Electrochemical Small-Angle Neutron Scattering

97 Pages·2012·6.63 MB·English

H+
Cu2+ ON THE COVER
Neutron powder diffraction pattern of a chabazite
zeolite that is a good candidate for CO absorption,
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indicating high selectivity sites.
See the highlight article by Hudson et al. on p.16
NIST Center for Neutron Research
2012
Accomplishments
and
Opportunities
NIST Special Publication 1143
Robert M. Dimeo, Director
Ronald L. Cappelletti, Editor
December 2012
National Institute of Standards and Technology
Patrick Gallagher, Under Secretary of Commerce
for Standards and Technology, Director
U.S. Department of Commerce
Rebecca Blank, Acting Secretary
2012 ACCOMPLISHMENTS AND OPPORTUNITIES
DISCLAIMER
Certain commercial entities, equipment, or materials may be
identified in this document in order to describe an experimental
procedure or concept adequately. Such identification is not
intended to imply recommendation or endorsement by the
National Institute of Standards and Technology, nor is it
intended to imply that the entities, materials, or equipment
are necessarily the best available for the purpose.
National Institute of Standards and Technology
Special Publications 1143
Natl. Inst. Stand. Technol. Spec. Publ. 1143, 92 pages
(December 2012)
CODEN: NSPUE2
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WASHINGTON: 2012
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NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY – NIST CENTER FOR NEUTRON RESEARCH
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Table of Contents T
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FOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iii f

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THE NIST CENTER FOR NEUTRON RESEARCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
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NIST CENTER FOR NEUTRON RESEARCH INSTRUMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
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NCNR IMAGES 2011 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 n
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HIGHLIGHTS
ARCHEOLOGY
Foreigners or not: new data prior to the Maya collapse in the western lowlands of mesoamerica,
R. Bishop, et al. ........................................................................ 6
BIOLOGY
Walking the line between life and death: membrane binding and regulation of
the PTEN tumor suppressor, S. S. Shenoy, et al. ............................................... 8
Towards the elucidation of antiboitic resistance transfer in bacteria: structural studies
of the Tral protein, N.T. Wright, et al. (CHRNS) .............................................10
Structures and conformations of voltage-sensor domains and voltage-gated K+
channel proteins, S. Gupta, et al. ..........................................................12
The role of electrostatic interactions in the local dynamics of biological and
synthetic polyelectrolytes, J.H. Roh, et al. (CHRNS) ...........................................14
CHEMICAL PHYSICS
Powder neutron diffraction reveals new CO adsorption interactions in chabazite
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zeolites, M.R. Hudson, et al. (CHRNS) ....................................................16
Evolving structure of the solid electrolyte interphase in Li-ion batteries characterized
by in situ neutron reflectometry, J.A. Dura, et al. ..............................................18
Activated dihydrogen bonding to a supported organometallic compound,
J.M. Simmons, et al. (CHRNS) ..........................................................20
CONDENSED MATTER
Electronic delocalization in the correlation gap insulator LaMnPO, J.W. Simonson, et al. ...............22
Spin-orbital short-range order on a honeycomb-based lattice, S. Nakatsuji, et al. (CHRNS) .............24
Common origin of the two types of magnetic excitations in iron chalcogenide
superconductors, Songxue Chi, et al. (CHRNS) ..............................................26
Correlation between spin-flop transition and enhanced spin polarized supercurrents in
ferromagnetic Josephson junctions, C. Klose, et al. ............................................28
Charge ordering and magnetic frustration in the fluoride pyrochlore, RbFe2+Fe3+F , S.W. Kim, et al. ......30
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2012 ACCOMPLISHMENTS AND OPPORTUNITIES
T Table of Contents
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Measuring yield stresses in biaxial deformation, T. Gnäupel-Herold, et al. ...........................32
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NEUTRON PHYSICS
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Self-assembling organohydrogels: liquid dispersions with solid-like behavior,
M.E. Helgeson, et al. (CHRNS) ..........................................................36
Thickness fluctuations in model membranes, A.C. Woodka, et al. (CHRNS) .........................38
Electrochemical Small-Angle Neutron Scattering (eSANS) for studies of nanoparticle
redox reactions, V.M. Prabhu, et al. (CHRNS) ...............................................40
Identifying the shape of copper-seamed nanocapsules in solution, H. Kumari, et al. (CHRNS) ..........42
Characterizing dense polymer-nanoparticle mixtures by neutron scattering, S.Y. Kim, et al. (CHRNS) .....44
