Date of Award

Spring 2018

Document Type

Thesis

Terms of Use

© 2018 Jaron Shrock. All rights reserved. This work is freely available courtesy of the author. It may only be used for non-commercial, educational, and research purposes. For all other uses, including reproduction and distribution, please contact the copyright holder.

Degree Name

Bachelor of Arts

Department

Physics & Astronomy Department

First Advisor

Michael R. Brown

Abstract

We aim to describe the fundamental physics and results of compression and acceleration experiments performed on the Swarthmore Spheromak Experiment (SSX). The fundamental research objective is to maximize the energy and density of a Taylor state (a relaxed, twisted, and force-free equilibrium which will be discussed in detail in chapter 2) plasmas with the potential goal of forming a target for magneto-inertial fusion (MIF). This includes characterizing the equation of state for compression of Taylor state plasma structures and evaluating the effectiveness of acceleration modules acting on these states.

We present a comprehensive review of both the theory and experimental procedure followed in these investigations. First, the basic ideas of plasma physics are discussed. This includes key parameters and basic theoretical models including magnetohydrodynamic theory. Next we explore more advanced concepts related to SSX physics, such as Woltjer-Taylor relaxation and thermodynamic properties of magnetized plasmas.

Since the ultimate purpose of the compression and acceleration experiments is to provide a target for MIF schemes, we will also discuss the essentials of fusion theory and review research being conducted in the fields of fusion and plasma compression. Next, we will give an in depth description of the SSX apparatus and the experimental set up for the compression and acceleration experiments. This will include a discussion of the three primary diagnostics used in SSX as well as the design approach for the new acceleration modules. Finally, we will present our findings as well as analysis and remaining research questions.

Ultimately, we will show that, although unable to maintain cohesive Taylor plumes, the acceleration modules succeeded in inducing substantial plasma acceleration while introducing some unexpected dynamics. We will also show that the magnetohydrodynamic equation of state does not describe the observed compression. And we will give evidence suggesting that the compression of Taylor state plasmas in SSX is predominately governed by the conservation of J, the adiabatic invariant corresponding to particle motion parallel to magnetic field lines. Finally, we will address whether or not the plasma structures formed on SSX could possibly be used for MIF experiments, and present next steps in exploring their viability.

Download

Included in

Physics Commons

Share

COinS