Analytical models of transmission probabilities for electron sources
Abstract
Electron emission from coated surfaces as a result of thermal, field, and photoemission effects is often described theoretically using models dependent on the Kemble approximation for the transmission probability D(k). The validity of the approximation for the simple potential profiles (rectangular, triangular, and parabolic) is examined, and generalizations with respect to the exponential of the Gamow tunneling factor and the coefficients of D(k), which are generally ignored, are examined and extended to when the barriers become wells. As a result, unity transmission probabilities (D(k)→1) with regard to both resonant tunneling barrier and reflectionless well behavior are contrasted. The adaptation of the findings to a general thermal-field-photoemission equation is considered. Consequences for the usage of general emission equations in beam optics code [e.g., Particle-in-Cell (PIC)] such as MICHELLE are discussed.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 14, 2018
- Source ID
- 10.1063/1.5018602
Entities
People
- Andrew Shabaev
- D. Shiffler
- Daniel Finkenstadt
- John Petillo
- Kevin L. Jensen
- Nathan A Moody
- Samuel G. Lambrakos
Organizations
- Air Force Office of Scientific Research
- Air Force Research Laboratory
- Los Alamos National Laboratory
- United States Department of Energy
- United States Naval Academy
- United States Naval Research Laboratory