Developing High-Brightness Electron Beam Sources for Producing Quantum Degenerate Electron Beams
Kohler, Jonathan
:
2011-04
Abstract
The Pauli Exclusion Principle places a fundamental limit on the brightness
of an electron beam. Developing a cathode which can reach this limit is
useful for achieving maximum operation in current applications of electron
beams, but also opens new areas of physics to be explored. When the phase
space of the electron beam is filled to the maximum density, the electrons
will experience a degeneracy pressure, similar to that which keeps a neutron
star from collapsing. One promising source for a quantum degenerate beam is
field emission from adsorbates on carbon nanotubes. Adsorbates have been
shown to provide several orders of magnitude enhancement to emission
brightness, which approaches the degeneracy limit. We have developed
experiments to test various adsorbates, in order to find those which bind
tightest and provide the largest enhancement in brightness. Continuing work
to discover better adsorbates should soon allow for the generation of a
quantum degenerate electron beam.