scholarly journals The suite of small-angle neutron scattering instruments at Oak Ridge National Laboratory

2018 ◽  
Vol 51 (2) ◽  
pp. 242-248 ◽  
Author(s):  
William T. Heller ◽  
Matthew Cuneo ◽  
Lisa Debeer-Schmitt ◽  
Changwoo Do ◽  
Lilin He ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Large Scale ◽  
National Laboratory ◽  
High Flux ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Oak Ridge National Laboratory ◽  
Scale Structures

Oak Ridge National Laboratory is home to the High Flux Isotope Reactor (HFIR), a high-flux research reactor, and the Spallation Neutron Source (SNS), the world's most intense source of pulsed neutron beams. The unique co-localization of these two sources provided an opportunity to develop a suite of complementary small-angle neutron scattering instruments for studies of large-scale structures: the GP-SANS and Bio-SANS instruments at the HFIR and the EQ-SANS and TOF-USANS instruments at the SNS. This article provides an overview of the capabilities of the suite of instruments, with specific emphasis on how they complement each other. A description of the plans for future developments including greater integration of the suite into a single point of entry for neutron scattering studies of large-scale structures is also provided.

The Bio-SANS Small-Angle Neutron Scattering Instrument at Oak Ridge National Laboratory

Neutron News ◽  
2008 ◽  
Vol 19 (2) ◽  
pp. 22-23 ◽  
Author(s):  
William T. Heller ◽  
Gary W. Lynn ◽  
Volker S. Urban ◽  
Kevin Weiss ◽  
Dean A.A. Myles
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
National Laboratory ◽  
Oak Ridge ◽  
Oak Ridge National Laboratory

The 40 m general purpose small-angle neutron scattering instrument at Oak Ridge National Laboratory

2012 ◽  
Vol 45 (5) ◽  
pp. 990-998 ◽  
Author(s):  
George D. Wignall ◽  
Kenneth C. Littrell ◽  
William T. Heller ◽  
Yuri B. Melnichenko ◽  
Kathy M. Bailey ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
National Laboratory ◽  
Scattering Data ◽  
Large Area ◽  
High Count ◽  
Incident Wavelength ◽  
Oak Ridge ◽  
Oak Ridge National Laboratory

A series of upgrades have been undertaken at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, including the installation of a supercritical hydrogen moderator (T≃ 20 K), which has boosted the flux of long-wavelength neutrons by over two orders of magnitude. In order to take advantage of the new capabilities, a 40 m-long small-angle neutron scattering (SANS) instrument has been constructed, which utilizes a mechanical velocity selector, pinhole collimation and a high-count-rate (>105 Hz) large-area (1 m2) two-dimensional position-sensitive detector. The incident wavelength (λ), resolution (Δλ/λ), incident collimation and sample-to-detector distance are independently variable under computer control. The detector can be moved up to 45 cm off-axis to increase the overallQrange [<0.001 <Q= (4π/λ)sinθ < 1 Å−1, where 2θ is the angle of scatter]. The design and characteristics of this instrument are described, along with examples of scattering data to illustrate the performance.

scholarly journals New search for mirror neutron regeneration

2019 ◽  
Vol 219 ◽  
pp. 07002
Author(s):  
L.J. Broussard ◽  
K.M. Bailey ◽  
W.B. Bailey ◽  
J.L. Barrow ◽  
K. Berry ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
National Laboratory ◽  
General Purpose ◽  
High Flux ◽  
Neutron Lifetime ◽  
Neutron State ◽  
Oak Ridge ◽  
Cold Neutrons

The possibility of relatively fast neutron oscillations into a mirror neutron state is not excluded experimentally when a mirror magnetic field is considered. Direct searches for the disappearance of neutrons into mirror neutrons in a controlled magnetic field have previously been performed using ultracold neutrons, with some anomalous results reported. We describe a technique using cold neutrons to perform a disappearance and regeneration search, which would allow us to unambiguously identify a possible oscillation signal. An experiment using the existing General Purpose-Small Angle Neutron Scattering instrument at the High Flux Isotope Reactor at Oak Ridge National Laboratory will have the sensitivity to fully explore the parameter space of prior ultracold neutron searches and confirm or refute previous claims of observation. This instrument can also conclusively test the validity of recently suggested oscillation-based explanations for the neutron lifetime anomaly.

