Energy-Spread Structure of Electron Beams to be ``Optically'' Modulated

Abstract

Electron beams of relatively high currents (0.5 μA) and 50‐keV energy with observable modulability at optical frequencies can be produced without violating the Langmuir brightness relationship by shaping the beam in a ``filamentary'' structure, whereby each single‐beam ``filament'' fulfills the recently reported monochromaticity requirement (energy spread better than 10 meV). The monochromator and the electron‐optical‐beam ``shaper'' have to be made adjustable for accurate spatial coherence between the electron‐beam ``filaments''.