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1

HFIR History - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Home › Facilities › HFIR › History Home › Facilities › HFIR › History History of HFIR HFIR was constructed in the mid-1960s to fulfill a need for the production of transuranic isotopes (i.e., "heavy" elements such as plutonium and curium). Since then its mission has grown to include materials irradiation, neutron activation, and, most recently, neutron scattering. In 2007, HFIR completed the most dramatic transformation in its 40-year history. During a shutdown of more than a year, the facility was refurbished and a number of new instruments were installed, as well as a cold neutron source. The reactor was restarted in mid-May; it attained its full power of 85 MW within a couple of days, and experiments resumed within a week. Improvements and upgrades to HFIR include an overhaul of the

2

Neutron Irradiation of Hydrided Cladding Material in HFIR Summary...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Neutron Irradiation of Hydrided Cladding Material in HFIR Summary of Initial Activities Neutron Irradiation of Hydrided Cladding Material in HFIR Summary of Initial Activities...

3

Spallation Neutron Source, SNS  

NLE Websites -- All DOE Office Websites (Extended Search)

Spallation Neutron Source Spallation Neutron Source Providing the most intense pulsed neutron beams in the world... Accumulator Ring Commissioning Latest Step for Spallation Neutron Source The Spallation Neutron Source, located at Oak Ridge National Laboratory, has passed another milestone on the way to completion this year--the commissioning of the proton accumulator ring. Brookhaven led the design and construction of the accumulator ring, which will allow an order of magnitude more beam power than any other facility in the world. The Spallation Neutron Source (SNS) is an accelerator-based neutron source being built in Oak Ridge, Tennessee, by the U.S. Department of Energy. The figure on the right shows a schematic of the accumulator ring and transport beam lines that are being designed and built by Brookhaven

4

HFIR Experiment Facilities | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Scattering Scattering Neutron Scattering Facilities at HFIR The fully instrumented HFIR will eventually include 15 state-of-the-art neutron scattering instruments, seven of which will be designed exclusively for cold neutron experiments, located in a guide hall south of the reactor building. The currently available instruments and the status of new instruments can be found on the HFIR Instrument Systems pages. Particularly prominent in the cold neutron guide hall are the two small-angle neutron scattering (SANS) instruments, each terminating in a 70-ft-long evacuated cylinder containing a large moveable neutron detector. In addition to the instruments, laboratories are equipped for users to prepare samples. Perhaps the most exciting development at HFIR is the successfully

5

HFIR Instrument Systems | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Click for more information about the HFIR beamline Experiment Hall Click for more information about the HFIR beamline Experiment Hall HFIR instrument layout. Click for details. Instruments at the High Flux Isotope Reactor The instrument suite at HFIR is supported by a variety of sample environments and on-site laboratories for user convenience. If you're unsure which instrument(s) would most benefit your research, or if you would like to request capabilities that you don't see here, please contact our user office. All HFIR Instrument fact sheets are also available in this single PDF document. Available to Users Beam Line Fact Sheet Instrument Name Contact CG-1 Development Beam Line Lee Robertson CG-1D PDF IMAGING - Neutron Imaging Prototype Facility Hassina Bilheux CG-2 PDF GP-SANS - General-Purpose Small-Angle Neutron Scattering Diffractometer Ken Littrell

6

HFIR Experiment Facilities | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Experiment Facilities Experiment Facilities HFIR Experiment Facilities Neutron Scattering Facilities Target Positions Experiment Facilities in the Beryllium Reflector Large Removable Beryllium Facilities Small Removable Beryllium Facilities Control-Rod Access Plug Facilities Small Vertical Experiment Facilities Large Vertical Experiment Facilities Hydraulic Tube Facility Peripheral Target Positions Neutron Activation Analysis (NAA) Laboratory and Pneumatic Tube Facilities Slant Engineering Facilities Gamma Irradiation Facility Quality Assurance Requirements Contact Information Neutron Scattering Facilities The fully instrumented HFIR will eventually include 15 state-of-the-art neutron scattering instruments, seven of which will be designed exclusively for cold neutron experiments, located in a guide hall south of the reactor

7

Spallation Neutron Source  

NLE Websites -- All DOE Office Websites (Extended Search)

D/gim D/gim Spallation Neutron Source SNS is an accelerator-based neutron source. This one-of-a-kind facility pro- vides the most intense pulsed neutron beams in the world. When ramped up to its full beam power of 1.4 MW, SNS will be eight times more powerful than today's best facility. It will give researchers more detailed snapshots of the smallest samples of physical and biological materials than ever before

8

HFIR Technical Parameters | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Reactor Technical Parameters Reactor Technical Parameters Overview HFIR Pool Layout HFIR pool layout. HFIR is a beryllium-reflected, light-water-cooled and -moderated, flux-trap type reactor that uses highly enriched uranium-235 as the fuel. The image on the right is a cutaway of the reactor which shows the pressure vessel, its location in the reactor pool, and some of the experiment facilities. The preliminary conceptual design of the reactor was based on the "flux trap" principle, in which the reactor core consists of four annular regions of fuel surrounding an unfueled moderating region or "island" (see cross section view). Such a configuration permits fast neutrons leaking from the fuel to be moderated in the island and thus produces a region of very high thermal-neutron flux at the center of the island. This reservoir of

9

Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600. Proposals for beam time at Oak Ridge National Laboratory's High Flux Isotope Reactor (HFIR)  

E-Print Network (OSTI)

Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600. Proposals for beam Wildgruber, wildgrubercu@ornl.gov. VISION CallforProposals neutrons.ornl.gov Neutron Scattering Science - Oak time at Oak Ridge National Laboratory's High Flux Isotope Reactor (HFIR) and Spallation Neutron Source

Pennycook, Steve

10

Neutron Irradiation of Hydrided Cladding Material in HFIR Summary of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Neutron Irradiation of Hydrided Cladding Material in HFIR Summary Neutron Irradiation of Hydrided Cladding Material in HFIR Summary of Initial Activities Neutron Irradiation of Hydrided Cladding Material in HFIR Summary of Initial Activities Irradiation is known to have a significant impact on the properties and performance of Zircaloy cladding and structural materials (material degradation processes, e.g., effects of hydriding). This UFD study examines the behavior and performance of unirradiated cladding and actual irradiated cladding through testing and simulation. Three capsules containing hydrogen-charged Zircaloy-4 cladding material have been placed in the High Flux Isotope Reactor (HFIR). Irradiation of the capsules was conducted for post-irradiation examination (PIE) metallography. Neutron Irradiation of Hydrided Cladding Material in HFIR Summary of

11

Spallation Neutron Source | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Spallation Neutron Source SNS site, Spring 2012 The 80-acre SNS site is located on the east end of the ORNL campus and is about a three-minute drive from her sister neutron...

12

Spallation Neutron Sources Around the World  

E-Print Network (OSTI)

Spallation Neutron Sources Around the World Bernie Riemer Thanks to others for the many shamelessly Laboratory #12;2 Managed by UT-Battelle for the U.S. Department of Energy Spallation Neutron Source Facilities Spallation Neutron Source Facilities Serve Neutron Science Programs · Neutron beams to suites

McDonald, Kirk

13

SNS | Spallation Neutron Source | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

SNS SNS Instruments Working with SNS Contact Us User Program Manager Laura Morris Edwards 865.574.2966 Spallation Neutron Source Home | User Facilities | SNS SNS | Spallation Neutron Source SHARE SNS is an accelerator-based neutron source in Oak Ridge, Tennessee, USA. This one-of-a-kind facility provides the most intense pulsed neutron beams in the world for scientific research and industrial development. The 80-acre SNS site is located on Chestnut Ridge and is part of Oak Ridge National Laboratory. Although most people don't know it, neutron scattering research has a lot to do with our everyday lives. For example, things like medicine, food, electronics, and cars and airplanes have all been improved by neutron scattering research. Neutron research also helps scientists improve materials used in a

14

Spallation Neutron Source The Spallation Neutron Source (SNS)  

NLE Websites -- All DOE Office Websites (Extended Search)

F/gim F/gim Spallation Neutron Source The Spallation Neutron Source (SNS) gives researchers more detailed informa- tion on the structure and dynamics of physical and biological materials than ever before possible. This accelerator- based facility provides the most intense pulsed neutron beams in the world. Scien- tists are able to count scattered neutrons, measure their energies and the angles at which they scatter, and map their final positions. SNS enables measurements of greater sensitivity, higher speed, higher resolution, and in more complex sample environments than have been possible at existing neutron facilities. Future Growth SNS was designed from the outset to accommodate a second target station, effectively doubling the capacity of the

15

HFIR Sample Environment | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

HFIR Sample Environment HFIR Sample Environment The Sample Environment Group provides equipment and support for studying materials under controlled conditions (temperature, pressure, magnetic field, chemical environment, etc.). When you come to HFIR to conduct an experiment, our front-line teams are there to support you. Although we currently offer a wide range of capabilities, we realize that these capabilities must continually grow. Therefore, we also have a busy research and development team, and we encourage you to partner with them to develop new equipment and techniques. The online Sample Environment Equipment Database allows you to search for information about the sample environment equipment available for HFIR instruments. Contact HFIR Team Leader Chris Redmon Resources Sample Environment Equipment Database

16

Protein structures by spallation neutron crystallography  

Science Journals Connector (OSTI)

The capabilities of the Protein Crystallography Station at Los Alamos Neutron Science Center for determining protein structures by spallation neutron crystallography are illustrated, and the methodological and technological advances that are emerging from the Macromolecular Neutron Crystallography consortium are described.

Langan, P.

2008-04-18T23:59:59.000Z

17

Protein crystallography with spallation neutrons  

SciTech Connect

proteins and oriented molecular complexes. With spallation neutrons and their time dependent wavelength structure, one can select data with an optimal wavelength bandwidth and cover the whole Laue spectrum as time (wavelength) resolved diffraction data. This optimizes data quality with best peak to background ratios and provides spatial and energy resolution to eliminate peak overlaps. Such a Protein Crystallography Station (PCS) has been built and tested at Los Alamos Neutron Science Center. A partially coupled moderator is used to increase flux and data are collected by a Cylindrical He3 detector covering 120' with 200mm height. The PCS is described along with examples of data collected from a number of proteins.

Langan, P. (Paul); Schoenborn, Benno P.

2003-01-01T23:59:59.000Z

18

HFIR Downloadable Data - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Downloadable Data Downloadable Data HFIR Downloadable Data The following data are provided to allow potential users of HFIR to perform analyses that will improve quality assurance and speed the review process prior to performing irradiation experiments. Monte Carlo N-Particle (MCNP) Transport Code Models Beginning of Cycle 400 data End of Cycle 400 data Accompanying Descriptions Modeling of the High Flux Isotope Reactor Cycle 400 Design Study for a Low-Enriched Uranium Core for the High Flux Isotope Reactor, Annual Report for FY 2008 MCNP Transport Code programs and libraries are distributed separately and might be subject to export controls. Please check MCNP for more information. Standardized Analysis for Licensing Evaluations (SCALE) Model Cycle 408 model Accompanying Description

19

Spallation Neutron Source reaches megawatt power  

ScienceCinema (OSTI)

The Department of Energy's Spallation Neutron Source (SNS), already the world's most powerful facility for pulsed neutron scattering science, is now the first pulsed spallation neutron source to break the one-megawatt barrier. "Advances in the materials sciences are fundamental to the development of clean and sustainable energy technologies. In reaching this milestone of operating power, the Spallation Neutron Source is providing scientists with an unmatched resource for unlocking the secrets of materials at the molecular level," said Dr. William F. Brinkman, Director of DOE's Office of Science.

Dr. William F. Brinkman

2010-01-08T23:59:59.000Z

20

Neutron Experiment descriptions: N1: Triple-Axis Spectrometers, HFIR HB1A & HB3  

E-Print Network (OSTI)

Neutron Experiment descriptions: N1: Triple-Axis Spectrometers, HFIR HB1A & HB3 Spin wave2A Magnetic structure of NiO Neutron diffraction measurements will be performed to investigate 600K to 288K, using the Neutron Powder Diffractometer at the HFIR. Rietveld analysis of the crystal

Pennycook, Steve

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Horizontal Beam Tubes - HFIR Technical Parameters | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Horizontal Beam Tubes Horizontal Beam Tubes The reactor has four horizontal beam tubes that supply the neutrons to the neutron scattering instruments. Details for each beam tube and instrument can be found on the HFIR instrument page. Each of the beam tubes that supply these instruments with neutrons is described subsequently. HB-1 and HB-3 The HB-1 and HB-3 thermal neutron beam tube designs are identical except for the length. Both are situated tangential to the reactor core so that the tubes point at reflector material and do not point directly at the fuel. An internal collimator is installed at the outboard end. This collimator is fabricated out of carbon steel and is plated with nickel. The collimator provides a 2.75-in by 5.5-in. rectangular aperture. A rotary shutter is located outboard of each of these beam tubes. The

22

Spallation-Driven Cold Neutron Sources Dr. Bradley J. Micklich  

E-Print Network (OSTI)

Neutrons were produced by spallation/fission by 450MeV protons striking depleted uranium target Proton

McDonald, Kirk

23

January 16, 2009: Expansion of Spallation Neutron Source | Department...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

the Spallation Neutron Source, expanding what is already the world's most powerful pulsed neutron scattering facility. The new station, which will cost approximately 1 billion,...

24

How the Spallation Neutron Source Works | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

high-energy proton pulses strike a heavy-metal target, which is a container of liquid mercury. Corresponding pulses of neutrons freed by the spallation process are slowed down in...

25

Protein crystallography with spallation neutrons: the user facility at Los Alamos Neutron Science Center  

Science Journals Connector (OSTI)

The protein crystallography user facility at the neutron spallation source run by Los Alamos Neutron Science Center is described.

Langan, P.

2004-01-17T23:59:59.000Z

26

Irradiation research capabilities at HFIR (High Flux Isotope Reactor) and ANS (Advanced Neutron Source)  

SciTech Connect

A variety of materials irradiation facilities exist in the High Flux Isotope Reactor (HFIR) and are planned for the Advanced Neutron Source (ANS) reactor. In 1986 the HFIR Irradiation Facilities Improvement (HIFI) project began modifications to the HFIR which now permit the operation of two instrumented capsules in the target region and eight capsules of 46-mm OD in the RB region. Thus, it is now possible to perform instrumented irradiation experiments in the highest continuous flux of thermal neutrons available in the western world. The new RB facilities are now large enough to permit neutron spectral tailoring of experiments and the modified method of access to these facilities permit rotation of experiments thereby reducing fluence gradients in specimens. A summary of characteristics of irradiation facilities in HFIR is presented. The ANS is being designed to provide the highest thermal neutron flux for beam facilities in the world. Additional design goals include providing materials irradiation and transplutonium isotope production facilities as good, or better than, HFIR. The reference conceptual core design consists of two annular fuel elements positioned one above the other instead of concentrically as in the HFIR. A variety of materials irradiation facilities with unprecedented fluxes are being incorporated into the design of the ANS. These will include fast neutron irradiation facilities in the central hole of the upper fuel element, epithermal facilities surrounding the lower fuel element, and thermal facilities in the reflector tank. A summary of characteristics of irradiation facilities presently planned for the ANS is presented. 2 tabs.

Thoms, K.R.

1990-01-01T23:59:59.000Z

27

UAL-BASED SIMULATION ENVIRONMENT FOR SPALLATION NEUTRON SOURCE RING.  

SciTech Connect

This paper outlines the major activities and applications of the Unified Accelerator Library environment for the Spallation Neutron Source (SNS) Ring.

MALITSKY,N.; SMITH,J.; WEI,J.

1999-03-29T23:59:59.000Z

28

Ashfia Huq Lead Scientist: POWGEN Spallation Neutron Source  

NLE Websites -- All DOE Office Websites (Extended Search)

do for characterizing battery materials? Ashfia Huq Lead Scientist: POWGEN Spallation Neutron Source Oak Ridge National Laboratory 2 Presentation name Outline of talk * An...

29

Spallation Neutron Source (SNS) | U.S. DOE Office of Science...  

Office of Science (SC) Website

(SUF) Division SUF Home About User Facilities User Facilities Dev X-Ray Light Sources Neutron Scattering Facilities High Flux Isotope Reactor (HFIR) Lujan Neutron Scattering...

30

The national spallation neutron source target station: A general overview  

SciTech Connect

The technologies that are being utilized to design and build a state-of-the-art neutron spallation source, the National Spallation Neutron Source (NSNS), are discussed. Emphasis is given to the technology issues that present the greatest scientific challenges. The present facility configuration, ongoing analysis and the planned hardware research and development program are also described.

Gabriel, T.A.; Barnes, J.N.; Charlton, L.A. [and others

1997-06-01T23:59:59.000Z

31

Getting Beam Time at HFIR and SNS | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Apply for Beam Time at HFIR and SNS Apply for Beam Time at HFIR and SNS Apply for Beam Time at HFIR and SNS 2014B Call for Proposals Proposal call 2014B All available beam lines will accept proposals through February 26, 2014 Beam time is granted through our general user program, which is open to all. In addition, we have opportunities for extended collaboration through programs such as internships and postdoctoral programs. The instruments at HFIR and SNS can be used free of charge with the understanding that researchers will publish their results, making them available to the scientific community. Our facilities are also available for proprietary research for a fee. ORNL User Portal The ORNL User Portal gives you access to all the resources you need as a new or returning user, such as the proposal system, data access and

32

POWDER: The Neutron Powder Diffractometer at HFIR | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Powder Diffractometer Neutron Powder Diffractometer Neutron Powder Diffractometer. Neutron Powder Diffractometer. The HB-2A diffractometer is a workhorse instrument used to conduct crystal structural and magnetic structural studies of powdered and ceramic samples, particularly as a function of intensive conditions (T, P, H, etc.). Powder diffraction data collected on this instrument are ideally suited for the Rietveld method. A full range of ancillary sample environments can be used, including cryofurnaces (4-800 K), furnaces (to 1800 K), cryostats (to 0.3 K), and cryomagnets (to 7 T). The Powder Diffractometer has a Debye-Scherrer geometry. The detector bank has 44 3He tubes, each with 6' Soller collimators. A germanium wafer-stack monochromator is vertically focusing and provides one of three principal

33

Slow neutron leakage spectra from spallation neutron sources  

SciTech Connect

An efficient technique is described for Monte Carlo simulation of neutron beam spectra from target-moderator-reflector assemblies typical of pulsed spallation neutron sources. The technique involves the scoring of the transport-theoretical probability that a neutron will emerge from the moderator surface in the direction of interest, at each collision. An angle-biasing probability is also introduced which further enhances efficiency in simple problems. These modifications were introduced into the VIM low energy neutron transport code, representing the spatial and energy distributions of the source neutrons approximately as those of evaporation neutrons generated through the spallation process by protons of various energies. The intensity of slow neutrons leaking from various reflected moderators was studied for various neutron source arrangements. These include computations relating to early measurements on a mockup-assembly, a brief survey of moderator materials and sizes, and a survey of the effects of varying source and moderator configurations with a practical, liquid metal cooled uranium source Wing and slab, i.e., tangential and radial moderator arrangements, and Be vs CH/sub 2/ reflectors are compared. Results are also presented for several complicated geometries which more closely represent realistic arrangements for a practical source, and for a subcritical fission multiplier such as might be driven by an electron linac. An adaptation of the code was developed to enable time dependent calculations, and investigated the effects of the reflector, decoupling and void liner materials on the pulse shape.

Das, S.G.; Carpenter, J.M.; Prael, R.E.

1980-02-01T23:59:59.000Z

34

SPALLATION NEUTRON SOURCE BEAM CURRENT MONITOR ELECTRONICS.  

SciTech Connect

The Spallation Neutron Source (SNS) to be constructed at ORNL is a collaboration of six laboratories. Beam current monitors for SNS will be used to monitor H-minus and H-plus beams ranging from the 15 mA (tune-up in the Front End and Linac) to over 60 A fully accumulated in the Ring. The time structure of the beams to be measured range from 645 nsec ''mini'' bunches, at the 1.05 MHz ring revolution rate, to an overall 1 mS long macro pulse. Beam current monitors (BCMs) for SNS have requirements depending upon their location within the system. The development of a general approach to satisfy requirements of various locations with common components is a major design objective. This paper will describe the development of the beam current monitors and electronics.

KESSELMAN, M.

2001-06-18T23:59:59.000Z

35

E-Print Network 3.0 - advanced spallation neutron Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

40 Lead-Bismuth Spallation Target Design Yousry Gohar Summary: . Protect the subcritical multiplier from the high-energy protons and neutrons. Contain the spallation... of...

36

HEATING DISTRIBUTIONS IN THE TARGET OF THE SPALLATION NEUTRON...  

Office of Scientific and Technical Information (OSTI)

IN THE TARGET OF THE SPALLATION NEUTRON SOURCE F. C. Difilippo and L. A. Charlton Oak Ridge National Laboratory* P.O. Box 2008, MS-6363 Oak Ridge, Tennessee 3783 l-6363...

37

EIS-0247: Construction and Operation of the Spallation Neutron Source |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

247: Construction and Operation of the Spallation Neutron 247: Construction and Operation of the Spallation Neutron Source EIS-0247: Construction and Operation of the Spallation Neutron Source SUMMARY The United States needs a high-flux, short- pulsed neutron source to provide its scientific and industrial research communities with a much more intense source of pulsed neutrons for neutron scattering research than is currently available. This source would assure the availability of a state-of-the-art neutron research facility in the United States in the decades ahead. This facility would be used to conduct research in areas such as materials science, condensed matter physics, the molecular structure of biological materials, properties of polymers and complex fluids, and magnetism. In addition to creating new scientific and

38

WAND: Wide-Angle Neutron Diffractometer at HFIR | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

US/Japan Wide-Angle Neutron Diffractometer US/Japan Wide-Angle Neutron Diffractometer WAND Instrument scientist Jaime Fernandez-Baca (left) with a visiting researcher at WAND. The Wide-Angle Neutron Diffractometer (WAND) at the HFIR HB-2C beam tube was designed to provide two specialized data-collection capabilities: (1) fast measurements of medium-resolution powder-diffraction patterns and (2) measurements of diffuse scattering in single crystals using flat-cone geometry. For these purposes, this instrument is equipped with a curved, one-dimensional 3He position-sensitive detector covering 125º of the scattering angle with the focal distance of 71 cm. The sample and detector can be tilted in the flat-cone geometry mode. These features enable measurement of single-crystal diffraction patterns in a short time over a

39

Reactor Core Assembly - HFIR Technical Parameters | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Home › Facilities › HFIR › Reactor Core Assembly Home › Facilities › HFIR › Reactor Core Assembly Reactor Core Assembly The reactor core assembly is contained in an 8-ft (2.44-m)-diameter pressure vessel located in a pool of water. The top of the pressure vessel is 17 ft (5.18 m) below the pool surface, and the reactor horizontal mid-plane is 27.5 ft (8.38 m) below the pool surface. The control plate drive mechanisms are located in a subpile room beneath the pressure vessel. These features provide the necessary shielding for working above the reactor core and greatly facilitate access to the pressure vessel, core, and reflector regions. In-core irradiation and experiment locations (cross section at horizontal midplane) Reactor core assembly Reactor core assembly: (1) in-core irradiation and experiment locations,

40

New detector array improves neutron count capability at HFIR's Bio-SANS |  

NLE Websites -- All DOE Office Websites (Extended Search)

Bio-SANS neutron count capability improves Bio-SANS neutron count capability improves New detector array improves neutron count capability at HFIR's Bio-SANS Agatha Bardoel - June 29, 2012 Bio-SANS team that worked on installation of the new detector system. Front row, left to right: Doug Selby, Steve Hicks, Shuo Qian, Sai Venkatesh Pingali, Kathy Bailey, Amy Black Jones, and Derrick Williams. Back row, left to right: Ed Blackburn, John Palatinus, William Brad O'Dell, Mike Humphreys, Justin Beal, Ken Littrell, Greg Jones, Kevin Berry, Volker Urban, Randy Summers, and Ron Maples. Bio-SANS, the Biological Small-Angle Neutron Scattering Instrument at HFIR recently had a detector upgrade that will provide significantly improved performance that is more in line with the instrument's capability. Shorter experiment times are expected, which means more experiments can be

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Polarized neutron diffraction at a spallation source for magnetic studies  

Science Journals Connector (OSTI)

The first results from polarized neutron diffraction experiments on a time-of-flight instrument at a spallation source are reported. Higher neutron beam flux and efficient spin polarization at the neutron beamline enable in situ studies of phenomena contributing to field-induced magnetization in materials including magnetic shape memory alloys.

Pramanick, A.

2012-09-01T23:59:59.000Z

42

HFIR In-Vessel Irradiation Facilities | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

the permanent beryllium reflector. Please refer to the accompanying graph showing the neutron flux values for these regions. Radio neutron flux graph Neutron flux distributions at...

43

A neutronic feasibility study for LEU conversion of the high flux isotope reactor (HFIR).  

SciTech Connect

A neutronic feasibility study was performed to determine the uranium densities that would be required to convert the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) from HEU (93%) to LEU (<20%)fuel. The LEU core that was studied is the same as the current HEU core, except for potential changes in the design of the fuel plates. The study concludes that conversion of HFIR from HEU to LEU fuel would require an advanced fuel with a uranium density of 6-7 gU/cm{sup 3} in the inner fuel element and 9-10 gU/cm{sup 3} in the outer fuel element to match the cycle length of the HEU core. LEU fuel with uranium density up to 4.8 gU/cm{sup 3} is currently qualified for research reactor use. Modifications in fuel grading and burnable poison distribution are needed to produce an acceptable power distribution.

Mo, S. C.

1998-01-14T23:59:59.000Z

44

The General-Purpose Small-Angle Neutron Scattering Diffractometer at HFIR -  

NLE Websites -- All DOE Office Websites (Extended Search)

General-Purpose Small-Angle Neutron Scattering Diffractometer at HFIR General-Purpose Small-Angle Neutron Scattering Diffractometer at HFIR Instrument scientist Ken Littrell at GP-SANS. Instrument scientist Ken Littrell at GP-SANS. The General-Purpose Small-Angle Neutron Scattering Diffractometer (GP-SANS) instrument is optimized for providing information about structure and interactions in materials in the size range of 0.5 - 200 nm. It has a cold neutron flux on sample and capabilities comparable to those of the best SANS instruments worldwide, including a wide range of neutron wavelengths λ 5 - 30 Å, resolution Δλ ⁄ λ 9=45%, and a 1m2 area detector with 5 × 5mm2 pixel resolution with a maximum counting capability of up to 2.5 kHz. The sample-to-detector distance can be varied from 1 to 20 m, and the detector can be offset horizontally by up to 45 cm, allowing

45

The Spallation Neutron Source A Powerful Tool for Materials Research  

E-Print Network (OSTI)

The wavelengths and energies of thermal and cold neutrons are ideally matched to the length and energy scales in the materials that underpin technologies of the present and future: ranging from semiconductors to magnetic devices, composites to biomaterials and polymers. The Spallation Neutron Source (SNS) will use an accelerator to produce the most intense beams of neutrons in the world when it is complete at the end of 2005. The project is being built by a collaboration of six U.S. Department of Energy laboratories. It will serve a diverse community of users drawn from academia, industry, and government labs with interests in condensed matter physics, chemistry, engineering materials, biology, and beyond.

Mason, Thomas E; Crawford, R K; Herwig, K W; Klose, F; Ankner, J F

2000-01-01T23:59:59.000Z

46

Stripped electron collection at the Spallation Neutron Source  

Science Journals Connector (OSTI)

One of the main sources of electrons in the Spallation Neutron Sources Accumulator Ring is the stripped electrons in the injection region. A magnetic field guides the stripped electrons to the bottom of the beam pipe, where an electron catcher with overhanging surface traps them. This paper describes the stripped electrons motion, the optimization of the catcher, and the build up of an electron cloud in this region.

L. Wang; Y. Y. Lee; G. Mahler; W. Meng; D. Raparia; J. Wei; S. Henderson

2005-09-13T23:59:59.000Z

47

Core Vessel Insert Handling Robot for the Spallation Neutron Source  

SciTech Connect

The Spallation Neutron Source provides the world's most intense pulsed neutron beams for scientific research and industrial development. Its eighteen neutron beam lines will eventually support up to twenty-four simultaneous experiments. Each beam line consists of various optical components which guide the neutrons to a particular instrument. The optical components nearest the neutron moderators are the core vessel inserts. Located approximately 9 m below the high bay floor, these inserts are bolted to the core vessel chamber and are part of the vacuum boundary. They are in a highly radioactive environment and must periodically be replaced. During initial SNS construction, four of the beam lines received Core Vessel Insert plugs rather than functional inserts. Remote replacement of the first Core Vessel Insert plug was recently completed using several pieces of custom-designed tooling, including a highly complicated Core Vessel Insert Robot. The design of this tool are discussed.

Graves, Van B [ORNL; Dayton, Michael J [ORNL

2011-01-01T23:59:59.000Z

48

Electron cloud instabilities in the Proton Storage Ring and Spallation Neutron Source  

Science Journals Connector (OSTI)

Electron cloud instabilities in the Los Alamos Proton Storage Ring and those foreseen for the Oak Ridge Spallation Neutron Source are examined theoretically, numerically, and experimentally.

M. Blaskiewicz; M. A. Furman; M. Pivi; R. J. Macek

2003-01-21T23:59:59.000Z

49

Device for Writing the Time Tail from Spallation Neutron Pulses  

SciTech Connect

Recent work at Los Alamos Neutron Science Center (LANSCE), has shown that there are large gains in neutron beam intensity to be made by using coupled moderators at spallation neutron sources. Most of these gains result from broadening the pulse-width in time. However the accompanying longer exponential tail at large emission times can be a problem in that it introduces relatively large beam-related backgrounds at high resolutions. We have designed a device that can reshape the moderated neutron beam by cutting the time-tail so that a sharp time resolution can be re-established without a significant loss in intensity. In this work the basic principles behind the tail-cutter and some initial results of Monte Carlo simulations are described. Unwanted neutrons in the long time-tail are diffracted out of the transmitted neutron beam by a nested stack of aperiodic multi-layers, rocking at the same frequency as the source. Nested aperiodic multi-layers have recently been used at X-ray sources and as band-pass filters in quasi-Laue neutron experiments at reactor neutron sources. Optical devices that rock in synchronization with a pulsed neutron beam are relatively new but are already under construction at LANSCE. The tail-cutter described here is a novel concept that uses existing multi-layer technology in a new way for spallation neutrons. Coupled moderators in combination with beam shaping devices offer the means of increasing flux whilst maintaining a sharp time distribution. A prototype device is being constructed for the protein crystallography station at LANSCE. The protein crystallography station incorporates a water moderator that has been judiciously coupled in order to increase the flux over neutron energies that are important to structural biology (3-80meV). This development in moderator design is particularly important because protein crystallography is flux limited and because conventional ambient water and cold hydrogen moderators do not provide relatively large neutron fluxes over this neutron energy range.

Langan, P. (Paul); Schoenborn, Benno P.; Langan, P. (Paul); Schoenborn, Benno P.; Daemen, L. L. (Luc L.)

2001-01-01T23:59:59.000Z

50

Fundamental Neutron Physics Beamline at the Spallation Neutron Source at ORNL  

E-Print Network (OSTI)

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. We present a detailed description of the design philosophy, beamline components, and measured fluxes of the polychromatic and monochromatic beams.

N. Fomin; G. L. Greene; R. Allen; V. Cianciolo; C. Crawford; T. Ito; P. R. Huffman; E. B. Iverson; R. Mahurin; W. M. Snow

2014-08-04T23:59:59.000Z

51

Optimizing Moderator Dimensions for Neutron Scattering at the Spallation Neutron Source  

SciTech Connect

In this work, we investigate the effect of neutron moderator dimensions on the performance of neutron scattering instruments at the Spallation Neutron Source. In a recent study of the planned second target station at the Spallation Neutron Source (SNS) facility [1,2], we have found that the dimensions of a moderator play a significant role in determining its surface brightness. A smaller moderator may be significantly brighter for a smaller viewing area [4]. One of the immediate implications of this finding is that for modern neutron scattering instrument designs, moderator dimensions and brightness have to be incorporated as an integrated optimization parameter. Here, we establish a strategy of matching neutron scattering instruments with moderators using analytical and Monte Carlo techniques. In order to simplify our treatment, we group the instruments into two broad categories, those with natural collimation and those that use neutron guide systems. We found that the cross-sections of the sample and the neutron guide, respectively, are the deciding factors for choosing the moderator. Beam divergence plays no role as long as it is within the reach of practical constraints. Namely, the required divergence is not too large for the guide or sample to be located close enough to the moderator on an actual spallation source.

Zhao, Jinkui [ORNL] [ORNL; Robertson, Lee [ORNL] [ORNL; Herwig, Kenneth W [ORNL] [ORNL; Gallmeier, Franz X [ORNL] [ORNL; Riemer, Bernie [ORNL] [ORNL

2013-01-01T23:59:59.000Z

52

Neutron Scattering Instrumentation for Biology at Spallation Neutron Sources  

Science Journals Connector (OSTI)

Conventional wisdom holds that since biological entities are large, they must be studied with cold neutrons, a domain in which reactor sources of neutrons are often supposed to be pre-eminent. ... fact, the curre...

Roger Pynn

1996-01-01T23:59:59.000Z

53

Electron Cloud Mitigation in the Spallation Neutron Source Ring  

SciTech Connect

The Spallation Neutron Source (SNS) accumulator ring is designed to accumulate, via H{sup -} injection, protons of 2 MW beam power at 1 GeV kinetic energy at a repetition rate of 60 Hz [1]. At such beam intensity, electron-cloud is expected to be one of the intensity-limiting mechanisms that complicate ring operations. This paper summarizes mitigation strategy adopted in the design, both in suppressing electron-cloud formation and in enhancing Landau damping, including tapered magnetic field and monitoring system for the collection of stripped electrons at injection, TiN coated beam chamber for suppression of the secondary yield, clearing electrodes dedicated for the injection region and parasitic on BPMs around the ring, solenoid windings in the collimation region, and planning of vacuum systems for beam scrubbing upon operation.

Wei, J.; Blaskiewicz, Michael; Brodowski, J.; Cameron, P.; Davino, Daniele; Fedotov, A.; He, P.; Hseuh, H.; Lee, Y.Y.; Ludewig, H.; Meng, W.; Raparia, D.; Tuozzolo, J.; Zhang, S.Y.; Catalan-Lasheras, N.; Macek, R.J.; Furman, Miguel A.; Aleksandrov, A.; Cousineau, S.; Danilov, V.; Henderson, S.; /Brookhaven /CERN /LANL, Ctr. for Nonlinear Studies /LBL, Berkeley /Oak Ridge /SLAC

2008-03-17T23:59:59.000Z

54

SNS/BNL Diagnostics System Group, Spallation Neutron Source, SNS  

NLE Websites -- All DOE Office Websites (Extended Search)

SNS/BNL Diagnostics System Group SNS/BNL Diagnostics System Group Homepage The Spallation Neutron Source project is a collaboration between six national laboratories of the United states to build a Mega Watt neutrons source driven by a proton accelerator. The complex is going to be build in Oak Ridge (Tennessee) and consists of a full energy (1 Gev) linac, an accumulator ring and a mercury target with several instruments for neutron scattering. Information on the project can be found at http://www.sns.gov. At Brookhaven National Laboratory we work mainly on the accumulator ring and transfer lines diagnostics (HEBT, Ring, RTBT). Some of the systems are SNS-wide ie: the Beam Loss Monitor system and Beam Current Monitor system. In addition our group provides parts of other systems to our partner laboratories. Our group is part or the Collider Accelerator Division that is also in charge of RHIC and the AGS complex. If you are looking for information on a particular topic you can contact the persons working on it.

