This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/66232
Description
Title
Ion Bunching at High Energies
Author(s)
Johnson, Gary Burton
Issue Date
1980
Department of Study
Electrical Engineering
Discipline
Electrical Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Physics, Fluid and Plasma
Energy
Language
eng
Abstract
Light ions offer several advantages over an electron beam or lasers as the driver for pellet fusion. This research deals with demonstrating that the electrostatic space charge fields produced by a reflex triode can be used to extract, accelerate, focus and bunch ions onto a target. The source of ions used in this experiment was a preformed plasma produced by a hollow cathode discharge.
A Nereus e-beam accelerator, on loan from Sandia Laboratories, is used to drive the reflex triode. This produces a 35 ns electron beam pulse of 300 kV and 50 kA. One can show that an electrostatic space charge well will be set up on the far side of the transparent anode. Ions in this region will be accelerated downstream and due to the distribution in their velocities, a bunching of their arrival times at a point downstream will occur.
Negatively biased Faraday cup probes are used to measure the intensity, pulse width, and time-of-flight of the ion beam downstream. Time-of-flight data indicate that the ions are being accelerated to > 90% of the applied anode potential. Ion beam current densities of up to 160 A/cm('2) have been obtained yielding electron beam to ion beam conversion efficiencies of > 25%, and bunching factors of greater than four have been observed.
This research demonstrates the feasibility of using efficient electron beam machines to produce intense high energy ion beams. Possible applications include using the device as the driver for pellet fusion.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
