Date of Award

Spring 2000

Document Type

Restricted Thesis

Terms of Use

© 2000 Vyacheslav S. Lukin. All rights reserved. Access to this work is restricted to users within the Swarthmore College network and may only be used for non-commercial, educational, and research purposes. Sharing with users outside of the Swarthmore College network is expressly prohibited. 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

In the recent years, computer simulations have become one of the main investigative tools in most areas of physics research. Computer modeling is also of particular importance in plasma physics, where highly dynamic nature of the conductive medium makes precise and detailed experimental measurements of the occurring processes very difficult. The Swarthmore Spheromak Experiment (SSX) studies the interaction of donut shaped magnetic structures known as spheromaks. The experimental measurements conducted on SSX can be approximately divided into two categories: 'internal' and 'external'. Internal measurements produce precise values of the quantities being measured, but cover only a small fraction of the volume of interest in the highly inhomogeneous medium and can interfere with the very processes being measured. On the other hand, external measurements are only capable of producing volume averaged values of the parameters of interest, thus integrating over the local structure and dynamics of plasma magnetofluid. We are thus forced to resort to modeling in our attempts to gain a better understanding of the physical processes taking place in the experiment. We currently employ two modeling codes: O-D time-dependent impurity emission model, and 2½-D resistive MHD simulation code. A VUV monochromator is used to collect time-resolved data from various plasma impurity lines. Line-ratios of the recorded intensities are then taken and compared with the predictions of the O-D time-dependent coronal equilibrium model. Significant restrictions are thus generated on the possible values of plasma parameters such as electron temperature Te and electron density ne. The MHD code is employed to support our understanding of the structure and dynamics of the magnetofluid in the experiment as a whole and in the, so called, reconnection region in particular. The output of the simulation is matched with the measurements of the energetic particle's orbits and the 2-D B-field measurements.

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