55

5 MW pulsed spallation neutron source, Preconceptual design study  

SciTech Connect

This report describes a self-consistent base line design for a 5 MW Pulsed Spallation Neutron Source (PSNS). It is intended to establish feasibility of design and as a basis for further expanded and detailed studies. It may also serve as a basis for establishing project cost (30% accuracy) in order to intercompare competing designs for a PSNS not only on the basis of technical feasibility and technical merit but also on the basis of projected total cost. The accelerator design considered here is based on the objective of a pulsed neutron source obtained by means of a pulsed proton beam with average beam power of 5 MW, in {approx} 1 {mu}sec pulses, operating at a repetition rate of 60 Hz. Two target stations are incorporated in the basic facility: one for operation at 10 Hz for long-wavelength instruments, and one operating at 50 Hz for instruments utilizing thermal neutrons. The design approach for the proton accelerator is to use a low energy linear accelerator (at 0.6 GeV), operating at 60 Hz, in tandem with two fast cycling booster synchrotrons (at 3.6 GeV), operating at 30 Hz. It is assumed here that considerations of cost and overall system reliability may favor the present design approach over the alternative approach pursued elsewhere, whereby use is made of a high energy linear accelerator in conjunction with a dc accumulation ring. With the knowledge that this alternative design is under active development, it was deliberately decided to favor here the low energy linac-fast cycling booster approach. Clearly, the present design, as developed here, must be carried to the full conceptual design stage in order to facilitate a meaningful technology and cost comparison with alternative designs.

Not Available

1994-06-01T23:59:59.000Z

56

The new cold neutron chopper spectrometer at the Spallation Neutron Source: Design and performance  

SciTech Connect

The design and performance of the new cold neutron chopper spectrometer (CNCS) at the Spallation Neutron Source in Oak Ridge are described. CNCS is a direct-geometry inelastic time-of-flight spectrometer, designed essentially to cover the same energy and momentum transfer ranges as IN5 at ILL, LET at ISIS, DCS at NIST, TOFTOF at FRM-II, AMATERAS at J-PARC, PHAROS at LANSCE, and NEAT at HZB, at similar energy resolution. Measured values of key figures such as neutron flux at sample position and energy resolution are compared between measurements and ray tracing Monte Carlo simulations, and good agreement (better than 20% of absolute numbers) has been achieved. The instrument performs very well in the cold and thermal neutron energy ranges, and promises to become a workhorse for the neutron scattering community for quasielastic and inelastic scattering experiments.

Ehlers, G.; Podlesnyak, A. A.; Niedziela, J. L.; Iverson, E. B. [Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Sokol, P. E. [Department of Physics, Indiana University, Bloomington, Indiana 47405 (United States)

2011-08-15T23:59:59.000Z

57

The Neutron Science TeraGrid Gateway, a TeraGrid Science Gateway to Support the Spallation Neutron Source  

E-Print Network (OSTI)

1 The Neutron Science TeraGrid Gateway, a TeraGrid Science Gateway to Support the Spallation Neutron Source John W. Cobb* , Al Geist* , James A. Kohl* , Stephen D. Miller , Peter F. Peterson] is entering its operational phase. An ETF science gateway effort is the Neutron Science TeraGrid Gateway (NSTG

Vazhkudai, Sudharshan

58

H- radio frequency source development at the Spallation Neutron Source  

SciTech Connect

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent {approx}38 mA peak current in the linac and an availability of {approx}90%. H{sup -} beam pulses ({approx}1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, {approx}60 kW) of a copper antenna that has been encased with a thickness of {approx}0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of {approx}99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of {approx}75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance/installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to {approx}100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

Welton, Robert F [ORNL; Pennisi, Terry R [ORNL; Roseberry, Ron T [ORNL; Stockli, Martin P [ORNL

2012-01-01T23:59:59.000Z

59

Optimizing moderator dimensions for neutron scattering at the spallation neutron source  

SciTech Connect

In this work, we investigate the effect of neutron moderator dimensions on the performance of neutron scattering instruments at the Spallation Neutron Source (SNS). In a recent study of the planned second target station at the SNS facility, we have found that the dimensions of a moderator play a significant role in determining its surface brightness. A smaller moderator may be significantly brighter over a smaller viewing area. One of the immediate implications of this finding is that for modern neutron scattering instrument designs, moderator dimensions and brightness have to be incorporated as an integrated optimization parameter. Here, we establish a strategy of matching neutron scattering instruments with moderators using analytical and Monte Carlo techniques. In order to simplify our treatment, we group the instruments into two broad categories: those with natural collimation and those that use neutron guide systems. For instruments using natural collimation, the optimal moderator selection depends on the size of the moderator, the sample, and the moderator brightness. The desired beam divergence only plays a role in determining the distance between sample and moderator. For instruments using neutron optical systems, the smallest moderator available that is larger than the entrance dimension of the closest optical element will perform the best (assuming, as is the case here that smaller moderators are brighter)

Zhao, J. K.; Robertson, J. L.; Herwig, Kenneth W.; Gallmeier, Franz X.; Riemer, Bernard W. [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2013-12-15T23:59:59.000Z

60

The Corrosion of Materials in Spallation Neutron Sources R. Scott Lillard, Darryl P. Butt  

E-Print Network (OSTI)

1 The Corrosion of Materials in Spallation Neutron Sources R. Scott Lillard, Darryl P. Butt Materials Corrosion and Environmental Effects Lab Materials Science and Technology Division, MST-6 Los current efforts to measure the real-time corrosion rates of Alloy 718 (718) during 800 MeV proton

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Synthesis of neutron-rich transuranic nuclei in fissile spallation targets  

E-Print Network (OSTI)

A possibility of synthesizing neutron-reach super-heavy elements in spallation targets of Accelerator Driven Systems (ADS) is considered. A dedicated software called Nuclide Composition Dynamics (NuCoD) was developed to model the evolution of isotope composition in the targets during a long-time irradiation by intense proton and deuteron beams. Simulation results show that transuranic elements up to Bk-249 can be produced in multiple neutron capture reactions in macroscopic quantities. However, the neutron flux achievable in a spallation target is still insufficient to overcome the so-called fermium gap. Further optimization of the target design, in particular, by including moderating material and covering it by a reflector will turn ADS into an alternative source of transuranic elements in addition to nuclear fission reactors.

Mishustin, Igor; Pshenichnov, Igor; Greiner, Walter

2014-01-01T23:59:59.000Z

62

The DOS 1 neutron dosimetry experiment at the HB-4-A key 7 surveillance site on the HFIR pressure vessel  

SciTech Connect

A comprehensive neutron dosimetry experiment was made at one of the prime surveillance sites at the High Flux Isotope Reactor (HFIR) pressure vessel to aid radiation embrittlement studies of the vessel and to benchmark neutron transport calculations. The thermal neutron flux at the key 7, position 5 site was found, from measurements of radioactivation of four cobalt wires and four silver wires, to be 2.4 {times} 10{sup 12} n{center_dot}m{sup {minus}2}{center_dot}s{sup {minus}1}. The thermal flux derived from two helium accumulation monitors was 2.3 {times} 10{sup 12} n{center_dot}m{sup {minus}2}{center_dot}{sup {minus}1}. The thermal flux estimated by neutron transport calculations was 3.7 {times} 10{sup 12} n{center_dot}m{sup {minus}2}s{sup {minus}1}. The fast flux, >1 MeV, determined from two nickel activation wires, was 1.5 {times} 10{sup 12} n{center_dot}m{sup {minus}2}{center_dot}s{sup {minus}1}, in keeping with values obtained earlier from stainless steel surveillance monitors and with a computed value of 1.2 {times} 10{sup 13} n{center_dot}m{sup {minus}2}{center_dot}{sup {minus}1}. The fast fluxes given by two reaction-product-type monitors, neptunium-237 and beryllium, were 2.6 {times} 10{sup 13} n{center_dot}m{sup {minus}2}{center_dot}s {sup {minus}1} and 2.2 {times} 10{sup 13} n{center_dot}m{sup {minus}2}s{sup {minus}1}, respectively. Follow-up experiments indicate that these latter high values of fast flux are reproducible but are false; they are due to the creation of greater levels of reaction products by photonuclear events induced by an exceptionally high ratio of gamma flux to fast neutron flux at the vessel.

Farrell, K.; Kam, F.B.; Baldwin, C.A. [and others

1994-01-01T23:59:59.000Z

63

Instruments | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

NScD Careers NScD Careers Supporting Organizations Neutron Science Home | Science & Discovery | Neutron Science | Instruments SHARE Instruments at SNS and HFIR SNS Instrument Name HFIR Instrument Name 1B NOMAD - Nanoscale-Ordered Materials Diffractometer CG-1 Development Beam Line 2 BASIS - Backscattering Spectrometer CG-1D IMAGING - Neutron Imaging Prototype Facility 3 SNAP - Spallation Neutrons and Pressure Diffractometer CG-2 GP-SANS - General-Purpose Small-Angle Neutron Scattering Diffractometer 4A MR - Magnetism Reflectometer CG-3 Bio-SANS - Biological Small-Angle Neutron Scattering Instrument 4B LR - Liquids Reflectometer CG-4C CTAX - Cold Neutron Triple-Axis Spectrometer 5 CNCS - Cold Neutron Chopper Spectrometer HB-1 PTAX - Polarized Triple-Axis Spectrometer

64

HYSPEC : A CRYSTAL TIME OF FLIGHT HYBRID SPECTROMETER FOR THE SPALLATION NEUTRON SOURCE.  

SciTech Connect

This document lays out a proposal by the Instrument Development Team (IDT) composed of scientists from leading Universities and National Laboratories to design and build a conceptually new high-flux inelastic neutron spectrometer at the pulsed Spallation Neutron Source (SNS) at Oak Ridge. This instrument is intended to supply users of the SNS and scientific community, of which the IDT is an integral part, with a platform for ground-breaking investigations of the low-energy atomic-scale dynamical properties of crystalline solids. It is also planned that the proposed instrument will be equipped with a polarization analysis capability, therefore becoming the first polarized beam inelastic spectrometer in the SNS instrument suite, and the first successful polarized beam inelastic instrument at a pulsed spallation source worldwide. The proposed instrument is designed primarily for inelastic and elastic neutron spectroscopy of single crystals. In fact, the most informative neutron scattering studies of the dynamical properties of solids nearly always require single crystal samples, and they are almost invariably flux-limited. In addition, in measurements with polarization analysis the available flux is reduced through selection of the particular neutron polarization, which puts even more stringent limits on the feasibility of a particular experiment. To date, these investigations have mostly been carried out on crystal spectrometers at high-flux reactors, which usually employ focusing Bragg optics to concentrate the neutron beam on a typically small sample. Construction at Oak Ridge of the high-luminosity spallation neutron source, which will provide intense pulsed neutron beams with time-averaged fluxes equal to those at medium-flux reactors, opens entirely new opportunities for single crystal neutron spectroscopy. Drawing upon experience acquired during decades of studies with both crystal and time-of-flight (TOF) spectrometers, the IDT has developed a conceptual design for a focused-beam, hybrid time-of-flight instrument with a crystal monochromator for the SNS called HYSPEC (an acronym for hybrid spectrometer). The proposed instrument has a potential to collect data more than an order of magnitude faster than existing steady-source spectrometers over a wide range of energy transfer ({h_bar}{omega}) and momentum transfer (Q) space, and will transform the way that data in elastic and inelastic single-crystal spectroscopy are collected. HYSPEC is optimized to provide the highest neutron flux on sample in the thermal and epithermal neutron energy ranges at a good-to-moderate energy resolution. By providing a flux on sample several times higher than other inelastic instruments currently planned for the SNS, the proposed instrument will indeed allow unique ground-breaking measurements, and will ultimately make polarized beam studies at a pulsed spallation source a realistic possibility.

SHAPIRO,S.M.; ZALIZNYAK,I.A.

2002-12-30T23:59:59.000Z

65

Prototype Spallation Neutron Source Rotating Target Assembly Final Test Report  

SciTech Connect

A full-scale prototype of an extended vertical shaft, rotating target assembly based on a conceptual target design for a 1 to 3-MW spallation facility was built and tested. Key elements of the drive/coupling assembly implemented in the prototype include high integrity dynamic face seals, commercially available bearings, realistic manufacturing tolerances, effective monitoring and controls, and fail-safe shutdown features. A representative target disk suspended on a 3.5 meter prototypical shaft was coupled with the drive to complete the mechanical tests. Successful operation for 5400 hours confirmed the overall mechanical feasibility of the extended vertical shaft rotating target concept. The prototype system showed no indications of performance deterioration and the equipment did not require maintenance or relubrication.

McManamy, Thomas J [ORNL; Graves, Van [Oak Ridge National Laboratory (ORNL); Garmendia, Amaia Zarraoa [IDOM Bilbao; Sorda, Fernando [ESS Bilbao; Etxeita, Borja [IDOM Bilbao; Rennich, Mark J [ORNL

2011-01-01T23:59:59.000Z

66

Coherent Scattering Investigations at the Spallation Neutron Source: a Snowmass White Paper  

SciTech Connect

The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, Tennessee, provides an intense flux of neutrinos in the few tens-of-MeV range, with a sharply-pulsed timing structure that is beneficial for background rejection. In this white paper, we describe how the SNS source can be used for a measurement of coherent elastic neutrino-nucleus scattering (CENNS), and the physics reach of different phases of such an experimental program (CSI: Coherent Scattering Investigations at the SNS).

Akimov, D. [Moscow Engineering Physics Institute (MEPhI), Russia] Moscow Engineering Physics Institute (MEPhI), Russia; Bernstein, A. [Lawrence Livermore National Laboratory (LLNL)] Lawrence Livermore National Laboratory (LLNL); BarbeauP., [Duke University; Barton, P. J. [Lawrence Berkeley National Laboratory (LBNL)] Lawrence Berkeley National Laboratory (LBNL); Bolozdynya, A. [Moscow Engineering Physics Institute (MEPhI), Russia] Moscow Engineering Physics Institute (MEPhI), Russia; Cabrera-Palmer, B. [Sandia National Laboratories (SNL)] Sandia National Laboratories (SNL); Cavanna, F. [Yale University] Yale University; Cianciolo, Vince [ORNL] ORNL; Collar, J. [University of Chicago, Enrico Fermi Institute] University of Chicago, Enrico Fermi Institute; Cooper, R. J. [Indiana University] Indiana University; Dean, D. J. [Oak Ridge National Laboratory (ORNL)] Oak Ridge National Laboratory (ORNL); Efremenko, Yuri [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL)] University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Etenko, A. [Moscow Engineering Physics Institute (MEPhI), Russia] Moscow Engineering Physics Institute (MEPhI), Russia; Fields, N. [University of Chicago, Enrico Fermi Institute] University of Chicago, Enrico Fermi Institute; Foxe, M. [Pennsylvania State University, University Park, PA] Pennsylvania State University, University Park, PA; Figueroa-Feliciano, E. [Massachusetts Institute of Technology (MIT)] Massachusetts Institute of Technology (MIT); Fomin, N. [University of Tennessee, Knoxville (UTK)] University of Tennessee, Knoxville (UTK); Gallmeier, F. [Oak Ridge National Laboratory (ORNL)] Oak Ridge National Laboratory (ORNL); Garishvili, I. [University of Tennessee, Knoxville (UTK)] University of Tennessee, Knoxville (UTK); Gerling, M. [Sandia National Laboratories (SNL)] Sandia National Laboratories (SNL); Green, M. [University of North Carolina, Chapel Hill] University of North Carolina, Chapel Hill; Greene, Geoffrey [University of Tennessee, Knoxville (UTK)] University of Tennessee, Knoxville (UTK); Hatzikoutelis, A. [University of Tennessee, Knoxville (UTK)] University of Tennessee, Knoxville (UTK); Henning, Reyco [University of North Carolina, Chapel Hill] University of North Carolina, Chapel Hill; Hix, R. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL)] University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Hogan, D. [University of California-Berkeley] University of California-Berkeley; Hornback, D. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL)] University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Jovanovic, I. [Pennsylvania State University, University Park, PA] Pennsylvania State University, University Park, PA; Hossbach, T. [Pacific Northwest National Laboratory (PNNL)] Pacific Northwest National Laboratory (PNNL); Iverson, Erik B [ORNL] ORNL; Klein, S. R. [Lawrence Berkeley National Laboratory (LBNL)] Lawrence Berkeley National Laboratory (LBNL); Khromov, A. [Moscow Engineering Physics Institute (MEPhI), Russia] Moscow Engineering Physics Institute (MEPhI), Russia; Link, J. [Virginia Polytechnic Institute and State University] Virginia Polytechnic Institute and State University; Louis, W. [Los Alamos National Laboratory (LANL)] Los Alamos National Laboratory (LANL); Lu, W. [Oak Ridge National Laboratory (ORNL)] Oak Ridge National Laboratory (ORNL); Mauger, C. [Los Alamos National Laboratory (LANL)] Los Alamos National Laboratory (LANL); Marleau, P. [Sandia National Laboratories (SNL)] Sandia National Laboratories (SNL); Markoff, D. [North Carolina Central University, Durham] North Carolina Central University, Durham; Martin, R. D. [University of South Dakota] University of South Dakota; Mueller, Paul Edward [ORNL] ORNL; Newby, J. [Oak Ridge National Laboratory (ORNL)] Oak Ridge National Laboratory (ORNL); Orrell, John L. [Pacific Northwest National Laboratory (PNNL)] Pacific Northwest National Laboratory (PNNL); O'Shaughnessy, C. [University of North Carolina, Chapel Hill] University of North Carolina, Chapel Hill

2013-01-01T23:59:59.000Z

67

Neutron Time-Of-Flight Spectrometer Based on HIRFL for Studies of Spallation Reactions Related to ADS Project  

E-Print Network (OSTI)

A Neutron Time-Of-Flight (NTOF) spectrometer based on Heavy Ion Research Facility in Lanzhou (HIRFL) is developed for studies of neutron production of proton induced spallation reactions related to the ADS project. After the presentation of comparisons between calculated spallation neutron production double-differential cross sections and the available experimental one, a detailed description of NTOF spectrometer is given. Test beam results show that the spectrometer works well and data analysis procedures are established. The comparisons of the test beam neutron spectra with those of GEANT4 simulations are presented.

Zhang, Suyalatu; Han, Rui; Wada, Roy; Liu, Xingquan; Lin, Weiping; Liu, Jianli; Shi, Fudong; Ren, Peipei; Tian, Guoyu; Luo, Fei

2014-01-01T23:59:59.000Z

68

Neutron Time-Of-Flight Spectrometer Based on HIRFL for Studies of Spallation Reactions Related to ADS Project  

E-Print Network (OSTI)

A Neutron Time-Of-Flight (NTOF) spectrometer based on Heavy Ion Research Facility in Lanzhou (HIRFL) is developed for studies of neutron production of proton induced spallation reactions related to the ADS project. After the presentation of comparisons between calculated spallation neutron production double-differential cross sections and the available experimental one, a detailed description of NTOF spectrometer is given. Test beam results show that the spectrometer works well and data analysis procedures are established. The comparisons of the test beam neutron spectra with those of GEANT4 simulations are presented.

Suyalatu Zhang; Zhiqiang Chen; Rui Han; Roy Wada; Xingquan Liu; Weiping Lin; Jianli Liu; Fudong Shi; Peipei Ren; Guoyu Tian; Fei Luo

2014-11-20T23:59:59.000Z

69

CTAX: the US/Japan Cold Neutron Triple-Axis Spectromete at HFIR | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

CTAX-US/Japan Cold Neutron Triple-Axis Spectrometer CTAX-US/Japan Cold Neutron Triple-Axis Spectrometer CTAX US/Japan Cold Neutron Triple-Axis Spectrometer (CG-4C). (larger image) The U.S.-Japan Cold Neutron Triple-Axis Spectrometer (CTAX) is a conventional triple-axis spectrometer with variable incident energy and variable monochromator-sample and sample-analyzer distances. The cold guide 4 bender and guide hall shielding reduce background levels at CG-4C, and the 15-cm-tall guide profile is well exploited by CG-4C's vertically focusing monochromator (PG 002). To enhance accommodation of strong magnetic fields at the sample position and to simplify future polarization analysis, the amount of ferromagnetic material has been minimized in the construction of this instrument. CG-4C is a collaboration of Oak Ridge National Laboratory, the Neutron

70

Physics Analyses in the Design of the HFIR Cold Neutron Source  

SciTech Connect

Physics analyses have been performed to characterize the performance of the cold neutron source to be installed in the High Flux Isotope Reactor at the Oak Ridge National Laboratory in the near future. This paper provides a description of the physics models developed, and the resulting analyses that have been performed to support the design of the cold source. These analyses have provided important parametric performance information, such as cold neutron brightness down the beam tube and the various component heat loads, that have been used to develop the reference cold source concept.

Bucholz, J.A.

1999-09-27T23:59:59.000Z

71

Experiment Automation with a Robot Arm using the Liquids Reflectometer Instrument at the Spallation Neutron Source  

SciTech Connect

The Liquids Reflectometer instrument installed at the Spallation Neutron Source (SNS) enables observations of chemical kinetics, solid-state reactions and phase-transitions of thin film materials at both solid and liquid surfaces. Effective measurement of these behaviors requires each sample to be calibrated dynamically using the neutron beam and the data acquisition system in a feedback loop. Since the SNS is an intense neutron source, the time needed to perform the measurement can be the same as the alignment process, leading to a labor-intensive operation that is exhausting to users. An update to the instrument control system, completed in March 2013, implemented the key features of automated sample alignment and robot-driven sample management, allowing for unattended operation over extended periods, lasting as long as 20 hours. We present a case study of the effort, detailing the mechanical, electrical and software modifications that were made as well as the lessons learned during the integration, verification and testing process.

Zolnierczuk, Piotr A [ORNL; Vacaliuc, Bogdan [ORNL; Sundaram, Madhan [ORNL; Parizzi, Andre A [ORNL; Halbert, Candice E [ORNL; Hoffmann, Michael C [ORNL; Greene, Gayle C [ORNL; Browning, Jim [ORNL; Ankner, John Francis [ORNL

2013-01-01T23:59:59.000Z

72

Electron cloud development in the Proton Storage Ring and in the Spallation Neutron Source  

Science Journals Connector (OSTI)

We have applied our simulation code POSINST to evaluate the contribution to the growth rate of the electron cloud instability in proton storage rings. In particular, we present here recent simulation results for the main features of the electron cloud in the storage ring of the Spallation Neutron Source at Oak Ridge, and updated results for the Proton Storage Ring at Los Alamos. A key ingredient in our model is a detailed description of the secondary electron emission process, including a refined model for the emitted energy spectrum, and for the three main components of the secondary yield, namely, the true secondary, rediffused and backscattered components.

M. T. F. Pivi and M. A. Furman

2003-03-05T23:59:59.000Z

73

High Flux Isotope Reactor (HFIR) | U.S. DOE Office of Science...  

Office of Science (SC) Website

(SUF) Division SUF Home About User Facilities User Facilities Dev X-Ray Light Sources Neutron Scattering Facilities High Flux Isotope Reactor (HFIR) Lujan Neutron Scattering...

74

Cross-Fertilization between Spallation Neutron Source and Third Generation Synchrotron Radiation Detectors  

SciTech Connect

Suffering presently from relatively low source strengths compared to synchrotron radiation investigations, neutron scattering methods will greatly benefit from the increase of instantaneous flux attained at the next generation of pulsed spallation neutron sources. In particular at ESS, the strongest projected source, the counting rate load on the detectors will rise by factors of up to 50-150 in comparison with present generic instruments. For these sources the detector requirements overlap partly with those for modern synchrotron radiation detectors as far as counting rate capability and two-dimensional position resolution are concerned. In this paper, examples of the current and forthcoming detector development, comprising e.g. novel solutions for low-pressure micro-strip gas chamber detectors, for silicon micro-strip detectors and for the related front-end ASICs and data acquisition (DAQ) systems, are summarized, which will be of interest for detection of synchrotron radiation as well.

Gebauer, B.; Schulz, Ch.; Alimov, S.S.; Wilpert, Th. [Hahn-Meitner-Instiut Berlin, Glienicker Str. 100, 14109 Berlin (Germany); Levchanovsky, F.V. [Hahn-Meitner-Instiut Berlin, Glienicker Str. 100, 14109 Berlin (Germany); Frank Laboratory of Neutron Physics, Joint Institute of Nuclear Research, 141980 Dubna (Russian Federation); Litvinenko, E.I.; Nikiforov, A.S. [Frank Laboratory of Neutron Physics, Joint Institute of Nuclear Research, 141980 Dubna (Russian Federation)

2004-05-12T23:59:59.000Z

75

A comparison of four direct geometry time-of-flight spectrometers at the Spallation Neutron Source  

SciTech Connect

The Spallation Neutron Source at Oak Ridge National Laboratory now hosts four direct geometry time-of-flight chopper spectrometers. These instruments cover a range of wave-vector and energy transfer space with varying degrees of neutron flux and resolution. The regions of reciprocal and energy space available to measure at these instruments are not exclusive and overlap significantly. We present a direct comparison of the capabilities of this instrumentation, conducted by data mining the instrument usage histories, and specific scanning regimes. In addition, one of the common science missions for these instruments is the study of magnetic excitations in condensed matter systems. We have measured the powder averaged spin wave spectra in one particular sample using each of these instruments, and use these data in our comparisons.

Stone, M. B.; Abernathy, D. L.; Ehlers, G.; Garlea, O.; Podlesnyak, A.; Winn, B. [Quantum Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Quantum Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Niedziela, J. L.; DeBeer-Schmitt, L.; Graves-Brook, M. [Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Granroth, G. E. [Neutron Data Analysis and Visualization Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Neutron Data Analysis and Visualization Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Kolesnikov, A. I. [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2014-04-15T23:59:59.000Z

76

A comparison of four direct geometry time-of-flight spectrometers at the Spallation Neutron Source  

SciTech Connect

The Spallation Neutron Source at Oak Ridge National Laboratory now hosts four direct geometry time-of-flight chopper spectrometers. These instruments cover a range of wave vector and energy transfer space with varying degrees of neutron flux and resolution. The regions of reciprocal and energy space available to measure at these instruments is not exclusive and overlaps significantly. We present a direct comparison of the capabilities of this instrumentation, conducted by data mining the instrument usage histories, and specific scanning regimes. In addition, one of the common science missions for these instruments is the study of magnetic excitations in condensed matter systems. We have measured the powder averaged spin wave spectra in one particular sample using each of these instruments, and use these data in our comparisons.

Stone, Matthew B [ORNL] [ORNL; Niedziela, Jennifer L [ORNL] [ORNL; Abernathy, Douglas L [ORNL] [ORNL; Debeer-Schmitt, Lisa M [ORNL] [ORNL; Garlea, Vasile O [ORNL] [ORNL; Granroth, Garrett E [ORNL] [ORNL; Graves-Brook, Melissa K [ORNL] [ORNL; Ehlers, Georg [ORNL] [ORNL; Kolesnikov, Alexander I [ORNL] [ORNL; Podlesnyak, Andrey A [ORNL] [ORNL; Winn, Barry L [ORNL] [ORNL

2014-01-01T23:59:59.000Z

77

Integrating advanced materials simulation techniques into an automated data analysis workflow at the Spallation Neutron Source  

SciTech Connect

This presentation will review developments on the integration of advanced modeling and simulation techniques into the analysis step of experimental data obtained at the Spallation Neutron Source. A workflow framework for the purpose of refining molecular mechanics force-fields against quasi-elastic neutron scattering data is presented. The workflow combines software components to submit model simulations to remote high performance computers, a message broker interface for communications between the optimizer engine and the simulation production step, and tools to convolve the simulated data with the experimental resolution. A test application shows the correction to a popular fixed-charge water model in order to account polarization effects due to the presence of solvated ions. Future enhancements to the refinement workflow are discussed. This work is funded through the DOE Center for Accelerating Materials Modeling.

Borreguero Calvo, Jose M [ORNL] [ORNL; Campbell, Stuart I [ORNL] [ORNL; Delaire, Olivier A [ORNL] [ORNL; Doucet, Mathieu [ORNL] [ORNL; Goswami, Monojoy [ORNL] [ORNL; Hagen, Mark E [ORNL] [ORNL; Lynch, Vickie E [ORNL] [ORNL; Proffen, Thomas E [ORNL] [ORNL; Ren, Shelly [ORNL] [ORNL; Savici, Andrei T [ORNL] [ORNL; Sumpter, Bobby G [ORNL] [ORNL

2014-01-01T23:59:59.000Z

78

Spallation Neutrons and Pressure ?? SNAP ?? DE-FG02-03ER46085 CLOSE-OUT MAY 2009  

SciTech Connect

The purpose of the grant was to build a community of scientist and to draw upon their expertise to design and build the world's first dedicated high pressure beamline at a spallation source - the so called Spallation Neutron And Pressure (SNAP) beamline at the Spallation Neutron Source (SNS) at OAk Ridge NAtional LAboratory. . Key to this endeavor was an annual meeting attended by the instrument design team and the executive committee. The discussions at those meeting set an ambitious agenda for beamline design and construction and highlighted key science areas of interest for the community. This report documents in 4 appendices the deliberations at the annual SNAP meetings and the evolution of the beamline optics from concept to construction. The appendices also contain key science opportunities for extreme conditions research.

John B Parise

2009-05-22T23:59:59.000Z

79

ORNL Neutron Sciences Instruments  

NLE Websites -- All DOE Office Websites (Extended Search)

Instruments banner Instruments banner ORNL Neutron Sciences Instruments SNS and HFIR provide researchers with two complementary world-class suites of neutron scattering instruments and beam lines. All the instruments are supported by a variety of sample environments and data analysis and visualization capabilities. Before submitting a proposal for a specific instrument, please contact the appropriate instrument scientist to make sure your research is feasible for that instrument. Instruments Currently Available to Users SNS Beam Line Instrument Name HFIR Beam Line Instrument Name 1B NOMAD Nanoscale-Ordered Materials Diffractometer CG-1 Development Beam Line 2 BASIS Backscattering Spectrometer CG-1D IMAGING Neutron Imaging Prototype Facility 3 SNAP Spallation Neutrons and Pressure Diffractometer CG-2 GP-SANS

80

Design of a horizontal neutron reflectometer for the European Spallation Source  

E-Print Network (OSTI)

A design study of a horizontal neutron reflectometer adapted to the general baseline of the long pulse European Spallation Source (ESS) is presented. The instrument layout comprises solutions for the neutron guide, high-resolution pulse shaping and beam bending onto a sample surface being so far unique in the field of reflectometry. The length of this instrument is roughly 55 m, enabling $\\delta \\lambda / \\lambda$ resolutions from 0.5% to 10%. The incident beam is focussed in horizontal plane to boost measurements of sample sizes of 1*1 cm{^2} and smaller with potential beam deflection in both downward and upward direction. The range of neutron wavelengths untilized by the instrument is 2 to 7.1 (12.2, ...) {\\AA}, if every (second, ...) neutron source ulse is used. Angles of incidence can be set between 0{\\deg} and 9{\\deg} with a total accessible q-range from 4*10^{-3} {\\AA}^{-1} up to 1 {\\AA}^{-1}. The instrument operates both in {\\theta}/{\\theta} (free liquid surfaces) and {\\theta}/2{\\theta} (solid/liquid, ...

Nekrassov, D; Lieutenant, K; Moulin, J -F; Strobl, M; Steitz, R

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

DOE/EIS0247; Final Environmental Impact Statement Construction and Operation of the Spallation Neutron Source  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

SNS FEIS SNS FEIS Cover Sheet COVER SHEET RESPONSIBLE AGENCY: U.S. Department of Energy (DOE) TITLE: Final Environmental Impact Statement (FEIS), Construction and Operation of the Spallation Neutron Source (DOE/EIS-0247) LOCATIONS OF ALTERNATIVE SITES: Illinois, New Mexico, New York, and Tennessee. CONTACT: For further information on this document, write or call: Mr. David Wilfert, EIS Document Manager Oak Ridge Operations Office U.S. Department of Energy 200 Administration Road, 146/FEDC Oak Ridge, TN 37831 Telephone: (800) 927-9964 Facsimile: (423) 576-4542 E-mail: NSNSEIS@ornl.gov Mr. Jeff Hoy, SNS Program Manager Office of Basic Energy Research U.S. Department of Energy (ER-10) Germantown, MD 20874 Telephone: (301) 903-4924 Facsimile: (301) 903-9513 E-mail: Jeff.Hoy@mailgw.er.doe.gov

82

Record of Decision for the Construction and Operation of the Spallation Neutron Source  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

140 140 Federal Register / Vol. 64, No. 125 / Wednesday, June 30, 1999 / Notices or minimize environmental harm that may result from implementing the Redevelopment Plan. Accordingly, Navy will dispose of the surplus Federal property at Naval Air Station Barbers Point in a manner that is consistent with the State of Hawaii's Redevelopment Plan for the property. Dated: June 17, 1999. William J. Cassidy, Jr., Deputy Assistant Secretary of the Navy (Conversion And Redevelopment). Dated: June 25, 1999. Ralph W. Corey, CDR, JAGC, USN, Alternate Federal Register Liaison Officer. [FR Doc. 99-16691 Filed 6-29-99; 8:45 am] BILLING CODE 3810-FF-M DEPARTMENT OF ENERGY Record of Decision for the Construction and Operation of the Spallation Neutron Source AGENCY: Department of Energy. ACTION: Record of decision.

83

EXPERIENCE WITH COLLABORATIVE DEVELOPMENT FOR THE SPALLATION NEUTRON SOURCE FROM A PARTNER LAB PERSPECTIVE.  

SciTech Connect

Collaborative development and operation of large physics experiments is fairly common. Less common is the collaborative development or operation of accelerators. A current example of the latter is the Spallation Neutron Source (SNS). The SNS project was conceived as a collaborative effort between six DOE facilities. In the SNS case, the control system was also developed collaboratively. The SNS project has now moved beyond the collaborative development phase and into the phase where Oak Ridge National Lab (ORNL) is integrating contributions from collaborating ''partner labs'' and is beginning accelerator operations. In this paper, the author reflects on the benefits and drawbacks of the collaborative development of an accelerator control system as implemented for the SNS project from the perspective of a partner lab.

HOFF, L.T.

2005-10-10T23:59:59.000Z

84

Radiation damage and lifetime estimation of the proton beam window at the Japan Spallation Neutron Source  

Science Journals Connector (OSTI)

Abstract The proton beam window (PBW) is a component that separates the high-vacuum area of the accelerator from the target area in the Japan Proton Accelerator Research Complexs Japan Spallation Neutron Source (JSNS). It is important to estimate the damage accumulated from proton beam irradiation to establish a safe lifetime for the window. The PBW is made of an aluminum alloy, which was chosen because of its successful use in the target safety hull of the Swiss Spallation Neutron Source (SINQ). Post-irradiation examination (PIE) performed on SINQ Target 3 after irradiation with a 0.6GeV proton beam measured the gas production in its aluminum safety hull. To estimate a safe lifetime for the JSNS PBW, we calculated the displacement per atom (DPA) and gas production rate using the Particle and Heavy Ion Transport code System (PHITS) for 0.6- and 3-GeV protons. For the hydrogen gas production rate, PHITS shows good agreement with the SINQ PIE results; however, for the helium production rate, it predicts a 45% lower value than the experimental result of 1125 appm. The calculated result for helium production was normalized to fit the experimental results of SINQ. We conservatively estimate the lifetime of the JSNS PBW using the condition that the hydrogen production rate does not exceed the value measured at SINQ. The lifetime of the PBW corresponds to a proton beam fluence of 1.8נ1021cm?2, which is equivalent to an integrated beam power of 8000MWh with the designed current density of 10?Acm?2. The peak density will be reduced to 8.4?Acm?2 to suppress cavitation pitting damage in the mercury target vessel. Consequently, the lifetime of the PBW will be 9500MWh.

