Shielding

1
A neutron microscope for nano-scale motion in
new materials Collin Broholm, Johns Hopkins
University, DMR 0116585
MACS will open a new window on atomic scale
structure and dynamics at the early stages of
materials development. Located at the NIST center
for neutron research, the instrument employs a
bold new configuration to probe minute crystals
and man-made nano-structures.
20 channel detection system
Shielding
Helium
20 ft
2
Maximizing neutron flux on small hot samples
Collin Broholm, Johns Hopkins University, DMR
0116585
High flux on small samples is achieved through a
neutron focusing Bragg lens. The device
reflects and concentrates neutrons from an area
of 221 square inches to the sample. The flux will
exceed that of conventional instrumentation by
more than an order of magnitude.
The PI inspects the MACS incident beam line at
the NIST Center for neutron research. Buried
within shielding is the neutron focusing Bragg
lens, which moves along the reactor beam to
select different neutron energies. The circular
region where the PI stands will accommodate an
adjustable super-mirror guide that further
concentrates reflected neutrons on the sample.
357 pieces of graphite are accurately positioned
to form a Bragg lens for exploring the
nano-world. It was built at Johns Hopkins
University by engineers with previous expertise
in optics for astronomy
Engineering by P. Brand, M. English, R.Hammond,
P. Hundertmark, J. LaRock, J. Moyer, J. Orndorff,
D. Pierce, T. Pike, G. Scharfstein, S. Smee, et
al.
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Window on the nano-world A multi-channel
neutron detector Collin Broholm, Johns Hopkins
University, DMR 0116585
20
The centerpiece in each channel is a vertically
focusing double crystal analyzer system actuated
by a single motor.
20 channels operate simultaneously to detect an
order of magnitude more neutrons than
conventional instrumentation.
Neutron scattering showing quasi-particle decay
in a quantum spin liquid (Stone et al Science
(2006))
Engineering by C. Brocker, Z. Huang, P.
Hundertmark, N. Maliszewskyj, T. Pike et al.