On momentum conservation and thermionic emission cooling

On momentum conservation and thermionic emission cooling

Conservation of Lateral Momentum in Heterostructure Integrated Thermionic Coolers

Thin film thermionic coolers use selective emission of hot electrons over a heterostructure barrier layer from emitter to collector resulting in evaporative cooling. In this paper a detailed theory of electron transport perpendicular to the multilayer superlattice structures is presented. Using Fermi-Dirac statistics, density-of-states for a finite quantum well and the quantum mechanical reflec...

Evaporative cooling of helium nanodroplets with angular momentum conservation.

Evaporative cooling of helium nanodroplets is studied with a statistical rate model that includes, for the first time, angular momentum conservation. While the final temperature of the droplets is almost identical to that previously predicted and later observed, the distribution of total droplet energy and angular momentum states is vastly more excited than a canonical distribution at the same ...

Thermionic emission from surface-terminated nanocrystalline diamond

Thermionic electron emission forms the basis of both electron sources for a variety of applications and a direct energy conversion process that is compact and scalable. The present study characterizes thermionic emission from boron-doped nanocrystalline diamond films with hydrogen and nitrophenyl surface termination layers. A hemispherical energy analyzer was used to measure electron energy dis...

Thermionic emission from defective carbon nanotubes

Using a nanomanipulation system contained within a scanning electron microscope we investigate the thermionic electron emission from multiwall carbon nanotubes. Peak emission currents of 65 nA are measured. The carbon nanotubes being grown at low temperature by the chemical vapor deposition method are defective with poor thermal conductivity. We believe it is crucial for the thermal conductivit...