Determination of the ion distribution function during magnetic reconnection in the versatile toroidal facility with a gridded energy analyzer
Name
52561908-MIT.pdf
Description
Full printable version
Size
1.33 MB
Format
Adobe PDF
Checksum (MD5)
368381ff367ed2881613d942cd3be17e
Author(s)
Nazemi, Jonathan H. (Jonathan Hesam), 1974-
Advisor(s)
Ambrogio Fasoli.
Alternative Title
Determination of ion distribution function in the versatile toroidal family facility during magnetic reconnection with a gridded energy analyzer
Date Issued
2002
Publisher
Massachusetts Institute of Technology
Abstract
A gridded energy analyzer (GEA) diagnostic and associated electronics are designed and built to explore the evolution of the ion distribution function during driven magnetic reconnection in the Versatile Toroidal Facility. The temporal evolution of the ion characteristic is measured at different locations throughout the reconnection region, for a number of magnetic field configurations. The measured ion characteristics are found to be in excellent agreement with a theoretical fit constructed from a double Maxwellian distribution, from which the temperatures and drift velocities are found as functions of space and time. It is found that the ion temperature of each Maxwellian exhibit minor temporal variations during reconnection which are negligible in terms of ion heating. Additionally, the temperatures do not significantly change with varying radial position, or magnetic cusp strength. The drift velocities are observed to evolve in time, scale with magnetic cusp strength, and to depend on the exact location throughout the reconnection region. The ions are thus subject to acceleration due to the electric field induced by the ohmic drive. The appearance of a double Maxwellian distribution during the reconnection drive is hypothesized to be due to double ionization of argon atoms. Repetition of the experiment with a hydrogen plasma verified that this scenario is most probable.
Description
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Physics, 2002.
Includes bibliographical references (leaf 44).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Subjects
Physics.
MIT Department
Massachusetts Institute of Technology. Department of Physics
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