beam then goes to a region (say C field) in which transitions to other quantum states may be induced, and the beam subsequently passes through B field quantum state selector to a detector. In contrast to the mode of operation of the usual absorption spectrometer, it is the flux of molecules, rather than the intensity of radiation, which is monitored: those changes are looked for in the flux of molecules, which can be correlated with the frequency of the radiation in the C field.