The research group
of Alex Pines has recorded the first bulk room-temperature NMR
hyperpolarization
of carbon-13 nuclei in diamond in situ at arbitrary
magnetic fields
and crystal orientations. (Photo by Christophoros Vassiliou)
(December 17, 2015) Berkeley
Lab/UC Berkeley Researchers Increase NMR/MRI Sensitivity through
Hyperpolarization of Nuclei in Diamond
Researchers with the U.S. Department of Energy (DOE)’s
Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of
California (UC) Berkeley have demonstrated that diamonds may hold the key to
the future for nuclear magnetic resonance (NMR) and magnetic resonance imaging
(MRI) technologies
In a study led by Alexander Pines, a senior faculty
scientist with Berkeley Lab’s Materials Sciences Division and UC Berkeley’s
Glenn T. Seaborg Professor of Chemistry, researchers recorded the first bulk
room-temperature NMR hyperpolarization of carbon-13 nuclei in diamond in situ
at arbitrary magnetic fields and crystal orientations. The signal of the
hyperpolarized carbon-13 spins showed an enhancement of NMR/MRI signal
sensitivity by many orders of magnitude above what is ordinarily possible with
conventional NMR/MRI magnets at room temperature. Furthermore, this
hyperpolarization was achieved with microwaves, rather than relying on precise
magnetic fields for hyperpolarization transfer.
(From left)
Claudia Avalos, Keunhong Jeong and Jonathan King were part of a team
led by Alex Pines
that used microwaves to enhance NMR/MRI signal sensitivity
many orders of
magnitude above what is ordinarily possible with conventional
NMR/MRI magnets at
room temperature. (Photo by Roy Kaltschmidt)
The authors report the observation of a bulk nuclear spin
polarization of six-percent, which is an NMR signal enhancement of
approximately 170,000 times over thermal equilibrium. The signal of the
hyperpolarized spins was detected in situ with a standard NMR probe without the
need for sample shuttling or precise crystal orientation. The authors believe
this new hyperpolarization technique should enable orders of magnitude
sensitivity enhancement for NMR studies of solids and liquids under ambient conditions.
