Distinguishing between target structure and ionization mechanisms in (e,3e) experiments.

Electron impact double ionization with full determination of the kinematics of the collision, (e,3e), can, in principle, provide direct information on the correlated motion of the ejected electrons at the instant of ejection, provided that the mechanism of ejection is known. The symmetries of the observed double ionization cross sections in a variety of kinematic regimes can be used to experimentally investigate ejection mechanisms. The sensitivities of various experimental geometries and kinematic regimes to different ionization mechanisms are discussed in the context of the double ionization of the 3s electrons of magnesium. The practical implications for extracting information about electron correlation are examined. [ABSTRACT FROM AUTHOR]