This file is from Wikimedia Commons and may be used by other projects.
The description on its file description page there is shown below.
Summary
DescriptionSchottky-Emitter 01.jpg
Deutsch: Schottky Emitter bei zunehmender Vergrößerung. Der Wolfram-Einkristall mit geätzter Spitze ist auf einem Wolfram-Filament befestigt und mit einer Manschette aus Zirconiumdioxid versehen. Dieses sorgt bei der hohen Arbeitstemperatur von ca. 1800 K für einen leichteren Elektronenaustritt aus der Spitze.
English: Schottky emitter at increasing magnification. The tungsten single crystal with an etched tip is attached to a tungsten filament and provided with a sleeve made of zirconium dioxide. At the high working temperature of approx. 1800 K, this ensures easier electron discharge from the tip.[1]
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.