Coulomb versus drag effects in a photoelectron bunch for extreme ultraviolet laser spectroscopy

Coulomb effects in an extreme ultraviolet laser-induced photoelectron bunch for spectroscopy were investigated computationally. Post-photoemission alteration of the trajectory, due to Coulombic interactions, hampers an accurate angle-resolved photoelectron spectroscopy. Simulations however demonstrated that operation in the redundant-population regime produces a drag-confined bunch, detached from a boundary sheath that experiences losses. Drastic reduction in the photoelectron density can loosen bunch-confinement and proportionally increase the boundary losses. Our simulations led to a critical number of photoelectrons per spot size equal to 1.5 x 10(4) e(-)/mm(2). (C) 2011 American Institute of Physics. [doi: 10.1063/1.3586768]