Dissertation
Ion wave-particle interactions in a dipole magnetic field
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Spring 2026
Abstract
Argon ion orbits are evaluated using methods of differential dynamical systems tounderstand the equilibrium ion density profile in the Iowa Multidipole Experiment (IME) plasma discharge chamber. A Monte Carlo method is developed to solve the linearized Vlasov equation for f1(v) in a magnetized plasma using the method of characteristics. Results are benchmarked against past experimental and analytical results for a uniformly magnetized plasma. The same methods are applied to perturbations generated by an electrostatic antenna in the IME where the plasma is immersed in a dipole magnetic field.
Details
- Title: Subtitle
- Ion wave-particle interactions in a dipole magnetic field
- Creators
- Daniel Vincent Pette
- Contributors
- Frederick N Skiff (Advisor)Gregory G Howes (Committee Member)Jasper S Halekas (Committee Member)David E Stewart (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Physics
- Date degree season
- Spring 2026
- Publisher
- University of Iowa
- Number of pages
- xvi, 110 pages
- Copyright
- Copyright 2026 Daniel Vincent Pette
- Language
- English
- Date submitted
- 04/26/2026
- Description illustrations
- illustrations (some color)
- Description bibliographic
- Includes bibliographical references (page 94-100).
- Public Abstract (ETD)
Plasma is often referred to as the fourth state of matter; it is essentially a gas that is ionized, consisting of a mixture of free electrons and charged particles (ions). One area of plasma physics concerns how electromagnetic waves interact with these charged particles. Electrons are very light, so they tend to move quickly in comparison to the ions; as a result, high-frequency waves are typically associated with electron motion, while low-frequency waves tend to interact with the ions.
Plasmas differ from ordinary gases in that they respond strongly to electric and magnetic fields. One major challenge - which we attempt to address in this thesis - is that in certain field geometries, charged particles exhibit dynamical ”chaos”. To avoid a common misconception, note that ”chaos” does not mean the motion is ”random” but rather that it is highly sensitive to how the motion is initiated. The double-pendulum is a great visual example of chaotic motion for newcomers.
Chaos is a challenge for plasma physicists who seek to describe particle motion with a manageable set of equations to understand how the particles interact with waves. To address this, we:
1. Use established mathematical methods of chaotic dynamics to explain how the particles are organized in their motion.
2. Develop a statistical computational approach, called a Monte Carlo simulation, to connect particle motion with wave propagation.
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9985177374902771
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