STUDY OF EXCHANGE IN COLLISIONS OF POLARIZED ELECTRONS WITH ATOMS AND MOLECULES

Exchange collisions of electrons with Na and Hg atoms and O2 and NO molecules have been studied by means of polarized electrons for energies between 4 and 15 eV and scattering angles ranging from 0-degrees to 110-degrees. While significant exchange effects have been observed for collisions of electrons with Na and Hg atoms, in agreement with theoretical predictions, differential spin-exchange cross sections for elastic collisions from the open-shell molecules O2 and NO are much smaller. This was not anticipated before. A satisfactory explanation of this different behavior is still missing.