Shin-ichiro Meigo; Motoki Ooi; Masahide Harada; Hidetaka Kinoshita; Atushi Akutsu

2014-01-01T23:59:59.000Z

85

Design of an Aluminum Proton Beam Window for the Spallation Neutron Source  

SciTech Connect

An aluminum proton beam window design is being considered at the Spallation Neutron Source primarily to increase the lifetime of the window, with secondary advantages of higher beam transport efficiency and lower activation. The window separates the core vessel, the location of the mercury target, from the vacuum of the accelerator, while withstanding the pass through of a proton beam of up to 2 MW with 1.0 GeV proton energy. The current aluminum alloy being investigated for the window material is 6061-T651 due to its combination of high strength, high thermal conductivity, and good resistance to aqueous corrosion, as well as demonstrated dependability in previous high-radiation environments. The window design will feature a thin plate with closely spaced cross drilled cooling holes. An analytical approach was used to optimize the dimensions of the window before finite element analysis was used to simulate temperature profiles and stress fields resulting from thermal and static pressure loading. The resulting maximum temperature of 60 C and Von Mises stress of 71 MPa are very low compared to allowables for Al 6061-T651. A significant challenge in designing an aluminum proton beam window for SNS is integrating the window with the current 316L SS shield blocks. Explosion bonding was chosen as a joining technique because of the large bonding area required. A test program has commenced to prove explosion bonding can produce a robust vacuum joint. Pending successful explosion bond testing, the aluminum proton beam window design will be proven acceptable for service in the Spallation Neutron Source.

Janney, Jim G [ORNL; McClintock, David A [ORNL

2012-01-01T23:59:59.000Z

86

Department of Energy review of the National Spallation Neutron Source Project  

SciTech Connect

A Department of Energy (DOE) review of the Conceptual Design Report (CDR) for the National Spallation Neutron Source (NSNS) was conducted. The NSNS will be a new high-power spallation neutron source; initially, it will operate at 1 megawatt (MW), but is designed to be upgradeable to significantly higher power, at lower cost, when accelerator and target technologies are developed for higher power. The 53-member Review Committee examined the projected cost, schedule, technical scope, and management structure described in the CDR. For each of the major components of the NSNS, the Committee determined that the project team had produced credible designs that can be expected to work well. What remains to be done is to integrate the design of these components. With the exception of the liquid mercury target, the NSNS Project will rely heavily on proven technologies and, thus, will face a relatively low risk to successful project completion. The Total Project Cost (TPC) presented to the Committee in the CDR was $1.266 billion in as-spent dollars. In general, the Committee felt that the laboratory consortium had presented a credible estimate for each of the major components but that value engineering might produce some savings. The construction schedule presented to the Committee covered six years beginning in FY 1999. The Committee questioned whether all parts of the project could be completed according to this schedule. In particular, the linac and the conventional facilities appeared to have overly optimistic schedules. The NSNS project team was encouraged to reexamine these activities and to consider a more conservative seven-year schedule. Another concern of the Committee was the management structure. In summary, the Committee felt that this Conceptual Design Report was a very credible proposal, and that there is a high probability for successful completion of this major project within the proposed budget, although the six-year proposed schedule may be optimistic.

NONE

1997-06-01T23:59:59.000Z

87

Accelerating Data Acquisition, Reduction, and Analysis at the Spallation Neutron Source  

SciTech Connect

ORNL operates the world's brightest neutron source, the Spallation Neutron Source (SNS). Funded by the US DOE Office of Basic Energy Science, this national user facility hosts hundreds of scientists from around the world, providing a platform to enable break-through research in materials science, sustainable energy, and basic science. While the SNS provides scientists with advanced experimental instruments, the deluge of data generated from these instruments represents both a big data challenge and a big data opportunity. For example, instruments at the SNS can now generate multiple millions of neutron events per second providing unprecedented experiment fidelity but leaving the user with a dataset that cannot be processed and analyzed in a timely fashion using legacy techniques. To address this big data challenge, ORNL has developed a near real-time streaming data reduction and analysis infrastructure. The Accelerating Data Acquisition, Reduction, and Analysis (ADARA) system provides a live streaming data infrastructure based on a high-performance publish subscribe system, in situ data reduction, visualization, and analysis tools, and integration with a high-performance computing and data storage infrastructure. ADARA allows users of the SNS instruments to analyze their experiment as it is run and make changes to the experiment in real-time and visualize the results of these changes. In this paper we describe ADARA, provide a high-level architectural overview of the system, and present a set of use-cases and real-world demonstrations of the technology.

Campbell, Stuart I [ORNL; Kohl, James Arthur [ORNL; Granroth, Garrett E [ORNL; Miller, Ross G [ORNL; Doucet, Mathieu [ORNL; Stansberry, Dale V [ORNL; Proffen, Thomas E [ORNL; Taylor, Russell J [ORNL; Dillow, David [None

2014-01-01T23:59:59.000Z

88

Design progress of cryogenic hydrogen system for China Spallation Neutron Source  

SciTech Connect

China Spallation Neutron Source (CSNS) is a large proton accelerator research facility with 100 kW beam power. Construction started in October 2011 and is expected to last 6.5 years. The cryogenic hydrogen circulation is cooled by a helium refrigerator with cooling capacity of 2200 W at 20 K and provides supercritical hydrogen to neutron moderating system. Important progresses of CSNS cryogenic system were concluded as follows. Firstly, process design of cryogenic system has been completed including helium refrigerator, hydrogen loop, gas distribution, and safety interlock. Secondly, an accumulator prototype was designed to mitigate pressure fluctuation caused by dynamic heat load from neutron moderation. Performance test of the accumulator has been carried out at room and liquid nitrogen temperature. Results show the accumulator with welding bellows regulates hydrogen pressure well. Parameters of key equipment have been identified. The contract for the helium refrigerator has been signed. Mechanical design of the hydrogen cold box has been completed, and the hydrogen pump, ortho-para hydrogen convertor, helium-hydrogen heat exchanger, hydrogen heater, and cryogenic valves are in procurement. Finally, Hydrogen safety interlock has been finished as well, including the logic of gas distribution, vacuum, hydrogen leakage and ventilation. Generally, design and construction of CSNS cryogenic system is conducted as expected.

Wang, G. P.; Zhang, Y.; Xiao, J.; He, C. C.; Ding, M. Y.; Wang, Y. Q.; Li, N.; He, K. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, P.R. (China)

2014-01-29T23:59:59.000Z

89

The Neutron Science TeraGrid Gateway, a TeraGrid Science Gateway to Support the Spallation Neutron Source  

SciTech Connect

The National Science Foundation's (NSF's) Extensible Terascale Facility (ETF), or TeraGrid [1] is entering its operational phase. An ETF science gateway effort is the Neutron Science TeraGrid Gateway (NSTG.) The Oak Ridge National Laboratory (ORNL) resource provider effort (ORNL-RP) during construction and now in operations is bridging a large scale experimental community and the TeraGrid as a large-scale national cyberinfrastructure. Of particular emphasis is collaboration with the Spallation Neutron Source (SNS) at ORNL. The U.S. Department of Energy's (DOE's) SNS [2] at ORNL will be commissioned in spring of 2006 as the world's brightest source of neutrons. Neutron science users can run experiments, generate datasets, perform data reduction, analysis, visualize results; collaborate with remotes users; and archive long term data in repositories with curation services. The ORNL-RP and the SNS data analysis group have spent 18 months developing and exploring user requirements, including the creation of prototypical services such as facility portal, data, and application execution services. We describe results from these efforts and discuss implications for science gateway creation. Finally, we show incorporation into implementation planning for the NSTG and SNS architectures. The plan is for a primarily portal-based user interaction supported by a service oriented architecture for functional implementation.

Cobb, John W [ORNL; Geist, Al [ORNL; Kohl, James Arthur [ORNL; Miller, Stephen D [ORNL; Peterson, Peter F [ORNL; Pike, Gregory [ORNL; Reuter, Michael A [ORNL; Swain, William [ORNL; Vazhkudai, Sudharshan S [ORNL; Vijayakumar, Nithya N [ORNL

2006-01-01T23:59:59.000Z

90

HFIR Plant Maintenance - August  

NLE Websites -- All DOE Office Websites (Extended Search)

students in the Spring Semester NE 401 class - The lecture covered reactor theory on subcritical multiplication, a description of the High Flux Isotope Reactor (HFIR) with emphasis...

91

HFIR Plant Maintenance - August  

NLE Websites -- All DOE Office Websites (Extended Search)

from HFIR irradiated target material at 7920 * Separation of the lanthanides, americium-curium, and transcurium elements using LiCl chromatographic anion exchange Heavy Element...

92

Nuclear Simulation and Radiation Physics Investigations of the Target Station of the European Spallation Neutron Source  

SciTech Connect

The European Spallation Neutron Source (ESS) delivers high-intensity pulsed particle beams with 5-MW average beam power at 1.3-GeV incident proton energy. This causes sophisticated demands on material and geometry choices and a very careful optimization of the whole target system. Therefore, complex and detailed particle transport models and computer code systems have been developed and used to study the nuclear assessment of the ESS target system. The purpose here is to describe the methods of calculation mainly based on the Monte Carlo code to show the performance of the ESS target station. The interesting results of the simulations of the mercury target system are as follows: time-dependent neutron flux densities, energy deposition and heating, radioactivity and afterheat, materials damage by radiation, and high-energy source shielding. The results are discussed in great detail. The validity of codes and models, further requirements to improve the methods of calculation, and the status of running and planned experiments are given also.

Filges, Detlef; Neef, Ralf-Dieter; Schaal, Hartwig [Forschungszentrum Juelich GmbH (Germany)

2000-10-15T23:59:59.000Z

93

DOE/EIS-0247; Draft Environmental Impact Statement Construction and Operation of the Spallation Neutron Source, December 1998  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

December 1998 December 1998 Construction and Operation of the S PALLATION N EUTRON S OURCE DRAFT ENVIRONMENTAL IMPACT STATEMENT U.S. Department of Energy Office of Science DOE/EIS-0247 Construction and Operation of the Spallation Neutron Source Facility Draft Environmental Impact Statement U.S. Department of Energy Office of Science December 1998 DOE/EIS-0247 Draft, December 1998 Cover Sheet COVER SHEET RESPONSIBLE AGENCY: U.S. Department of Energy (DOE) TITLE: Draft Environmental Impact Statement (DEIS), Construction and Operation of the Spallation Neutron Source (DOE/EIS-0247) LOCATIONS OF ALTERNATIVE SITES: Illinois, New Mexico, New York, and Tennessee. CONTACT: For further information on this document, write or call: Mr. David Wilfert, EIS Document Manager U.S. Department of Energy Oak Ridge Operations Office

94

E-Print Network 3.0 - ads spallation target Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

correlations of spallation neutrons on the neutron uctuations in accelerator-driven subcritical... of neutron uctuations in spallation-driven subcritical systems require the use...

95

The SpallaTion  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

SpallaTion neuTron Source projecT When the Department of Energy (DOE) set out in the 1990s to develop a neutron scattering research facility that was ten times more powerful than the state of the art, the concept for the project that it chose was as ambitious as the scientific capability it sought to deliver. The Spallation Neutron Source (SNS) Project called for unprecedented collaboration among six national laboratories as well as significant

96

Characterization of an explosively bonded aluminum proton beam window for the Spallation Neutron Source  

SciTech Connect

An effort is underway at the Spallation Neutron Source (SNS) to change the design of the 1st Generation high-nickel alloy proton beam window (PBW) to one that utilizes aluminum for the window material. One of the key challenges to implementation of an aluminum PBW at the SNS was selection of an appropriate joining method to bond an aluminum window to the stainless steel bulk shielding of the PBW assembly. An explosively formed bond was selected as the most promising joining method for the aluminum PBW design. A testing campaign was conducted to evaluate the strength and efficacy of explosively formed bonds that were produced using two different interlayer materials: niobium and titanium. The characterization methods reported here include tensile testing, thermal-shock leak testing, optical microscopy, and advanced scanning electron microscopy. All tensile specimens examined failed in the aluminum interlayer and measured tensile strengths were all slightly greater than the native properties of the aluminum interlayer, while elongation values were all slightly lower. A leak developed in the test vessel with a niobium interlayer joint after repeated thermal-shock cycles, and was attributed to an extensive crack network that formed in a layer of niobium-rich intermetallics located on the bond interfaces of the niobium interlayer; the test vessel with a titanium interlayer did not develop a leak under the conditions tested. Due to the experience gained from these characterizations, the explosively formed bond with a titanium interlayer was selected for the aluminum PBW design at the SNS.

McClintock, David A [ORNL] [ORNL; Janney, Jim G [ORNL] [ORNL; Parish, Chad M [ORNL] [ORNL

2014-01-01T23:59:59.000Z

97

Characterization of irradiated AISI 316L stainless steel disks removed from the Spallation Neutron Source  

SciTech Connect

Irradiated AISI 316L stainless steel disks were removed from the Spallation Neutron Source (SNS) for post-irradiation examination (PIE) to assess mechanical property changes due to radiation damage and erosion of the target vessel. Topics reviewed include high-resolution photography of the disk specimens, cleaning to remove mercury (Hg) residue and surface oxides, profile mapping of cavitation pits using high frequency ultrasonic testing (UT), high-resolution surface replication, and machining of test specimens using wire electrical discharge machining (EDM), tensile testing, Rockwell Superficial hardness testing, Vickers microhardness testing, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The effectiveness of the cleaning procedure was evident in the pre- and post-cleaning photography and permitted accurate placement of the test specimens on the disks. Due to the limited amount of material available and the unique geometry of the disks, machine fixturing and test specimen design were critical aspects of this work. Multiple designs were considered and refined during mock-up test runs on unirradiated disks. The techniques used to successfully machine and test the various specimens will be presented along with a summary of important findings from the laboratory examinations.

Vevera, Bradley J [ORNL] [ORNL; Hyres, James W [ORNL] [ORNL; McClintock, David A [ORNL] [ORNL; Riemer, Bernie [ORNL] [ORNL

2014-01-01T23:59:59.000Z

98

H{sup -} radio frequency source development at the Spallation Neutron Source  

SciTech Connect

The Spallation Neutron Source (SNS) now routinely operates nearly 1 MW of beam power on target with a highly persistent {approx}38 mA peak current in the linac and an availability of {approx}90%. H{sup -} beam pulses ({approx}1 ms, 60 Hz) are produced by a Cs-enhanced, multicusp ion source closely coupled with an electrostatic low energy beam transport (LEBT), which focuses the 65 kV beam into a radio frequency quadrupole accelerator. The source plasma is generated by RF excitation (2 MHz, {approx}60 kW) of a copper antenna that has been encased with a thickness of {approx}0.7 mm of porcelain enamel and immersed into the plasma chamber. The ion source and LEBT normally have a combined availability of {approx}99%. Recent increases in duty-factor and RF power have made antenna failures a leading cause of downtime. This report first identifies the physical mechanism of antenna failure from a statistical inspection of {approx}75 antennas which ran at the SNS, scanning electron microscopy studies of antenna surface, and cross sectional cuts and analysis of calorimetric heating measurements. Failure mitigation efforts are then described which include modifying the antenna geometry and our acceptance/installation criteria. Progress and status of the development of the SNS external antenna source, a long-term solution to the internal antenna problem, are then discussed. Currently, this source is capable of delivering comparable beam currents to the baseline source to the SNS and, an earlier version, has briefly demonstrated unanalyzed currents up to {approx}100 mA (1 ms, 60 Hz) on the test stand. In particular, this paper discusses plasma ignition (dc and RF plasma guns), antenna reliability, magnet overheating, and insufficient beam persistence.

Welton, R. F.; Gawne, K. R.; Han, B. X.; Murray, S. N.; Pennisi, T. R.; Roseberry, R. T.; Santana, M.; Stockli, M. P. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37830-6471 (United States); Dudnikov, V. G. [Muons, Inc., 552 N. Batavia Avenue, Batavia, Illinois 60510 (United States); Turvey, M. W. [Villanova University, 800E. Lancaster Ave, Villanova, Pennsylvania 19085 (United States)

2012-02-15T23:59:59.000Z

99

Pulsed spallation neutron source with an induction linac and a fixed-field alternating-gradient accelerator  

SciTech Connect

The paper describes an accelerator scenario of a Pulsed Spallation Neutron Source made of an Induction Linac injecting into a Fixed-Field Alternating-Gradient Accelerator (FFAG). The motivations underlying the proposal deal with the concern of removing technical risks peculiar to other scenarios involving RF Linacs, Synchrotrons and Accumulator Rings, which originate, for example, from the need of developing intense negative-ion sources and of multi-turn injection into the Compressor Rings. The system proposed here makes use of a positive-ion source of very short pulse duration, and of single-turn transfer into the circular accelerator.

Ruggiero, A.G. [Brookhaven National Lab., Upton, NY (United States); Bauer, G. [Paul Scherrer Institute, Villigen (Switzerland); Faltens, A. [Lawrence Berkeley National Lab., CA (United States)] [and others

1995-12-01T23:59:59.000Z

100

Thermal-hydraulic performance of a water-cooled tungsten-rod target for a spallation neutron source  

SciTech Connect

A thermal-hydraulic (T-H) analysis is conducted to determine the feasibility and limitations of a water-cooled tungsten-rod target at powers of 1 MW and above. The target evaluated has a 10-cm x 10-cm cross section perpendicular to the beam axis, which is typical of an experimental spallation neutron source - both for a short-pulse spallation source and long-pulse spallation source. This report describes the T-H model and assumptions that are used to evaluate the target. A 1-MW baseline target is examined, and the results indicate that this target should easily handle the T-H requirements. The possibility of operating at powers >1 MW is also examined. The T-H design is limited by the condition that the coolant does not boil (actual limits are on surface subcooling and wall heat flux); material temperature limits are not approached. Three possible methods of enhancing the target power capability are presented: reducing peak power density, altering pin dimensions, and improving coolant conditions (pressure and temperature). Based on simple calculations, it appears that this target concept should have little trouble reaching the 2-MW range (from a purely T-H standpoint), and possibly much higher powers. However, one must keep in mind that these conclusions are based solely on thermal-hydraulics. It is possible, and perhaps likely, that target performance could be limited by structural issues at higher powers, particularly for a short-pulse spallation source because of thermal shock issues.

Poston, D.I.

1997-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Concept for a Time-of-Flight Small Angle Neutron Scattering Instrument at the European Spallation Source  

E-Print Network (OSTI)

A new Small Angle Neutron Scattering instrument is proposed for the European Spallation Source. The pulsed source requires a time-of-flight analysis of the gathered neutrons at the detector. The optimal instrument length is found to be rather large, which allows for a polarizer and a versatile collimation. The polarizer allows for studying magnetic samples and incoherent background subtraction. The wide collimation will host VSANS and SESANS options that increase the resolution of the instrument towards um and tens of um, respectively. Two 1m2 area detectors will cover a large solid angle simultaneously. The expected gains for this new instrument will lie in the range between 20 and 36, depending on the assessment criteria, when compared to up-to-date reactor based instruments. This will open new perspectives for fast kinetics, weakly scattering samples, and multi-dimensional contrast variation studies.

S. Jaksch; D. Martin-Rodriguez; A. Ostermann; J. Jestin; S. Duarte Pinto; W. G. Bouwman; J. Uher; R. Engels; G. Kemmerling; R. Hanslik; H. Frielinghaus

2014-03-11T23:59:59.000Z

102

Three-dimensional calculations of neutron streaming in the beam tubes of the ORNL HFIR (High Flux Isotope Reactor) Reactor  

SciTech Connect

The streaming of neutrons through the beam tubes in High Flux Isotope Reactor at Oak Ridge National Laboratory has resulted in a reduction of the fracture toughness of the reactor vessel. As a result, an evaluation of vessel integrity was undertaken in order to determine if the reactor can be operated again. As a part of this evaluation, three-dimensional neutron transport calculations were performed to obtain fluxes at points of interest in the wall of the vessel. By comparing the calculated and measured activation of dosimetry specimens from the vessel surveillance program, it was determined that the calculated flux shape was satisfactory to transpose the surveillance data to the locations in the vessel. A bias factor was applied to correct for the average C/E ratio of 0.69. 8 refs., 7 figs., 3 tabs.

Childs, R.L.; Rhoades, W.A.; Williams, L.R.

1988-01-01T23:59:59.000Z

103

Lead-Bismuth-Eutectic Spallation Neutron Source for Nuclear Transmuter Y. Gohar, J. Herceg, L Krajtl, D. Pointer, J. Saiveau, T. Sofu, and P. Finck  

E-Print Network (OSTI)

-driven test facility (ADTF). The ADTF is a major nuclear research facility that will provide multiple testing to operate as a user facility that allows testing advanced nuclear technologies and applications, materialLead-Bismuth-Eutectic Spallation Neutron Source for Nuclear Transmuter Y. Gohar, J. Herceg, L

McDonald, Kirk

104

Instrument performance study on the short and long pulse options of the second Spallation Neutron Source target station  

SciTech Connect

The Spallation Neutron Source (SNS) facility at the Oak Ridge National Laboratory is designed with an upgrade option for a future low repetition rate, long wavelength second target station. This second target station is intended to complement the scientific capabilities of the 1.4 MW, 60 Hz high power first target station. Two upgrade possibilities have been considered, the short and the long pulse options. In the short pulse mode, proton extraction occurs after the pulse compression in the accumulator ring. The proton pulse structure is thus the same as that for the first target station with a pulse width of ?0.7 ?s. In the long pulse mode, protons are extracted as they are produced by the linac, with no compression in the accumulator ring. The time width of the uncompressed proton pulse is ?1 ms. This difference in proton pulse structure means that neutron pulses will also be different. Neutron scattering instruments thus have to be designed and optimized very differently for these two source options which will directly impact the overall scientific capabilities of the SNS facility. In order to assess the merits of the short and long pulse target stations, we investigated a representative suit of neutron scattering instruments and evaluated their performance under each option. Our results indicate that the short pulse option will offer significantly better performance for the instruments and is the preferred choice for the SNS facility.

Zhao, J. K.; Herwig, Kenneth W.; Robertson, J. L.; Gallmeier, Franz X.; Riemer, Bernard W. [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2013-10-15T23:59:59.000Z

105

Status of Cryogenic System for Spallation Neutron Source's Superconducting Radiofrequency Test Facility at Oak Ridge National Lab  

SciTech Connect

Spallation Neutron Source (SNS) at Oak Ridge National Lab (ORNL) is building an independent cryogenic system for its Superconducting Radiofrequency Test Facility (SRFTF). The scope of the system is to support the SNS cryomodule test and cavity test at 2-K (using vacuum pump) and 4.5K for the maintenance purpose and Power Upgrade Project of SNS, and to provide the part of the cooling power needed to backup the current CHL to keep Linac at 4.5-K during CHL maintenance period in the future. The system is constructed in multiple phases. The first phase is to construct an independent 4K helium refrigeration system with helium Dewar and distribution box as load interface. It is schedule to be commissioned in 2013. Here we report the concept design of the system and the status of the first phase of this project.

Xu, Ting [ORNL; Casagrande, Fabio [ORNL; Ganni, Venkatarao [ORNL; Knudsen, Peter N [ORNL; Strong, William Herb [ORNL

2011-01-01T23:59:59.000Z

106

Active beam position stabilization of pulsed lasers for long-distance ion profile diagnostics at the Spallation Neutron Source (SNS)  

SciTech Connect

A high peak-power Q-switched laser has been used to monitor the ion beam profiles in the superconducting linac at the Spallation Neutron Source (SNS). The laser beam suffers from position drift due to movement, vibration, or thermal effects on the optical components in the 250-meter long laser beam transport line. We have designed, bench-tested, and implemented a beam position stabilization system by using an Ethernet CMOS camera, computer image processing and analysis, and a piezo-driven mirror platform. The system can respond at frequencies up to 30 Hz with a high position detection accuracy. With the beam stabilization system, we have achieved a laser beam pointing stability within a range of 2 rad (horizontal) to 4 rad (vertical), corresponding to beam drifts of only 0.5 mm 1 mm at the furthest measurement station located 250 meters away from the light source.

Hardin, Robert A [ORNL; Liu, Yun [ORNL; Long, Cary D [ORNL; Aleksandrov, Alexander V [ORNL; Blokland, Willem [ORNL

2011-01-01T23:59:59.000Z

107

HFIR spent fuel management alternatives  

SciTech Connect

The High Flux Isotope Reactor (HFIR) at Martin Marietta Energy Systems' Oak Ridge National Laboratory (ORNL) has been unable to ship its spent fuel to Savannah River Site (SRS) for reprocessing since 1985. The HFIR storage pools are expected to fill up in the February 1994 to February 1995 time frame. If a management altemative to existing HFIR pool storage is not identified and implemented before the HFIR pools are full, the HFIR will be forced to shut down. This study investigated several alternatives for managing the HFIR spent fuel, attempting to identify options that could be implemented before the HFIR pools are full. The options investigated were: installing a dedicated dry cask storage facility at ORNL, increasing HFIR pool storage capacity by clearing the HFIR pools of debris and either close-packing or stacking the spent fuel elements, storing the spent fuel at another ORNL pool, storing the spent fuel in one or more hot cells at ORNL, and shipping the spent fuel offsite for reprocessing or storage elsewhere.

Begovich, J.M.; Green, V.M.; Shappert, L.B.; Lotts, A.L.

1992-10-15T23:59:59.000Z

108

HFIR spent fuel management alternatives  

SciTech Connect

The High Flux Isotope Reactor (HFIR) at Martin Marietta Energy Systems` Oak Ridge National Laboratory (ORNL) has been unable to ship its spent fuel to Savannah River Site (SRS) for reprocessing since 1985. The HFIR storage pools are expected to fill up in the February 1994 to February 1995 time frame. If a management altemative to existing HFIR pool storage is not identified and implemented before the HFIR pools are full, the HFIR will be forced to shut down. This study investigated several alternatives for managing the HFIR spent fuel, attempting to identify options that could be implemented before the HFIR pools are full. The options investigated were: installing a dedicated dry cask storage facility at ORNL, increasing HFIR pool storage capacity by clearing the HFIR pools of debris and either close-packing or stacking the spent fuel elements, storing the spent fuel at another ORNL pool, storing the spent fuel in one or more hot cells at ORNL, and shipping the spent fuel offsite for reprocessing or storage elsewhere.

Begovich, J.M.; Green, V.M.; Shappert, L.B.; Lotts, A.L.

1992-10-15T23:59:59.000Z

109

Spin exchange optical pumping based polarized {sup 3}He filling station for the Hybrid Spectrometer at the Spallation Neutron Source  

SciTech Connect

The Hybrid Spectrometer (HYSPEC) is a new direct geometry spectrometer at the Spallation Neutron Source at the Oak Ridge National Laboratory. This instrument is equipped with polarization analysis capability with 60 Degree-Sign horizontal and 15 Degree-Sign vertical detector coverages. In order to provide wide angle polarization analysis for this instrument, we have designed and built a novel polarized {sup 3}He filling station based on the spin exchange optical pumping method. It is designed to supply polarized {sup 3}He gas to HYSPEC as a neutron polarization analyzer. In addition, the station can optimize the {sup 3}He pressure with respect to the scattered neutron energies. The depolarized {sup 3}He gas in the analyzer can be transferred back to the station to be repolarized. We have constructed the prototype filling station. Preliminary tests have been carried out demonstrating the feasibility of the filling station. Here, we report on the design, construction, and the preliminary results of the prototype filling station.

Jiang, C. Y.; Tong, X.; Brown, D. R.; Culbertson, H.; Kadron, B.; Robertson, J. L. [Instrument and Source Design Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Graves-Brook, M. K. [Research Accelerator Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Hagen, M. E. [Neutron Data Analysis and Visualization Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Lee, W. T. [Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234 (Australia); Winn, B. [Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2013-06-15T23:59:59.000Z

110

PERFORMING DIAGNOSTICS ON THE SPALLATION NEUTRON SOURCE VISION BEAM LINE TO ELIMINATE HIGH VIBRATION LEVELS AND PROVIDE A SUSTAINABLE OPERATION  

SciTech Connect

The Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL) provides variable energy neutrons for a variety of experiments. The neutrons proceed down beam lines to the experiment hall, which houses a variety of experiments and test articles. Each beam line has one or more neutron choppers which filter the neutron beam based on the neutron energy by using a rotating neutron absorbing material passing through the neutron beam. Excessive vibration of the Vision beam line, believed to be caused by the T0 chopper, prevented the Vision beam line from operating at full capacity. This problem had been addressed several times by rebalancing/reworking the T0 beam chopper but the problem stubbornly persisted. To determine the cause of the high vibration, dynamic testing was performed. Twenty-seven accelerometer and motor current channels of data were collected during drive up, drive down, coast down, and steady-state conditions; resonance testing and motor current signature analysis were also performed. The data was analyzed for traditional mechanical/machinery issues such as misalignment and imbalance using time series analysis, frequency domain analysis, and operating deflection shape analysis. The analysis showed that the chopper base plate was experiencing an amplified response to the excitation provided by the T0 beam chopper. The amplified response was diagnosed to be caused by higher than expected base plate flexibility, possibly due to improper grouting or loose floor anchors. Based on this diagnosis, a decision was made to dismantle the beam line chopper and remount the base plate. Neutron activation of the beam line components make modifications to the beam line especially expensive and time consuming due to the radiation handling requirements, so this decision had significant financial and schedule implications. It was found that the base plate was indeed loose because of improper grouting during its initial installation. The base plate was modified by splitting it into multiple sections, isolating the T0 chopper from the rest of the beam line, and each section was then reinstalled and re-grouted. After these modifications, the vibration levels were reduced by a factor of 30. The reduction in vibration level was sufficient to allow the Vision beam line to operate at full capacity for the first time since its completed construction date.

Van Hoy, Blake W [ORNL

2014-01-01T23:59:59.000Z

111

Instrument and Source Design Division | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Ron Crone, RRD Director Ron Crone, RRD Director ISDD Director Ron Crone. Instrument and Source Design Division The Instrument and Source Design Division (ISDD) supports the engineering and development of scientific instruments at the High Flux Isotope Reactor and the Spallation Neutron Source. ISDD continuously develops facilities and capabilities associated with neutron science through research and development. Organization Chart A PDF version of the ISDD Organization Chart is available. Key Division Contacts Director Ron Crone Administrative Assistant Wendy Brooks HFIR Instrument Engineering Doug Selby SNS Instrument Engineering David Vandergriff Instrumentation Projects and Development Ken Herwig Project Management/Operations and Analysis Barbara Thibadeau Source Development and Engineering Analysis Phil Ferguson

112

A Neutron Resonance Capture Analysis Experimental Station at the ISIS Spallation Source  

Science Journals Connector (OSTI)

Neutron resonance capture analysis (NRCA) is a nuclear technique that is used to determine the elemental composition of materials and artifacts (e.g., bronze objects) of...

Pietropaolo, Antonino; Gorini, Giuseppe; Festa, Giulia; Reali, Enzo; Grazzi, Francesco; Schooneveld, Erik M

2010-01-01T23:59:59.000Z

113

Protein crystallography with spallation neutrons: collecting and processing wavelength-resolved Laue protein data  

Science Journals Connector (OSTI)

Methods for collecting and processing wavelength-resolved Laue data at the protein crystallography station at Los Alamos Neutron Science Center have been developed.

Langan, P.

2004-03-17T23:59:59.000Z

114

08-G00333B_SNS_HFIR  

NLE Websites -- All DOE Office Websites (Extended Search)

SNS PARKING CNMS PARKING COVERED BRIDGE 83 10 870 0 891 0 891 3 891 1 810 0 83 30 C H E S T N U T R I D G E R D TO: BETHEL VALLEY ROAD 86 00 87 00 8 6 1 0 SNS Spallation Neutron S...

115

Data Analysis & Visualization | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Data Analysis and Visualization SHARE Neutron Data Analysis and Visualization As the data sets generated by the increasingly powerful neutron scattering instruments at HFIR...

116

HFIR vessel probabilistic fracture mechanics analysis  

SciTech Connect

The life of the High Flux Isotope Reactor (HFIR) pressure vessel is limited by a radiation induced reduction in the material`s fracture toughness. Hydrostatic proof testing and probabilistic fracture mechanics analyses are being used to meet the intent of the ASME Code, while extending the life of the vessel well beyond its original design value. The most recent probabilistic evaluation is more precise and accounts for the effects of gamma as well as neutron radiation embrittlement. This analysis confirms the earlier estimates of a permissible vessel lifetime of at least 50 EFPY (100 MW).

Cheverton, R.D. [Delta-21 Resources, Inc., Oak Ridge, TN (United States); Dickson, T.L. [Oak Ridge National Lab., TN (United States)

1997-01-01T23:59:59.000Z

117

High Flux Isotope Reactor (HFIR) | Nuclear Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

High Flux Isotope Reactor High Flux Isotope Reactor May 30, 2013 The High Flux Isotope Reactor (HFIR) first achieved criticality on August 25, 1965, and achieved full power in August 1966. It is a versatile 85-MW isotope production, research, and test reactor with the capability and facilities for performing a wide variety of irradiation experiments and a world-class neutron scattering science program. HFIR is a beryllium-reflected, light water-cooled and moderated flux-trap type swimming pool reactor that uses highly enriched uranium-235 as fuel. HFIR typically operates seven 23-to-27 day cycles per year. Irradiation facility capabilities include Flux trap positions: Peak thermal flux of 2.5X1015 n/cm2/s with similar epithermal and fast fluxes (Highest thermal flux available in the

118

Design and Testing of a Prototype Spallation Neutron Source Rotating Target Assembly  

SciTech Connect

The mechanical aspects of an extended vertical shaft rotating target have been evaluated in a full-scale mockup test. A prototype assembly based on a conceptual target design for a 1 to 3-MW spallation facility was built and tested. Key elements of the drive/coupling assembly implemented in the prototype include high integrity dynamic face seals, commercially available bearings, realistic manufacturing tolerances, effective monitoring and controls, and fail-safe shutdown features. A representative target disk suspended on a 3.5 meter prototypical shaft was coupled with the drive to complete the mechanical tests. After1800 hours of operation the test program has confirmed the overall mechanical feasibility of the extended vertical shaft rotating target concept. Precision alignment of the suspended target disk; successful containment of the water and verification of operational stability over the full speed range of 30 to 60 rpm were primary indications the proposed mechanical design is valid for use in a high power target station.

Rennich, Mark J [ORNL; McManamy, Thomas J [ORNL; Graves, Van [Oak Ridge National Laboratory (ORNL); Garmendia, Amaia Zarraoa [IDOM Bilbao; Sorda, Fernando [ESS Bilbao

2010-01-01T23:59:59.000Z

119

NXS 2010 - Neutron Scattering School  

NLE Websites -- All DOE Office Websites (Extended Search)

2-26, 2010 2-26, 2010 Argonne National Laboratory, Argonne, IL Oak Ridge National Laboratory, Oak Ridge, TN NXS2010 Travel Airport Shuttles Departure Flights Schedule Participants Lectures Lecturers Lecture Notes/Videos Experiments Schedule, Desc, Groups Student Presentations ANL Facilities APS Facility ANL Map ANL Visitor's Guide ORNL Facilities HFIR Facility SNS Facility HFIR/SNS Map Access Requirements ANL ORNL Rad Worker Training Study Guide Wireless Networks ANL ORNL Safety & Security Rules ANL ORNL NSSA New Initiatives NSSA Weblink Contacts ANL ORNL 12th National School on Neutron & X-ray Scattering 2009 Neutron Scattering School participants 2010 National School Participants Students share their thoughts about NXS 2010. Purpose: The main purpose of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major neutron and x-ray facilities. Lectures, presented by researchers from academia, industry, and national laboratories, will include basic tutorials on the principles of scattering theory and the characteristics of the sources, as well as seminars on the application of scattering methods to a variety of scientific subjects. Students will conduct four short experiments at Argonne's Advanced Photon Source and Oak Ridge's Spallation Neutron Source and High Flux Isotope Reactor facilities to provide hands-on experience for using neutron and synchrotron sources.

120

SciTech Connect: 2010 Neutron Review: ORNL Neutron Sciences Progress...  

Office of Scientific and Technical Information (OSTI)

117; GREENHOUSE GASES; HEAVY ION ACCELERATORS; HELIUM 3; HFIR REACTOR; IRON; JINR; MAGNETIC FIELDS; NEUTRON DETECTORS; NEUTRON SOURCES; NEUTRONS; ORNL; RELIABILITY;...

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

The Spallation Neutron Source (SNS) project: a fertile ground for radiation protection and shielding challenges  

Science Journals Connector (OSTI)

......pulse intensity(18). A heavy water-cooled beryllium and...outer plug, which is a heavy water-cooled steel reflector...experience at modern research reactors, neutron beam lines at...International Conference on Advanced Monte Carlo for Radiation......

