Electron Transit Time in Central Virtual Anode Wells
Abstract
In the computation of electron residence time within the core cavity of Polywell(tm)/HEPS devices, it is necessary to determine the average time of transit of the electrons in the system across the system. This is needed in the EKXL code as a parameter in the basic code algorithm relating electron edge densities at successive time increments within each time interval computation. The time intervals are those periods over which the succession of linked steady- state solutions are obtained for particle density and potential distributions. An analogous parameter is required for the algorithm relating ion edge density dependence, as well. For ions, this parameter can be calculated readily from the data available in each code computation; simply summing the ratio of spatial grid width to local grid average radial speed, over the complete grid range characterizing the problem. This works effectively, even though the ions are specified with a square function energy distribution, because all of the ions go to or through the central core of the system. This is not the case for the electrons, however, as their radial and transverse energy spreads, coupled with the square distribution used to model these spreads, forces them to experience (in the computer code computation) a wide range of transit times.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1992
- Accession Number
- ADA257940
Entities
People
- Katherine E. King
- Robert W. Bussard