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 chirality as intrinsic degree of freedom. i.e. the electron pair as a whole has the ability to distinguish a right-handed coordinate frame from a left-handed one. This property of the two-electron continuum state results from a transfer of initial target orientation to the final two-electron continuum state. In particular. we show that inversion of the initial target orientation leads to a non-trivial change of the angular and energy correlation of the continuum electron pair. This orientational dichroism may be used, for example, to determine the direction of the orbital angular momentum vector of the initially bound target electron. For the purpose of illustration we have calculated the triply differential cross section for electron impact ionization of H(2p; M = +/-1) employing a correlated double continuum wavefunction. These results show that this orientational dichroism is large enough to be observable in a coincidence experiment.