F. X. Gallmeier; P. D. Ferguson; I. I. Popova; E. B. Iverson

2005-12-20T23:59:59.000Z

122

Correlation between simulations and cavitation-induced erosion damage in Spallation Neutron Source target modules after operation  

SciTech Connect

An explicit finite element (FE) technique developed for estimating dynamic strain in the Spallation Neutron Source (SNS) mercury target module vessel is now providing insight into cavitation damage patterns observed in used targets. The technique uses an empirically developed material model for the mercury that describes liquid-like volumetric stiffness combined with a tensile pressure cut-off limit that approximates cavitation. The longest period each point in the mercury is at the tensile cut-off threshold is denoted its saturation time. Now, the pattern of saturation time can be obtained from these simulations and is being positively correlated with observed damage patterns and is interpreted as a qualitative measure of damage potential. Saturation time has been advocated by collaborators at J-Parc as a factor in predicting bubble nuclei growth and collapse intensity. The larger the ratio of maximum bubble size to nucleus, the greater the bubble collapse intensity to be expected; longer saturation times result in greater ratios. With the recent development of a user subroutine for the FE solver saturation time is now provided over the entire mercury domain. Its pattern agrees with spots of damage seen above and below the beam axis on the SNS inner vessel beam window and elsewhere. The other simulation result being compared to observed damage patterns is mercury velocity at the wall. Related R&D has provided evidence for the damage mitigation that higher wall velocity provides. In comparison to observations in SNS targets, inverse correlation of high velocity to damage is seen. In effect, it is the combination of the patterns of saturation time and low velocity that seems to match actual damage patterns.

Riemer, Bernie [ORNL] [ORNL; McClintock, David A [ORNL] [ORNL; Kaminskas, Saulius [ORNL] [ORNL; Abdou, Ashraf A [ORNL] [ORNL

2014-01-01T23:59:59.000Z

123

Operational characteristics of the J-PARC cryogenic hydrogen system for a spallation neutron source  

SciTech Connect

The J-PARC cryogenic hydrogen system provides supercritical hydrogen with the para-hydrogen concentration of more than 99 % and the temperature of less than 20 K to three moderators so as to provide cold pulsed neutron beams of a higher neutronic performance. Furthermore, the temperature fluctuation of the feed hydrogen stream is required to be within 0.25 K. A stable 300-kW proton beam operation has been carried out since November 2012. The para-hydrogen concentrations were measured during the cool-down process. It is confirmed that para-hydrogen always exists in the equilibrium concentration because of the installation of an ortho-para hydrogen convertor. Propagation characteristics of temperature fluctuation were measured by temporarily changing the heater power under off-beam condition to clarify the effects of a heater control for thermal compensation on the feed temperature fluctuation. The experimental data gave an allowable temperature fluctuation of 1.05 K. It is clarified through a 286-kW and a 524-kW proton beam operations that the heater control would be applicable for the 1-MW proton beam operation by extrapolating from the experimental data.

Tatsumoto, Hideki; Ohtsu, Kiichi; Aso, Tomokazu; Kawakami, Yoshihiko; Teshigawara, Makoto [J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195 (Japan)

2014-01-29T23:59:59.000Z

124

Biology and Soft Matter | Neutron Sciences | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Biology and Soft Matter Biology and Soft Matter SHARE Biology and Soft Matter This is a time of unprecedented opportunity for using neutrons in biological and soft matter research. The US Department of Energy (DOE) has invested in two forefront neutron user facilities, the accelerator-based Spallation Neutron Source (SNS) and the reactor-based High Flux Isotope Reactor (HFIR), at Oak Ridge National Laboratory (ORNL). Researchers have access to new instrumentation on some of the world's most intense neutron beam lines for studying the structure, function, and dynamics of complex systems. We anticipate that soft matter and biological sciences of tomorrow will require understanding, predicting, and manipulating complex systems to produce the new materials and products required to meet our nation's

125

Development of nanodiamond foils for H- stripping to Support the Spallation Neutron Source (SNS) using hot filament chemical vapor deposition  

SciTech Connect

Thin diamond foils are needed in many particle accelerator experiments regarding nuclear and atomic physics, as well as in some interdisciplinary research. Particularly, nanodiamond texture is attractive for this purpose as it possesses a unique combination of diamond properties such as high thermal conductivity, mechanical strength and high radiation hardness; therefore, it is a potential material for energetic ion beam stripper foils. At the ORNL Spallation Neutron Source (SNS), the installed set of foils must be able to survive a nominal five-month operation period, without the need for unscheduled costly shutdowns and repairs. Thus, a small foil about the size of a postage stamp is critical to the operation of SNS and similar sources in U.S. laboratories and around the world. We are investigating nanocrystalline, polycrystalline and their admixture films fabricated using a hot filament chemical vapor deposition (HFCVD) system for H- stripping to support the SNS at Oak Ridge National Laboratory. Here we discuss optimization of process variables such as substrate temperature, process gas ratio of H2/Ar/CH4, substrate to filament distance, filament temperature, carburization conditions, and filament geometry to achieve high purity diamond foils on patterned silicon substrates with manageable intrinsic and thermal stresses so that they can be released as free standing foils without curling. An in situ laser reflectance interferometry tool (LRI) is used for monitoring the growth characteristics of the diamond thin film materials. The optimization process has yielded free standing foils with no pinholes. The sp3/sp2 bonds are controlled to optimize electrical resistivity to reduce the possibility of surface charging of the foils. The integrated LRI and HFCVD process provides real time information on the growth of films and can quickly illustrate growth features and control film thickness. The results are discussed in the light of development of nanodiamond foils that will be able to withstand a few MW proton beam and hopefully will be able to be used after possible future upgrades to the SNS to greater than a 3MW beam.

Vispute, R D [Blue Wave Semiconductors; Ermer, Henry K [Blue Wave Semiconductors; Sinsky, Phillip [Blue Wave Semiconductors; Seiser, Andrew [Blue Wave Semiconductors; Shaw, Robert W [ORNL; Wilson, Leslie L [ORNL

2014-01-01T23:59:59.000Z

126

Utilization of Monte Carlo Calculations in Radiation Transport Analyses to Support the Design of the U.S. Spallation Neutron Source (SNS)  

SciTech Connect

The Department of Energy (DOE) has given the Spallation Neutron Source (SNS) project approval to begin Title I design of the proposed facility to be built at Oak Ridge National Laboratory (ORNL) and construction is scheduled to commence in FY01 . The SNS initially will consist of an accelerator system capable of delivering an {approximately}0.5 microsecond pulse of 1 GeV protons, at a 60 Hz frequency, with 1 MW of beam power, into a single target station. The SNS will eventually be upgraded to a 2 MW facility with two target stations (a 60 Hz station and a 10 Hz station). The radiation transport analysis, which includes the neutronic, shielding, activation, and safety analyses, is critical to the design of an intense high-energy accelerator facility like the proposed SNS, and the Monte Carlo method is the cornerstone of the radiation transport analyses.

Johnson, J.O.

2000-10-23T23:59:59.000Z

127

The European Spallation Source  

SciTech Connect

In 2003 the joint European effort to design a European Spallation Source (ESS) resulted in a set of reports, and in May 2009 Lund was agreed to be the ESS site. The ESS Scandinavia office has since then worked on setting all the necessary legal and organizational matters in place so that the Design Update and construction can be started in January 2011, in collaboration with European partners. The Design Update phase is expected to end in 2012, to be followed by a construction phase, with first neutrons expected in 2018-2019.

Lindroos M.; Calaga R.; Bousson S.; Danared H.; Devanz G. et al

2011-04-20T23:59:59.000Z

128

WATER PURITY DEVELOPMENT FOR THE COUPLED CAVITY LINAC (CCL) AND DRIFT TUBE LINAC (DTL) STRUCTURES OF THE SPALLATION NEUTRON SOURCE (SNS) LINAC  

SciTech Connect

The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. SNS will generate and use neutrons as a diagnostic tool for medical purposes, material science, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of two room temperature copper structures, the drift tube linac (DTL), and the coupled cavity linac (CCL). Both of these accelerating structures use large amounts of electrical energy to accelerate the proton beam. Approximately 60-80% of the electrical energy is dissipated in the copper structure and must be removed. This is done using specifically designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by specially designed resonance control and water cooling systems. One of the primary components in the DTL and CCL water cooling systems, is a water purification system that is responsible for minimizing erosion, corrosion, scaling, biological growth, and hardware activation. The water purification system consists of filters, ion exchange resins, carbon beds, an oxygen scavenger, a UV source, and diagnostic instrumentation. This paper reviews related issues associated with water purification and describes the mechanical design of the SNS Linac water purification system.

D. KATONAK; J. BERNARDIN; S. HOPKINS

2001-06-01T23:59:59.000Z

129

HFIR Plant Maintenance - August  

NLE Websites -- All DOE Office Websites (Extended Search)

October 2012 October 2012 2 Managed by UT-Battelle for the U.S. Department of Energy ORNL Isotope Infrastructure Description * Submission is to support first formal "Beta" release of selected components of CASL's Virtual Environment for Reactor Applications (VERA) * Currently limited to CASL partners * Precursor to deployment for partner Test Stands and more broad releases in FY13 * Completes L2 Milestone VRI.P5.02 First Submission of CASL Software to the Radiation Safety Information Computational Center (RSICC) Science Highlight Physics Area Application Area(s) VERA Component(s) Simulation Capability Supported Coupling All LIME + DAKOTA coupling software infrastructure + uncertainty quantification (UQ) Neutronics Multiple Denovo pin-homogenized transport

130

Materials irradiation subpanel report to BESAC neutron sources and research panel  

SciTech Connect

The future success of the nuclear power option in the US (fission and fusion) depends critically on the continued existence of a healthy national materials-irradiation program. Consideration of the requirements for acceptable materials-irradiation systems in a new neutron source has led the subcommittee to identify an advanced steady-state reactor (ANS) as a better choice than a spallation neutron source. However, the subcommittee also hastens to point out that the ANS cannot stand alone as the nation`s sole high-flux mixed-spectrum neutron irradiation source in the next century. It must be incorporated in a broader program that includes other currently existing neutron irradiation facilities. Upgrading and continuing support for these facilities must be planned. In particular, serious consideration should be given to converting the HFIR into a dedicated materials test reactor, and long-term support for several university reactors should be established.

Birtcher, R.C. [Argonne National Lab., IL (United States); Goland, A.N. [Brookhaven National Lab., Upton, NY (United States); Lott, R. [Westinghouse Electric Corp., Pittsburgh, PA (United States). Science and Technology Center; Odette, G.R. [California Univ., Santa Barbara, CA (United States)

1992-09-10T23:59:59.000Z

131

Simulation of a suite of generic long-pulse neutron instruments to optimize the time structure of the European Spallation Source  

SciTech Connect

We here describe the result of simulations of 15 generic neutron instruments for the long-pulsed European Spallation Source. All instruments have been simulated for 20 different settings of the source time structure, corresponding to pulse lengths between 1 ms and 2 ms; and repetition frequencies between 10 Hz and 25 Hz. The relative change in performance with time structure is given for each instrument, and an unweighted average is calculated. The performance of the instrument suite is proportional to (a) the peak flux and (b) the duty cycle to a power of approximately 0.3. This information is an important input to determining the best accelerator parameters. In addition, we find that in our simple guide systems, most neutrons reaching the sample originate from the central 3-5 cm of the moderator. This result can be used as an input in later optimization of the moderator design. We discuss the relevance and validity of defining a single figure-of-merit for a full facility and compare with evaluations of the individual instrument classes.

Lefmann, Kim; Kleno, Kaspar H.; Holm, Sonja L.; Sales, Morten [Nanoscience and eScience Centers, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen O (Denmark); Danish Workpackage for the ESS Design Update Phase, Universitetsparken 5, 2100 Copenhagen O (Denmark); Birk, Jonas Okkels [Nanoscience and eScience Centers, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen O (Denmark); Danish Workpackage for the ESS Design Update Phase, Universitetsparken 5, 2100 Copenhagen O (Denmark); Laboratory for Quantum Magnetism, Ecole Polytecnique Federale de Lausanne (EPFL), 1015 Lausanne (Switzerland); Hansen, Britt R.; Knudsen, Erik; Willendrup, Peter K. [Institute of Physics, Technical University of Denmark, 2800 Lyngby (Denmark); Danish Workpackage for the ESS Design Update Phase, 2800 Lyngby (Denmark); Lieutenant, Klaus [Institute for Energy Technology, Instituttveien 18, 2007 Kjeller (Norway); Helmholtz Center for Energy and Materials, Hahn-Meitner Platz, 14109 Berlin (Germany); German Work Package for the ESS Design Update, Hahn-Meitner Platz, 14109 Berlin (Germany); Moos, Lars von [Department of Energy Conversion and Storage, Technical University of Denmark, 4000 Roskilde (Denmark); Danish Workpackage for the ESS Design Update Phase, 2800 Lyngby (Denmark); Institute for Energy Conversion, Technical University of Denmark, 4000 Roskilde (Denmark); Andersen, Ken H. [European Spallation Source ESS AB, 22100 Lund (Sweden)

2013-05-15T23:59:59.000Z

132

Neutron Data Analysis & Visualization | More Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Data Analysis and Visualization As the data sets generated by the increasingly powerful neutron scattering instruments at HFIR and SNS grow ever more massive, the facilities'...

133

Data Analysis & Visualization | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Data Analysis and Visualization As the data sets generated by the increasingly powerful neutron scattering instruments at HFIR and SNS grow ever more massive, the facilities'...

134

Fracture analysis of HFIR beam tube caused by radiation embrittlement  

SciTech Connect

With an attempt to estimate the neutron beam tube embrittlement condition for the Oak Ridge High Flux Isotope Reactor (HFIR), fracture mechanics calculations are carried out in this paper. The analysis provides some numerical result on how the tube has been structurally weakened. In this calculation, a lateral impact force is assumed. Numerical result is obtained on how much the critical crack size should be reduced if the beam tube has been subjected to an extended period of irradiation. It is also calculated that buckling strength of the tube is increased, not decreased, with irradiation.

Chang, S.J. [Oak Ridge National Lab., TN (United States). Research Reactors Div.

1994-12-31T23:59:59.000Z

135

Postirradiation evaluations of capsules HANS-1 and HANS-2 irradiated in the HFIR target region in support of fuel development for the advanced neutron source  

SciTech Connect

This report describes the design, fabrication, irradiation, and evaluation of two capsule tests containing U{sub 3}Si{sub 2} fuel particles in contact with aluminum. The tests were in support of fuel qualification for the Advanced Neutron Source (ANS) reactor, a high-powered research reactor that was planned for the Oak Ridge National Laboratory. At the time of these tests, the fuel consisted of U{sub 3}Si{sub 2}, containing highly enriched uranium dispersed in aluminum at a volume fraction of {approximately}0.15. The extremely high thermal flux in the target region of the High Flux Isotope Reactor provided up to 90% burnup in one 23-d cycle. Temperatures up to 450{degrees}C were maintained by gamma heating. Passive SiC temperature monitors were employed. The very small specimen size allowed only microstructural examination of the fuel particles but also allowed many specimens to be tested at a range of temperatures. The determination of fission gas bubble morphology by microstructural examination has been beneficial in developing a fuel performance model that allows prediction of fuel performance under these extreme conditions. The results indicate that performance of the reference fuel would be satisfactory under the ANS conditions. In addition to U{sub 3}Si{sub 2}, particles of U{sub 3}Si, UAl{sub 2}, UAl{sub x}, and U{sub 3}O{sub 8} were tested.

Hofman, G.L.; Snelgrove, J.L. [Argonne National Lab., IL (United States); Copeland, G.L. [Oak Ridge National Lab., TN (United States)

1995-08-01T23:59:59.000Z

136

Design of a TOF-SANS instrument for the proposed Long Wavelength Target Station at the Spallation Neutron Source.  

SciTech Connect

We have designed a versatile high-throughput SANS instrument [Broad Range Intense Multipurpose SANS (BRIMS)] for the proposed Long Wavelength Target Station at the SNS by using acceptance diagrams and the Los Alamos NISP Monte Carlo simulation package. This instrument has been fully optimized to take advantage of the 10 Hz source frequency (broad wavelength bandwidth) and the cold neutron spectrum from a tall coupled solid methane moderator (12 cm x 20 cm). BRIMS has been designed to produce data in a Q range spanning from 0.001 to 0.7 {angstrom}{sup {minus}1} in a single measurement by simultaneously using neutrons with wavelengths ranging from 1 to 14.5 {angstrom} in a time of flight mode. A supermirror guide and bender assembly is employed to separate and redirect the useful portion of the neutron spectrum with {lambda} > 1 {angstrom}, by 2.3{degree} away from the direct beam containing high energy neutrons and {gamma} rays. The effects of the supermirror coating of the guide, the location of the bender assembly with respect to the source, the bend angle, and various collimation choices on the flux, resolution and Q{sub min} have been characterized using spherical particle and delta function scatterers. The overall performance of BRIMS has been compared with that of the best existing reactor-based SANS instrument D22 at ILL.

Thiyagarajan, P.; Littrell, K.; Seeger, P. A.

2000-11-28T23:59:59.000Z

137

HFIR Technical Parameters | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Other characteristics of PT-1 apply Rabbits These are made of both high-density polyethylene or graphite. Internal volume for these is 1.5 cc. Laboratory Equipment PC-based...

138

Impact of strongly absorbing experiments in the HFIR reflector on control plate strength  

SciTech Connect

Several improvements in the experimental irradiation facilities of the High-Flux Isotope Reactor (HFIR) were incorporated at the time of its restart in 1989 in order to enhance its capabilities for materials irradiations. One improvement that is of particular interest in regard to its impact on the reactor`s nuclear characteristics is the increase in number and size of the larger irradiation holes in the HFIR`s removable beryllium reflector (RB). A principal use for these larger-diameter holes has been to accommodate spectrally tailored materials irradiations where fast neutron reactions are of principal interest and the suppression of thermal neutron reactions is important to the interpretation of the results. Such experiments typically require thermal neutron-absorbing shrouds around the experimental capsules. Reactor operation with strong thermal neutron absorbers directly outboard of the control elements has significant impact on core power distribution, cycle length, control rod worths, and on other experimental facilities nearby. This paper specifically discusses the impacts on control rod strength due to the strong localized thermal neutron absorbers.

Rothrock, R.B. [Oak Ridge National Lab., TN (United States)

1998-09-01T23:59:59.000Z

139

Proceedings of the international workshop on spallation materials technology  

SciTech Connect

This document contains papers which were presented at the International Workshop on Spallation Materials Technology. Topics included: overviews and thermal response; operational experience; materials experience; target station and component design; particle transport and damage calculations; neutron sources; and compatibility.

Mansur, L.K.; Ullmaier, H. [comps.] [comps.

1996-10-01T23:59:59.000Z

140

Impact of HFIR LEU Conversion on Beryllium Reflector Degradation Factors  

SciTech Connect

An assessment of the impact of low enriched uranium (LEU) conversion on the factors that may cause the degradation of the beryllium reflector is performed for the High Flux Isotope Reactor (HFIR). The computational methods, models, and tools, comparisons with previous work, along with the results obtained are documented and discussed in this report. The report documents the results for the gas and neutronic poison production, and the heating in the beryllium reflector for both the highly enriched uranium (HEU) and LEU HFIR configurations, and discusses the impact that the conversion to LEU may have on these quantities. A time-averaging procedure was developed to calculate the isotopic (gas and poisons) production in reflector. The sensitivity of this approach to different approximations is gauged and documented. The results show that the gas is produced in the beryllium reflector at a total rate of 0.304 g/cycle for the HEU configuration; this rate increases by ~12% for the LEU case. The total tritium production rate in reflector is 0.098 g/cycle for the HEU core and approximately 11% higher for the LEU core. A significant increase (up to ~25%) in the neutronic poisons production in the reflector during the operation cycles is observed for the LEU core, compared to the HEU case, for regions close to the core s horizontal midplane. The poisoning level of the reflector may increase by more than two orders of magnitude during long periods of downtime. The heating rate in the reflector is estimated to be approximately 20% lower for the LEU core than for the HEU core. The decrease is due to a significantly lower contribution of the heating produced by the gamma radiation for the LEU core. Both the isotopic (gas and neutronic poisons) production and the heating rates are spatially non-uniform throughout the beryllium reflector volume. The maximum values typically occur in the removable reflector and close to the midplane.

Ilas, Dan [ORNL] ORNL

2013-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

2014 | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Source (SSRL) High Flux Isotope Reactor (HFIR) Spallation Neutron Source (SNS) Lujan Neutron Scattering Center (Lujan) Center for Functional Nanomaterials (CFN) Center for...

142

2011 U.S. National School on Neutron and X-ray Scattering  

SciTech Connect

The 13th annual U.S. National School on Neutron and X-ray Scattering was held June 11 to 25, 2011, at both Oak Ridge and Argonne National Laboratories. This school brought together 65 early career graduate students from 56 different universities in the US and provided them with a broad introduction to the techniques available at the major large-scale neutron and synchrotron x-ray facilities. This school is focused primarily on techniques relevant to the physical sciences, but also touches on cross-disciplinary bio-related scattering measurements. During the school, students received lectures by over 30 researchers from academia, industry, and national laboratories and participated in a number of short demonstration experiments at Argonne's Advanced Photon Source (APS) and Oak Ridge's Spallation neutron Source (SNS) and High Flux Isotope Reactor (HFIR) facilities to get hands-on experience in using neutron and synchrotron sources. The first week of this year's school was held at Oak Ridge National Lab, where Lab director Thom Mason welcomed the students and provided a shitorical perspective of the neutron and x-ray facilities both at Oak Ridge and Argonne. The first few days of the school were dedicated to lectures laying out the basics of scattering theory and the differences and complementarity between the neutron and x-ray probes given by Sunil Sinha. Jack Carpenter provided an introduction into how neutrons are generated and detected. After this basic introduction, the students received lectures each morning on specific techniques and conducted demonstration experiments each afternoon on one of 15 different instruments at either the SNS or HFIR. Some of the topics covered during this week of the school included inelastic neutron scattering by Bruce Gaulin, x-ray and neutron reflectivity by Chuck Majkrazak, small-angle scattering by Volker Urban, powder diffraction by Ashfia Huq and diffuse scattering by Gene Ice.

Lang, Jonathan [Argonne National Laboratory (ANL); te Vethuis, Suzanne [Argonne National Laboratory (ANL); Ekkebus, Allen E [ORNL; Chakoumakos, Bryan C [ORNL; Budai, John D [ORNL

2012-01-01T23:59:59.000Z

143

Joint Institute for Neutron Sciences | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Facilities and Capabilities High Flux Isotope Reactor Spallation Neutron Source Joint Institute for Neutron Sciences Scientific Labs Neutron Science Home | Science & Discovery |...

144

Neutron Imaging of Advanced Engine Technologies  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

the development process * Spallation Neutron Source (SNS) - Most intense pulsed neutron beams in the world; energy selective - Multi-laboratory effort funded by DOE Office of...

145

Fuel loading and homogeneity analysis of HFIR design fuel plates loaded with uranium silicide fuel  

SciTech Connect

Twelve nuclear reactor fuel plates were analyzed for fuel loading and fuel loading homogeneity by measuring the attenuation of a collimated X-ray beam as it passed through the plates. The plates were identical to those used by the High Flux Isotope Reactor (HFIR) but were loaded with uranium silicide rather than with HFIR`s uranium oxide fuel. Systematic deviations from nominal fuel loading were observed as higher loading near the center of the plates and underloading near the radial edges. These deviations were within those allowed by HFIR specifications. The report begins with a brief background on the thermal-hydraulic uncertainty analysis for the Advanced Neutron Source (ANS) Reactor that motivated a statistical description of fuel loading and homogeneity. The body of the report addresses the homogeneity measurement techniques employed, the numerical correction required to account for a difference in fuel types, and the statistical analysis of the resulting data. This statistical analysis pertains to local variation in fuel loading, as well as to ``hot segment`` analysis of narrow axial regions along the plate and ``hot streak`` analysis, the cumulative effect of hot segment loading variation. The data for all twelve plates were compiled and divided into 20 regions for analysis, with each region represented by a mean and a standard deviation to report percent deviation from nominal fuel loading. The central regions of the plates showed mean values of about +3% deviation, while the edge regions showed mean values of about {minus}7% deviation. The data within these regions roughly approximated random samplings from normal distributions, although the chi-square ({chi}{sup 2}) test for goodness of fit to normal distributions was not satisfied.

Blumenfeld, P.E.

1995-08-01T23:59:59.000Z

146

Monte Carlo modeling of spallation targets containing uranium and americium  

E-Print Network (OSTI)

Neutron production and transport in spallation targets made of uranium and americium are studied with a Geant4-based code MCADS (Monte Carlo model for Accelerator Driven Systems). A good agreement of MCADS results with experimental data on neutron- and proton-induced reactions on $^{241}$Am and $^{243}$Am nuclei allows to use this model for simulations with extended Am targets. Several geometry options and material compositions (U, U+Am, Am, Am$_2$O$_3$) are considered for spallation targets to be used in Accelerator Driven Systems. It was demonstrated that MCADS model can be reliably used for calculating critical masses of fissile materials. All considered options operate as deep subcritical targets having neutron multiplication factor of $k \\sim 0.5$. It is found that more than 4 kg of Am can be burned in one spallation target during the first year of operation.

Malyshkin, Yury; Mishustin, Igor; Greiner, Walter

2013-01-01T23:59:59.000Z

147

Monte Carlo modeling of spallation targets containing uranium and americium  

E-Print Network (OSTI)

Neutron production and transport in spallation targets made of uranium and americium are studied with a Geant4-based code MCADS (Monte Carlo model for Accelerator Driven Systems). A good agreement of MCADS results with experimental data on neutron- and proton-induced reactions on $^{241}$Am and $^{243}$Am nuclei allows to use this model for simulations with extended Am targets. It was demonstrated that MCADS model can be used for calculating the values of critical mass for $^{233,235}$U, $^{237}$Np, $^{239}$Pu and $^{241}$Am. Several geometry options and material compositions (U, U+Am, Am, Am$_2$O$_3$) are considered for spallation targets to be used in Accelerator Driven Systems. All considered options operate as deep subcritical targets having neutron multiplication factor of $k \\sim 0.5$. It is found that more than 4 kg of Am can be burned in one spallation target during the first year of operation.

Yury Malyshkin; Igor Pshenichnov; Igor Mishustin; Walter Greiner

2014-05-02T23:59:59.000Z

148

The Neutron Residual Stress Mapping Facility at HFIR | ORNL Neutron  

NLE Websites -- All DOE Office Websites (Extended Search)

Specifications of the NRSF2 Instrument Specifications of the NRSF2 Instrument Beam Spectrum thermal Selectable Wavelength (Monochromator setting) 88°, λ = 1.452 Å (Si 511); 1.540 Å (Si 422); 1.731 Å (Si 331); 1.886 Å (Si 400); 2.275 Å (Si 311); 2.667 Å (Si 220) Flux on sample 3 x 107 n/cm2/s (Si 331 and Si 400) Detector angle range 70 - 110° Detection system 7 linear position-sensitive detectors Position-sensitive detector coverage 5° 2Θ ± 17° out of plane Z elevator Z translation Z ± 100 mm, 500 Kg Z ± 200 mm, 50 Kg Nominal Gauge volume Width: 0.3-5 mm; Height: 0.3-20 mm Peak location precision 0.003° 2Θ Sample environments *Load frame for ten- sion and compres- sion (2,267-kg) *Huber Eulerian cradle for tensor and texture *Vacuum and envi- ronmental furnaces *5-T superconducting magnet with induction heater

149

Source Terms for HFIR Beam Tube Shielding Analyses, and a Complete Shielding Analysis of the HB-3 Tube  

SciTech Connect

The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory is in the midst of a massive upgrade program to enhance experimental facilities. The reactor presently has four horizontal experimental beam tubes, all of which will be replaced or redesigned. The HB-2 beam tube will be enlarged to support more guide tubes, while the HB-4 beam tube will soon include a cold neutron source.

Bucholz, J.A.

2000-07-01T23:59:59.000Z

150

Impact of high-energy nuclear data on radioprotection in spallation sources  

Science Journals Connector (OSTI)

......the neutron spectrum, which is...spallation neutron sources and...problems induced by high-energy reactions...low-energy neutron fluxes...tail in the spectrum of neutrons...evaporation-fission models...leading to a thermal flux of 3......

S. Leray; A. Boudard; J. C. David; L. Donadille; C. Villagrasa; C. Volant

2005-12-20T23:59:59.000Z

151

E-Print Network 3.0 - advanced neutron beam Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

level Summary: . Neutrons have SPIN. They can be formed into polarized neutron beams, used to study nuclear (atomic... Spallation Neutron Source (SNS) The world's most...

152

Spallation reactions for nuclear waste transmutation and production of radioactive nuclear beams  

Science Journals Connector (OSTI)

Spallation reactions are considered an optimum neutron source for nuclear waste transmutation in accelerator-driven systems (ADS). ... They are also used to produce intense radioactive nuclear beams in ISOL facil...

J. Benlliure

2005-09-01T23:59:59.000Z

153

Spallation reactions for nuclear waste transmutation and production of radioactive nuclear beams  

Science Journals Connector (OSTI)

Spallation reactions are considered an optimum neutron source for nuclear waste transmutation in accelerator-driven systems (ADS). ... They are also used to produce intense radioactive nuclear beams in ISOL facil...

J. Benlliurea

2005-01-01T23:59:59.000Z

154

The European Spallation Source  

SciTech Connect

The European Spallation Source (ESS) is a 5 MW, 2.5 GeV long pulse proton linac, to be built and commissioned in Lund, Sweden. The Accelerator Design Update (ADU) project phase is under way, to be completed at the end of 2012 by the delivery of a Technical Design Report. Improvements to the 2003 ESS design will be summarised, and the latest design activities will be presented.

Peggs, S; Eshraqi, M; Hahn, H; Jansson, A; Lindroos, M; Ponton, A; Rathsman, K; Trahern, G; Bousso, S; Calaga, R; Devanz, G; Duperrier, R D; Eguia, J; Gammino, S; Moller, S P; Oyon, C; Ruber, R.J.M.Y.

2011-03-01T23:59:59.000Z

155

Preliminary Evaluation of Alternate Designs for HFIR Low-Enriched Uranium Fuel  

SciTech Connect

Engineering design studies of the feasibility of conversion of the High Flux Isotope Reactor (HFIR) from high-enriched uranium (HEU) to low-enriched uranium (LEU) fuel are ongoing at Oak Ridge National Laboratory (ORNL) as part of an effort sponsored by the U.S. Department of Energys Global Threat Reduction Initiative (GTRI)/Reduced Enrichment for Research and Test Reactors (RERTR) program. The fuel type selected by the program for the conversion of the five high-power research reactors in the U.S. that still use HEU fuel is a new U-Mo monolithic fuel. Studies by ORNL have previously indicated that HFIR can be successfully converted using the new fuel provided (1) the reactor power can be increased from 85 MW to 100 MW and (2) the fuel can be fabricated to a specific reference design. Fabrication techniques for the new fuel are under development by the program but are still immature, especially for the complex aspects of the HFIR fuel design. In FY 2012, the program underwent a major shift in focus to emphasize developing and qualifying processes for the fabrication of reliable and affordable LEU fuel. In support of this new focus and in an effort to ensure that the HFIR fuel design is as suitable for reliable fabrication as possible, ORNL undertook the present study to propose and evaluate several alternative design features. These features include (1) eliminating the fuel zone axial contouring in the previous reference design by substituting a permanent neutron absorber in the lower unfueled region of all of the fuel plates, (2) relocating the burnable neutron absorber from the fuel plates of the inner fuel element to the side plates of the inner fuel element (the fuel plates of the outer fuel element do not contain a burnable absorber), (3) relocating the fuel zone inside the fuel plate to be centered on the centerline of the depth of the plate, and (4) reshaping the radial contour of the relocated fuel zone to be symmetric about this centerline. The present studies used current analytical tools to evaluate the various alternate designs for cycle length, scientific performance (e.g., neutron scattering), and steady-state and transient thermal performance using both safety limit and nominal parameter assumptions. The studies concluded that a new reference design combining a permanent absorber in the lower unfueled region of all of the fuel plates, a burnable absorber in the inner element side plates, and a relocated and reshaped (but still radially contoured) fuel zone will allow successful conversion of HFIR. Future collaboration with the program will reveal whether the new reference design can be fabricated reliably and affordably. Following this feedback, additional studies using state-of-the-art developmental analytical tools are proposed to optimize the design of the fuel zone radial contour and the amount and location of both types of neutron absorbers to further flatten thermal peaks while maximizing the performance of the reactor.

Renfro, David [ORNL; Chandler, David [ORNL; Cook, David [ORNL; Ilas, Germina [ORNL; Jain, Prashant [ORNL; Valentine, Jennifer [ORNL

2014-10-30T23:59:59.000Z

156

Fabrication procedures for HFIR control plates  

SciTech Connect

The HFIR control system uses Alclad cylindrically shaped components, which have regions containing 31 vol % Eu/sub 2/O/sub 3/ and 38 vol % Ta, respectively. Exacting control of the water passage between these components and adjacent reactor parts is mandatory, and precise dimensional control of the finished products is required. This report describes the procedures developed for manufacturing outer control plates and inner control cylinders. Results are cited which demonstrate that circular-shaped outer control plates can be produced with less than 0.025-in. variation from the specified 9.300-in. radius in any region of the plate. Other results show that, by the exercise of careful control, inner control, inner control plates can be welded into cylindrical geometry with diametrical variations held to less than +- 0.010 in. of the intended 17.846-in. average diam. The cylinders can then be explosively sized, while under compression, with diametric variations of less than 0.005 in. while controlling roundness variations to less than 0.030 in. from the specified 17.842-in. finished diam.

Bowden, G.A.; Hicks, G.R.; Knight, R.W.

1984-10-01T23:59:59.000Z

157

External event Probabilistic Risk Assessment for the High Flux Isotope Reactor (HFIR)  

SciTech Connect

The High Flux Isotope Reactor (HFIR) is a high performance isotope production and research reactor which has been in operation at Oak Ridge National Laboratory (ORNL) since 1965. In late 1986 the reactor was shut down as a result of discovery of unexpected neutron embrittlement of the reactor vessel. In January of 1988 a level 1 Probabilistic Risk Assessment (PRA) (excluding external events) was published as part of the response to the many reviews that followed the shutdown and for use by ORNL to prioritize action items intended to upgrade the safety of the reactor. A conservative estimate of the core damage frequency initiated by internal events for HFIR was 3.11 {times} 10{sup {minus}4}. In June 1989 a draft external events initiated PRA was published. The dominant contributions from external events came from seismic, wind, and fires. The overall external event contribution to core damage frequency is about 50% of the internal event initiated contribution and is dominated by seismic events.

Flanagan, G.F.; Johnson, D.H.; Buttemer, D.; Perla, H.F.; Chien, S.H. (Oak Ridge National Lab., TN (USA))

1989-01-01T23:59:59.000Z

158

Development of High Flux Isotope Reactor (HFIR) subcriticality monitoring methods  

SciTech Connect

Use of subcritical source multiplication measurements during refueling has been investigated as a possible replacement for out-of-reactor subcriticality measurements formerly made on fresh HFIR fuel elements at the ORNL Critical Experiment Facility. These measurements have been used in the past for preparation of estimated critical rod positions, and as a partial verification, prior to reactor startup, that the requirements for operational shutdown margin would be met. Results of subcritical count rate data collection during recent HFIR refuelings and supporting calculations are described illustrating the intended measurement method and its expected uncertainty. These results are compared to historical uses of the out-of-reactor core measurements and their accuracy requirements, and a planned in-reactor test is described which will establish the sensitivity of the method and calibrate it for future routine use during HFIR refueling. 2 refs., 1 fig., 2 tabs.

Rothrock, R.B.

1991-01-01T23:59:59.000Z

159

Facilities and Capabilities | Neutron Science | ORNL  

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SHARE Facilities and Capabilities ORNL operates two of the world's most powerful neutron scattering user facilities: the High Flux Isotope Reactor and the Spallation...