ADVANCES IN MEASUREMENT
A Liquid Deuterium Cold Neutron Source for the NBSR, R.E. Williams, et al. ......................46
EXPANSION ACTIVITIES DURING THE PLANNED OUTAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
NEUTRON SOURCE OPERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
FACILITY DEVELOPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
SERVING THE SCIENCE AND TECHNOLOGY COMMUNITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
THE CENTER FOR HIGH RESOLUTION NEUTRON SCATTERING (CHRNS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
2012 AWARDS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
PUBLICATIONS: AUGUST 1, 2011 TO JULY 31, 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
INSTRUMENTS AND CONTACTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
NIST CENTER FOR NEUTRON RESEARCH CONTACTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (inside back cover)
NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY – NIST CENTER FOR NEUTRON RESEARCH
Foreword F
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t is with pleasure that I present this year’s annual report for the NIST Center for Neutron Research. r
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When looking back over the last year, the only word that I can use to describe this time period is
dynamic. User operations were successful and productive, the reactor operating for 142 days out of a
scheduled 142 days. The cold source continued to operate reliably and deliver neutrons 99 % of the
scheduled operating time. This period was marked by considerable scientific productivity and impact as the
highlights in this report illustrate. The productivity is due to many factors, but it is worth noting that the
number of user experiments on the MACS spectrometer continued to grow as the amount of time available
to the user community was increased, industrial research participation on many of the neutron instruments,
especially uSANS, was strong, and research opportunities with other laboratories grew, particularly in the area
of biology and biosciences. Moreover, significant progress was made towards bringing the isotope labeling laboratory on line which will
certainly prove to be a valuable resource for NCNR users.
This year was also marked by a period of many facility enhancements that can best be described as historic. On April 3, the reactor shut
down, as planned, for a period of 11 months. As I described in last year’s annual report this outage was scheduled in order to execute
many tasks towards the expansion of our cold neutron measurement capability and enhance the reliability of the reactor. A few of the
activities include installation of a new neutron guide system in our expanded guide hall which will hold new and relocated instruments,
installation of a new cold source dedicated to the MACS instrument, relocation of MACS, and installation of a new cooling system for
the reactor’s thermal shield. In addition significant construction in and around the site has taken place during the outage, including
the construction of a new secondary cooling system, the addition of a new cooling tower cell, and additional electrical capacity. The
commencement and execution of this outage marks the culmination of a significant amount of planning and coordination as well
as the hard work and diligent efforts of our staff, especially those from Reactor Operations and Engineering and Research Facility
Operations. You can read more about the progress we have made during the outage within this report and on our website: http://www.
ncnr.nist.gov/expansion2/ where you will find technical details and photos. I am also pleased to inform you of the release this year of an
informal history, “The NIST Center for Neutron Research: Over 40 Years Serving NIST/NBS and the Nation”, by Jack Rush and Ron
Cappelletti, NIST Special Publication 1120. Contained therein is an account of major events of the NCNR spanning the period from
conception of the NIST reactor to the NCNR Expansion Project.
As of this writing we just announced our first call for proposals for experiments to be run upon restart of the reactor. In just a few short
months the reactor will restart and users will return to the NCNR. The reason for the outage and expansion is for you, our users. I
am looking forward to restoration of user operations and especially offering new measurement capabilities that our expansion project
will provide through the coming year. I invite you to take a look at the research highlights from the past year as well as the description
of what we have been up to during the outage. As you read through this report, I hope you get the same sense of excitement and
opportunity that we are all feeling here.
2012 ACCOMPLISHMENTS AND OPPORTUNITIES
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A view of new guides emerging into the guide hall in a Nov . 6, 2012 photo . The group of people is standing by NG-D, emerging through the square hole
just to their right . Behind them are shields blocking the view of the newly installed PBR and MAGIk instruments, taking beams off the side of NG-D . The
guide visible just behind the striped safety marker is NG-C, and to its right, emerging from NG-Blower, is the tank of the 10 m SANS instrument being
installed . NG-Bupper is behind the two grey shields to the left of the tank . Not visible is NG-A, to the right of the 10 m SANS, still under development .
NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY – NIST CENTER FOR NEUTRON RESEARCH
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The NIST Center for Neutron Research T
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eutrons provide a uniquely effective probe of
the structure and dynamics of materials ranging Why Neutrons? I
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from water moving near the surface of proteins to
Neutrons reveal properties not readily probed by T
magnetic domains in memory storage materials.
The properties of neutrons (outlined at left) can be exploited photons or electrons . They are electrically neutral
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using a variety of measurement techniques to provide and therefore easily penetrate ordinary matter . They
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information not otherwise available. The positions of atomic behave like microscopic magnets, propagate as
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nuclei in crystals, especially of those of light atoms, can waves, can set particles into motion, losing or gaining
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be determined precisely. Atomic motion can be directly energy and momentum in the process, and they can e
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measured and monitored as a function of temperature or
be absorbed with subsequent emission of radiation to
pressure. Neutrons are especially sensitive to hydrogen, f
uniquely fingerprint chemical elements . o
so that hydrogen motion can be followed in H-storage r
materials and water flow in fuel cells can be imaged. WAVELENGTHS − in practice range from ≈ 0 .01 nm
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Residual stresses such as those deep within oil pipelines (thermal) to ≈ 1 .5 nm (cold) (1 nm = 10 Å), allowing the
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or in highway trusses can be mapped. Neutron-based formation of observable interference patterns when
u
measurements contribute to a broad spectrum of activities
scattered from structures as small as atoms to as large t
including in engineering, materials development, polymer r
as biological cells .
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dynamics, chemical technology, medicine, and physics.
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ENERGIES − of millielectronvolts, the same magnitude

The NCNR’s neutron source provides the intense, conditioned as atomic motions . Exchanges of energy as small R
beams of neutrons required for these types of measurements. In
as nanoelectronvolts and as large as tenths of e
addition to the thermal neutron beams from the heavy water or s
electronvolts can be detected between samples and e
graphite moderators, the NCNR has a large area liquid hydrogen
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neutrons, allowing motions in folding proteins, melting
moderator, or cold source, that provides long wavelength guided r
neutron beams for the major cold neutron facility in the U.S. glasses and diffusing hydrogen to be measured . c
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SELECTIVITY − in scattering power varies from nucleus
There are currently 27 experiment stations: four provide
to nucleus somewhat randomly . Specific isotopes
high neutron flux positions for irradiation, and 23 are beam
can stand out from other isotopes of the same kind
facilities most of which are used for neutron scattering research.
The subsequent pages provide a schematic description of our of atom . Specific light atoms, difficult to observe with
instruments. More complete descriptions can be found at x-rays, are revealed by neutrons . Hydrogen, especially,
www.ncnr.nist.gov/instruments/. Construction of a second guide can be distinguished from chemically equivalent
hall is now complete (see p. 47) and five new instruments are deuterium, allowing a variety of powerful contrast
under development. techniques .
The Center supports important NIST measurement needs, but MAGNETISM − makes the neutron sensitive to the
is also operated as a major national user facility with merit- magnetic moments of both nuclei and electrons,
based access made available to the entire U.S. technological
allowing the structure and behavior of ordinary and
community. Each year, about 2000 research participants from
exotic magnetic materials to be detailed precisely .
government, industry, and academia from all areas of the country
are served by the facility (see p.57). Beam time for research to NEUTRALITY − of the uncharged neutrons allows
be published in the open literature is without cost to the user, them to penetrate deeply without destroying samples,
but full operating costs are recovered for proprietary research. passing through walls that condition a sample’s
Access is gained mainly through a web-based, peer-reviewed environment, permitting measurements under
proposal system with user time allotted by a beamtime allocation
extreme conditions of temperature and pressure .
committee twice a year. For details see www.ncnr.nist.gov/
beamtime.html. The National Science Foundation and NIST CAPTURE − characteristic radiation emanating from
co-fund the Center for High Resolution Neutron Scattering specific nuclei capturing incident neutrons can be used
(CHRNS) that operates six of the world’s most advanced to identify and quantify minute amounts of elements
instruments (see p. 60). Time on CHRNS instruments is made in samples as diverse as ancient pottery shards and
available through the proposal system. Some access to beam time
lake water pollutants .
for collaborative measurements with the NIST science staff can
also be arranged on other instruments.
2012 ACCOMPLISHMENTS AND OPPORTUNITIES
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