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Title: ORNL Neutron Sciences Update

Abstract

No abstract prepared.

Authors:
 [1]
  1. ORNL
Publication Date:
Research Org.:
High Flux Isotope Reactor; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
931839
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Notiziario Neutroni E Luce di Sincrotrone; Journal Volume: 12; Journal Issue: 2
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; NEUTRONS; ORNL; HFIR REACTOR; Neutron; SNS; HFIR

Citation Formats

Ekkebus, Allen E. ORNL Neutron Sciences Update. United States: N. p., 2007. Web.
Ekkebus, Allen E. ORNL Neutron Sciences Update. United States.
Ekkebus, Allen E. Mon . "ORNL Neutron Sciences Update". United States. doi:.
@article{osti_931839,
title = {ORNL Neutron Sciences Update},
author = {Ekkebus, Allen E},
abstractNote = {No abstract prepared.},
doi = {},
journal = {Notiziario Neutroni E Luce di Sincrotrone},
number = 2,
volume = 12,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • In recent years the discipline of earth sciences at ORNL has grown in recognition. Asked to prepare an overview of the earth sciences in the Environmental Sciences Division (ESD) for the annual information meeting, the author became interested in tracing their evolution before ESD was formed in 1972, as well as in exploring the truly interdisciplinary nature of the earth sciences since ESD was established: the author was struck by the fascinating historical tale that unfolded. What are the earth sciences? Some areas fall easily under this umbrella-geology, geochemistry, and hydrology (the science that treats the distribution, properties, and environmentalmore » behavior of water on the earth), for instance. Others, such as soil science, oceanography, and atmospheric systems, are less obvious. Many engineering disciplines, especially those dealing with chemistry, soils, and groundwater, can be legitimately included. The line of demarcation between areas of {open_quotes}earth science{close_quotes} and {open_quotes}life science{close_quotes} is poorly defined, a situation that seems to encourage interdisciplinary work, as this article reveals. Three messages emerge from the story of the earth sciences in ESD: (1) they have been important to the operation of ORNL since the earliest days; (2) even in those early days, there were individuals sincerely concerned about proper disposal of liquid nuclear waste; and (3) the more things change, the more they seem to stay the same.« less
  • Cited by 7
  • In this paper, we describe the Fundamental Neutron Physics Beamline (FnPB) facility located at the Spallation Neutron Source at Oak Ridge National Laboratory. The FnPB was designed for the conduct of experiments that investigate scientific issues in nuclear physics, particle physics, astrophysics and cosmology using a pulsed slow neutron beam. Finally, we present a detailed description of the design philosophy, beamline components, and measured fluxes of the polychromatic and monochromatic beams.
  • During 2010, the Neutron Sciences Directorate focused on producing world-class science, while supporting the needs of the scientific community. As the instrument, sample environment, and data analysis tools at High Flux Isotope Reactor (HFIR ) and Spallation Neutron Source (SNS) have grown over the last year, so has promising neutron scattering research. This was an exciting year in science, technology, and operations. Some topics discussed are: (1) HFIR and SNS Experiments Take Gordon Battelle Awards for Scientific Discovery - Battelle Memorial Institute presented the inaugural Gordon Battelle Prizes for scientific discovery and technology impact in 2010. Battelle awards the prizesmore » to recognize the most significant advancements at national laboratories that it manages or co-manages. (2) Discovery of Element 117 - As part of an international team of scientists from Russia and the United States, HFIR staff played a pivotal role in the discovery by generating the berkelium used to produce the new element. A total of six atoms of ''ununseptium'' were detected in a two-year campaign employing HFIR and the Radiochemical Engineering Development Center at Oak Ridge National Laboratory (ORNL) and the heavy-ion accelerator capabilities at the Joint Institute for Nuclear Research in Dubna, Russia. The discovery of the new element expands the understanding of the properties of nuclei at extreme numbers of protons and neutrons. The production of a new element and observation of 11 new heaviest isotopes demonstrate the increased stability of super-heavy elements with increasing neutron numbers and provide the strongest evidence to date for the existence of an island of enhanced stability for super-heavy elements. (3) Studies of Iron-Based High-Temperature Superconductors - ORNL applied its distinctive capabilities in neutron scattering, chemistry, physics, and computation to detailed studies of the magnetic excitations of iron-based superconductors (iron pnictides and chalcogenides), a class of materials discovered in 2008. This research is yielding new insights into the relationship between magnetism and superconductivity and has established several key features of this family of high-temperature superconducting (HTS ) materials: the maximum magnetic field at which they can function, the nature of the electrons involved in the superconductivity, the dependence of the properties upon chemical substitution, and the character of the magnetic fluctuations in the material. The results suggest that despite important differences between these materials and the HTS copper oxides, a universal mechanism may be responsible for the unconventional superconductivity. (4) Coal Sequestration Research: A New Home for Greenhouse Gases - One possibility for slowing down the increasing levels of carbon dioxide (CO{sub 2}) in the atmosphere is to capture the gas in natural underground features such as coal seams. Critical to the feasibility of this technology is determining how much CO{sub 2} can be stored, no method for which has been found - until now. (5) Accelerator Reliability Passes 92% - In December 2010, SNS set a new record for itself when the accelerator ran at 1 MW with 100% reliability. Target Performance Exceeds All Expectations - The mercury target used at SNS is the first of its kind. During the design and planning for SNS, many people were skeptical that the target would work. In 2010, it was confirmed that the target was working not only well but much better than anyone would have imagined. (6) Changing the World of Data Acquisition - Researchers at SNS are starting to benefit from event-based data analysis. Event data mode captures and stores an individual data set for every single neutron that strikes a detector - precisely when and where the neutron is detected. This technique provides numerous advantages over traditional methods. Event data mode allows researchers to process their data at the highest resolution possible with no loss of data. This method of data collection provides a much more efficient way for users to gather data and get the most from their beam time. (7) New Laboratories for Users - The HFIR and SNS user communities continue to grow dramatically. In 2010, HFIR hosted 862 users and SNS 796, outpacing projections for both facilities. To meet the needs of those users, a new complex of 13 laboratories is now open for users at SNS. (8) Innovative Detectors Provide Relief from Helium-3 Shortage - Helium-3 ({sup 3}He) has been the gas of choice for gaseous detectors since the early days of neutron science. About two years ago, detector scientists worldwide faced the reality that stockpiles of {sup 3}He are dwindling rapidly, while demand for it has risen by a factor of five. The Neutron Sciences Detectors Group has developed two new types of detectors that don't rely on {sup 3}He: the Anger camera and the wavelength shifting fiber neutron detector, both of which use lithium ({sup 6}Li).« less