160

Overcoming High Energy Backgrounds at Pulsed Spallation Sources  

E-Print Network (OSTI)

Instrument backgrounds at neutron scattering facilities directly affect the quality and the efficiency of the scientific measurements that users perform. Part of the background at pulsed spallation neutron sources is caused by, and time-correlated with, the emission of high energy particles when the proton beam strikes the spallation target. This prompt pulse ultimately produces a signal, which can be highly problematic for a subset of instruments and measurements due to the time-correlated properties, and different to that from reactor sources. Measurements of this background have been made at both SNS (ORNL, Oak Ridge, TN, USA) and SINQ (PSI, Villigen, Switzerland). The background levels were generally found to be low compared to natural background. However, very low intensities of high-energy particles have been found to be detrimental to instrument performance in some conditions. Given that instrument performance is typically characterised by S/N, improvements in backgrounds can both improve instrument pe...

Cherkashyna, Nataliia; DiJulio, Douglas D; Khaplanov, Anton; Pfeiffer, Dorothea; Scherzinger, Julius; Cooper-Jensen, Carsten P; Fissum, Kevin G; Ansell, Stuart; Iverson, Erik B; Ehlers, Georg; Gallmeier, Franz X; Panzner, Tobias; Rantsiou, Emmanouela; Kanaki, Kalliopi; Filges, Uwe; Kittelmann, Thomas; Extegarai, Maddi; Santoro, Valentina; Kirstein, Oliver; Bentley, Phillip M

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

ORNL Neutron Scattering School May 30 -June 5, 2009  

E-Print Network (OSTI)

ORNL Neutron Scattering School May 30 - June 5, 2009 Oak Ridge National Laboratory Oak Ridge, 2009, for the first week of the Neutron Xray Scattering School. Please be certain to bring photo for Neutron Scattering Users � Radiological Worker Training for HFIR and SNS Users In addition

Pennycook, Steve

162

SNS Ring, Spallation Neutron Source, SNS  

NLE Websites -- All DOE Office Websites (Extended Search)

RING RING Lattice Version 1.0 in MAD structure Version 1.1: SNSRing.v.1.1 | 623_620_00.mad Version 1.2 SNSRing.v.1.2 | 623_620_00.mad Matching example MAD optics outputs UAL compatible input example Schematic (one super-period) and mechanical drawing Diagnostics Impedance budget Magnets List and mechanical parameters Mechanical drawings Magnetic field modeling and measurements Installation and survey Power supplies summary and changes Polarity conventions tech.memo and schematic (A polarity) Magnet assemblies Documentation ASAC review presentations DOE review presentations SNS/BNL tech.notes, conference and journal papers SNS/ORNL papers SNS project documentation Other links SNS ring aperture, collimation and beam losses SNS transfer lines SNS/BNL Accelerator Physics SNS/ORNL Accelerator Physics

163

Decommissioning and PIE of the MEGAPIE spallation target  

SciTech Connect

A key experiment in the Accelerated Driven Systems roadmap, the MEGAwatt PIlot Experiment (MEGAPIE) (1 MW) was initiated in 1999 in order to design and build a liquid lead-bismuth spallation target, then to operate it into the Swiss spallation neutron facility SINQ at Paul Scherrer Institute. The target has been designed, manufactured, and tested during integral tests, before irradiation carried out end of 2006. During irradiation, neutron and thermo hydraulic measurements were performed allowing deep interpretation of the experiment and validation of the models used during design phase. The decommissioning, Post Irradiation Examinations and waste management phases were defined properly. The phases dedicated to cutting, sampling, cleaning, waste management, samples preparation and shipping to various laboratories were performed by PSI teams: all these phases constitute a huge work, which allows now to perform post-irradiation examination (PIE) of structural material, irradiated in relevant conditions. Preliminary results are presented in the paper, they concern chemical characterization. The following radio-nuclides have been identified by ?-spectrometry: {sup 60}Co, {sup 101}Rh, {sup 102}Rh, {sup 108m}Ag, {sup 110m}Ag, {sup 133}Ba, {sup 172}Hf/Lu, {sup 173}Lu, {sup 194}Hg/Au, {sup 195}Au, {sup 207}Bi. For some of these nuclides the activities can be easily evaluated from ?-spectrometry results ({sup 207}Bi, {sup 194}Hg/Au), while other nuclides can only be determined after chemical separations ({sup 108m}Ag, {sup 110m}Ag, {sup 195}Au, {sup 129}I, {sup 36}Cl and ?-emitting {sup 208-210}Po). The concentration of {sup 129}I is lower than expected. The chemical analysis already performed on spallation and corrosion products in the lead-bismuth eutectic (LBE) are very relevant for further applications of LBE as a spallation media and more generally as a coolant.

Latge, C.; Henry, J. [CEA-Cadarache, DEN-DTN, 13108 Saint-Paul-les-Durance (France); Wohlmuther, M.; Dai, Y.; Gavillet, D.; Hammer, B.; Heinitz, S.; Neuhausen, J.; Schumann, D.; Thomsen, K.; Tuerler, A.; Wagner, W. [PSI, Villigen (Switzerland); Gessi, A. [ENEA, Brasimone (Italy); Guertin, A. [CNRS, Subatech, Nantes (France); Konstantinovic, M. [SCK-CEN, Mol (Belgium); Lindau, R. [KIT, Karlsruhe (Germany); Maloy, S. [DOE-LANL, Los Alamos (United States); Saito, S. [JAEA, Tokai (Japan)

2013-07-01T23:59:59.000Z

164

Design and implementation of low-Q diffractometers at spallation sources  

SciTech Connect

Low-Q diffractometers at spallation sources that use time of flight methods have been successfully implemented at several facilities, including the Los Alamos Neutron Scattering Center. The proposal to build new, more powerful, advanced spallation sources using advanced moderator concepts will provide luminosity greater than 20 times the brightest spallation source available today. These developments provide opportunity and challenge to expand the capabilities of present instruments with new designs. The authors review the use of time of flight for low-Q measurements and introduce new designs to extend the capabilities of present-day instruments. They introduce Monte Carlo methods to optimize design and simulate the performance of these instruments. The expected performance of the new instruments are compared to present day pulsed source- and reactor-based small-angle neutron scattering instruments. They review some of the new developments that will be needed to use the power of brighter sources effectively.

Seeger, P.A.; Hjelm, R.P.

1993-07-01T23:59:59.000Z

165

Design and implementation of low-Q diffractometers at spallation sources  

SciTech Connect

Low-Q diffractometers at spallation sources that use time of flight methods have been successfully implemented at several facilities, including the Los Alamos Neutron Scattering Center. The proposal to build new, more powerful, advanced spallation sources using advanced moderator concepts will provide luminosity greater than 20 times the brightest spallation source available today. These developments provide opportunity and challenge to expand the capabilities of present instruments with new designs. The authors review the use of time of flight for low-Q measurements and introduce new designs to extend the capabilities of present-day instruments. They introduce Monte Carlo methods to optimize design and simulate the performance of these instruments. The expected performance of the new instruments are compared to present day pulsed source- and reactor-based small-angle neutron scattering instruments. They review some of the new developments that will be needed to use the power of brighter sources effectively.

Seeger, P.A.; Hjelm, R.P.

1993-01-01T23:59:59.000Z

166

Challenges and design solutions of the liquid hydrogen circuit at the European Spallation Source  

SciTech Connect

The European Spallation Source (ESS), Lund, Sweden will be a 5MW long-pulse neutron spallation research facility and will enable new opportunities for researchers in the fields of life sciences, energy, environmental technology, cultural heritage and fundamental physics. Neutrons are produced by accelerating a high-energy proton beam into a rotating helium-cooled tungsten target. These neutrons pass through moderators to reduce their energy to an appropriate range (< 5 meV for cold neutrons); two of which will use liquid hydrogen at 17 K as the moderating and cooling medium. There are several technical challenges to overcome in the design of a robust system that will operate under such conditions, not least the 20 kW of deposited heat. These challenges and the associated design solutions will be detailed in this paper.

Gallimore, S.; Nilsson, P.; Sabbagh, P.; Takibayev, A.; Weisend II, J. G. [European Spallation Source ESS AB, SE-22100 Lund (Sweden); Beler, Y. [Forschungzentrum Jlich, Jlich (Germany); Klaus, M. [Technische Universitt Dresden, Dresden (Germany)

2014-01-29T23:59:59.000Z

167

High Flux Isotope Reactor | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

How to Work with HFIR How to Work with HFIR HFIR Workflow Please contact the experiment interface or coordinator for additional information and guidance. There are many...

168

NXS 2013 - Neutron Scattering School  

NLE Websites -- All DOE Office Websites (Extended Search)

5th National School on Neutron and X-Ray Scattering 5th National School on Neutron and X-Ray Scattering August 10-24, 2013 Argonne National Laboratory, Argonne, IL Oak Ridge National Laboratory, Oak Ridge, TN NXS2013 Schedule Participants Image Gallery Travel Info Thank you Lectures Lecture Notes/Videos Experiments ANL Facilities ANL Map (jpg) ANL Map (pdf) ANL Visitor's Guide ORNL Facilities HFIR Facility SNS Facility HFIR/SNS Map Wireless Networks ORNL Safety & Security Rules ORNL NSSA Weblink Contacts ANL ORNL 2013 NXS School Participants 2013 NXS Participants. NXS interveiws 2013 Click the image to download the video. Video Interviews: Participants answer questions about their experiences at NXS 2011. Your feedback about lectures and experiments is important for evaluating this year's Neutron and X-ray Scattering School and for making improvements for future participants. We sincerely hope that each of you will complete the survey by the end of the school.

169

E-Print Network 3.0 - advanced pulsed neutron Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

... Source: Controlled Fusion Atomic Data Center (CFADC) Collection: Plasma Physics and Fusion 5 Spallation-Driven Cold Neutron Sources Dr. Bradley J. Micklich Summary: probe the...

170

E-Print Network 3.0 - accelerator neutron science Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

... Source: Controlled Fusion Atomic Data Center (CFADC) Collection: Plasma Physics and Fusion 4 Spallation-Driven Cold Neutron Sources Dr. Bradley J. Micklich Summary: 2009 2...

171

News & Events | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

News › 2005 News News › 2005 News Neutron Science In the News - 2005 December November October September August July June May April March February January John Sullivan, Associate Under Secretary, took a tour of the Spallation Neutron Source (SNS), October 4, 2005 John Sullivan, Associate Under Secretary, took a tour of the Spallation Neutron Source (SNS), October 4, 2005. Because some media sources archive past articles and require a subscription for access, some of the links below might not be active. If a citation listed here is no longer available, please contact the newspaper or your library directly. December Spallation Neutron Source Amazing Science Facts Newswise 12/22 The New Year is bringing the science community a grand present: The Spallation Neutron Source at Oak Ridge National Laboratory. On schedule for

172

Research Highlights | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Battery Studies Battery Studies A Wealth of New Battery Research at SNS and HFIR Technical Contacts: Xun-Li Wang, Ashfia Huq, Jung-Hyun Kim October 2010, Written by Carolyn Krause Neutron scattering, capable of looking deep inside the structures of materials used in technologies such as batteries and fuel cells, is a natural tool for research in energy storage and production. Several users of neutron scattering instruments at the SNS and HFIR presented details of their energy-related research to prospective scientific facility users attending the opening session of ORNL's User Week at SNS. Most of the energy-related research reported in the session dealt with batteries for electric and hybrid electric cars. Better batteries are also needed for storing excess electricity generated by wind and solar power so

173

Industry - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Industry and Neutron Science Industry and Neutron Science Industry and Neutron Science: Working To Make a Match "In fundamental research, we want to know everything. Industry wants to know enough to answer a question." Research Contact: Mike Crawford September 2011, Written by Deborah Counce Mike Crawford and Souleymane Diallo Mike Crawford of Dupont (right) and Souleymane Diallo, instrument scientist for the Backscattering Spectrometer at SNS, prepare a material sample for an experiment on the instrument. Industrial users are starting to eye the potential of neutron science for solving problems that can't be solved in any other way. At the same time, the SNS and HFIR neutron science facilities at ORNL are exploring ways to woo such users and to make a match of it, to the benefit of both.

174

Research Highlights | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Research Highlights Research Highlights Biology & Medicine Biotechnology & Energy Fundamental Physics Imaging Magnetism Materials Nanotechnology Superconductivity Facilities and Capabilities Instruments User Program Publications and Resources Science and Education News and Awards NScD Careers Supporting Organizations Neutron Science Home | Science & Discovery | Neutron Science | Research Highlights SHARE Research Highlights No current Research Highlights found. 1-10 of 43 Results Comprehensive phonon "map" offers direction for engineering new thermoelectric devices January 08, 2014 - To understand how to design better thermoelectric materials, researchers are using neutron scattering at SNS and HFIR to study how a compound known as AgSbTe2, or silver antimony telluride, is

175

National School on Neutron and X-ray Scattering Building 223 Auditorium, Room B002 September 24 -October 11, 2008 Argonne National Laboratory  

E-Print Network (OSTI)

National School on Neutron and X-ray Scattering Building 223 Auditorium, Room B002 September 24 (HFIR) Neutron Scattering Science Division Oak Ridge Laboratory 10:15 - 10:30 Break 9:30 - 9:45 Break 10 School on Neutron and X-ray Scattering Building 8600, Main Lobby September 24 - October 11, 2008 Oak

Pennycook, Steve

176

Radiological Hazard of Spallation Products in Accelerator-Driven System  

SciTech Connect

The central issue underlying this paper is related to elucidating the hazard of radioactive spallation products that might be an important factor affecting the design option of accelerator-driven systems (ADSs). Hazard analysis based on the concept of Annual Limit on Intake identifies alpha-emitting isotopes of rare earths (REs) (dysprosium, gadolinium, and samarium) as the dominant contributors to the overall toxicity of traditional (W, Pb, Pb-Bi) targets. The matter is addressed from several points of view: code validation to simulate their yields, choice of material for the neutron producing targets, and challenging the beam type. The paper quantitatively determines the domain in which the toxicity of REs exceeds that of polonium activation products broadly discussed now in connection with advertising lead-bismuth technology for the needs of ADSs.

Saito, M.; Stankovskii, A.; Artisyuk, V.; Korovin, Yu.; Shmelev, A.; Titarenko, Yu. [Tokyo Institute of Technology (Japan)

2002-09-15T23:59:59.000Z

177

Test of time reversal symmetry with resonance neutron scattering  

Science Journals Connector (OSTI)

Discussions for using thermal neutron scattering from nuclei for symmetry measurements stem from past experiments which have observed large parity violating effects in neutron scattering. The proposed LAMPF II proton storage ring spallation neutron source is a vast improvement over the neutron source used in the parity measurements. A proposal for a time reversal symmetry measurement at the LAMPF II facility is presented. (AIP)

J. David Bowman

1986-01-01T23:59:59.000Z

178

Research Highlights | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconductivity Superconductivity Research Highlights Superconductivity Archive New Neutron Studies Support Magnetism's Role in Superconductors Recent neutron scattering experiments give strong evidence that if superconductivity is related to a material's magnetic properties, the same mechanisms are behind both copper-based, high-temperature superconductors and the newly discovered iron-based superconductors. The research was performed at SNS and HFIR and the ISIS Facility at Rutherford Appleton Laboratory in England. (2010) Published Work: "Evolution of spin excitations into the superconducting state in FeTe1-xSex" Contact: Mark Lumsden Advances in Unconventional Iron-Based Superconductors The discovery of more diverse superconducting materials will lead to more

179

Large break loss of coolant severe accident sequences at the HFIR (High Flux Isotope Reactor)  

SciTech Connect

An assessment of many potential HFIR severe accident phenomena was conducted during the HFIR design effort, and many severe accident mitigating features were designed into the plant. These evaluation typically incorporated a bounding'' or highly conservative analysis approach and employed tools and techniques representative of the state of knowledge in the mid-1960s. Recently, programs to address severe accident issues were initiated at the Oak Ridge National Laboratory (ORNL) to support the HFIR probabilistic risk assessment (PRA) and equipment qualification and accident management studies. This paper presents the results of environment condition calculations conducted to evaluate a response of HFIR's heat exchanger cell environment to a double-ended rupture of a 0.25 m diameter coolant loop downstream of the circulating pump and check valve. The confinement calculations were performed using an atmospheric fission product source for the heat exchanger cell consistent with, but more conservative than that stipulated in Regulatory Guide 1.89. The results of the calculations indicate that the heat exchanger cell atmospheric temperature peaks at 377 K 225 seconds into the transient and then begins decreasing at approximately 1.7 K per minute. 8 refs., 5 figs.

Simpson, D.B.; Greene, S.R.

1990-01-01T23:59:59.000Z

180

Countercurrent flow limited (CCFL) heat flux in the high flux isotope reactor (HFIR) fuel element  

SciTech Connect

The countercurrent flow (CCF) performance in the fuel element region of the HFIR is examined experimentally and theoretically. The fuel element consists of two concentric annuli filled with aluminum clad fuel plates of 1.27 mm thickness separated by 1.27 mm flow channels. The plates are curved as they go radially outward to accomplish constant flow channel width and constant metal-to-coolant ratio. A full-scale HFIR fuel element mock-up is studied in an adiabatic air-water CCF experiment. A review of CCF models for narrow channels is presented along with the treatment of CCFs in system of parallel channels. The experimental results are related to the existing models and a mechanistic model for the annular'' CCF in a narrow channel is developed that captures the data trends well. The results of the experiment are used to calculate the CCFL heat flux of the HFIR fuel assembly. It was determined that the HFIR fuel assembly can reject 0.62 Mw of thermal power in the CCFL situation. 31 refs., 17 figs.

Ruggles, A.E.

1990-10-12T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Enhanced HFIR overpower margin through improvements in fuel plate homogeneity inspection  

SciTech Connect

Fuel homogeneity inspection techniques used on the HFIR fuel plates have recently been improved through conversion of the X-ray inspection device to acquire, store, and process data digitally. This paper reports some early results from using the improved equipment and describes future plans for obtaining enhanced fuel thermal performance by exploiting this improved inspection capability.

Rothrock, R.B.; Hale, R.E.; Knight, R.W. [Oak Ridge National Lab., TN (United States); Cheverton, R.D.

1995-09-01T23:59:59.000Z

182

ORNL/TM-2008/046 Analysis of HFIR Dosimetry Experiments  

E-Print Network (OSTI)

ORNL/TM-2008/046 Analysis of HFIR Dosimetry Experiments Performed in Cycles 400 and 401 September contractors, Energy Technology Data Exchange (ETDE) representatives, and International Nuclear Information or reflect those of the United States Government or any agency thereof. #12;ORNL/TM-2008/046 Nuclear Science

Pennycook, Steve

183

Imaging and Neutrons - IAN 2006 - Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

SNS Home Saturday, January 11, 2014 SNS Home Saturday, January 11, 2014 Go IAN 2006 Imaging and Neutrons 2006 October 23-25, 2006 Iran Thomas Auditorium Central Laboratory and Office Building Spallation Neutron Source Oak Ridge National Laboratory, Oak Ridge, TN Who Should Attend Synopsis Goals and Expected Outcomes Application Areas Techniques International Advisory Committee Local Organizing Committee Agenda with Presentations NEW Confirmed Speakers Frequently Asked Questions - FAQ Satellite Workshop - Progress in Electron Volt Neutron Spectroscopy eV Worshop Agenda presentations NEW Lodging, Transportation, Bus Schedule Location Directions and Map Registration CLOSED Abstracts, Posters, Contributed Talks Scholarships Sponsors Vendors May Attend Relevant Reports Important Dates Weather Attractions

184

Industry - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Former User Group Chair Enthusiastic About Relevance of Neutron Scattering Former User Group Chair Enthusiastic About Relevance of Neutron Scattering to Industrial Research Former User Group Chair Mike Crawford Mike Crawford, DuPont Research and Development. The drive is intensifying to encourage research partnerships between Neutron Sciences and private industry. Such partnerships, a long-term strategic goal set by the DOE's Basic Energy Sciences Advisory Committee, will deliver industry and its technological problems to SNS and HFIR, where joint laboratory-industry teams can use the unparalleled resources available here to resolve them. "SNS is a tremendous facility. It has the potential to have a couple of thousand user visits a year and, if they build another target station in the future, you're probably talking about 4000 user visits a year,"

185

Neutron Macromolecular Crystallography (NMC) can provide accurate hydrogen atom  

E-Print Network (OSTI)

Neutron Macromolecular Crystallography (NMC) can provide accurate hydrogen atom positions crystals at a moderate 2 ? resolution. The advent of the Spallation Neutron Source (SNS neutron diffractometer (MaNDi) has been constructed at the SNS and is now operational. July 15-16, 2014

Pennycook, Steve

186

Radiation embrittlement of the neutron shield tank from the Shippingport reactor  

SciTech Connect

The irradiation embrittlement of neutron shield tank (NST) material (A212 Grade B steel) from the Shippingport reactor has been characterized. Irradiation increases the Charpy transition temperature (CTT) by 23--28{degrees}C (41--50{degrees}F) and decreases the upper-shelf energy. The shift in CTT is not as severe as that observed in high-flux isotope reactor (HFIR) surveillance specimens. However, the actual value of the CTT is higher than that for the HFIR data. The increase in yield stress is 51 MPa (7.4 ksi), which is comparable to HFIR data. The NST material is weaker in the transverse orientation than in the longitudinal orientation. Some effects of position across the thickness of the wall are also observed; the CTT shift is slightly greater for specimens from the inner region of the wall. Annealing studies indicate complete recovery from embrittlement after 1 h at 400{degrees}C (752{degrees}F). Although the weld metal is significantly tougher than the base metal, the shifts in CTT are comparable. The shifts in CTT for the Shippingport NST are consistent with the test and Army reactor data for irradiations at <232{degrees}C (<450{degrees}F) and show very good agreement with the results for HFIR A212-B steel irradiated in the Oak Ridge Research Reactor (ORR). The effects of irradiation temperature, fluence rate, and neutron flux spectrum are discussed. The results indicate that fluence rate has no effect on radiation embrittlement at rates as low as 2 {times} 10{sup 8} n/cm{sup 2}{center dot}s and at the low operating temperatures of the Shippingport NST, i.e., 55{degrees}C (130{degrees}F). This suggests that the accelerated embrittlement of HFIR surveillance samples is most likely due to the relatively higher proportion of thermal neutrons in the HFIR spectrum compared to that for the test reactors. 28 refs., 25 figs.

Chopra, O.K.; Shack, W.J. (Argonne National Lab., IL (United States)); Rosinski, S.T. (Sandia National Labs., Albuquerque, NM (United States))

1991-10-01T23:59:59.000Z

187

Validation of a Monte Carlo Based Depletion Methodology Using HFIR Post-Irradiation Measurements  

SciTech Connect

Post-irradiation uranium isotopic atomic densities within the core of the High Flux Isotope Reactor (HFIR) were calculated and compared to uranium mass spectrographic data measured in the late 1960s and early 70s [1]. This study was performed in order to validate a Monte Carlo based depletion methodology for calculating the burn-up dependent nuclide inventory, specifically the post-irradiation uranium

Chandler, David [ORNL; Maldonado, G Ivan [ORNL; Primm, Trent [ORNL

2009-11-01T23:59:59.000Z

188

Comparison of the effects of long-term thermal aging and HFIR irradiation on the microstructural evolution of 9Cr-1MoVNb steel  

SciTech Connect

Both thermal aging at 482--704{degree}C for up to 25,000h and HFIR irradiation at 300--600{degree}C for up to 39 dpa produce substantial changes in the as-tempered microstructure of 9Cr-1MoVNb martensitic/ferritic steel. However, the changes in the dislocation/subgrain boundary and the precipitate structures caused by thermal aging or neutron irradiation are quite different in nature. During thermal aging, the as-tempered lath/subgrain boundary and carbide precipitate structures remain stable below 650{degree}C, but coarsen and recover somewhat at 650--704{degree}C. The formation of abundant intergranular Laves phase, intra-lath dislocation networks, and fine dispersions of VC needles are thermal aging effects that are superimposed upon the as-tempered microstructure at 482--593{degree}C. HFIR irradiation produces dense dispersions of very small black-dot'' dislocations loops at 300{degree}C and produces helium bubbles and voids at 400{degree}C At 300--500{degree}C, there is considerable recovery of the as-tempered lath/subgrain boundary structure and microstructural/microcompositional instability of the as-tempered carbide precipitates during irradiation. By contrast, the as-tempered microstructure remains essentially unchanged during irradiation at 600{degree}C. Comparison of thermally aged with irradiation material suggests that the instabilities of the as-tempered lath/subgrain boundary and precipitate structures at lower irradiation temperatures are radiation-induced effects, whereas the absence of both Laves phase and fine VC needles during irradiation is a radiation-retarded thermal effect.

Maziasz, P.J.; Klueh, R.L.

1990-01-01T23:59:59.000Z

189

New precision measurements of free neutron beta decay with cold neutrons  

E-Print Network (OSTI)

Precision measurements in free neutron beta decay serve to determine the coupling constants of beta decay, and offer several stringent tests of the Standard Model. This paper describes the free neutron beta decay program planned for the Fundamental Physics Beamline at the Spallation Neutron Source at Oak Ridge National Laboratory, and puts it into the context of other recent and planned measurements of neutron beta decay observables.

S. Baeler; J. D. Bowman; S. Penttil; D. Po?ani?

2014-08-20T23:59:59.000Z

190

Awards 2007 | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

7 7 Staff Awards: 2007 Chakoumakos elected MSA Fellow Bryan Chakoumakos Neutron scientist Bryan Chakoumakos was recently elected a fellow of the Mineralogical Society of America. A member of the Neutron Scattering Science Division, Bryan leads the Single-Crystal Diffraction Group. The group has five neutron scattering instruments in various stages of design and construction, located at HFIR and SNS. The MSA was founded in 1919 and, among other goals, encourages fundamental research on natural materials and supports education through its publications, educational grants, and courses. Pharos Neutron Detector System Researchers at the Department of Energy's Oak Ridge National Laboratory have won six R&D 100 Awards, given annually by R&D Magazine to the year's

191

Neutron sources and applications  

SciTech Connect

Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications.

Price, D.L. [ed.] [Argonne National Lab., IL (United States); Rush, J.J. [ed.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

1994-01-01T23:59:59.000Z

192

The cryomodule test stand at the European Spallation Source  

SciTech Connect

The European Spallation Source (ESS) is an intergovernmental project building a multidisciplinary research laboratory based upon the world's most powerful neutron source to be built in Lund, Sweden. The ESS will use a linear accelerator which will deliver protons with 5 MW of power to the target at 2.5 GeV with a nominal current of 50 mA. The superconducting part of the linac consists of over 150 niobium cavities cooled with superfluid helium at 2 K. A dedicated cryoplant will supply the cryomodules with single phase helium through an external cryogenic transfer line. The elliptical cavity cryomodules will undergo their site acceptance tests at the ESS cryomodule test stand in Lund. This test stand will use a 4.5 K cryoplant and warm sub-atmospheric compression to supply the 2 K helium. We will show the requirements for the test stand, a layout proposal and discuss the factors determining the required cryogenic capacity, test sequence and schedule.

Hees, W.; Weisend II, J. G.; Wang, X. L.; Kttig, T. [European Spallation Source ESS AB, P.O. Box 176, SE-221 00 Lund (Sweden)

2014-01-29T23:59:59.000Z

193

Surface modification to prevent oxide scale spallation  

DOE Patents (OSTI)

A surface modification to prevent oxide scale spallation is disclosed. The surface modification includes a ferritic stainless steel substrate having a modified surface. A cross-section of the modified surface exhibits a periodic morphology. The periodic morphology does not exceed a critical buckling length, which is equivalent to the length of a wave attribute observed in the cross section periodic morphology. The modified surface can be created using at least one of the following processes: shot peening, surface blasting and surface grinding. A coating can be applied to the modified surface.

Stephens, Elizabeth V; Sun, Xin; Liu, Wenning; Stevenson, Jeffry W; Surdoval, Wayne; Khaleel, Mohammad A

2013-07-16T23:59:59.000Z

194

TWO-DIMENSIONAL MODELING OF LASER SPALLATION DRILLING OF ROCKS  

NLE Websites -- All DOE Office Websites (Extended Search)

DIMENSIONAL MODELING OF LASER SPALLATION DRILLING OF ROCKS DIMENSIONAL MODELING OF LASER SPALLATION DRILLING OF ROCKS P532 Zhiyue Xu, Yuichiro Yamashita 1 , and Claude B. Reed Argonne National Laboratory, Argonne, IL 60439, USA 1 Now with Kyushu University, Japan Abstract High power lasers can weaken, spall, melt and vaporize natural earth materials with thermal spallation being the most energy efficient rock removal mechanism. Laser rock spallation is a very complex phenomenon that depends on many factors. Computer numerical modeling would provides great tool to understand the fundamental of this complex phenomenon, which is crucial to the success of its applications. Complexity of modeling laser rock spallation is due to: 1) rock is a porous media, to which traditional theories of heat transfer and rock mechanics can not be directly

195

High Flux Isotope Reactor cold neutron source reference design concept  

SciTech Connect

In February 1995, Oak Ridge National Laboratory`s (ORNL`s) deputy director formed a group to examine the need for upgrades to the High Flux Isotope Reactor (HFIR) system in light of the cancellation of the Advanced neutron Source Project. One of the major findings of this study was that there was an immediate need for the installation of a cold neutron source facility in the HFIR complex. In May 1995, a team was formed to examine the feasibility of retrofitting a liquid hydrogen (LH{sub 2}) cold source facility into an existing HFIR beam tube. The results of this feasibility study indicated that the most practical location for such a cold source was the HB-4 beam tube. This location provides a potential flux environment higher than the Institut Laue-Langevin (ILL) vertical cold source and maximizes the space available for a future cold neutron guide hall expansion. It was determined that this cold neutron beam would be comparable, in cold neutron brightness, to the best facilities in the world, and a decision was made to complete a preconceptual design study with the intention of proceeding with an activity to install a working LH{sub 2} cold source in the HFIR HB-4 beam tube. During the development of the reference design the liquid hydrogen concept was changed to a supercritical hydrogen system for a number of reasons. This report documents the reference supercritical hydrogen design and its performance. The cold source project has been divided into four phases: (1) preconceptual, (2) conceptual design and testing, (3) detailed design and procurement, and (4) installation and operation. This report marks the conclusion of the conceptual design phase and establishes the baseline reference concept.

Selby, D.L.; Lucas, A.T.; Hyman, C.R. [and others

1998-05-01T23:59:59.000Z

196

Report of the ANS Project Feasibility Workshop for a High Flux Isotope Reactor-Center for Neutron Research Facility  

SciTech Connect

The Advanced Neutron Source (ANS) Conceptual Design Report (CDR) and its subsequent updates provided definitive design, cost, and schedule estimates for the entire ANS Project. A recent update to this estimate of the total project cost for this facility was $2.9 billion, as specified in the FY 1996 Congressional data sheet, reflecting a line-item start in FY 1995. In December 1994, ANS management decided to prepare a significantly lower-cost option for a research facility based on ANS which could be considered during FY 1997 budget deliberations if DOE or Congressional planners wished. A cost reduction for ANS of about $1 billion was desired for this new option. It was decided that such a cost reduction could be achieved only by a significant reduction in the ANS research scope and by maximum, cost-effective use of existing High Flux Isotope Reactor (HFIR) and ORNL facilities to minimize the need for new buildings. However, two central missions of the ANS -- neutron scattering research and isotope production-were to be retained. The title selected for this new option was High Flux Isotope Reactor-Center for Neutron Research (HFIR-CNR) because of the project`s maximum use of existing HFIR facilities and retention of selected, central ANS missions. Assuming this shared-facility requirement would necessitate construction work near HFIR, it was specified that HFIR-CNR construction should not disrupt normal operation of HFIR. Additional objectives of the study were that it be highly credible and that any material that might be needed for US Department of Energy (DOE) and Congressional deliberations be produced quickly using minimum project resources. This requirement made it necessary to rely heavily on the ANS design, cost, and schedule baselines. A workshop methodology was selected because assessment of each cost and/or scope-reduction idea required nearly continuous communication among project personnel to ensure that all ramifications of propsed changes.

Peretz, F.J.; Booth, R.S. [comp.

1995-07-01T23:59:59.000Z

197

Neutron Diffraction @ TOPAZ  

NLE Websites -- All DOE Office Websites (Extended Search)

Topaz Guide Bender Topaz Guide Bender Neutron Diffraction @ TOPAZ Workshop on Single Crystal Neutron Diffraction picture 2 September 29 - October 1, 2011 * Spallation Neutron Source * Oak Ridge National Laboratory * Oak Ridge TN, USA TOPAZ 2011 Home Contacts Agenda and Important Deadlines Registration and Payment filler Workshop summary and purpose A workshop on single crystal neutron diffraction will be held at the Spallation Neutron Source at the Oak Ridge National Laboratory (ORNL). It will present invited and contributed talks to showcase cutting edge science and examples where neutron diffraction can make significant contributions; and provide training in neutron structure analysis and sample screening for the preparation of instrument beam-time proposals. TOPAZ is a high resolution wavelength-resolved Laue diffractometer with a versatile sample environment. Commissioning user experiments have demonstrated successfully the instrument capability for structural study of a vitamin B12 derivative, ion distribution in Li-ion battery materials, order and disorder in shape memory intermetallics, magnetic phase transition in multiferroic single crystal and functional thin films. The workshop is directed towards experienced neutron diffraction users and new users alike and encourages members to highlight their research and interest in structure analysis and investigation. The workshop will give opportunity to bring your own single crystal and screen sample quality and scattering power on TOPAZ @ room temperature, to evaluate data collection time and quality for an anticipated experiment. Finally, an opportunity to compose a proposal for neutron beam time (http://neutrons.ornl.gov/users/proposals.shtml) with staff will be provided in the framework of the workshop. The workshop format is well suited for researchers to contribute by showcasing their research and bring their research group or graduate student, who would like to test a single crystal sample. User access training for the ORNL neutron scattering facility will be included. It will be valid for future experiments.

198

Waste heat recovery from the European Spallation Source cryogenic helium plants - implications for system design  

SciTech Connect

The European Spallation Source (ESS) neutron spallation project currently being designed will be built outside of Lund, Sweden. The ESS design includes three helium cryoplants, providing cryogenic cooling for the proton accelerator superconducting cavities, the target neutron source, and for the ESS instrument suite. In total, the cryoplants consume approximately 7 MW of electrical power, and will produce approximately 36 kW of refrigeration at temperatures ranging from 2-16 K. Most of the power consumed by the cryoplants ends up as waste heat, which must be rejected. One hallmark of the ESS design is the goal to recycle waste heat from ESS to the city of Lund district heating system. The design of the cooling system must optimize the delivery of waste heat from ESS to the district heating system and also assure the efficient operation of ESS systems. This report outlines the cooling scheme for the ESS cryoplants, and examines the effect of the cooling system design on cryoplant design, availability and operation.

Jurns, John M. [European Spallation Source ESS AB, P.O. Box 176, 221 00 Lund (Sweden); Bck, Harald [Sweco Industry AB, P.O. Box 286, 201 22 Malm (Sweden); Gierow, Martin [Lunds Energikoncernen AB, P.O. Box 25, 221 00 Lund (Sweden)

2014-01-29T23:59:59.000Z

199

Advanced Neutron Source Reactor thermal analysis of fuel plate defects  

SciTech Connect

The Advanced Neutron Source Reactor (ANSR) is a research reactor designed to provide the highest continuous neutron beam intensity of any reactor in the world. The present technology for determining safe operations were developed for the High Flux Isotope Reactor (HFIR). These techniques are conservative and provide confidence in the safe operation of HFIR. However, the more intense requirements of ANSR necessitate the development of more accurate, but still conservative, techniques. This report details the development of a Local Analysis Technique (LAT) that provides an appropriate approach. Application of the LAT to two ANSR core designs are presented. New theories of the thermal and nuclear behavior of the U{sub 3}Si{sub 2} fuel are utilized. The implications of lower fuel enrichment and of modifying the inspection procedures are also discussed. Development of the computer codes that enable the automate execution of the LAT is included.

Giles, G.E.

