POEEMS - PHYSICS OF ELECTRON EMITTING MATERIALS
Abstract
There is a constant technological need for the development of new sources of electrons. This need is reflected by the search for new materials likely to produce very high electrical currents in extreme operating conditions (electric field, temperature, long time intervals). In this respect field emission electron cathode materials offer an alternative to thermal emission cathode materials for vacuum electronic applications. We propose to investigate the physics of such extreme field emission sources under real operating conditions via the use of a suitable characterization tool, namely the electron photoemission microscopy / low energy electron microscopy whose imaging principle is directly based on the acquisition of the electronic distribution emitted by the material surface [Douillard & Charra 2011]. LEEM / PEEM appears therefore as an experimental technique of choice for this kind of study. The proposed objectives are to answer fundamental questions related to the emission of electrons by a surface under extreme electric and / or electromagnetic excitation. In particular, this involves determining physical electron distributions of interest at the micro- and nano-scales such as spatial mapping of potential emission hot spots and energy mapping through the determination of the electron kinetic energy spectra. Beyond pure static Fowler-Nordheim regime, pulsed laser light excitation gives access to the emission dynamics of the charge carriers through pump probe experiments as well as additional electron emission mechanisms to investigate: ponderomotive effects, rescattering phenomenon, plasmon assisted electron emission.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 11, 2021
- Source ID
- FA86552017039
Entities
People
- Ludovic Douillard
Organizations
- Air Force Office of Scientific Research
- Alternative Energies and Atomic Energy Commission
- United States Air Force