The Bio-SANS instrument at the High Flux Isotope Reactor of Oak Ridge National Laboratory

2014 ◽  
Vol 47 (4) ◽  
pp. 1238-1246 ◽  
Author(s):  
William T. Heller ◽  
Volker S. Urban ◽  
Gary W. Lynn ◽  
Kevin L. Weiss ◽  
Hugh M. O'Neill ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
National Laboratory ◽  
Isotopic Labeling ◽  
High Flux ◽  
Oak Ridge ◽  
Oak Ridge National Laboratory ◽  
User Facility ◽  
Technical Specifications ◽  
And Performance ◽  
Sans Instrument

Small-angle neutron scattering (SANS) is a powerful tool for characterizing complex disordered materials, including biological materials. The Bio-SANS instrument of the High Flux Isotope Reactor of Oak Ridge National Laboratory (ORNL) is a high-flux low-background SANS instrument that is, uniquely among SANS instruments, dedicated to serving the needs of the structural biology and biomaterials communities as an open-access user facility. Here, the technical specifications and performance of the Bio-SANS are presented. Sample environments developed to address the needs of the user program of the instrument are also presented. Further, the isotopic labeling and sample preparation capabilities available in the Bio-Deuteration Laboratory for users of the Bio-SANS and other neutron scattering instruments at ORNL are described. Finally, a brief survey of research performed using the Bio-SANS is presented, which demonstrates the breadth of the research that the instrument's user community engages in.

DCD USANS and SESANS: a comparison of two neutron scattering techniques applicable for the study of large-scale structures

2013 ◽  
Vol 46 (2) ◽  
pp. 354-364 ◽  
Author(s):  
Christine Rehm ◽  
John Barker ◽  
Wim G. Bouwman ◽  
Roger Pynn
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Large Scale ◽  
Bragg Reflection ◽  
Spin Echo ◽  
Double Crystal ◽  
Large Scale Structures ◽  
Silicon Crystals ◽  
Performance Gains

This paper provides a comparison of the capabilities of two techniques for extending the range of conventional small-angle neutron scattering (SANS) towards the micrometre length scale, namely the double-crystal diffraction ultra-small-angle neutron scattering (DCD USANS) technique, which uses perfect silicon crystals in Bragg reflection, and spin-echo SANS (SESANS), a method that uses the spin precessions of a polarized neutron beam. Both methods encode the scattering angle to very high precision. Based on round-robin test measurements, the strengths and weaknesses of the two techniques are discussed with respect to the measurement of the particle size of monodisperse scatterers, and potential performance gains for state-of-the-art DCD USANS and SESANS instruments are investigated.

First data acquired on the extendedQ-range small-angle neutron scattering (EQ-SANS) diffractometer at the Spallation Neutron Source

2011 ◽  
Vol 44 (5) ◽  
pp. 1120-1122 ◽  
Author(s):  
Dazhi Liu ◽  
Kunlun Hong ◽  
Carrie Y. Gao ◽  
Yuri Melnichenko ◽  
Ken Littrell ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Neutron Source ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
National Laboratory ◽  
Model Fitting ◽  
Scattering Data ◽  
Radius Of Gyration ◽  
Spallation Neutron Source ◽  
Oak Ridge

Initial experimental results are reported from the extendedQ-range small-angle neutron scattering (EQ-SANS) diffractometer at the Spallation Neutron Source at Oak Ridge National Laboratory (ORNL). A generation-8 polyamidoamine dendrimer was measured and the conformation parameters (radius of gyration, thickness of the soft shelletc.) extracted by model fitting to the scattering data. The results are compared with data collected at the general-purpose small-angle neutron scattering (GP-SANS) beamline at the High-Flux Isotopic Reactor at ORNL and show that EQ-SANS is ready for scientific studies for the small-angle neutron scattering community.

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

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