Hello ME Community,
You are invited to join the PhD Proposal Defense of Ethan Bowers on Wednesday, September 3, beginning at 1pm, in the ME Conference Room (ENGR210-I).
Advisor: Carlos Romero-Talamás
Title: Construction and Validation of the Adjustable Long Pulsed High-Field Apparatus and Corresponding Plasma Experiments
Abstract:
A 7 T Bitter type electromagnet denoted the Adjustable Long Pulsed High-Field Apparatus (ALPHA) is being constructed at the University of Maryland Baltimore County (UMBC) for plasma and dusty plasma experimentation. Bitter magnets are resistive, water cooled electromagnets with a well defined inverse radial current density which allows increased field generation when compared with traditional resistive electromagnets. ALPHA contains optimized Bitter disks which form an isothermal surface reducing the stress gradients in the solenoid. The field profile for ALPHA corresponds to a magnetic mirror, a plasma confinement configuration, with a mirror ratio of 1.1. ALPHA may be operated in both pulsed and steady state. ALPHA is intended to be a robust device operating under a wide range of field conditions. The construction progress, design elements, and remaining work to complete ALPHA is discussed along with applications for the finished device and limitations to its function.
One application for ALPHA is exploration of breakdown parameters for various gasses at high magnetic fields. This Paschen breakdown has been thoroughly investigated for varying geometries, species and ramp rates. Yet, the influence of magnetic field on the breakdown voltage has only been studied with fields on the order of 1 Tesla. ALPHA will serve as a device to quantify the effects of high magnetic and electric fields on breakdown and transitions between breakdown regimes in both pulsed and steady state.
Another application is gas separation. Fusion energy requires isotopes of hydrogen. Specifically, the reaction between deuterium and tritium is considered one of the easiest fusion reactions. While deuterium is abundant and stable, tritium is not. Because of this, lithium 6 and neutrons from the deuterium tritium fusion reaction are intended to breed tritium in line with the fusion power plant. For this purpose plasma centrifuges are promising candidates for inline tritium separation as mass separation factors for low atomic mass species are theorized to be significantly higher when compared to mechanical centrifuges. ALPHA will be used as a plasma centrifuge with E × B rotation to test the effectiveness of a magnetic mirror plasma centrifuge.