1995-08-01T23:59:59.000Z

200

Superconductivity Highlights | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconductivity Superconductivity SHARE Superconductivity Highlights 1-6 of 6 Results Doug Scalapino discusses "common thread" linking unconventional superconducting materials December 01, 2012 - Douglas Scalapino was the inaugural speaker for a new joint lecture series sponsored by the Spallation Neutron Source and the Center for Nanophase Materials Sciences at Oak Ridge National Laboratory. New VULCAN tests of Japanese cable for US ITER's central magnet system February 01, 2012 - Neutron testing of the Japanese-made superconducting cable for the central solenoid (CS) magnetic system for US ITER begins next Tuesday, says Ke An, lead instrument scientist for the VULCAN Engineering Materials Diffractometer at the Spallation Neutron Source. ARCS maps collaborative magnetic spin behavior in iron telluride

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

SINGLE CRYSTAL NEUTRON DIFFRACTION.  

SciTech Connect

Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for information on magnetic scattering of neutrons see Unit 14.3. Instruments for single-crystal diffraction (single-crystal diffractometers or SCDs) are generally available at the major neutron scattering center facilities. Beam time on many of these instruments is available through a proposal mechanism. A listing of neutron SCD instruments and their corresponding facility contacts is included in an appendix accompanying this unit.

KOETZLE,T.F.

2001-03-13T23:59:59.000Z

202

An evaluation of life extension of the HFIR pressure vessel. Supplement 1  

SciTech Connect

Preliminary analyses were performed in 1994 to determine the remaining useful life of the HFIR pressure vessel. The estimated total permissible life was {approximately} 50 EFPY (100 MW). More recently, the analyses have been updated, including a more precise treatment of uncertainties in the calculation of the hydrostatic-proof-test conditions and also including the contribution of gammas to the radiation-induced reduction in fracture toughness. These and other refinements had essentially no effect on the predicted useful life of the vessel or on the specified hydrostatic proof-test conditions.

Cheverton, R.D.

1996-08-01T23:59:59.000Z

203

Development of a Hydrothermal Spallation Drilling System for EGS Geothermal  

Open Energy Info (EERE)

Hydrothermal Spallation Drilling System for EGS Geothermal Hydrothermal Spallation Drilling System for EGS Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Development of a Hydrothermal Spallation Drilling System for EGS Project Type / Topic 1 Recovery Act: Enhanced Geothermal Systems Component Research and Development/Analysis Project Type / Topic 2 Drilling Systems Project Description Potter Drilling has recently demonstrated hydrothermal spallation drilling in the laboratory. Hydrothermal spallation drilling creates boreholes using a focused jet of superheated water, separating individual grains ("spalls") from the rock surface without contact between the rock and the drill head. This process virtually eliminates the need for tripping. Previous tests of flame-jet spallation achieved ROP of 50 ft/hr and higher in hard rock with minimal wear on the drilling assembly, but operating this technology in an air-filled borehole created challenges related to cuttings transport and borehole stability. The Potter Drilling system uses a water based jet technology in a fluid-filled borehole and as a result has the potential to achieve similarly high ROP that is uncompromised by stability or cuttings transport issues.

204

Achieving increased spent fuel storage capacity at the High Flux Isotope Reactor (HFIR)  

SciTech Connect

The HFIR facility was originally designed to store approximately 25 spent cores, sufficient to allow for operational contingencies and for cooling prior to off-site shipment for reprocessing. The original capacity has now been increased to 60 positions, of which 53 are currently filled (September 1994). Additional spent cores are produced at a rate of about 10 or 11 per year. Continued HFIR operation, therefore, depends on a significant near-term expansion of the pool storage capacity, as well as on a future capability of reprocessing or other storage alternatives once the practical capacity of the pool is reached. To store the much larger inventory of spent fuel that may remain on-site under various future scenarios, the pool capacity is being increased in a phased manner through installation of a new multi-tier spent fuel rack design for higher density storage. A total of 143 positions was used for this paper as the maximum practical pool capacity without impacting operations; however, greater ultimate capacities were addressed in the supporting analyses and approval documents. This paper addresses issues related to the pool storage expansion including (1) seismic effects on the three-tier storage arrays, (2) thermal performance of the new arrays, (3) spent fuel cladding corrosion concerns related to the longer period of pool storage, and (4) impacts of increased spent fuel inventory on the pool water quality, water treatment systems, and LLLW volume.

Cook, D.H.; Chang, S.J.; Dabs, R.D.; Freels, J.D.; Morgan, K.A.; Rothrock, R.B. [Oak Ridge National Lab., TN (United States); Griess, J.C. [Griess (J.C.), Knoxville, TN (United States)

1994-12-31T23:59:59.000Z

205

Fast-neutron radiation effects in a silica-core optical fiber studied by a CCD-camera spectrometer  

Science Journals Connector (OSTI)

A simple CCD-camera spectrometer was deployed at the Los Alamos Spallation Radiation Effects Facility to characterize fast-neutron irradiation effects in several silica-based optical...

Griscom, D L; Gingerich, M E; Friebele, E J; Putnam, M; Unruh, W

1994-01-01T23:59:59.000Z

206

Industry - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

PartTec PartTec ORNL, PartTec Inc. Licensing Agreement ORNL and PartTec sign licensing agreement (Front) ORNL Deputy Director for Science & Technology Thomas Zacharia and PartTec CEO Herschel Workman. (Back) Bruce Hannan (SNS), PartTec production manager Craig Kline, Rick Riedel (SNS), Jason Hodges (SNS) and Ron Cooper (SNS). The SNS guys were on the development team. Representatives from Oak Ridge National Laboratory and PartTec, an Indiana-based firm, formally signed a licensing agreement Thursday, Aug. 12, to market an advanced neutron detector system developed for the Spallation Neutron Source. The Shifting Scintillator Neutron Detector can determine the time and position of captured neutrons, which enables researchers to obtain very accurate time-of-flight measurements.

207

Education | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Education banner Education banner Sunil Sinha A Chat with Sunil Sinha, Distinguished Professor of Physics at the University of California-San Diego and speaker at the recent CNMS-SNS Research Forum more... The purpose of the Spallation Neutron Source and the High Flux Isotope Reactor is to facilitate neutron scattering as an integral tool for scientific research and technological development across many scientific and engineering domains within the scientific, academic,and industrial communities. Coupled with this role is a recognized need to inspire, educate, and facilitate the next generation of users and hence foster enhanced use of the unique neutron scattering facilities at ORNL. This is the central theme of the education activities within the Neutron Sciences Directorate (NScD).

208

Neutron Science In the News - 2014 | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Science In the News - 2014 Neutron Science In the News - 2014 Because some media sources archive past articles and require a subscription for access, some of the links below might not be active. If a citation listed here is no longer available, please contact the newspaper or your library directly. January Multiphysics Simulations Transmuting Designs for Safer Nuclear Power Engineering.com 1/7 Like the rest of the US's nuclear research reactors, Oak Ridge National Lab's (ORNL) high flux isotope reactor (HFIR) is moving from high-enriched uranium (HEU) fuel to low-enriched uranium (LEU). As such, the safety of the system must be assessed to incorporate the changes in fuel properties and the subsequently modified fuel plate. Due to the recent growth in multiphysics, fluid-structure dynamics

209

Fast neutron background measurements at shallow depths  

SciTech Connect

We report on measurements of the neutron backgrounds for neutrino experiments at shallow depth (such as the proposed San Onofre neutrino oscillation experiment). A detector capable of pulse-shape discrimination measured the flux of fast neutrons at 20 mwe depth in the Stanford Underground Facility to be (1.07 {+-} 0.30) X 10{sup -6} cm{sup -2} s{sup -1}. An experiment, situated in the Tendon Gallery of the San Onofre Unit 2 reactor. studied spallation neutrons from muons traversing Pb and Cu. An underground experiment in the SUF, employing a detector filled with Gd-loaded liquid scintillator, is measuring the neutron production rate and multiplicity for muon spallation in low-A material (hydrocarbon-based liquid scintillator).

Chen, M.; Hertenberger, R.; Novikov, V. [Inst. of Nuclear Research, Moscow (Russian Federation); Dougherty, B.

1993-10-01T23:59:59.000Z

210

International workshop on cold neutron sources  

SciTech Connect

The first meeting devoted to cold neutron sources was held at the Los Alamos National Laboratory on March 5--8, 1990. Cosponsored by Los Alamos and Oak Ridge National Laboratories, the meeting was organized as an International Workshop on Cold Neutron Sources and brought together experts in the field of cold-neutron-source design for reactors and spallation sources. Eighty-four people from seven countries attended. Because the meeting was the first of its kind in over forty years, much time was spent acquainting participants with past and planned activities at reactor and spallation facilities worldwide. As a result, the meeting had more of a conference flavor than one of a workshop. The general topics covered at the workshop included: Criteria for cold source design; neutronic predictions and performance; energy deposition and removal; engineering design, fabrication, and operation; material properties; radiation damage; instrumentation; safety; existing cold sources; and future cold sources.

Russell, G.J.; West, C.D. (comps.) (Los Alamos National Lab., NM (United States)) [comps.; Los Alamos National Lab., NM (United States)

1991-08-01T23:59:59.000Z

211

DEVELOPMENT OF THE CRYOGENIC HYDROGEN SYSTEM FOR A SPALLATION NEUTRTON SOURCE IN J-PARC  

SciTech Connect

An intense spallation neutron source (JSNS) driven by a proton beam of 1-MW has been constructed as one of the main experimental facilities in J-PARC. Supercritical hydrogen at around 20 K and 1.5 MPa was selected as a moderator material in JSNS. Three kinds of hydrogen moderators (coupled, decoupled, and poisoned) were installed to provide pulsed neutron beam of higher neutronic performance. The total nuclear heating in the moderators was estimated to be 3.75 kW for a proton beam power of 1 MW. The cryogenic hydrogen system, where the hydrogen circulation system is cooled by a helium refrigerator system with the refrigerator capacity of 6.45 kW at 15.6 K, provides the supercritical hydrogen for the moderators and absorbs nuclear heating in the moderators. The off-beam commissioning has confirmed that the cryogenic hydrogen system can be cooled down to 18 K within 19 hours. The supercritical hydrogen with a mass flow rate of 190 g/s can be circulated in the rated condition. It was verified that the cryogenic hydrogen system satisfied the performance requirements. The first cold neutron beam cooled by the cryogenic hydrogen system was successfully generated in May 2008.

Tatsumoto, H.; Aso, T.; Ohtsu, K.; Uehara, T.; Sakurayama, H.; Kawakami, Y.; Kato, T.; Futakawa, M. [J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195 (Japan)

2010-04-09T23:59:59.000Z

212

CAMEA ESS - The Continuous Angle Multi-Energy Analysis Indirect Geometry Spectrometer for the European Spallation Source  

E-Print Network (OSTI)

The CAMEA ESS neutron spectrometer is designed to achieve a high detection efficiency in the horizontal scattering plane, and to maximize the use of the long pulse European Spallation Source. It is an indirect geometry time-of-flight spectrometer that uses crystal analysers to determine the final energy of neutrons scattered from the sample. Unlike other indirect gemeotry spectrometers CAMEA will use ten concentric arcs of analysers to analyse scattered neutrons at ten different final energies, which can be increased to 30 final energies by use of prismatic analysis. In this report we will outline the CAMEA instrument concept, the large performance gain, and the potential scientific advancements that can be made with this instrument.

Freeman, P G; Mark, M; Bertelsen, M; Larsen, J; Christensen, N B; Lefmann, K; Jacobsen, J; Niedermayer, Ch; Juranyi, F; Ronnow, H M

2014-01-01T23:59:59.000Z

213

Detectors - Instrument Support | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Detectors Detectors Detectors The detector design group, led by Yacouba Diawara is responsible for supporting the design of HFIR and SNS instruments by developing the necessary infrastructure and acquiring detector components that will be used to complete the functionality of the instruments. The group's mission also includes supporting detector research and development (R&D) for the various instruments and their different needs. The support effort for instrument design entails monitoring detector development worldwide as neutron facilities around the globe are getting upgraded and adopting the newest technologies. Detector group technician Ted Visscher inspects a parahedreal lens on an Anger camera Detector group technician Ted Visscher inspects a parahedreal lens on an

214

Analysis of HFIR pressurizer pump overspeed transients and relief valve performance  

SciTech Connect

The pressurizer pump overspeed transients at the High Flux Isotope Reactor (HFIR) fall in the category of {open_quotes}increase in coolant inventory transients.{close_quotes} They are among the accident transients to be performed for Chapter 15 of the HFIR safety analysis report (SAR). The pressurizer pump speed starting to increase inadvertently to reach its maximum speed of 3,560 rpm while the reactor operates under normal conditions is the cause of this transient. Increased primary coolant system pressure due to increased pressurizer pump flow into the primary coolant head tank challenges the relief valves to open. If the relief valves do not open, increased primary coolant system pressure will challenge the integrity of the high pressure boundary. Two sets of analyses were performed to analyze the pressurizer pump overspeed transients. The purpose of the first analysis is to estimate how long it will take for the relief valves to open under different conditions and whether or not they will chatter or flutter for a considerable amount of time. The analysis estimates relief valve performance and stability using four different relief valve subsystem models. The relief valve subsystem models are not attached to the primary coolant system model. Vigorous pressure oscillations were produced in all of the computations performed as part of the first analysis. The second analysis includes new simulations of the pressurizer pump overspeed transients that were previously simulated using the RELAP5 thermal-hydraulic computer code. The HFIRSYS, High Flux Isotope Reactor System Transient Analysis computer code, was utilized for these simulations providing referable results for comparisons. The increased pressurizer pump flow due to runaway pressurizer pump speed pressurizes the primary coolant system. The assumptions were made in such a way to form constraining conditions at initiation of and during the transients to generate as high an overpressure situation as possible.

Sozer, M.C.

1992-09-11T23:59:59.000Z

215

Neutron scattering, a powerful tool to study clay minerals  

Science Journals Connector (OSTI)

Abstract Of the techniques used to study clay minerals, neutron scattering has become more familiar to clay scientists over the past decade. A brief account of neutron scattering theory is given in this review, followed by a description of measurements that can be made using neutron diffraction and neutron scattering spectroscopy, and especially quasi-elastic neutron scattering. Then recent examples of the application of neutron scattering methods to the study of clay minerals are presented, and finally the potential advantages of such experimental results when combined to molecular dynamics are discussed. To conclude, the potential perspectives that the European Spallation Source brings to this subject are pointed out.

Murillo L. Martins; Will P. Gates; Laurent Michot; Eric Ferrage; Virginie Marry; Heloisa N. Bordallo

2014-01-01T23:59:59.000Z

216

Magnetism and magnetic materials probed with neutron scattering  

Science Journals Connector (OSTI)

Abstract Neutron scattering techniques are becoming increasingly accessible to a broader range of scientific communities, in part due to the onset of next-generation, high-power spallation sources, high-performance, sophisticated instruments and data analysis tools. These technical advances also advantageously impact research into magnetism and magnetic materials, where neutrons play a major role. In this Current Perspective series, the achievements and future prospects of elastic and inelastic neutron scattering, polarized neutron reflectometry, small angle neutron scattering, and neutron imaging, are highlighted as they apply to research into magnetic frustration, superconductivity and magnetism at the nanoscale.

S.G.E. te Velthuis; C. Pappas

2014-01-01T23:59:59.000Z

217

Spall-Fracture Physics and Spallation-Resistance-Based Material Selection  

E-Print Network (OSTI)

Spall-Fracture Physics and Spallation-Resistance-Based Material Selection M. Grujicic, B. Pandurangan, B.A. Cheeseman, and C.-F. Yen (Submitted July 29, 2011) Spallation is a fracture mode commonly cause material damage and ultimate fracture (spallation). In this study, the phenomenon of spall-fracture

Grujicic, Mica

218

Biotechnology & Energy Highlights | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Biotechnology & Energy Biotechnology & Energy SHARE Biotechnology and Energy Highlights 1-10 of 10 Results Neutron Imaging Reveals Lithium Distribution in Lithium-Air Electrodes January 01, 2013 - Using neutron-computed tomography, researchers at the CG-1D neutron imaging instrument at Oak Ridge National Laboratory's High Flux Isotope Reactor (HFIR) have successfully mapped the three-dimensional spatial distribution of lithium products in electrochemically discharged lithium-air cathodes. Theory meets experiment: structure-property relationships in an electrode material for solid-oxide fuel cells December 01, 2012 - Fuel cell technology is one potentially very efficient and environmentally friendly way to convert the chemical energy of fuels into electricity. Solid-oxide fuel cells (SOFCs) can convert a

219

Neutron Sciences at Oak Ridge National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Research Research Find out how neutron scattering can benefit your research. Call for Proposals Proposals for beam time at HFIR and SNS will be accepted via the web-based proposal system until 11:59 a.m. EST, (NOON) Wednesday, February 26, 2014. Comprehensive phonon "map" offers direction for engineering new thermoelectric devices. Comprehensive phonon "map" offers direction for engineering new thermoelectric devices. High-pressure studies of rare earth material could lead to lighter, cheaper magnets High-pressure studies of rare earth material could lead to lighter, cheaper magnets Unfrozen mystery: H2O reveals a new secret Unfrozen mystery: H2O reveals a new secret Neutron scattering workshop promotes high-pressure research Neutron scattering workshop promotes high-pressure research.

220

Chemical and Engineering Materials | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Chemical and Engineering Materials Chemical and Engineering Materials SHARE Chemical and Engineering Materials Neutron-based research at SNS and HFIR in Chemical and Engineering Materials strives to understand the structure and dynamics of chemical systems and novel engineering materials. The user community takes advantage of capabilities of neutron scattering for measurements over wide ranges of experimental and operating conditions, including studies of chemical and physical changes in situ. User experiments with diffraction, small-angle scattering, inelastic and quasi-elastic scattering, and neutron imaging instruments address a range of problems in chemistry and in engineering materials research. Current areas of research supported within Chemical and Engineering Materials include: The structure and dynamics of electrical energy storage materials

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

News & Events | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

8 News 8 News Neutron Science In the News - 2008 November October September August July June May March February January Because some media sources archive past articles and require a subscription for access, some of the links below might not be active. If a citation listed here is no longer available, please contact the newspaper or your library directly. October Research Visits Just Budding at Spallation Neutron Source Knoxville News Sentinel 10/29 When the Spallation Neutron Source was in the proposal stage and under construction, its supporters said the $1.4 billion research complex would eventually attract about 2,000 scientists a year to Oak Ridge to perform experiments and otherwise do their thing. That number, as I recall, was lumped together with researchers at the recently upgraded High Flux Isotope

222

Published Research 2012 | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

2 2 Most publications are in Adobe Portable Document Format. Download Adobe Reader. For more information about any of these publications, please contact the Neutrons Sciences Communications Office. Primary Author Index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A Abdou A., Wendel M., Riemer B., Volpenheini E., Brewster R., "Two-phase flow simulations of protective gas layer for Spallation Neutron Source target", ASME International Mechanical Engineering Congress and Exposition 2011. Abernathy D. L., Stone M. B., Loguillo M. J., Lucas M. S., Delaire O., Tang X., Lin J. Y.Y., Fultz B., "Design and operation of the wide angular-range chopper spectrometer ARCS at the Spallation Neutron Source", Review of Scientific Instruments 83, 15114. Aczel A. A., Granroth G. E., MacDougall G. J., Buyers W. J.L.,

223

Department founded in 1957 Produced over 1000 graduates in the past  

E-Print Network (OSTI)

) · Awards = $7.1 million · Nuclear Fuels and Materials · Nuclear Security · Radiological Sciences and Health Physics · Nuclear I&C, Reliability, and Safety · Nuclear Fuel Cycles · Advanced Modeling and Simulation · 85 MW High Flux Isotope Reactor (HFIR) · Spallation Neutron Source (SNS) Accelerator · Nuclear

Tennessee, University of

224

Research Collaboration with local Centers of  

E-Print Network (OSTI)

Faculty 2014 Enrollment 2013 Graduates Brief History For more information, see our Annual Report at www.engr.utk.edu/nuclear, and Control Laboratory · PWR Simulator (hardware and software) · Radiochemistry and Nuclear Forensics in the past 56 years · 85 MW High Flux Isotope Reactor (HFIR) · Spallation Neutron Source (SNS) · Nuclear

Tennessee, University of

225

Brief History Degrees Offered  

E-Print Network (OSTI)

Testing and Analysis Center · Y-12 National Security Complex · Reliability and Maintainability Center Laboratory · Prognostics, Reliability, and Control Laboratory · PWR Simulator (hardware and software · Expenditures = $8.2 million: ($635K per FTE) · 85 MW High Flux Isotope Reactor (HFIR) · Spallation Neutron

Wang, Xiaorui "Ray"

226

Spallation-Fission Competition in Heavy-Element Reactions: Th232+He4 and U233+d  

Science Journals Connector (OSTI)

Cross sections and excitation functions have been determined for spallation and fission products from bombardments of Th232 with helium ions (15 to 46 Mev) and U233 with deuterons (9 to 24 Mev). This work extends a series of investigations of charged particle (?, d, and p) induced reactions in heavy elements (Z?88). Radiochemical methods were employed to isolate products corresponding to the following spallation reactions: neutron emission, (?,4n), (?,5n), (d,n), (d,2n), and (d,3n); emission of one proton and neutrons (?,p), (?,pn), (?,p2n), and (?,p3n); and emission of two protons and neutrons, (?,2p), (?,2pn), and (?,?n), and (d,?n). In addition, the following fission products were isolated from one or more bombardments: Zn72, Ge77, As77, Br82,83, Rb86, Sr89,91, Y93, Zr95,97, Nb96, Mo99, Ru103,105,106, Pd109,112, Ag111, Cd115,115m,117, I131,133, Cs136, Ba139,140, La140, Ce141,143,144, Nd147, Eu157, and Gd159.The results show that fission is the predominant reaction at all energies for Th232 and to an even greater extent for U233. The data for the surviving spallation products are consistent with several mechanisms of reaction, including compound-nucleus formation and evaporation, direct interactions between nucleons of the incoming helium ion or deuteron and nucleons of the nucleus, and a combination of these types of processes (direct interaction followed by evaporation). In general, the results confirm and extend previously established concepts.The neutron-emission spallation reactions as well as fission are best explained as proceeding through compound-nucleus formation. The shapes and magnitudes of (?,4n), (d,2n), and (d,3n) excitation functions correlate well with a compound-nucleus treatment modified to include fission competition. According to this treatment, ratios of neutron to total-reaction level width, ?n?i?i, are 0.49 for U236-233 [from Th232(?,4n)], 0.17 for Np235-234 [from U233(d,2n)], and 0.20 for Np235-233 [from U233(d,3n)]. In addition the total-reaction excitation functions (consisting mostly of the fission excitation functions) are consistent with theoretical cross sections for compound-nucleus formation calculated with a nuclear radius parameter r0=1.510-13A13.The fission mass-yield curves are similar to those found for other heavy target isotopes (for elements from thorium to plutonium). The minimum in the curves in the region of mass 120 tends to disappear as helium-ion or deuteron energy is increased.The (?,pxn), (?,2pxn), (?,?n), (d,n), and (d,?n) products are attributed to direct interactions, with complex particles emitted in preference to a series of protons and neutrons. Thus (?,d), (?,t), and (?,tn) mechanisms would account for most of the (?,pn), (?,p2n), and (?,p3n) products, respectively. In the case of the (?,t) and (?,tn) reactions, analysis of the ratio ?(?,tn)?(?,t) leads one to the conclusion that with 35-Mev helium ions only 9% of outgoing tritons leave the residual nucleus with sufficient energy to evaporate a neutron or undergo fission, and with 44-Mev helium ions only 20% do so. The (d,n) product probably results from the stripping reaction.

Bruce M. Foreman, Jr., Walter M. Gibson, Richard A. Glass, and Glenn T. Seaborg

1959-10-15T23:59:59.000Z

227

Stress analysis of the HFIR HB-2 and HB-3 beam tube nozzles  

SciTech Connect

The results of three-dimensional linear elastic stress analyses of the HFIR HB-2 and HB-3 nozzles are presented in this report. Finite element models were developed using the PATRAN pre-processing code and translated into ABAQUS input file format. A scoping analysis using simple geometries with internal pressure loading was carried out to assess the capabilities of the ABAQUS/Standard code to calculate maximum principal stress distributions within cylinders with and without holes. These scoping calculations were also used to provide estimates for the variation in tangential stress around the rim of a nozzle using the superposition of published closed-form solutions for the stress around a hole in an infinite flat plate under uniaxial tension. From the results of the detailed finite element models, peak stress concentration factors (based on the maximum principal stresses in tension) were calculated to be 3.0 for the HB-2 nozzle and 2.8 for the HB-3 nozzle. Submodels for each nozzle were built to calculate the maximum principal stress distribution in the weldment region around the nozzle, where displacement boundary conditions for the submodels were automatically calculated by ABAQUS using the results of the global nozzle models. Maximum principal stresses are plotted and tabulated for eight positions around each nozzle and nozzle weldment.

Williams, P.T.

1998-08-01T23:59:59.000Z

228

Thermal-Hydraulic Bases for the Safety Limits and Limiting Safety System Settings for HFIR Operation at 100 MW and 468 psig Primary Pressure, Using Specially Selected Fuel Elements  

SciTech Connect

This report summarizes thermal hydraulic analyses performed to support HFIR operation at 100 MW and 468 psig pressure using specially selected fuel elements. The analyses were performed with the HFIR steady state heat transfer code, originally developed during HFIR design. This report addresses the increased core heat removal capability which can be achieved in fuel elements having coolant channel thicknesses that exceed the minimum requirements of the HFIR fuel fabrication specifications. Specific requirements for the minimum value of effective uniform as-built coolant channel thickness are established for fuel elements to be used at 100 MW. The burnout correlation currently used in the steady-state heat transfer code was also compared with more recent experimental results for stability of high-velocity flow in narrow heated channels, and the burnout correlation was found to be conservative with respect to flow stability at typical HFIR hot channel exit conditions at full power.

Rothrock, R.B.

1998-09-01T23:59:59.000Z

229

Biology and Soft Matter Division - ORNL Neutron Sciences  

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Home › Neutron Sciences Directorate › Biology and Soft Matter Division Home › Neutron Sciences Directorate › Biology and Soft Matter Division Biology and Soft Matter Division Paul Langan, BSMD Director BSMD Director Paul Langan. The Biology and Soft Matter Division (BSMD) operates an external user program for biological and soft matter research using neutron techniques at SNS and HFIR. Division personnel enable the research initiated by external users by acting as instrument responsible scientists and local contacts on a range of different beam lines. BSMD works closely with the Center for Structural Molecular Biology. Diffraction, small-angle scattering, and reflectometry are ideal methods for studying structure and organization from the atomic to the micron length scales, and neutron spectroscopic methods characterize self and

230

Dr. George Wignall | ORNL Neutron Sciences  

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Dr. George D. Wignall Dr. George D. Wignall Consultant: General-Purpose SANS Instrument (CG-2), HFIR Education Ph.D. in Physics, Sheffield University, England Description of Research Dr. Wignall uses small-angle neutron scattering (SANS) to study the structure of homo-polymers, block-copolymers and polymer blends, using deuterium labeling techniques to "color" polymer molecules and make them "visible" in the condensed state. He makes SANS techniques and instrumentation available to the scientific community through the operation of user-friendly facilities. Selected Publications (from over 240) Y. B. Melnichenko and G. D. Wignall, "Small Angle Neutron Scattering in Materials Science: Recent Practical Applications," Journal of Applied Physics 102 021102 (2007)

231

Dr. Georg Ehlers - ORNL Neutron Sciences  

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Georg Ehlers Georg Ehlers Lead Instrument Scientist: Cold Neutron Chopper Spectrometer (CNCS), SNS Education PhD in Experimental Condensed Matter Physics, the Hahn Meitner Institut, in Berlin, Germany Description of Research Dr. Ehlers joined the Spallation Neutron Source (SNS) in 2003 as the lead instrument scientist for beam line 5, the Cold Neutron Chopper Spectrometer (CNCS). CNCS is a high-resolution, direct geometry, cold neutron, inelastic multi-chopper spectrometer, designed to make use of neutrons with an energy of <50 meV. Before joining the SNS, Dr. Ehlers worked at the Institute Laue-Langevin (ILL), a leading European neutron research facility situated in Grenoble, France for six years. At the ILL, he was instrument-responsible for the spin-echo spectrometers IN11 and IN15, and established a strong research

232

Application of /sup 252/Cf-source driven noise analysis measurements for subcriticality of HFIR fuel elements  

SciTech Connect

The approach-to-critical measurements reported were for a plate-type fuel element where the height of the water moderator and side and top reflector were increased. Measurements were also performed with each of the two annuli of the fuel element to verify both the presence of boron in the fuel plates and the proper uranium loading prior to assembly of the two annuli for full submersion measurements. Measurements were also performed with detectors external to the reflector (> 15 cm of water on top, bottom, and side) for the assembled, submerged HFIR fuel element.

King, W.T.; Mihalczo, J.T.

1983-01-01T23:59:59.000Z

233

E-Print Network 3.0 - ags spallation target Sample Search Results  

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carried out to analyze and design... a Lead-Bismuth spallation target for driving a subcritical ... Source: McDonald, Kirk - Department of Physics, Princeton University...

234

Assessment of radiation exposure for materials in the LANSCE Spallation Irradiation Facility  

SciTech Connect

Materials samples were irradiated in the Los Alamos Radiation Effects Facility (LASREF) at the Los Alamos Neutron Science Center (LANSCE) to provide data for the Accelerator Production of Tritium (APT) project on the changes in mechanical and physical properties of materials in a spallation target environment. The targets were configured to expose samples to a variety of radiation environments including high-energy protons, mixed protons and neutrons, and predominantly neutrons. The irradiation was driven by an 800 MeV 1 mA proton beam with a circular Gaussian shape of approximately 2{sigma} = 3.5 cm. Two irradiation campaigns were conducted in which samples were exposed for approximately six months and two months, respectively. At the end of this period, the samples were extracted and tested. Activation foils that had been placed in proximity to the materials samples were used to quantify the fluences in various locations. The STAYSL2 code was used to estimate the fluences by combining the activation foil data with calculated data from the LAHET Code System (LCS) and MCNPX. The exposure for each sample was determined from the estimated fluences using interpolation based on a mathematical fitting to the fluence results. The final results included displacement damage (dpa) and gas (H, He) production for each sample from the irradiation. Based on the activation foil analysis, samples from several locations in both irradiation campaigns were characterized. The radiation damage to each sample was highly dependent upon location and varied from 0.023 to 13 dpa and was accompanied by high levels of H and He production.

James, M. R. (Michael R.); Maloy, S. A. (Stuart A.); Sommer, W. F. (Walter F.), Jr.; Fowler, Malcolm M.; Dry, D. E. (Donald E.); Ferguson, P. D. (Phillip D.); Corzine, R. K. (R. Karen); Mueller, G. E. (Gary E.)

2001-01-01T23:59:59.000Z

235

Simulated Irradiation of Samples in HFIR for use as Possible Test Materials in the MPEX (Material Plasma Exposure Experiment) Facility  

SciTech Connect

The importance of Plasma Material Interaction (PMI) is a major concern in fusion reactor design and analysis. The Material-Plasma Exposure eXperiment (MPEX) facility will explore PMI under fusion reactor plasma conditions. Samples with accumulated displacements per atom (DPA) damage produced by irradiations in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) will be studied in the MPEX facility. The project presented in this paper involved performing assessments of the induced radioactivity and resulting radiation fields of a variety of potential fusion reactor materials. The scientific code packages MCNP and SCALE were used to simulate irradiation of the samples in HFIR; generation and depletion of nuclides in the material and the subsequent composition, activity levels, gamma radiation fields, and resultant dose rates as a function of cooling time. These state-of-the-art simulation methods were used in addressing the challenge of the MPEX project to minimize the radioactive inventory in the preparation of the samples for inclusion in the MPEX facility.

Ellis, Ronald James [ORNL; Rapp, Juergen [ORNL

2014-01-01T23:59:59.000Z

236

Cryogenic Neutron Protein Crystallography: routine methods and potential benefits  

SciTech Connect

The use of cryocooling in neutron diffraction has been hampered by several technical challenges such as the need for specialized equipment and techniques. Recently we have developed and deployed equipment and strategies that allow for routine neutron data collection on cryocooled crystals using off the shelf components. This system has several advantages, compared to a closed displex cooling system such as fast cooling coupled with easier crystal mounting and centering. The ability to routinely collect cryogenic neutron data for analysis will significantly broaden the range of scientific questions that can be examined by neutron protein crystallography. Cryogenic neutron data collection for macromolecules has recently become available at the new Biological Diffractometer BIODIFF at FRM II and the Macromolecular Diffractometer (MaNDi) at the Spallation Neutron Source, Oak Ridge National Laboratory. To evaluate the benefits of a cryocooled neutron structure we collected a full neutron data set on the BIODIFF instrument on a Toho-1 lactamase structure at 100K.

Weiss, Kevin L [ORNL; Tomanicek, Stephen J [ORNL; NG, Joseph D [ORNL

2014-01-01T23:59:59.000Z

237

Neutron Scattering Application of Polarized Solid Target in Materials Research  

SciTech Connect

Neutron scattering is one of the most important tools for materials research. However, neutrons are very expensive to produce. Even with the best sources, such as the newly completed Spallation Neutron Source at the Oak Ridge National Laboratory, most neutron scattering experiments are still flux limited. One way to improve the experimental data is polarized neutron scattering from polarized solid target: the strong spin-dependent neutron scattering cross-section can increase the coherent scattering and decrease the incoherent scattering at the same time, thereby significantly enhancing the signal to noise ratio. Hydrogen, abundant in most soft condensed matters, has a strong spin-dependent scattering cross-section. Early applications of polarized neutron scattering in biological soft condensed matters have already demonstrated the huge potential of this technique. Here we describe the polarized target program at the SNS. The program is under active construction and is aimed at serving neutron scattering at the SNS.

Zhao, Jinkui [ORNL

2008-09-01T23:59:59.000Z

238

Workshop on NEUtron WAVElength Dependent Imaging  

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NEUtron WAVElength Dependent Imaging NEUtron WAVElength Dependent Imaging (NEUWAVE-4) Workshop October 2 - 5, 2011 Spallation Neutron Source * Oak Ridge National Laboratory * Gatlinburg, TN, USA About the Workshop Workshop Agenda Contact Information Important Dates NEUWAVE-4 Program Registration Lodging Social Events Tourist Information Organizing Committee Program Committee Workshop Flyer filler About the Workshop The Oak Ridge National Laboratory's Neutron Sciences Directorate and Energy & Environmental Sciences Directorate are pleased to host the 4th Workshop on NEUtron WAVElength Dependent Imaging (NEUWAVE-4). This meeting discusses the latest development in energy selective imaging techniques, applications and existing and future instrumentation. This meeting follows the successful meeting held in Garching, Germany (April 2008,) Abingdon, UK (June 2009,) and Hokkaido University (June 2010.)

239

Breast Tissue Imaging | ORNL Neutron Sciences  

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Neutron scattering measures samples too hot to hold Neutron scattering measures samples too hot to hold Research Contact: Kenneth Kelton August 2013 Liquids and glasses can have unique optical, electronic, and structural applications but are poorly understood compared to crystalline materials, limiting the ability to take advantage of the characteristics of glasses in a range of applications. Containers can react with molten samples at high temperatures or can favor the growth of crystals over the formation of glasses. Using the chemical and isotopic sensitivity of neutron scattering to understand these disordered structures requires a new capability to hold samples in a neutron beam at high temperature without using a solid physical container. New sample environment equipment at Oak Ridge National Laboratory's (ORNL) Spallation Neutron Source (SNS) enables scientists to

240

Chemical & EngChemical/Engineering Materials Division | Neutron Science |  

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Chemical and Engineering Materials Division Chemical and Engineering Materials Division SHARE Chemical and Engineering Materials Division CEMD Director Mike Simonson The Chemical and Engineering Materials Division (CEMD) supports neutron-based research at SNS and HFIR in understanding the structure and dynamics of chemical systems and novel engineering materials. The user community takes advantage of division-supported capabilities of neutron scattering for measurements over wide ranges of experimental and operating conditions, including studies of chemical and physical changes in situ. User experiments with diffraction, small-angle scattering, inelastic and quasielastic scattering, and neutron imaging instruments address a range of problems in chemistry and in engineering materials research. Current areas of research supported by the division include the structure

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241

Scientific opportunities with advanced facilities for neutron scattering  

SciTech Connect

The present report documents deliberations of a large group of experts in neutron scattering and fundamental physics on the need for new neutron sources of greater intensity and more sophisticated instrumentation than those currently available. An additional aspect of the Workshop was a comparison between steady-state (reactor) and pulsed (spallation) sources. The main conclusions were: (1) the case for a new higher flux neutron source is extremely strong and such a facility will lead to qualitatively new advances in condensed matter science and fundamental physics; (2) to a large extent the future needs of the scientific community could be met with either a 5 x 10/sup 15/ n cm/sup -2/s/sup -1/ steady state source or a 10/sup 17/ n cm/sup -2/s/sup -1/ peak flux spallation source; and (3) the findings of this Workshop are consistent with the recommendations of the Major Materials Facilities Committee.

