A Unified, Universal Model for Electron Emission and Breakdown
Abstract
This effort has focused on assessing the impact of submicroscale phenomena on gas breakdown and electron emission, specifically the transition between mechanisms in the presence of collisions, which are important for microplasma devices as the effective gap decreases below one micron where space charge may dominate over field emission and for vacuum electronics devices where leakage may result in collisions. Year 1 focused on incorporating collisions into analytic equations describing the transition from the Fowler-Nordheim (FN) equation to the Child-Langmuir (CL) law for vacuum space-charge limited emission (SCLE) at high mobility mu, and the Mott-Gurney (MG) law for collisional SCLE at low mu. We also observed a nexus where the asymptotic solutions of all three electron emission regimes converge with a unique value of V, mu or gap distance D. We next extended this to include resistance to account for the series resistors used to mitigate the rapid increase in current density that reduces device stability, demonstrating the transition to Ohms law for high resistance. In Year 2, we extended the emission theory from Year 1 by incorporating (1) thermionic emission and (2) quantum effects in SCLE by Schrodingers equation, (3) applying the theory to liquids, and (4) beginning our analysis of SCLE for non-planar geometries using variational calculus. Byusing the generalized thermo-field (GTF) model for electron emission, we demonstrated the transitions between Richard-Lau-Dushman (RLD), FN, CL, MG, and OL asymptotically and published this work in Physical Review Research during Year 3. We also incorporated quantum effects into our nexus theory, which is currently under review. To assess the broad applicability of this theory, we have also applied the general emission theory to liquids, which also undergo field emission and MG. This work was published in the Journal of Applied Physics during Year 3.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 07, 2021
- Accession Number
- AD1146023
Entities
People
- Allen L Garner
Organizations
- Purdue University