A5084824518- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Particle accelerators and beam dynamics
- Quantum, superfluid, helium dynamics
- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Radiation Therapy and Dosimetry
- Dark Matter and Cosmic Phenomena
- Graphite, nuclear technology, radiation studies
- Particle Detector Development and Performance
- Magnetic confinement fusion research
- Advanced NMR Techniques and Applications
- High-pressure geophysics and materials
- Particle Accelerators and Free-Electron Lasers
- Nuclear physics research studies
- NMR spectroscopy and applications
- Methane Hydrates and Related Phenomena
- Quantum Chromodynamics and Particle Interactions
- Nuclear and radioactivity studies
- Spacecraft and Cryogenic Technologies
- X-ray Diffraction in Crystallography
- Astrophysics and Cosmic Phenomena
- Superconducting Materials and Applications
Oak Ridge National Laboratory
2015-2024
Spallation Neutron Source
2002-2023
Office of Scientific and Technical Information
2023
National Technical Information Service
2023
Oak Ridge Associated Universities
2016
Argonne National Laboratory
1997-1999
Massachusetts Institute of Technology
1997
The coherent elastic scattering of neutrinos off nuclei has eluded detection for four decades, even though its predicted cross section is by far the largest all low-energy neutrino couplings. This mode interaction offers new opportunities to study properties and leads a miniaturization detector size, with potential technological applications. We observed this process at 6.7σ confidence level, using low-background, 14.6-kilogram CsI[Na] scintillator exposed emissions from Spallation Neutron...
The design and performance of the new cold neutron chopper spectrometer (CNCS) at Spallation Neutron Source in Oak Ridge are described. CNCS is a direct-geometry inelastic time-of-flight spectrometer, designed essentially to cover same energy momentum transfer ranges as IN5 ILL, LET ISIS, DCS NIST, TOFTOF FRM-II, AMATERAS J-PARC, PHAROS LANSCE, NEAT HZB, similar resolution. Measured values key figures such flux sample position resolution compared between measurements ray tracing Monte Carlo...
The neutron powder diffractometer POWGEN at the Spallation Neutron Source has recently (2017-2018) undergone an upgrade which resulted in increased detector complement along with a full overhaul of structural design instrument. current instrument solid angular coverage 1.2 steradians and maintains original third-generation concept, providing single-histogram data set over wide d-spacing range high resolution to access large unit cells, detailed refinements situ/operando measurements.
The violation of Baryon Number, $\mathcal{B}$, is an essential ingredient for the preferential creation matter over antimatter needed to account observed baryon asymmetry in universe. However, such a process has yet be experimentally observed. HIBEAM/NNBAR %experiment program proposed two-stage experiment at European Spallation Source (ESS) search number violation. will include high-sensitivity searches processes that violate by one or two units: free neutron-antineutron oscillation...
The Macromolecular Neutron Diffractometer (MaNDi) is located on beamline 11B of the Spallation Source at Oak Ridge National Laboratory. instrument a neutron time-of-flight wavelength-resolved Laue diffractometer optimized to collect diffraction data from single crystals. has been designed provide flexibility in several instrumental parameters, such as beam divergence and wavelength bandwidth, allow collection range macromolecular systems.
An unexplained >4σ discrepancy persists between "beam" and "bottle" measurements of the neutron lifetime. A new model proposed that conversions neutrons n into mirror n^{'}, part a dark sector, can increase apparent lifetime by 1% via small mass splitting Δm n^{'} inside 4.6 T magnetic field National Institute Standards Technology Beam Lifetime experiment. search for in 6.6 was performed at Spallation Neutron Source which excludes this explanation discrepancy.
Interaction of molecular hydrogen with the surface ortho–para conversion catalyst.
We report the first observation of parity-violating 2.2 MeV gamma-ray asymmetry $A^{np}_\gamma$ in neutron-proton capture using polarized cold neutrons incident on a liquid parahydrogen target at Spallation Neutron Source Oak Ridge National Laboratory. isolates $\Delta I=1$, \mbox{$^{3}S_{1}\rightarrow {^{3}P_{1}}$} component weak nucleon-nucleon interaction, which is dominated by pion exchange and can be directly related to single coupling constant either DDH meson model or pionless EFT....
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is a pulsed source of neutrons and, as by-product this operation, an intense neutrinos via stopped-pion decay. COHERENT collaboration uses to investigate coherent elastic neutrino-nucleus scattering and other physics with suite detectors. This work includes description our geant4 simulation neutrino production the SNS flux calculation which informs studies. We estimate uncertainty $\ensuremath{\sim}10%$ level based on...
On Friday June 26, 2009, the neutron beam shutter for VULCAN diffractometer at SNS was opened first time. Initial measurements to characterize instrument performance are reported. It is shown that measurement results by and large in agreement with design calculations. New research opportunities discussed.
Instrument backgrounds at neutron scattering facilities directly affect the quality and efficiency of scientific measurements that users perform. Part background pulsed spallation sources is caused by, time-correlated with, emission high energy particles when proton beam strikes target. This prompt pulse ultimately produces a signal, which can be highly problematic for subset instruments due to properties, different from reactor sources. Measurements this have been made both SNS (ORNL, Oak...
The possibility of relatively fast neutron oscillations into a mirror state is not excluded experimentally when magnetic field considered. Direct searches for the disappearance neutrons in controlled have previously been performed using ultracold neutrons, with some anomalous results reported. We describe technique cold to perform and regeneration search, which would allow us unambiguously identify possible oscillation signal. An experiment existing General Purpose-Small Angle Neutron...
We report the first precision measurement of parity-violating asymmetry in direction proton momentum with respect to neutron spin, reaction ^{3}He(n,p)^{3}H, using capture polarized cold neutrons an unpolarized active ^{3}He target. The is a result weak interaction between nucleons, which remains one least well-understood aspects electroweak theory. provides important benchmark for modern effective field theory and potential model calculations. Measurements like this are necessary determine...
Conversions between neutrons <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>n</a:mi></a:math> and dark matter candidate sterile <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msup><c:mi>n</c:mi><c:mo>′</c:mo></c:msup></c:math> have been proposed as a mechanism for baryon number <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mi mathvariant="script">B</e:mi></e:math> violation. In the case that there is small mass...