Self-Focused Electron Beams Produced by Pyroelecric Crystals on Heating or Cooling in Dilute Gases

摘要

Self-focusing, spatially stable, electron beams arising from heating up to160 degrees C and cooling to room temperature pyroelectric LiNbO3 crystals indilute gases have been observed for the first time. The current (up tonanoamperes) and energies (up to 170 keV) of these electron beams attainedmaximum values and then decreased during the cooling phase of the thermalcycle. Cylindrical crystals produced spatially stable beams with typical focallengths of 22 mm and 1mm spot sizes. Here we present photographic as well aselectronic proof of their existence.