Apr 20 2005
Users of the National High Magnetic Field Laboratory soon will have a new state-of-the-art magnet system for their research in physics and materials science. Engineers at the facility, led by project leader Mark Bird, recently tested a specially designed, 31-tesla-powered magnet that has a 50-millimeter experimental space. The magnet is the highest field DC magnet with this bore size anywhere in the world, and represents a 6-tesla — or 20 percent — upgrade over existing facilities at the NHMFL.
“Generating high magnetic fields over a large region of space is exceedingly difficult,” said NHMFL Director Gregory Boebinger. “This new magnet generates 31.3 teslas in a 50-millimeter diameter volume. It is another NHMFL world record — and another newly opened door for the future of high magnetic field research.”
The first user of the magnet will be Professor James Valles of Brown University, who will continue studies of the effects of magnetic fields on single-cell, microscopic animals in pond water. Recent work established that they can use magnetic forces to simulate an environment with 4.5 times the Earth’s gravity, and they have obtained high-resolution video of individual swimming tracks of the Paramecium in magnetic fields and are analyzing them to learn about their swimming mechanics. The new 50-mm bore, 31 T magnet will allow samples to be evaluated with greater resolution.
In early May, a group from the University of Florida, led by Professor David Reitze, will use the magnet for spatial, temporal and spectral investigations of superfluorescence from quantum dots created in strong magnetic fields. Superfluorescence is a quantum optical phenomenon similar to the process of light generation in lasers; however, it has never been observed in semiconductors. Strong magnetic confinement of charge carriers (magneto-plasma) by the 31 T magnet will allow them to create a higher density of quantum dots and enhance superfluorescence. In addition to better understanding of the quantum optics of solids, this work may lead to devices that produce extremely bright, short, coherent light pulses.
Next up will be a research group headed by FSU Professor James Brooks that is studying the properties of organic magnetic materials. According to Brooks, also a member of the NHMFL Condensed Matter Science Program, “the larger experimental volume will allow for larger samples to be rotated in the magnetic field, and the significantly higher magnetic fields provide much higher resolution. This allows us to study materials where high fields change their properties. For many systems, the direction of the magnetic field is crucial for their understanding, and this new magnet will allow such experiments as high-pressure studies, which literally bring closer the distances between atoms and molecules, to be carried out. Properties measured under high pressures tell chemists and physicists how to better engineer the makeup of these materials for superior magnetic, conducting, or even superconducting properties.”
The National High Magnetic Field Laboratory is funded by the National Science Foundation and the State of Florida. It is operated by a consortium comprising Florida State University, the University of Florida, and Los Alamos National Laboratory, with world-class facilities at all three sites. The NHMFL is a dedicated national user laboratory providing magnets for research in all areas of science, including biology, bio-medical, chemistry, geology, engineering, materials science, and physics. The NHMFL is the largest and highest-powered laboratory of its kind in the world and the only one in the Western Hemisphere.
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