The use of high magnetic fields in the spectroscopy of simple atoms and molecules

Abstract

This paper will briefly review the use of moderate and high magnetic fields in atomic and molecular spectroscopy. Magnetically tuned anticrossing experiments between electronic states of different multiplicity (e.g. singlet-triplet and doublet-quartet) have considerably advanced our knowledge of intersystem interactions and separations. Systems studied include some of the simplest and most important atoms and molecules: He, H 2, He 2, CN, NO and O 2 +. Laser magnetic resonance experiments have also benefited from the use of high magnetic fields. Recent experiments on Rydberg states of He with CO 2 laser radiation have not only measured accurately zero-field separations and Zeeman tuning parameters but have also discovered an entirely new spectral lineshape caused by the motional Stark field seen by the atoms moving in the magnetic field. High magnetic fields have also been found to be useful in the study of atomic collisional processes, and some of these applications will be briefly surveyed.