Aw. Malcherek et Js. Briggs, THE N-ELECTRON COULOMB CONTINUUM, Journal of physics. B, Atomic molecular and optical physics, 30(20), 1997, pp. 4419-4433
It is shown that, when the n-electron continuum state is treated in LS
-coupling, both the amplitude and the cross section for photo-and elec
tron-impact ionization to such a state can be expressed as a linear co
mbination of n-polar harmonics in the angles of emission of the n elec
trons. The analysis utilizes re-coupling techniques, largely avoiding
redundant sums over products of Clebsch-Gordan coefficients. The Clebs
ch-Gordan series is generalized to n particles. Two selection rules ar
e proved and the operation of such selection rules is illustrated by c
alculations of-the differential cross section for (i) the complete pho
to-fragmentation of the lithium atom and (ii) the complete fragmentati
on of the helium atom under electron impact.