Spin-exchange cross section for electron excitation of Na 3S-3P determined by a novel spectroscopic technique.

Abstract

An experimental technique is described which enables determination of the partial cross sections for electron excitation of atoms as a function of changes in spin and orbital angular momentum. This method provides a good signal-to-noise ratio in the energy region near threshold, and could be used to study long- or short-lived excited states of many atomic systems. Measurements for Na 3s-3p, near-threshold excitation are reported here. The results are generally in good agreement with the close-coupling calculations of D. L. Moores and D. W. Norcross (J. Phys. B 5, 1482 (1972)) for the largest ..delta..m/sub S/ and ..delta..m/sub L/ components of the cross section, but not for the component with chemically bond..delta..m/sub S/chemically bond = 1 and chemically bond..delta..m/sub L/chemically bond = 1, indicating that the exchange interaction is larger than previously recognized.