0000000000358806
AUTHOR
J R Götz
Cross-sections for (e, 3e) collisions on helium: the DS6C wavefunction
A dynamically screened product of six pairwise Coulomb functions (DS6C) is used as an analytic approximation to describe the four-body Coulomb continuum state produced by electron-impact full fragmentation of helium. Good agreement is obtained with experimental data close to threshold, where four-body effects are expected to be important. Even for the high impact energy of 640 eV, four-body effects still play a role in deciding the shape of multi-differential cross-sections.
The effect of dynamical screening on helium (e, 3e) differential cross-sections
A simplified derivation of dynamic screening in the case of three Coulomb-interacting particles in the continuum is given and applied to describe the shapes of multi-differential cross-sections for the (e, 3e) process on the helium atom in which the incident fast electron is treated in first-order Born approximation. A very good agreement with experimental multi-differential cross-sections is obtained for two slow ejected electrons (specifically both electrons have 5 eV) but the strategy appears to be breaking down at intermediate emission energies.