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Warm Detectors Look At Brain Magnetism |
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News -
Experimental Methods and Techiques
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Written by xScience.Info
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Tuesday, 05 December 2006 |
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 Three-layer magnetic shields for the brain imager. Patient's brain on top of the imaging cell.
Michael Romalis, a Princeton University physicist, detects the brain's faint
magnetic fields using instead a vessel filled with potassium atoms,
which have been polarized by a laser beam. The brain fields cause
the potassium atoms to precess in a measurable way. Already, Romalis
says, his device has attained a sensitivity
30 times better than previous atomic magnetometers used for
biosensors, and a spatial resolution comparable to that for SQUIDs,
with the prospect of improving by another factor of ten.
In a related
paper, Romalis's group in collaboration with Karen Sauer from George
Mason University used a different kind of potassium magnetometer to detect
radio-frequency signals generated by ammonium nitrate (which is
often
used in explosives) with a sensitivity some 10 times better than
with conventional devices.
Source: AIP
Related Links:
Xia et
al. and Lee
et al., two articles
in Applied Physics Letters, 20 November 2006.
Romalis's Web page
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