Neutron Sciences 2008 Annual Report - 17.79 MB - Spallation ...

INTRODUCTION 2008 ANNUAL REPORT
Year in Review ORNL Director Thom Mason with the Guinness World Record award for SNS. The
record was reached when beam power was ramped up to more than 300 kilowatts,
producing 4.8 x 10 16 neutrons per second. With every
increase in power during the year, we continued to break
that record and ended the year at more than twice the
record-breaking power. In total, beam power was increased
to 625 kilowatts—nearly a factor of four.
Saad Elorfi and Andrew Church
work on Slim SAM.
SNS Now Home to World’s First Actively Shielded
Magnet for Neutron Scattering
Neutron scattering scientists often need to apply strong magnetic fields to the
materials they study, but the stray magnetic fields generated can wreak havoc on their (and their neighbors’)
experiments. SNS has taken a big step toward solving this problem by commissioning the world’s
first actively shielded magnet system, known as Slim SAM (SAM = shielded asymmetric magnet), designed
specifically for neutron scattering.
Slim SAM not only eliminates the detrimental effects of stray fields but also offers new opportunities for
the growing number of scientists interested in polarized neutron diffraction. To produce Slim SAM, a team
of ORNL scientists, led by Hal Lee, developed detailed magnetic field profile specifications to ensure superior
polarized beam performance. They drafted a comprehensive solicitation package, evaluated vendor
proposals, and ultimately guided the winning vendor in producing an excellent design.
The past year was exciting and productive, as research
results started to appear in publication, six
new instruments were completed, and technology
developments continued to rise. Many more users
than expected conducted experiments at both SNS
and HFIR, and SNS became the official Guinness
World Record holder for the most powerful pulsed
neutron source.
Science Highlights
High-Temperature Superconductors
Scientists are excited about last year’s discovery of
a new class of high-temperature superconductors
(HTSs). Continuing work begun at other facilities,
researchers from ORNL, the University of Tennessee,
and the National Institute of Standards and
Technology conducted groundbreaking experiments
confirming that the iron-based materials were indeed
superconductors at 43 kelvin, a higher temperature
than any recorded conventional superconductor. This
work is helping shed a light on the puzzling phenomenon
of how HTSs work, which, when better understood,
could have a tremendous impact on energy
use.
Protein Studies on Huntington’s Disease
Scientists are studying the aggregation of protein
fibrils (threadlike fibers) to determine their role in
ORNL NEUTRON SCIENCES The Next Generation of Materials Research
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INTRODUCTION
INTRODUCTION