Being a physics major, I feel almost comfortable admitting between classes last spring I would often wander around Chamberlain Hall and look at the research facilities like normal people wander around a museum. I’d ogle at the glittering metal chambers and the technicolor web of entangled wires that surround them, the vast arrays of batteries providing intense bursts of DC current, and ponder the displays with charts of data I don’t really understand. It was a very effective way to waste time between lectures and discussions.
Recently I heard rumor of a new and intriguing experiment that will soon be under way in Sterling Hall. The Madison Plasma Dynamo Experiment takes place in a massive aluminum sphere that spans three meters in diameter and tips the scales at a whopping 5,000 kilograms. According to University of Wisconsin physics professor Cary Forest, it looks like the Death Star from “Star Wars.” Inside the sphere, microwaves will heat gases above 200,000 degrees Celsius and convert them to plasma, while thousands of powerful magnets embedded in the aluminum shell stir the mix. All the while, arrays of probes and interferometers will collect never-before-seen data on the resulting home-grown plasma dynamo. After years of experimental design, the MPDX is slated to begin sometime next fall.
Plasma has often been referred to as the fourth state of matter – it is essentially a gas in which all nuclei have been stripped of their electrons. When plasma is stirred and begins to flow, electrical dynamics generate magnetic fields, and voila, you have a plasma dynamo. Today, these plasma dynamos are only vaguely understood. Says Forest, “We’re basically trying to stir the plasma like a big blender. It’s turbulent. And magically, magnetic fields come out of this mess.”
Magnetic dynamos, and especially plasma dynamos, represent the cutting edge of physics research. Astrophysicists have identified plasma dynamos within stars, galaxies and galaxy clusters, but until now, scientists have resorted to studying these phenomena from a distance. The MPDX will allow physicists to observe plasma dynamos under controlled conditions in the lab and gain powerful insights which may lead to a further understanding of the dynamics of stars and galaxies.
The genius of the Plasma Dynamo Experiment is it closely approximates cosmic processes in the lab, where various conditions can be replicated and more precise data will be collected. Inside Sterling Hall, researchers will be able to generate and study plasma dynamos with a precision impossible to achieve from astronomical measurements. In the words of Professor Forest, “We can’t build a star. We can’t build an earth. But we can build some parts of them.” Forest speaks of a shining example of sifting and winnowing at its best. Experiments like the MPDX highlight the strength of the UW as a research institution – those who are interested have a front seat view of the frontiers of science and technology.
Gov. Scott Walker would be thrilled to know that the massive Death-Star-shaped Plasma Dynamo sphere was fabricated in Wisconsin at Portage Casting and Mold. Dan Griep, the company’s director of tooling, reassured everyone “the foundry-tooling industry in Wisconsin is alive and well, and we are definitely open for this business.” Three other Wisconsin companies participated in the project – D&S Machine Services, Metallic Bonds and Lafayette Testing Services contributed the seal between the two separate halves of the sphere, a heat-resistant ceramic coating for the interior and X-ray structural analysis, respectively.
All told, it is impressive that the central piece of technology for an experiment as advanced as the MPDX could be constructed locally in the state of Wisconsin. This is a reassuring sign the state’s science and technology industry is still alive and kicking, and the decision to build the dynamo in Wisconsin is a strong vote of confidence in the state’s engineering expertise. Beyond its impact in the physics world, the plasma dynamo has already benefitted Wisconsin’s economy and provided national recognition for numerous Wisconsin companies. This experiment has probably made a greater impact on the state economy than Walker’s special legislative session to create jobs. It has certainly been a more scientific undertaking, despite the Walker’s effort to focus on jobs “like a laser.”
Charles Godfrey ([email protected]) is a sophomore majoring in math and physics.