Lander, G.H.; Emery, V.J. (eds.)

1984-01-01T23:59:59.000Z

242

ENGINEERING NEUTRON DIFFRACTION INSTRUMENTS AT HFIR AND SNS AND THEIR APPLICATION TO STUDIES OF THE BEHAVIOR OF STRUCTURAL  

E-Print Network (OSTI)

for Energy Efficiency and Renewable Energy, Vehicle Technologies Program, as part of the High Temperature lightweight magnets, aluminum bridge decks, hydrogen storage, fuel cells, diesel engines, and stronger plastic

Pennycook, Steve

243

Investigations of low-temperature neutron embrittlement of ferritic steels  

SciTech Connect

Investigations were made into reasons for accelerated embrittlement of surveillance specimens of ferritic steels irradiated at 50C at the High Flux Isotope Reactor (HFIR) pressure vessel. Major suspects for the precocious embrittlement were a highly thermalized neutron spectrum,a low displacement rate, and the impurities boron and copper. None of these were found guilty. A dosimetry measurement shows that the spectrum at a major surveillance site is not thermalized. A new model of matrix hardening due to point defect clusters indicates little effect of displacement rate at low irradiation temperature. Boron levels are measured at 1 wt ppM or less, inadequate for embrittlement. Copper at 0.3 wt % and nickel at 0.7 wt % are shown to promote radiation strengthening in iron binary alloys irradiated at 50 to 60C, but no dependence on copper and nickel was found in steels with 0.05 to 0.22% Cu and 0.07 to 3.3% Ni. It is argued that copper impurity is not responsible for the accelerated embrittlement of the HFIR surveillance specimens. The dosimetry experiment has revealed the possibility that the fast fluence for the surveillance specimens may be underestimated because the stainless steel monitors in the surveillance packages do not record an unexpected component of neutrons in the spectrum at energies just below their measurement thresholds of 2 to 3 MeV.

Farrell, K.; Mahmood, S.T.; Stoller, R.E.; Mansur, L.K.

1992-12-31T23:59:59.000Z

244

News & Events | ORNL Neutron Sciences  

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1 News 1 News Neutron Science In the News - 2001 December November October September August July June May April March February January Because some media sources archive past articles and require a subscription for access, some of the links below might not be active. If a citation listed here is no longer available, please contact the newspaper or your library directly. December When the dust settles, what'll happen to Y12? Knoxville News-Sentinel, 12/19 "...The Oak Ridge community is currently enthralled with construction of the Spallation eutron Source and other good things at Oak Ridge National Laboratory and doesn't seem to care about Y-12." [Dr. Bill Bibb] Spallation director's early success is surprising, but not unique Knoxville News-Sentinel, 12/11 Mason is only 37 years old, which doesn't even qualify as mid-career for a

245

Cryogenic hydrogen circulation system of neutron source  

SciTech Connect

Cold neutron sources of reactors and spallation neutron sources are classic high flux neutron sources in operation all over the world. Cryogenic fluids such as supercritical or supercooled hydrogen are commonly selected as a moderator to absorb the nuclear heating from proton beams. By comparing supercritical hydrogen circulation systems and supercooled hydrogen circulation systems, the merits and drawbacks in both systems are summarized. When supercritical hydrogen circulates as the moderator, severe pressure fluctuations caused by temperature changes will occur. The pressure control system used to balance the system pressure, which consists of a heater as an active controller for thermal compensation and an accumulator as a passive volume controller, is preliminarily studied. The results may provide guidelines for design and operation of other cryogenic hydrogen system for neutron sources under construction.

Qiu, Y. N. [Institute of Physics and Chemistry, Chinese Academy of Sciences, BJ100190 China and University of Chinese Academy of Sciences, Chinese Academy of Sciences, BJ100049 (China); Hu, Z. J.; Wu, J. H.; Li, Q.; Zhang, Y. [Institute of Physics and Chemistry, Chinese Academy of Sciences, BJ100190 (China); Zhang, P. [School of Energy and Power Engineering, HuaZhong University of Science and Technology, WH430074 (China); Wang, G. P. [Institute of High Energy Physics, Chinese Academy of Sciences, BJ100049 (China)

2014-01-29T23:59:59.000Z

246

First Measurements of the Inclined Boron Layer Thermal-Neutron Detector for Reflectometry  

SciTech Connect

A prototype detector based on the inclined boron layer principle is introduced. For typical measurement conditions at the Liquids Reflectometer at the Spallation Neutron Source, its count rate capability is shown to be superior to that of the current detector by nearly two orders of magnitude.

Clonts, Lloyd G [ORNL; Crow, Lowell [ORNL; Van Vuure, Thorwald L [ORNL; Robertson, Lee [ORNL; Riedel, Richard A [ORNL; Richards, John D [ORNL; Cooper, Ronald G [ORNL; Remec, Igor [ORNL; Ankner, John Francis [ORNL; Browning, Jim [ORNL

2010-01-01T23:59:59.000Z

247

First Measurements of the Inclined Boron Layer Thermal-Neutron Detector for Reflectometry  

SciTech Connect

A prototype detector based on the inclined absorber layer principle is introduced. For the Liquids Reflectometer at the Spallation Neutron Source, it is shown to be a significant improvement over its current detector, which imposes an instantaneous count rate limitation of 50 kcps.

Van Vuure, Thorwald L [ORNL] [ORNL; Clonts, Lloyd G [ORNL] [ORNL; Crow, Lowell [ORNL] [ORNL; Cooper, Ronald G [ORNL] [ORNL; Richards, John D [ORNL] [ORNL; Riedel, Richard A [ORNL] [ORNL; Robertson, Lee [ORNL] [ORNL

2008-01-01T23:59:59.000Z

248

2009 International Conference on Neutron Scattering (ICNS 2009)  

SciTech Connect

The ICNS provides a focal point for the worldwide neutron user community to strengthen ties within this diverse group, while at the same time promoting neutron research among colleagues in related disciplines identified as ?¢????would-be?¢??? neutron users. The International Conference on Neutron Scattering thus serves a dual role as an international user meeting and a scientific meeting. As a venue for scientific exchange, the ICNS showcases recent results and provides forums for scientific discussion of neutron research in diverse fields such as hard and soft condensed matter, liquids, biology, magnetism, engineering materials, chemical spectroscopy, crystal structure, and elementary excitations, fundamental physics and development of neutron instrumentation through a combination of invited talks, contributed talks and poster sessions. Each of the major national neutron facilities (NIST, LANSCE, ANL, HFIR and SNS), along with their international counterparts, has an opportunity to exchange information with each other and to update users, and potential users, of their facility. This is also an appropriate forum for users to raise issues that relate to the facilities.

Gopal Rao, PhD; Donna Gillespie

2010-08-05T23:59:59.000Z

249

Publications from Research Conducted at CG-1 | ORNL Neutron Sciences  

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Publications from Research Conducted at CG-1 Publications from Research Conducted at CG-1 2013 Publications Wang C. L., Clonts L. G., Diawara Y., Hannan B. W., Hodges J. P., "Elimination of ghosting artifacts from wavelength-shifting fiber neutron detectors", Review of Scientific Instruments 84, 013308 (2013). 2011 Publications Crow L., Robertson L., Bilheux H., Fleenor M., Iverson E., Tong X., Stoica D., Lee W. T., "The CG1 instrument development test station at the High Flux Isotope Reactor", Nuclear Instruments and Methods in Physics Research A 634, S71-S74 (2011). 2010 Publications Bilheux H. Z., Horita J., Warren J. M., Perfect E., Kang M., "Neutron imaging of fluids in plantsoil- rock systems using the ORNL/HFIR CG-1 beamline", Goldschmidt Abstracts B, Geochimica et Cosmochimica Acta

250

Biology and Soft Matter Division | Neutron Science | ORNL  

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Biology and Soft Matter Division Biology and Soft Matter Division SHARE Biology and Soft Matter Division BSMD Director Paul Langan The Biology and Soft Matter Division (BSMD) operates an external user program for biological and soft matter research using neutron techniques at SNS and HFIR. Division personnel enable the research initiated by external users by acting as instrument responsible scientists and local contacts on a range of different beam lines. BSMD works closely with the Center for Structural Molecular Biology. Diffraction, small-angle scattering, and reflectometry are ideal methods for studying structure and organization from the atomic to the micron length scales, and neutron spectroscopic methods characterize self and collective motions from picosecond to microsecond timescales. These

251

Joint Institute for Neutron Sciences | ornl.gov  

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Joint Institute for Neutron Sciences Joint Institute for Neutron Sciences SHARE Joint Institute for Neutron Sciences JINS is located on Chestnut Ridge within the 80-acre SNS site, part of Oak Ridge National Laboratory. The Joint Institute for Neutron Sciences (JINS) was founded as a collaborative effort between Oak Ridge National Laboratory (ORNL) and The University of Tennessee to promote the use of neutron scattering in various fields of research. Through worldwide collaborations between researchers of the biological and life sciences, energy sciences, polymer science, condensed matter physics and computational sciences, a synergistic consortium will be created at ORNL to elevate the field of neutron sciences to a new level of efficacy for industry, medicine and frontier research. The goal of JINS is to serve as a gateway for users of the Spallation

252

New measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission  

E-Print Network (OSTI)

Slow neutron scattering provides quantitative information on the structure and dynamics of materials of interest in physics, chemistry, materials science, biology, geology, and other fields. Liquid hydrogen is a widely-used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. In particular the rapid drop of the slow neutron scattering cross section of liquid parahydrogen below 14.5~meV is especially interesting and important. We have measured the total cross section and the scattering cross section for slow neutrons with energies between 0.43~meV and 16.1~meV on liquid hydrogen at 15.6~K using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge National Laboratory. At 1~meV this measurement is a factor of 3 below the data from previous work which has been used in the design of liquid hydrogen moderators at slow neutron sources. We describe our measurements, compare them with previous work, and discuss the implications for designing more intense slow neutron sources.

K. B. Grammer; R. Alarcon; L. Barrn-Palos; D. Blyth; J. D. Bowman; J. Calarco; C. Crawford; K. Craycraft; D. Evans; N. Fomin; J. Fry; M. Gericke; R. C. Gillis; G. L. Greene; J. Hamblen; C. Hayes; S. Kucuker; R. Mahurin; M. Maldonado-Velzquez; E. Martin; M. McCrea; P. E. Mueller; M. Musgrave; H. Nann; S. I. Penttil; W. M. Snow; Z. Tang; W. S. Wilburn

2014-12-12T23:59:59.000Z

253

The High Flux Isotope Reactor at Oak Ridge National Laboratory  

NLE Websites -- All DOE Office Websites

The High Flux Isotope Reactor at ORNL The High Flux Isotope Reactor at ORNL Aerial of the High Flux Isotope Reactor Site The High Flux Isotope Reactor site is located on the south side of the ORNL campus and is about a three-minute drive from her sister neutron facility, the Spallation Neutron Source. Operating at 85 MW, HFIR is the highest flux reactor-based source of neutrons for research in the United States, and it provides one of the highest steady-state neutron fluxes of any research reactor in the world. The thermal and cold neutrons produced by HFIR are used to study physics, chemistry, materials science, engineering, and biology. The intense neutron flux, constant power density, and constant-length fuel cycles are used by more than 500 researchers each year for neutron scattering research into

254

Thermodynamics of Quantum Ultra-cold Neutron Gas under Gravity of The Earth  

E-Print Network (OSTI)

The stored ultra-cold neutrons have been developed. A high density ultra-cold neutron gas has been recently produced by using the nuclear spallation method. We investigate the thermodynamic properties of the quantum ultra-cold neutron gas in the Earth's gravitational field. We find that the quantum effects increase temperature dependence of the chemical potential and the internal energy in the low temperature region. The density distribution of quantum ultra-cold neutron gas is modified by the Earth's gravitational field.

Hiromi Kaneko; Akihiro Tohsaki; Atsushi Hosaka

2012-06-29T23:59:59.000Z

255

Neutron reflectometry  

Science Journals Connector (OSTI)

Neutron reflectivity is a powerful tool for the ... chapter include: the theory of elastic specular neutron diffraction; polarized neutron reflectivity; surface roughness; experimental methodology; resolution in ...

G. S. Smith; C. F. Majkrzak

2004-01-01T23:59:59.000Z

256

Neutron-Neutron Interaction  

Science Journals Connector (OSTI)

The present status of the problem of charge dependence is discussed. The information about the neutron-neutron interaction derived from the two-neutron system, three-nucleon systems, final-state interactions in multiparticle reactions, and peripheral processes is critically evaluated. The experimental data indicate the breakdown of charge independence by about 3-5%. Evidence concerning the violation of charge symmetry is inconclusive, but it seems that most of the data are consistent with the assumption that charge symmetry is satisfied within 0.5-1%. The most suitable studies which might improve the knowledge of the neutron-neutron forces are indicated.

IVO LAUS

1967-07-01T23:59:59.000Z

257

Fabrication development for the Advanced Neutron Source Reactor  

SciTech Connect

This report presents the fuel fabrication development for the Advanced Neutron Source (ANS) reactor. The fuel element is similar to that successfully fabricated and used in the High Flux Isotope Reactor (HFIR) for many years, but there are two significant differences that require some development. The fuel compound is U{sub 3}Si{sub 2} rather than U{sub 3}O{sub 8}, and the fuel is graded in the axial as well as the radial direction. Both of these changes can be accomplished with a straightforward extension of the HFIR technology. The ANS also requires some improvements in inspection technology and somewhat more stringent acceptance criteria. Early indications were that the fuel fabrication and inspection technology would produce a reactor core meeting the requirements of the ANS for the low volume fraction loadings needed for the highly enriched uranium design (up to 1.7 Mg U/m{sup 3}). Near the end of the development work, higher volume fractions were fabricated that would be required for a lower- enrichment uranium core. Again, results look encouraging for loadings up to {approx}3.5 Mg U/m{sup 3}; however, much less evaluation was done for the higher loadings.

Pace, B.W. [Babcock and Wilcox, Lynchburg, VA (United States); Copeland, G.L. [Oak Ridge National Lab., TN (United States)

1995-08-01T23:59:59.000Z

258

Small Gas Bubble Experiment for Mitigation of Cavitation Damage and Pressure Waves in Short-pulse Mercury Spallation Targets  

SciTech Connect

Populations of small helium gas bubbles were introduced into a flowing mercury experiment test loop to evaluate mitigation of beam-pulse induced cavitation damage and pressure waves. The test loop was developed and thoroughly tested at the Spallation Neutron Source (SNS) prior to irradiations at the Los Alamos Neutron Science Center - Weapons Neutron Research Center (LANSCE-WNR) facility. Twelve candidate bubblers were evaluated over a range of mercury flow and gas injection rates by use of a novel optical measurement technique that accurately assessed the generated bubble size distributions. Final selection for irradiation testing included two variations of a swirl bubbler provided by Japan Proton Accelerator Research Complex (J-PARC) collaborators and one orifice bubbler developed at SNS. Bubble populations of interest consisted of sizes up to 150 m in radius with achieved gas void fractions in the 10^-5 to 10^-4 range. The nominal WNR beam pulse used for the experiment created energy deposition in the mercury comparable to SNS pulses operating at 2.5 MW. Nineteen test conditions were completed each with 100 pulses, including variations on mercury flow, gas injection and protons per pulse. The principal measure of cavitation damage mitigation was surface damage assessment on test specimens that were manually replaced for each test condition. Damage assessment was done after radiation decay and decontamination by optical and laser profiling microscopy with damaged area fraction and maximum pit depth being the more valued results. Damage was reduced by flow alone; the best mitigation from bubble injection was between half and a quarter that of flow alone. Other data collected included surface motion tracking by three laser Doppler vibrometers (LDV), loop wall dynamic strain, beam diagnostics for charge and beam profile assessment, embedded hydrophones and pressure sensors, and sound measurement by a suite of conventional and contact microphones.

Wendel, Mark W [ORNL] [ORNL; Felde, David K [ORNL] [ORNL; Sangrey, Robert L [ORNL] [ORNL; Abdou, Ashraf A [ORNL] [ORNL; West, David L [ORNL] [ORNL; Shea, Thomas J [ORNL] [ORNL; Hasegawa, Shoichi [Japan Atomic Energy Agency (JAEA)] [Japan Atomic Energy Agency (JAEA); Kogawa, Hiroyuki [Japan Atomic Energy Agency (JAEA)] [Japan Atomic Energy Agency (JAEA); Naoe, Dr. Takashi [Japan Atomic Energy Agency (JAEA)] [Japan Atomic Energy Agency (JAEA); Farny, Dr. Caleb H. [Boston University] [Boston University; Kaminsky, Andrew L [ORNL] [ORNL

2014-01-01T23:59:59.000Z

259

Temperature and thermal stress distributions for the HFIR permanent reflector generated by nuclear heating  

SciTech Connect

The beryllium permanent reflector of the High Flux Isotope Reactor has the main functions for slowing down and reflecting the neutrons and housing the experimental facilities. The reflector is heated as a result of the nuclear reaction. Heat is removed mainly by the cooling water passing through the densely distributed coolant holes along the vertical or axial direction of the reflector. The reflector neutronic distribution and its heating rate are calculated by J.C. Gehin of the Oak Ridge National Laboratory by applying the Monte Carlo Code MCNP. The heat transfer boundary conditions along several reflector interfaces are estimated to remove additional heat from the reflector. The present paper is to report the calculation results of the temperature and the thermal stress distributions of the permanent reflector by applying the computer aided design code I-DEAS and the finite element code ABAQUS. The present calculation is to estimate the high stress areas as a result of the new beam tube cutouts along the horizontal mid-plane of the reflector of the recent reactor upgrade project. These high stresses were not able to be calculated in the preliminary design analysis in earlier 60`s. The heat transfer boundary conditions are used in this redesigned calculation. The material constants and the acceptance criteria for the allowable stresses are mainly based on that assumed in the preliminary design report.

Chang, S.J.

1998-04-01T23:59:59.000Z

260

La premire pierre de la source europenne de neutrons ESS, Lund Communiqu de presse, le 10 octobre 2014  

E-Print Network (OSTI)

La première pierre de la source européenne de neutrons ESS, à Lund (Suède) Communiqué de presse, le 10 octobre 2014 La construction de ESS, l'European Spallation Source (ESS). La première pierre de ce grand

van Tiggelen, Bart

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Static compression and H disorder in brucite, Mg(OH)2, to 11 GPa: a powder neutron diffraction study  

Science Journals Connector (OSTI)

Neutron diffraction data suitable for Rietveld refinements were collected on a powder sample of synthetic Mg(OH)2 by the Polaris time-of-flight spectrometer (ISIS spallation source, U.K.) at 10-4 7.8(3) and 10.9(...

M. Catti; G. Ferraris; S. Hull; A. Pavese

1995-04-01T23:59:59.000Z

262

Recovery and purification of nickel-63 from HFIR-irradiated targets  

SciTech Connect

The production of large quantities of high-specific-activity {sup 63}Ni (>10 Ci/g) requires both a highly enriched {sup 62}Ni target and a long irradiation period at high neutron flux. Trace impurities in the nickel and associated target materials are also activated and account for a significant fraction of the discharged activity and essentially all of the gamma activity. While most of these undesirable activation products can be removed as chloride complexes during anion exchange, chromium, present at {sup 51}Cr, and scandium, present as {sup 46}Sc, are exceptions and require additional processing to achieve the desired purity. Optimized flowsheets are discussed based upon the current development and production experience.

Williams, D.F.; O`Kelley, G.D.; Knauer, J.B.; Porter, C.E.; Wiggins, J.T.

1993-06-01T23:59:59.000Z

263

Environmental Impact Statement for Siting, Construction and Operation of the National Spallation Neutron Source  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

62 62 Federal Register / Vol. 62, No. 143 / Friday, July 25, 1997 / Notices Internet address: http:\www.nawcwpns.navy.mil/∼pmeis. Navy will set up several information stations at these scoping meetings; each information station will be staffed by a Navy representative who will be available to answer questions from meeting attendees. In addition, Navy representatives will give a brief presentation about current NAWCWPNS activities on the Point Mugu Sea Range followed by a description of the proposed action and alternatives (including the No-Action alternative). Members of the public may offer verbal or written comments at the scoping meetings, or subsequent to the meetings by mail, by facsimile, or by toll-free telephone at (888) 217-9045. Verbal comments will be limited to three

264

Building 7602 Decontamination and Decommissioning for Reuse by Spallation Neutron Source  

SciTech Connect

Building 7602 at the Oak Ridge National Laboratory (ORNL) was constructed in 1963 as a Reactor Service Building for the Experimental Gas-Cooled Reactor; the reactor was never fueled or operated, and the project was terminated in 1965. Significant building modifications were performed during the late 1970s and early 1980s. Beginning in 1984, separation processes and equipment development and testing were initiated for the Consolidated Fuel Reprocessing Program (CFRP). The principal materials used in the processes were depleted and natural uranium, nitric acid, and organic solvents. CFRP operations continued until 1994 when the program was discontinued and the facility declared surplus to the U.S. Department of Energy (DOE). Systems and equipment were shut down; feed and waste materials were removed; and process fluids, chemicals, and uranium were drained and flushed from systems. This paper will present an overview of the Building 7602 D&D activities, final radiological survey , facility modifications, and project interfaces.

Brill, A.; Berger, J.; Kelsey, A.; Plummer, K.

2002-02-26T23:59:59.000Z

265

Value engineering study final report on -- Spallation Neutron Source, Oak Ridge, Tennessee  

SciTech Connect

The SNS Project has had numerous DOE/SC reviews to validate the technical baseline, management approach, cost, schedule, and Conceptual Design Report. As a result, in FY 1999 the SNS received $130 million and approval from Congress to initiate Title 1 design and construction activities. Since this funding was less than requested for FY 1999 ($157 million) and validated in previous reviews, and because of improved costing information, the SNS Project team will reassess the cost and schedule baselines in an upcoming DOE review in January 1999. In preparation for this reassessment, the SNS has initiated a value engineering process to improve the design and to recover cost and contingency. Value engineering will continue throughout the life of the project, but the results described in this report are our initial efforts.

None

1999-01-31T23:59:59.000Z

266

Feasibility of Once Through Subcritical Cores Driven by an Accelerator Spallation Neutron Source  

Science Journals Connector (OSTI)

Other Concepts and Assessments / Proceedings of the Fifteenth International Conference on Emerging Nuclear Energy Systems

Anselmo Cisneros; Nicholas Zweibaum; Christian Di Sanzo; Jeremie Cohen; Ehud Greenspan; Per Peterson; Bernhard Ludwigt

267

Elastic scattering research at a 1 MW long pulse spallation neutron source  

SciTech Connect

The elastic scattering working group investigated instrumentation for powder diffraction, single-crystal diffraction, small-angle diffraction, and reflectometry. For this purpose, three subgroups were formed; one for powder diffraction and single-crystal diffraction, one for small-angle diffraction, and one for reflectometry. For the most part these subgroups worked separately, but for part of the time the reflectometry and small-angle diffraction subgroups met together to discuss areas of common interest. Contributors in each of these subgroups are indicated below along with the discussion of these subgroup deliberations.

Crawford, R.K.

1995-12-31T23:59:59.000Z

268

Neutronic Analysis of an Advanced Fuel Design Concept for the High Flux Isotope Reactor  

SciTech Connect

This study presents the neutronic analysis of an advanced fuel design concept for the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) that could significantly extend the current fuel cycle length under the existing design and safety criteria. A key advantage of the fuel design herein proposed is that it would not require structural changes to the present HFIR core, in other words, maintaining the same rated power and fuel geometry (i.e., fuel plate thickness and coolant channel dimensions). Of particular practical importance, as well, is the fact that the proposed change could be justified within the bounds of the existing nuclear safety basis. The simulations herein reported employed transport theory-based and exposure-dependent eigenvalue characterization to help improve the prediction of key fuel cycle parameters. These parameters were estimated by coupling a benchmarked three-dimensional MCNP5 model of the HFIR core to the depletion code ORIGEN via the MONTEBURNS interface. The design of an advanced HFIR core with an improved fuel loading is an idea that evolved from early studies by R. D. Cheverton, formerly of ORNL. This study contrasts a modified and increased core loading of 12 kg of 235U against the current core loading of 9.4 kg. The simulations performed predict a cycle length of 39 days for the proposed fuel design, which represents a 50% increase in the cycle length in response to a 25% increase in fissile loading, with an average fuel burnup increase of {approx}23%. The results suggest that the excess reactivity can be controlled with the present design and arrangement of control elements throughout the core's life. Also, the new power distribution is comparable or even improved relative to the current power distribution, displaying lower peak to average fission rate densities across the inner fuel element's centerline and bottom cells. In fact, the fission rate density in the outer fuel element also decreased at these key locations for the proposed design. Overall, it is estimated that the advanced core design could increase the availability of the HFIR facility by {approx}50% and generate {approx}33% more neutrons annually, which is expected to yield sizeable savings during the remaining life of HFIR, currently expected to operate through 2014. This study emphasizes the neutronics evaluation of a new fuel design. Although a number of other performance parameters of the proposed design check favorably against the current design, and most of the core design features remain identical to the reference, it is acknowledged that additional evaluations would be required to fully justify the thermal-hydraulic and thermal-mechanical performance of a new fuel design, including checks for cladding corrosion performance as well as for industrial and economic feasibility.

Xoubi, Ned [ORNL; Primm, Trent [ORNL; Maldonado, G. Ivan [University of Tennessee, Knoxville (UTK)

2009-01-01T23:59:59.000Z

269

Broad Energy Spectrum of Laser-Accelerated Protons for Spallation-Related Physics  

Science Journals Connector (OSTI)

A beam of MeV protons, accelerated by ultraintense laser-pulse interactions with a thin target foil, is used to investigate nuclear reactions of interest for spallation physics. The laser-generated proton beam is shown (protons were measured) to have a broad energy distribution, which closely resembles the expected energy spectrum of evaporative protons (below 50MeV) produced in GeV-proton-induced spallation reactions. The protons are used to quantify the distribution of residual radioisotopes produced in a representative spallation target (Pb), and the results are compared with calculated predictions based on spectra modeled with nuclear Monte Carlo codes. Laser-plasma particle accelerators are shown to provide data relevant to the design and development of accelerator driven systems.

P. McKenna; K. W. D. Ledingham; S. Shimizu; J. M. Yang; L. Robson; T. McCanny; J. Galy; J. Magill; R. J. Clarke; D. Neely; P. A. Norreys; R. P. Singhal; K. Krushelnick; M. S. Wei

2005-03-04T23:59:59.000Z

270

A workshop on enhanced national capability for neutron scattering  

SciTech Connect

This two-day workshop will engage the international neutron scattering community to vet and improve the Lujan Center Strategic Plan 2007-2013 (SP07). Sponsored by the LANL SC Program Office and the University of California, the workshop will be hosted by LANSCE Professor Sunny Sinha (UCSD). Endorsement by the Spallation Neutron Source will be requested. The discussion will focus on the role that the Lujan Center will play in the national neutron scattering landscape assuming full utilization of beamlines, a refurbished LANSCE, and a 1.4-MW SNS. Because the Lujan Strategic Plan is intended to set the stage for the Signature Facility era at LANSCE, there will be some discussion of the long-pulse spallation source at Los Alamos. Breakout groups will cover several new instrument concepts, upgrades to present instruments, expanded sample environment capabilities, and a look to the future. The workshop is in keeping with a request by BES to update the Lujan strategic plan in coordination with the SNS and the broader neutron community. Workshop invitees will be drawn from the LANSCE User Group and a broad cross section of the US, European, and Pacific Rim neutron scattering research communities.

Hurd, Alan J [Los Alamos National Laboratory; Rhyne, James J [Los Alamos National Laboratory; Lewis, Paul S [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

271

Neutron imaging of alkali metal heat pipes  

SciTech Connect

High-temperature heat pipes are two-phase, capillary driven heat transfer devices capable of passively providing high thermal fluxes. Such a device using a liquid-metal coolant can be used as a solution for successful thermal management on hypersonic flight vehicles. Imaging of the liquid-metal coolant inside will provide valuable information in characterizing the detailed heat and mass transport. Neutron imaging possesses an inherent advantage from the fact that neutrons penetrate the heat pipe metal walls with very little attenuation, but are significantly attenuated by the liquid metal contained inside. Using the BT-2 beam line at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland, preliminary efforts have been conducted on a nickel-sodium heat pipe. The contrast between the attenuated beam and the background is calculated to be approximately 3%. This low contrast requires sacrifice in spatial or temporal resolution so efforts have since been concentrated on lithium (Li) which has a substantially larger neutron attenuation cross section. Using the CG-1D beam line at the High Flux Isotope Reactor (HFIR) of Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, the first neutron images of high-temperature molybdenum (Mo)-Li heat pipes have been achieved. The relatively high neutron cross section of Li allows for the visualization of the Li working fluid inside the heat pipes. The evaporator region of a gravity assisted cylindrical heat pipe prototype 25 cm long was imaged from start-up to steady state operation up to approximately 900 C. In each corner of the square bore inside, the capillary action raises the Li meniscus above the bulk Li pool in the evaporator region. As the operational temperature changes, the meniscus shapes and the bulk meniscus height also changes. Furthermore, a three-dimensional tomographic image is also reconstructed from the total of 128 projection images taken 1.4o apart in which the Li had already cooled and solidified.

Kihm, Ken [University of Tennessee, Knoxville (UTK); Kirchoff, Eric [University of Tennessee, Knoxville (UTK); Golden, Matt [University of Tennessee, Knoxville (UTK); Rosenfeld, J. [Thermacore Inc.; Rawal, S. [Lockheed Martin Space Systems Company; Pratt, D. [United States Air Force Research Laboratory, Wright-Patterson Air Force Base; Bilheux, Hassina Z [ORNL; Walker, Lakeisha MH [ORNL; Voisin, Sophie [ORNL; Hussey, Dan [NIST Center for Neutron Research (NCRN), Gaithersburg, MD

2013-01-01T23:59:59.000Z

272

Research Highlights | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Unconventional Superconductors Unconventional Superconductors Doug Scalapino discusses "common thread" linking unconventional superconducting materials Dec 2011, Written by Deborah Counce Douglas Scalapino Professor Emeritus Douglas Scalapino. Douglas Scalapino was the inaugural speaker for a new joint lecture series sponsored by the Spallation Neutron Source and the Center for Nanophase Materials Sciences at Oak Ridge National Laboratory. He is Research Professor of Physics at the University of California-Santa Barbara. A leading theorist in condensed matter physics, he has been a fellow of the American Physical Society and a member of the National Academy Sciences. He has been awarded the John Bardeen Prize for theoretical work in superconductivity and the Julius Lilienfeld Prize for outstanding

273

Capabilities of the WAND Instrument | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Capabilities of the WAND Instrument Capabilities of the WAND Instrument The HFIR HB-2C Wide Angle Neutron Diffractometer (WAND) is a dual purpose instrument that can be used as a fast coarse-resolution powder diffractometer or as a single crystal diffractometer to explore broad regions of reciprocal space. This instrument is most beneficial to the condensed matter, materials science, as well as the planetary sciences communities. Due to its versatility and easy access this instrument can be used for parametric studies using a variety of ancillary sample environments to provide a complete control of thermodynamic variables such as temperature, magnetic field, and pressure. Most of the recent demand for this instrument has been focused in studies of unconventional superconductors, low-dimensional magnets, multiferroics and geophysics.

274

A radial collimator for a time-of-flight neutron spectrometer  

SciTech Connect

We have engineered and installed a radial collimator for use in the scattered beam of a neutron time-of-flight spectrometer at a spallation neutron source. The radial collimator may be used with both thermal and epithermal neutrons, reducing the detected scattering intensity due to material outside of the sample region substantially. The collimator is located inside of the sample chamber of the instrument, which routinely cycles between atmospheric conditions and cryogenic vacuum. The oscillation and support mechanism of the collimator allow it to be removed from use without breaking vacuum. We describe here the design and characterization of this radial collimator.

Stone, Matthew B [ORNL; Niedziela, Jennifer L [ORNL; Loguillo, Mark [ORNL; Overbay, Mark A [ORNL; Abernathy, Douglas L [ORNL

2013-01-01T23:59:59.000Z

275

International Conference on Surface X-ray and Neutron Scattering (SXNS-11)  

SciTech Connect

The 11th International Surface X-ray and Neutron Scattering (SXNS) Conference was held on July 13-17, 2010, on the Northwestern University (NU) campus, in Evanston Illinois and hosted by the NU Materials Research Science and Engineering Center. This biennial conference brought together a community of 164 attendees from 16 countries. The field now makes use of a broad range of new experimental capabilities that have been made possible through the development of increasingly brilliant X-ray and neutron sources around the world, including third generation synchrotron sources, neutron reactor and spallation sources, as well as the recent development of X-ray lasers.

Michael J. Bedzyk

2011-06-17T23:59:59.000Z

276

Capabilities of the ARCS Instrument - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Capabilities of the ARCS Instrument Capabilities of the ARCS Instrument ARCS Overview The wide angular-range chopper spectrometer ARCS at the Spallation Neutron Source (SNS) is optimized to provide a high neutron flux at the sample position with a large solid angle of detector coverage. The instrument incorporates modern neutron instrumentation, such as an elliptically focused neutron guide, high speed magnetic bearing choppers, and a massive array of 3He linear position sensitive detectors. Novel features of the spectrometer include the use of a large gate valve between the sample and detector vacuum chambers and the placement of the detectors within the vacuum, both of which provide a window-free final flight path to minimize background scattering while allowing rapid changing of the sample and

277

Dr. J. K. (Jinkui) Zhao - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Dr. J.K. (Jinkui) Zhao Dr. J.K. (Jinkui) Zhao Research Staff Dr. Zhao is a research staff in the Neutron Facility Development Division at the Spallation Neutron Source. He has broad interests in many areas ranging from biophysics to neutrons scattering techniques. He was the lead scientist for Extended Q-Range Small-Angle Neutron Scattering Diffractometer (EQ-SANS) instrument during its design, construction and commissioning phases. Resources Software by J.K. Zhao EQ-SANS design documentation Selected Publications Metabolic Scaling in Biology Zhao, Jinkui. "A common origin for 3/4- and 2/3-power rules in metabolic scaling" Submitted Zhao, Jinkui. "Plants' metabolism and metabolic scaling" Submitted Zhao, Jinkui. "Tree growth model" In preparation Biomolecular Structures

278

Neutron Polarimetry  

Science Journals Connector (OSTI)

8 July 1993 research-article Neutron Polarimetry P. Jane Brown J. Bruce Forsyth Francis Tasset Zero-field neutron polarimetry is a technique which has...polarization analysis to be carried out in a neutron scattering experiment. The incident...

