Theoretical Study of Collective Ion Acceleration in the Luce Diode.
Abstract
The most successful collective ion acceleration to date has been observed when a relativistic electron beam has been discharged in the Luce diode (dielectric anode) geometry. In these experiments the ratio of peak proton energy to beam kinetic energy has been as high as 30. The ion source is a plasma formed on the anode surface by electron impact ionization of the dielectric material. The diode physics, which couples the electron beam generation to the number of ions extracted from the plasma, is an essential feature of the acceleration mechanism in the Luce configuration. Simulations where the electron beam is injected through a preformed dense plasma are significantly different from those where the electron beam self-consistently determines the ion plasma density and dynamics in the diode. The main difference is in unstable wave growth. In the Luce diode the instability is predominant. In other localized plasma source collective ion accelerators the main acceleration takes place due to a hydrodynamic plasma free expansion. However, both Luce diodes and other plasma source accelerators can display both mechanisms to some extent. Originator supplied keywords include: Collective ion acceleration, Computer simulation, Luce diode, Electron-ion streaming instability, Ion acoustic instability.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1984
- Accession Number
- ADA150107
Entities
People
- D. J. Sullivan
- R. J. Faehl