New Magnet Design Could Shed Light On Nanoscience
Posted on Wednesday, October 31, 2007 @ 21:48:06 UTC by vlad
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 Engineers at Florida State University’s National High Magnetic Field
Laboratory have successfully tested a groundbreaking new magnet design
that could literally shed new light on nanoscience and semiconductor
research.
When the magnet -- called the
Split Florida Helix -- is operational in 2010, researchers will have
the ability to direct and scatter laser light at a sample not only down
the bore, or center, of the magnet, but also from four ports on the
sides of the magnet, while still reaching fields above 25 tesla. By
comparison, the highest-field split magnet in the world attains 18
tesla. “Tesla” is a measurement of the strength of a magnetic field; 1 tesla is equal to 20,000 times the Earth’s magnetic field.
Magnetism is a critical
component of a surprising number of modern technologies, including MRIs
and disk drives, and high-field magnets stand beside lasers and
microscopes as essential research tools for probing the mysteries of
nature. With this new magnet, scientists will be able to expand the
scope of their experimental approach, learning more about the intrinsic
properties of materials by shining light on crystals from angles not
previously available in such high magnetic fields.
In materials research, scientists look at which kinds of light are
absorbed or reflected at different crystal angles, giving them insight
into the fundamental electronic structure of matter.
The Split Florida Helix design
represents a significant accomplishment for the magnet lab’s
engineering staff. High magnetic fields exert tremendous forces inside
the magnet, and those forces are directed at the small space in the
middle . . . that’s where Mag Lab engineers cut big holes in it.
“You have enough to worry about with traditional magnets, and then
you try to cut huge holes from all four sides from which you can access
the magnet,” said lab engineer Jack Toth, who is spearheading the
project. “Basically, near the midplane, more than half of the magnet
structure is cut away for the access ports, and it’s still supposed to
work and make high magnetic fields.”
Magnet engineers worldwide have been trying to solve the problem of
creating a magnet with side access at the midsection, but they have met
with little success in higher fields. Magnets are created by packing
together dense, high-performance copper alloys and running a current
through them, so carving out empty space at the heart of a magnet
presents a huge engineering challenge.
Instead of fashioning a tiny pinhole to create as little disruption
as possible, as other labs have tried, Toth and his team created a
design with four big elliptical ports crossing right through the
midsection of the magnet. The ports open 50 percent of the total space
available for experiments, a capability the laboratory’s visiting
scientists have long desired.
“It’s different from any traditional magnet that we’ve ever built
before, and even the fabrication of our new parts was very
challenging,” Toth said. “In search of a vendor for manufacturing the
prototypes, I had phone conversations where people would promise me,
‘Jack, we looked at it from every possible angle and this part is
impossible to machine.’”
Of course, that wasn’t the case, and the model coil, crafted from a
mix of copper-beryllium blocks and copper-silver plates, met
expectations during its testing in a field higher than 32 tesla with no
damage to its parts.
Though the National Science Foundation-funded model has reached an
important milestone, years of work will go into the final product. The
lab hopes to have a working magnet for its User Program by 2010, and
other research facilities have expressed great interest in having split
magnets that can generate high magnetic fields.
Source: FSU
Via: http://www.physorg.com/news113061219.html
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