ORIENTATIONAL DICHROISM IN (E, 2E) REACTIONS

Electron impact ionization of an oriented atomic or molecular orbital is shown to produce a pair of escaping electrons possessing a chiralit y as intrinsic degree of freedom. i.e. the electron pair as a whole ha s the ability to distinguish a right-handed coordinate frame from a le ft-handed one. This property of the two-electron continuum state resul ts from a transfer of initial target orientation to the final two-elec tron continuum state. In particular. we show that inversion of the ini tial target orientation leads to a non-trivial change of the angular a nd energy correlation of the continuum electron pair. This orientation al dichroism may be used, for example, to determine the direction of t he orbital angular momentum vector of the initially bound target elect ron. For the purpose of illustration we have calculated the triply dif ferential cross section for electron impact ionization of H(2p; M = +/ -1) employing a correlated double continuum wavefunction. These result s show that this orientational dichroism is large enough to be observa ble in a coincidence experiment.