Production of uniform micropellets of hydrogen and hydrogen pellet injection on ORMAK
Foster, Christopher Alan
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/2142/25636
Description
Title
Production of uniform micropellets of hydrogen and hydrogen pellet injection on ORMAK
Author(s)
Foster, Christopher Alan
Issue Date
1977
Doctoral Committee Chair(s)
Hendricks, Charles D.
Department of Study
Physics
Discipline
Physics
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
uniform micropellets
hydrogen pellet injection
ORMAK
solid deutrium-tritium
refueling fusion reactions
magnetic confinement of plasma
plasma
Language
en
Abstract
Injecting pellets of solid deutrium-tritium has been previously proposed as a method for refueling fusion reactors based on the magnetic confinement of a plasma. An experimental study was undertaken to determine the interaction of a hydrogen pellet with a high temperature plasma. An apparatus was developed which produced 70 micrometer diameter droplets of hydrogen by the acoustic disintegration of a liquid jet. The liquid drops were frozen and injected into vacuum at a speed of 95 M/sec. The pellet injection apparatus was mounted on ORMAK a tokamak magnetic confinement device located at Oak Ridge National Laboratory. Hydrogen pellets were injected into the ORMAK plasma. The pellet-plasma interaction was monitored by the enhanced neutral line emission of the ablating molecular hydrogen excited by the plasma electrons. The data indicated a pellet lifetime of 350 -450
u sec which implied an injection distance of 3.3 to 4.1 cm into the edge of the ORMAK plasma along the injection path which was at an angle of 450 from a radial line. FASTAX movies were taken of the pellets entering the plasma. A luminous cloud much larger than the pellets was observed sequentially on four frames. A model was developed in which the ablation rate of the pellets was regulated by the dynamic formation of a dense shielding cloud surrounding the pellet. The cloud thickness is such that the electrons from the plasma lose most of their energy before striking the pellet surface. The model was in good agreement with both the experimental pellet lifetime and the observed ablation cloud. This
model predicts that a 400 micrometer diameter pellet injected at 3/.
2.5 x 10 M sec would penetrate to the center of the ORMAK plasma.
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.