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"It's a testament to Brandeis' strength in this
area that the magnet is located on our campus and under our
stewardship," noted Pochapsky.
Brought in by crane and located at a site protected
from large metal objects and radio frequency interference, the
superconducting behemoth was actually energized with about the same
amount of power consumed by a big stereo, Pochapsky explained.
First, the superconducting electric coils that
create the magnetic field were bathed in liquid helium to drop the
temperature to 2 degrees Kelvin or minus 456 degrees Fahrenheit. Once
the coils were supercooled, electric current was able to pass through
them without resistance, creating the magnetic field. Once at field,
the magnet uses no power at all, although the large liquid helium tank
surrounding the coil needs to be refilled every six weeks or so.
Once the magnet has been fully tested, Brandeis
researchers, as well as other Boston-area universities engaged in
NIH-funded biomedical research, will use it around the clock.
Experiments usually run in weeklong blocks, though some may run for
several weeks at a time, according to Pochapsky.
Magnetic resonance is a physical phenomenon based
on the magnetic property of an atom's nucleus. It occurs when the
nuclei of certain atoms are immersed in a static magnetic field and
then exposed to a second oscillating field, causing them to
essentially line up and act in unison, like a battalion of marching
soldiers, said Pochapsky.
The electrons, neutrons and protons within the atom
have an intrinsic property known as "spin" and within the
electromagnetic field created by the magnet, the frequency of the
spinning motion of the atoms reveals information about the physical,
chemical, structural and electronic characteristics of the molecule in
solution.
Magnetic resonance spectroscopy was first described
more than a half century ago, and is related to MRI (magnetic
resonance imaging) used in hospitals as a soft-tissue diagnostic tool.
It is used in chemical and biochemical research because it is the most
sophisticated analytical tool available for determining the
three-dimensional structure and motion of biological molecules in
solution. The average hospital-based MRI has an electromagnetic field
of about 7 Tesla, while this superconducting magnet is more than twice
as powerful, measuring a magnetic field of 18.8 Tesla, said Pochapsky.
"Brandeis has done pioneering work in structural
biology for decades, and this magnet helps keep us at the cutting edge
of research," said Pochapsky. "It's an investment in the future." |