1993-01-01T23:59:59.000Z

279

Fission neutron spectra measurements at LANSCE - status and plans  

SciTech Connect

A program to measure fission neutron spectra from neutron-induced fission of actinides is underway at the Los Alamos Neutron Science Center (LANSCE) in a collaboration among the CEA laboratory at Bruyeres-le-Chatel, Lawrence Livermore National Laboratory and Los Alamos National Laboratory. The spallation source of fast neutrons at LANSCE is used to provide incident neutron energies from less than 1 MeV to 100 MeV or higher. The fission events take place in a gas-ionization fission chamber, and the time of flight from the neutron source to that chamber gives the energy of the incident neutron. Outgoing neutrons are detected by an array of organic liquid scintillator neutron detectors, and their energies are deduced from the time of flight from the fission chamber to the neutron detector. Measurements have been made of the fission neutrons from fission of {sup 235}U, {sup 238}U, {sup 237}Np and {sup 239}Pu. The range of outgoing energies measured so far is from 1 MeV to approximately 8 MeV. These partial spectra and average fission neutron energies are compared with evaluated data and with models of fission neutron emission. Results to date will be presented and a discussion of uncertainties will be given in this presentation. Future plans are to make significant improvements in the fission chambers, neutron detectors, signal processing, data acquisition and the experimental environment to provide high fidelity data including mea urements of fission neutrons below 1 MeV and improvements in the data above 8 MeV.

Haight, Robert C [Los Alamos National Laboratory; Noda, Shusaku [Los Alamos National Laboratory; Nelson, Ronald O [Los Alamos National Laboratory; O' Donnell, John M [Los Alamos National Laboratory; Devlin, Matt [Los Alamos National Laboratory; Chatillon, Audrey [CEA-FRANCE; Granier, Thierry [CEA-FRANCE; Taieb, Julien [CEA-FRANCE; Laurent, Benoit [CEA-FRANCE; Belier, Gilbert [CEA-FRANCE; Becker, John A [LLNL; Wu, Ching - Yen [LLNL

2009-01-01T23:59:59.000Z

280

News & Events - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

0 News 0 News Neutron Science In the News - 2000 December November October September August July June May April March February January Because some media sources archive past articles and require a subscription for access, some of the links below might not be active. If a citation listed here is no longer available, please contact the newspaper or your library directly. December Construction trade program graduates first class Oak Ridger, 12/19 Lawrence T. Young, president and chief executive officer of CROET, "Apprenticeships and pre-apprenticeship programs ensure East Tennesseans have access to the economic opportunities that are opening up at SNS." SNS Holds Construction Job Fair Dec. 20 Oak Ridger, 12/19 The Spallation Neutron Source project is sponsoring a construction worker

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Published Research 2011 | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

1 1 Most publications are in Adobe Portable Document Format. Download Adobe Reader. For more information about any of these publications, please contact the Neutrons Sciences Communications Office. Primary Author Index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A Abdou A., Wendel M., Riemer B., Volpenhein E., Brewster R., "Two-phase flow simulations of protective gas layer for Spallation Neutron Source target", Proceedings of the ASME 2011 International Mechanical Engineering Congress & Exposition, IMECE2011-64346. Abdulbaki M. K., "Nanoparticle effects on polymer crystallization and dynamics", University of Houston. Abell D. T., Bruhwiler D. L., Choi Y., Mahalingam S., Stoltz P., Han B., Stock M. P., "Simulation of H- beam chopping in a solenoid-based

282

Neutron Position Sensitive Detectors for the ESS  

E-Print Network (OSTI)

The European Spallation Source (ESS) in Lund, Sweden will become the world's leading neutron source for the study of materials. The instruments are being selected from conceptual proposals submitted by groups from around Europe. These instruments present numerous challenges for detector technology in the absence of the availability of Helium-3, which is the default choice for detectors for instruments built until today and due to the extreme rates expected across the ESS instrument suite. Additionally a new generation of source requires a new generation of detector technologies to fully exploit the opportunities that this source provides. The detectors will be sourced from partners across Europe through numerous in-kind arrangements; a process that is somewhat novel for the neutron scattering community. This contribution presents briefly the current status of detectors for the ESS, and outlines the timeline to completion. For a conjectured instrument suite based upon instruments recommended for construction, ...

Kirstein, Oliver; Stefanescu, Irina; Etxegarai, Maddi; Anastasopoulos, Michail; Fissum, Kevin; Gulyachkina, Anna; Hglund, Carina; Imam, Mewlude; Kanaki, Kalliopi; Khaplanov, Anton; Kittelmann, Thomas; Kolya, Scott; Nilsson, Bjrn; Ortega, Luis; Pfeiffer, Dorothea; Piscitelli, Francesco; Ramos, Judith Freita; Robinson, Linda; Scherzinger, Julius

2014-01-01T23:59:59.000Z

283

MERCURY PURIFICATION IN THE MEGAWATT LIQUID METAL SPALLATION TARGET OF EURISOL-DS Joerg Neuhausena  

E-Print Network (OSTI)

MERCURY PURIFICATION IN THE MEGAWATT LIQUID METAL SPALLATION TARGET OF EURISOL-DS Joerg Neuhausena. For the development of a purification procedure, knowledge about the chemical state of the different elements present-components are of different origin: Gaseous impurities include oxygen, nitrogen and water. The construction materials

McDonald, Kirk

284

Mats Lindroos, Cristina Oyon and Stevey OECD "A High Power Spallation Source in each Global Region"  

E-Print Network (OSTI)

ESS Mats Lindroos, Cristina Oyon and Stevey Peggs #12;ESS 2 #12;OECD "A High Power Spallation Source in each Global Region" SNS Oak Ridge J-PARC Tokai ESS in Lund #12;ESS: Site selection process · ESS high up on the ESFRI list Th ti biddi f th it (Bilb L d d· Three consortia bidding for the site

McDonald, Kirk

285

Atomistic Modeling of Short Pulse Laser Ablation of Metals: Connections between Melting, Spallation, and Phase Explosion  

E-Print Network (OSTI)

, and Phase Explosion Leonid V. Zhigilei,* Zhibin Lin, and Dmitriy S. Ivanov§ Department of Materials Science spallation to phase explosion is signified by an abrupt change in the composition of the ejected plume (from of thermodynamic stability of the target material (90% of the critical temperature) into a two-phase mixture

Zhigilei, Leonid V.

286

Effect of Substrate Thickness on Oxide Scale Spallation for Solid Oxide Fuel Cells  

SciTech Connect

In this paper, the effect of the ferritic substrate's thickness on the delamination/spallation of the oxide scale was investigated experimentally and numerically. At the high-temperature oxidation environment of solid oxide fuel cells (SOFCs), a combination of growth stress with thermal stresses may lead to scale delamination/buckling and eventual spallation during SOFC stack cooling, even leading to serious degradation of cell performance. The growth stress is induced by the growth of the oxide scale on the scale/substrate interface, and thermal stress is induced by a mismatch of the coefficient of thermal expansion between the oxide scale and the substrate. The numerical results show that the interfacial shear stresses, which are the driving force of scale delamination between the oxide scale and the ferritic substrate, increase with the growth of the oxide scale and also with the thickness of the ferritic substrate; i.e., the thick ferritic substrate can easily lead to scale delamination and spallation. Experimental observation confirmed the predicted results of the delamination and spallation of the oxide scale on the ferritic substrate.

Liu, Wenning N.; Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

2011-07-01T23:59:59.000Z

287

The uTPC Method: Improving the Position Resolution of Neutron Detectors Based on MPGDs  

E-Print Network (OSTI)

Due to the Helium-3 crisis, alternatives to the standard neutron detection techniques are becoming urgent. In addition, the instruments of the European Spallation Source (ESS) require advances in the state of the art of neutron detection. The instruments need detectors with excellent neutron detection efficiency, high-rate capabilities and unprecedented spatial resolution. The Macromolecular Crystallography instrument (NMX) requires a position resolution in the order of 200 um over a wide angular range of incoming neutrons. Solid converters in combination with Micro Pattern Gaseous Detectors (MPGDs) are proposed to meet the new requirements. Charged particles rising from the neutron capture have usually ranges larger than several millimetres in gas. This is apparently in contrast with the requirements for the position resolution. In this paper, we present an analysis technique, new in the field of neutron detection, based on the Time Projection Chamber (TPC) concept. Using a standard Single-GEM with the catho...

Pfeiffer, Dorothea; Birch, Jens; Hall-Wilton, Richard; Hglund, Carina; Hultman, Lars; Iakovidis, George; Oliveri, Eraldo; Oksanen, Esko; Ropelewski, Leszek; Thuiner, Patrik

2015-01-01T23:59:59.000Z

288

Ship Effect Neutron Measurements And Impacts On Low-Background Experiments  

SciTech Connect

The primary particles entering the upper atmosphere as cosmic rays create showers in the atmosphere that include a broad spectrum of secondary neutrons, muons and protons. These cosmic-ray secondaries interact with materials at the surface of the Earth, yielding prompt backgrounds in radiation detection systems, as well as inducing long-lived activities through spallation events, dominated by the higher-energy neutron secondaries. For historical reasons, the multiple neutrons produced in spallation cascade events are referred to as ship effect neutrons. Quantifying the background from cosmic ray induced activities is important to low-background experiments, such as neutrino-less double beta decay. Since direct measurements of the effects of shielding on the cosmic-ray neutron spectrum are not available, Monte Carlo modeling is used to compute such effects. However, there are large uncertainties (orders of magnitude) in the possible cross-section libraries and the cosmic-ray neutron spectrum for the energy range needed in such calculations. The measurements reported here were initiated to validate results from Monte Carlo models through experimental measurements in order to provide some confidence in the model results. The results indicate that the models provide the correct trends of neutron production with increasing density, but there is substantial disagreement between the model and experimental results for the lower-density materials of Al, Fe and Cu.

Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Siciliano, Edward R.

2013-10-01T23:59:59.000Z

289

2010 American Conference on Neutron Scattering (ACNS 2010)  

SciTech Connect

The ACNS provides a focal point for the national neutron user community to strengthen ties within this diverse group, while at the same time promoting neutron research among colleagues in related disciplines identified as would-be neutron users. The American Conference on Neutron Scattering thus serves a dual role as a national user meeting and a scientific meeting. As a venue for scientific exchange, the ACNS showcases recent results and provides forums for scientific discussion of neutron research in diverse fields such as hard and soft condensed matter, liquids, biology, magnetism, engineering materials, chemical spectroscopy, crystal structure, and elementary excitations, fundamental physics and development of neutron instrumentation through a combination of invited talks, contributed talks and poster sessions. As a super-user meeting, the ACNS fulfills the main objectives of users' meetings previously held periodically at individual national neutron facilities, with the advantage of a larger and more diverse audience. To this end, each of the major national neutron facilities (NIST, LANSCE, HFIR and SNS) have an opportunity to exchange information and update users, and potential users, of their facility. This is also an appropriate forum for users to raise issues that relate to the facilities. For many of the national facilities, this super-user meeting should obviate the need for separate user meetings that tax the time, energy and budgets of facility staff and the users alike, at least in years when the ACNS is held. We rely upon strong participation from the national facilities. The NSSA intends that the American Conference on Neutron Scattering (ACNS) will occur approximately every two years, but not in years that coincide with the International or European Conferences on Neutron Scattering. The ACNS is to be held in association with one of the national neutron centers in a rotating sequence, with the host facility providing local organization and planning assistance. Additional logistical support is being provided this year through a partnership with the conferencing office of the Materials Research Society (MRS). The ACNS, targeting the entire potential neutron North American user community, complements the annual NIST, ANL and LANSCE neutron and scattering schools which give hands-on experience primarily to graduate students who anticipate using neutron scattering in their thesis research. The summer schools are promoted at the ACNS and represent a natural path for students to take after being inspired by the activities of the ACNS.

Professor Simon Billinge

2011-06-17T23:59:59.000Z

290

New upper bound on the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission  

E-Print Network (OSTI)

The scattering of slow neutron beams provides unique, non-destructive, quantitative information on the structure and dynamics of materials of interest in physics, chemistry, materials science, biology, geology, and other fields. Liquid hydrogen is a widely-used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. In particular the rapid drop of the slow neutron scattering cross section of liquid parahydrogen below 15 meV, which renders the moderator volume transparent to the neutron energies of most interest for scattering studies, is therefore especially interesting and important. We have placed an upper bound on the total cross section and the scattering cross section for slow neutrons with energies between 0.43 meV and 16.1 meV on liquid hydrogen at 15.6 K using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge Nati...

Grammer, K B; Barrn-Palos, L; Blyth, D; Bowman, J D; Calarco, J; Crawford, C; Craycraft, K; Evans, D; Fomin, N; Fry, J; Gericke, M; Gillis, R C; Greene, G L; Hamblen, J; Hayes, C; Kucuker, S; Mahurin, R; Maldonado-Velzquez, M; Martin, E; McCrea, M; Mueller, P E; Musgrave, M; Nann, H; Penttil, S I; Snow, W M; Tang, Z; Wilburn, W S

2014-01-01T23:59:59.000Z

291

Neutron Production, Neutron Facilities and Neutron Instrumentation  

Science Journals Connector (OSTI)

...Mexico, 87545, U.S.A, e-mail: sven@lanl.gov Hans-Georg Priesmeyer Geesthacht Neutron Scattering Facility, GKSS Research Center, 21502 Geesthacht, Germany, e-mail: hans-georg.priesmeyer@gkss.de NEUTRON GENERATION The...

Sven C. Vogel; Hans-Georg Priesmeyer

292

Neutron Reflectivity  

Science Journals Connector (OSTI)

Neutron Reflectivity ... This article is part of the Neutron Reflectivity special issue. ... The articles in this special issue on neutron reflectivity cover a broad range of the applications of this technique and the related X-ray and neutron scattering experiments of SAXS, SANS, GISAXS, and GISANS. ...

Jeffrey Penfold

2009-03-31T23:59:59.000Z

293

About Neutrons  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Basics Neutron Basics A neutron is one of the fundamental particles that make up matter. This uncharged particle exists in the nucleus of a typical atom, along with its positively charged counterpart, the proton. Protons and neutrons each have about the same mass, and both can exist as free particles away from the nucleus. In the universe, neutrons are abundant, making up more than half of all visible matter. Find Out What a Neutron Is Youtube icon Properties of Neutrons How Can Neutrons Be Used for Research? Image of glucose movement in plants Neutron imaging techniques have been able to determine the precise movement of glucose in plants. This knowledge can help scientists better understand how biomass can be efficiently converted into fuel. Neutrons have many properties that make them ideal for certain types of

294

Study of Neutron-Induced Fission Cross Sections of U, Am, and Cm at n{sub T}OF  

SciTech Connect

Neutron induced fission cross sections of several isotopes have been measured at the CERN n{sub T}OF spallation neutron facility. Between them some measurements involve isotopes ({sup 233}U, {sup 241}Am, {sup 243}Am, {sup 245}Cm) relevant for applications to nuclear technologies. The n{sub T}OF facility delivers neutrons with high instantaneous flux and in a wide energy range, from thermal up to 250 MeV. The experimental apparatus consists of an ionization chamber that discriminates fission fragments and {alpha} particles coming from natural radioactivity of the samples. All the measurements were performed referring to the standard cross section of {sup 235}U.

Milazzo, P. M.; Abbondanno, U.; Belloni, F.; Fujii, K. [INFN, Trieste (Italy); Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.; Ferrant, L.; Gunsing, F.; Pancin, J.; Perrot, L.; Plukis, A.; Stephan, C.; Tassan-Got, L. [CNRS/IN2P3-IPN, Orsay (France); Alvarez, H.; Duran, I.; Paradela, C. [Universidade de Santiago de Compostela (Spain); Alvarez-Velarde, F.; Cano-Ott, D. [CIEMAT, Madrid (Spain)

2010-08-04T23:59:59.000Z

295

PowerPoint Presentation  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Crone, Director Crone, Director Research Reactors Division Oak Ridge National Laboratory UT-Battelle, LLC September 20, 2012 - Bethesda, MD High Flux Isotope Reactor Spallation Neutron Source Oak Ridge National Laboratory - Main Campus Materials Irradiation Testing * Fusion Energy - provides best available neutron spectrum for radiation damage testing on fusion components; collaboration between U.S. and Japan for over thirty years * Fission Energy - research supporting next-generation commercial power reactors including accident tolerant fuel and reactor materials * National Security - Neutron Activation Analysis supporting IAEA non-proliferation monitoring 1,021 Materials and NAA Irradiations in FY2011 Reliable Source of Unique Isotopes * Californium-252 - HFIR supplies 80% of the world

296

A proton?driven, intense, subcritical, fission neutron source for radioisotope production  

Science Journals Connector (OSTI)

99mTc the most frequently used radioisotope in nuclear medicine is distributed as 99Mo?99mTc generators. 99 Mo is a fission product of 235U. To replace the aging nuclear reactors used today for this production we propose to use a spallation neutron source with neutron multiplication by fission. A 150 MeV H? cyclotron can produce a 225 kW proton beam with 50% total system energy efficiency. The proton beam would hit a molten lead target surrounded by a water moderator and a graphite reflector producing around 0.96 primary neutron per proton. The primary spallation neutrons moderated would strike secondary targets containing a subcritical amount of 235U. The assembly would show a keff of 0.8 yielding a fivefold neutron multiplication. The thermal neutron flux at the targets location would be 2 1014 n/cm2.s resulting in a fission power of 500 to 750 kW. One such system could supply the world demand in 99 Mo as well as other radioisotopes. Preliminary indications show that the cost would be lower than the cost of a commercial 10 MW isotope production reactor. The cost of operation of disposal of radiowaste and of decommissioning should be significantly lower as well. Finally the non?critical nature of the system would make it more acceptable for the public than a nuclear reactor and should simplify the licensing process.

Yves Jongen

1995-01-01T23:59:59.000Z

297

HFIR Plant Maintenance - August  

NLE Websites -- All DOE Office Websites (Extended Search)

July 2012 July 2012 2 Managed by UT-Battelle for the U.S. Department of Energy ORNL Isotope Infrastructure DataTransferKit Public release of CASL infra- structure software TriBITS Three key components of the VERA (Virtual Environment for Reactor Applications) infrastructure have been released and made publicly-available. Lightweight Integrating Multiphysics Environment (LIME) * The Tribal Build, Integrate, and Test System is built on the open-source Kitware CMake, CTest, CDash tools and provides a solution for very large scale projects, especially meta- projects resulting from the integration of many different (but interrelated) projects. * Available at: http://code.google.com/p/tribits/ * DataTransferKit (DTK) is being developed to implement the rendezvous algorithm and the

298

HFIR Plant Maintenance - August  

NLE Websites -- All DOE Office Websites (Extended Search)

April 2012 April 2012 2 Managed by UT-Battelle for the U.S. Department of Energy ORNL Isotope Infrastructure Public Release of CASL Infrastructure Software The Lightweight Integrating Multiphysics Environment (LIME), which has formed the infrastructure for the simulation tools being developed within the Consortium for Advanced Simulation of Light-Water Reactors (CASL), has been publicly-released under an open-source license: * http://sourceforge.net/projects/lime1/ 3 Managed by UT-Battelle for the U.S. Department of Energy ORNL Isotope Infrastructure Key Highlights and Activities * Jess Gehin and Syd Ball participated in the Subgroup Technical Meeting under the US- Russia Civil NE Cooperation Action Plan as the respective US Leads for Small Modular Reactors and High-Temperature Gas Reactors.

299

HFIR Plant Maintenance - August  

NLE Websites -- All DOE Office Websites (Extended Search)

November 2012 November 2012 2 Managed by UT-Battelle for the U.S. Department of Energy ORNL Isotope Infrastructure Description * CFD boiling/multiphase models rely on tunable parameters * We study sensitivities of key outputs of a CFD benchmark problem using two codes: Star-CD and NPhase-CMFD. * We present validation of boiling models in Star-CD and Star- CCM+ for DEBORA and PSBT benchmark problems Sensitivity, verification, and validation studies of CFD boiling models (L3 milestone - THM.CFD.P5.03) Approach Results * Nphase will require wall boiling models in order to faithfully simulate CASL-relevant applications * We observed the largest sensitivities to the bubble diameter, the lift coefficient, and the turbulence dispersion model * For current boiling models, a systematic overestimation of

300

HFIR Plant Maintenance - August  

NLE Websites -- All DOE Office Websites (Extended Search)

June 2012 June 2012 2 Managed by UT-Battelle for the U.S. Department of Energy ORNL Isotope Infrastructure helicon launcher whistler wave launcher EBW launcher moveable diagnostic disk-target ballast tank magnetic field lines magnets Physics Integration eXperiment (PhIX) helicon plasma electron heating flow back neutral & plasma density control plasma heat flux * PhIX investigates the addition of electron heating to helicon plasma - the first building blocks of the new high-intensity plasma source needed by a powerful plasma materials test station. - Heating of helicon plasma electrons - Effects back on helicon plasma production - Neutral and plasma density control - RF power-to-plasma heat flux efficiency - Effects of plasma and impurity flow-back

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


301

HFIR Plant Maintenance - August  

NLE Websites -- All DOE Office Websites (Extended Search)

of recorded long decay chain match the four events of 294 117 observed at JINR Dubna (Russia) by Russia-US collaboration 1,2 during 2010-2012 campaigns with ORNL-made 249 Bk...

302

HFIR Plant Maintenance - August  

NLE Websites -- All DOE Office Websites (Extended Search)

of Campaign 75 rework material which will be stored until Heavy Element Campaign 76. Heavy Element Campaign C75 * Completed Cleanex Extraction for Zirc removal. * Performed...

303

HFIR Plant Maintenance - August  

NLE Websites -- All DOE Office Websites (Extended Search)

wave launcher EBW launcher moveable diagnostic disk-target ballast tank magnetic field lines magnets Physics Integration eXperiment (PhIX) helicon plasma electron heating...

304

HFIR Plant Maintenance - August  

NLE Websites -- All DOE Office Websites (Extended Search)

for the U.S. Department of Energy ORNL Isotope Infrastructure Description * Vogtle Unit 1 cycle 13 observed CRUD Induced Power Shift (CIPS) while cycles 12 and 14 did not. -...

305

Neutron-Neutron Scattering Length  

Science Journals Connector (OSTI)

The final-state interaction of the two neutrons from the reaction ?-+d?2n+? has a pronounced and distinctive effect on the momentum spectrum of the outgoing particles. In particular, the neutron spectrum is sharply peaked in the neighborhood of 2 Mev, with a shape that is quite sensitive to the strength of the nn interaction. In the region of this peak, the relative neutron-neutron momentum is so small that the nn interaction is completely characterized by its scattering length. Hence it is proposed that a measurement of the shape of the neutron spectrum from this reaction may provide a convenient means of measuring the neutron-neutron scattering length. Neutron spectra are calculated in an impulse approximation, for several assumed values of the scattering length. It appears from their shapes that, in this way, present neutron-detection techniques should be capable of determining the scattering length to within 25%.

Kirk W. McVoy

1961-03-01T23:59:59.000Z

306

Neutron skins and neutron stars  

SciTech Connect

The neutron-skin thickness of heavy nuclei provides a fundamental link to the equation of state of neutron-rich matter, and hence to the properties of neutron stars. The Lead Radius Experiment ('PREX') at Jefferson Laboratory has recently provided the first model-independence evidence on the existence of a neutron-rich skin in {sup 208}Pb. In this contribution we examine how the increased accuracy in the determination of neutron skins expected from the commissioning of intense polarized electron beams may impact the physics of neutron stars.

Piekarewicz, J. [Department of Physics, Florida State University, Tallahassee, FL 32306-4350 (United States)

2013-11-07T23:59:59.000Z

307

Neutron scattering  

Science Journals Connector (OSTI)

... likely to be able to contribute to many different branches of chemistry and secondly because neutron ...neutronscattering ...

A. J. Leadbetter

1977-12-01T23:59:59.000Z

308

Note: Versatile sample stick for neutron scattering experiments in high electric fields  

SciTech Connect

We present a versatile high voltage sample stick that fits into all cryomagnets and standard cryostats at the Swiss Spallation Neutron Source, Paul Scherrer Institut, and which provides a low effort route to neutron scattering experiments that combine electric field with low temperature and magnetic field. The stick allows for voltages up to 5 kV and can be easily adapted for different scattering geometries. We discuss the design consideration and thermal behavior of the stick, and give one example to showcase the abilities of the device.

Bartkowiak, M., E-mail: marek.bartkowiak@psi.ch [Laboratory for Developments and Methods, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); White, J. S. [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen (Switzerland) [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Laboratory for Quantum Magnetism, Ecole Polytechnique Fdrale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Rnnow, H. M.; Pra, K. [Laboratory for Quantum Magnetism, Ecole Polytechnique Fdrale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)] [Laboratory for Quantum Magnetism, Ecole Polytechnique Fdrale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

2014-02-15T23:59:59.000Z

309

Neutron guide  

DOE Patents (OSTI)

A neutron guide in which lengths of cylindrical glass tubing have rectangular glass plates properly dimensioned to allow insertion into the cylindrical glass tubing so that a sealed geometrically precise polygonal cross-section is formed in the cylindrical glass tubing. The neutron guide provides easier alignment between adjacent sections than do the neutron guides of the prior art.

Greene, Geoffrey L. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

310

Neutron Diffraction  

Science Journals Connector (OSTI)

22 February 1949 research-article Neutron Diffraction G. E. Bacon J. Thewlis The problem of neutron diffraction by crystals is treated by analogy...deals with a comparison between X-ray and neutron diffraction and it is shown that quantitatively...

1949-01-01T23:59:59.000Z

311

UA/ORNL Collaboration: Neutron Scattering Studies of Antiferromagnetic Films, Final Report  

SciTech Connect

The work reported here was a collaborative project between the research groups of Dr. J.L. Robertson at Oak Ridge National Laboratory and Dr. G.J. Mankey at the University of Alabama. The main thrust is developing neutron optical devices and materials for the study of magnetic thin films and interfaces. The project is particularly timely, since facility upgrades are currently underway at the High Flux Isotope Reactor. A new neutron optical device, a multicrystal analyzer, was designed and built to take maximum advantage of the increased flux that the upgraded beamlines at HFIR will provide. This will make possible detailed studies of the magnetic structure of thin films, multilayers, and interfaces that are not feasible at present. We performed studies of the antiferromagnetic order in thin films and crystals using neutron scattering, determined magnetic structures at interfaces with neutron reflectometry and measured order in magnetic dispersions using small angle neutron scattering. The collaboration has proved fruitful: generating eleven publications, contributing to the training of a postdoc who is now on staff at the High Flux Isotope Reactor and providing the primary support for two recent Ph.D. recipients. The collaboration is still vibrant, with anticipated implementation of the multicrystal analyzer on one of the new cold source beamlines at the High Flux Isotope Reactor.

Mankey, Gary J.

2006-07-26T23:59:59.000Z

312

Neutron Brillouin scattering in a metallic glass  

SciTech Connect

The dispersion of collective modes in a metallic glass (Mg{sub 70}Zn{sub 30}) measured earlier at the thermal neutron time-of-flight spectrometer IN4 of the HFR of the ILL could be extended towards lower momentum transfers down to the first pseudo-Brillouin zone for the first time. This extension to momentum transfer not accessible up to now was possible using the highly resolving time-of-flight spectrometer HET of the new spallation source ISIS. In the region of overlap the two parts of the dispersion determined with different samples of the same metallic glass on different instruments agree very well. Also the earlier discrepancies with the dispersion determined for this metallic glass from a computer simulation could be nearly completely eliminated due to a more recent and more complete investigations of this glass.

Suck, J.B. (Kernforschungszentrum Karlsruhe GmbH (Germany). Inst. fuer Nukleare Festkoerperphysik); Egelstaff, P.A. (Guelph Univ., ON (Canada). Dept. of Physics); Robinson, R.A.; Sivia, D.S. (Los Alamos National Lab., NM (United States)); Taylor, A.D. (Rutherford Appleton Lab., Chilton (United Kingdom))

1991-01-01T23:59:59.000Z

313

Neutron skins and neutron stars  

Science Journals Connector (OSTI)

Background: The neutron skin of a heavy nucleus as well as many neutron-star properties are highly sensitive to the poorly constrained density dependence of the symmetry energy.Purpose: To provide for the first time meaningful theoretical errors and to assess the degree of correlation between the neutron-skin thickness of 208Pb and several neutron-star properties.Methods: A proper covariance analysis based on the predictions of an accurately calibrated relativistic functional FSUGold is used to quantify theoretical errors and correlation coefficients.Results: We find correlation coefficients of nearly 1 (or ?1) between the neutron-skin thickness of 208Pb and a host of observables of relevance to the structure, dynamics, and composition of neutron stars.Conclusions: We suggest that a follow-up Lead Radius Experiment (PREX) measurement, ideally with a 0.5% accuracy, could significantly constrain the equation of state of neutron-star matter.

F. J. Fattoyev and J. Piekarewicz

2012-07-05T23:59:59.000Z

314

Neutron Scattering Tutorials | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Scattering Tutorials SHARE Neutron Scattering Tutorials The following lectures were presented at the 2011 and 2010 National School on Neutron & X-Ray Scattering. This...

315

Neutron detector  

DOE Patents (OSTI)

A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

Stephan, Andrew C. (Knoxville, TN); Jardret; Vincent D. (Powell, TN)

2011-04-05T23:59:59.000Z

316

Neutron and X-Ray Scattering - Argonne National Laboratories, Materials  

NLE Websites -- All DOE Office Websites (Extended Search)

Home Home Neutron and X-Ray Scattering Neutron and X-ray Scattering Science Recent advances in neutron and x-ray scattering instrumentation at major DOE facilities such as the Spallation Neutron Source and Advanced Photon Source provide unprecedented insights into complex phenomena in bulk and interfacial materials. The vision of our group is to harness the complementarity of neutrons and x-rays to study how materials respond on a range of length and time scales to phase competition, so that we can learn to control emergent behavior and generate functional properties in energy-related materials. We use neutrons and x-rays to investigate the structure and dynamics of bulk and interfacial materials with properties that are useful for energy applications, such as superconductivity, magnetism and thermoelectricity. Phase competition can generate or enhance such properties, but it is extremely challenging to characterize fluctuations in the competing order, whether in bulk disordered materials, or artificial heterostructures. Our goal is to utilize efficient techniques that we have been developing for measuring nanoscale phase fluctuations, both static and dynamic, to enable the rational design of new materials for energy within MSD.

317

Advanced Materials Facilities & Capabilites | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Research Highlights Research Highlights Facilities and Capabilities Science to Energy Solutions News & Awards Events and Conferences Supporting Organizations Advanced Materials Home | Science & Discovery | Advanced Materials | Facilities and Capabilities SHARE Facilities and Capabilities ORNL has resources that together provide a unique environment for Advanced Materials Researchers. ORNL hosts two of the most advanced neutron research facilities in the world, the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor (HFIR). In addition, the Center for Nanophase Materials Sciences offers world-class capabilities and expertise for nanofabrication, scanning probe microscopy, chemical and laser synthesis, spectroscopy, and computational modeling and their. The ORNL

318

Neutron Scattering  

Science Journals Connector (OSTI)

... Magnetic Neutron Diffraction By Yurii A. Izyumov and Ruslan P. Ozerov. Translated from the Russian. ... York; Heydon: London, June 1970.) 350s; $37.50; 150 DM.

G. L. SQUIRES

1970-12-05T23:59:59.000Z

319

DNA hydration studied by neutron fiber diffraction  

SciTech Connect

The development of neutron high angle fiber diffraction to investigate the location of water around the deoxyribonucleic acid (DNA) double-helix is described. The power of the technique is illustrated by its application to the D and A conformations of DNA using the single crystal diffractometer, D19, at the Institute Laue-Langevin, Grenoble and the time of flight diffractometer, SXD, at the Rutherford Appleton ISIS Spallation Neutron Source. These studies show the existence of bound water closely associated with the DNA. The patterns of hydration in these two DNA conformations are quite distinct and are compared to those observed in X-ray single crystal studies of two-stranded oligodeoxynucleotides. Information on the location of water around the DNA double-helix from the neutron fiber diffraction studies is combined with that on the location of alkali metal cations from complementary X-ray high angle fiber diffraction studies at the Daresbury Laboratory SRS using synchrotron radiation. These analyses emphasize the importance of viewing DNA, water and ions as a single system with specific interactions between the three components and provide a basis for understanding the effect of changes in the concentration of water and ions in inducing conformations] transitions in the DNA double-helix.

Fuller, W.; Forsyth, V.T.; Mahendrasingam, A.; Langan, P.; Pigram, W.J. [Keele Univ. (United Kingdom)] [and others

1994-12-31T23:59:59.000Z

320

Neutron activation analysis  

Science Journals Connector (OSTI)

Neutron activation analysis ... Describes the science and techniques of neutron activation analysis. ...

H. R. Lukens

1967-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Deuterium Depth Profile in Neutron-Irradiated Tungsten Exposed to Plasma  

SciTech Connect

The effect of radiation damage has been mainly simulated using high-energy ion bombardment. The ions, however, are limited in range to only a few microns into the surface. Hence, some uncertainty remains about the increase of trapping at radiation damage produced by 14 MeV fusion neutrons, which penetrate much farther into the bulk material. With the Japan-US joint research project: Tritium, Irradiations, and Thermofluids for America and Nippon (TITAN), the tungsten samples (99.99 % pure from A.L.M.T., 6mm in diameter, 0.2mm in thickness) were irradiated to high flux neutrons at 50 C and to 0.025 dpa in the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL). Subsequently, the neutron-irradiated tungsten samples were exposed to a high-flux deuterium plasma (ion flux: 1021-1022 m-2s-1, ion fluence: 1025-1026 m-2) in the Tritium Plasma Experiment (TPE) at the Idaho National Laboratory (INL). First results of deuterium retention in neutron-irradiated tungsten exposed in TPE have been reported previously. This paper presents the latest results in our on-going work of deuterium depth profiling in neutron-irradiated tungsten via nuclear reaction analysis. The experimental data is compared with the result from non neutron-irradiated tungsten, and is analyzed with the Tritium Migration Analysis Program (TMAP) to elucidate the hydrogen isotope behavior such as retention and depth distribution in neutron-irradiated and non neutron-irradiated tungsten.

Masashi Shimada; G. Cao; Y. Hatano; T. Oda; Y. Oya; M. Hara; P. Calderoni

2011-05-01T23:59:59.000Z

322

Neutron Microscope  

Science Journals Connector (OSTI)

We report successful operation of a neutron microscope using ultracold neutrons at the high-flux reactor at Grenoble. A sharp, achromatic image of an object slit was obtained at a magnification of 50. The measured resolution of 0.1 mm was limited mainly by the available beam intensity, not by aberrations.

P. Herrmann; K. -A. Steinhauser; R. Ghler; A. Steyerl; W. Mampe

1985-05-06T23:59:59.000Z

323

Neutron scattering  

Science Journals Connector (OSTI)

... statements that the EMBL outstation in Grenoble "[has an] uncertain future" and that "neutrons have not turned out to be particularly useful for biologists" in Peter Newmark's ... on the European Molecular Biology Laboratory (Nature 338, 724; 1989) require some comment.Neutron ...

S. CUSACK; B. JACROT; R. LEBERMAN; R. MAY; P. TlMMINS; G. ZACCAI

1989-06-01T23:59:59.000Z

324

Effects of surface deposition, hole blockage, and thermal barrier coating spallation on vane endwall film cooling  

SciTech Connect

With the increase in usage of gas turbines for power generation and given that natural gas resources continue to be depleted, it has become increasingly important to search for alternate fuels. One source of alternate fuels is coal derived synthetic fuels. Coal derived fuels, however, contain traces of ash and other contaminants that can deposit on vane and turbine surfaces affecting their heat transfer through reduced film cooling. The endwall of a first stage vane is one such region that can be susceptible to depositions from these contaminants. This study uses a large-scale turbine vane cascade in which the following effects on film cooling adiabatic effectiveness were investigated in the endwall region: the effect of near-hole deposition, the effect of partial film cooling hole blockage, and the effect of spallation of a thermal barrier coating. The results indicated that deposits near the hole exit can sometimes improve the cooling effectiveness at the leading edge, but with increased deposition heights the cooling deteriorates. Partial hole blockage studies revealed that the cooling effectiveness deteriorates with increases in the number of blocked holes. Spallation studies showed that for a spalled endwall surface downstream of the leading edge cooling row, cooling effectiveness worsened with an increase in blowing ratio.

Sundaram, N.; Thole, K.A. [Virginia Polytechnic Institute & State University, Blacksburg, VA (USA)

2007-07-15T23:59:59.000Z

325

Neutron science research project in JAERI  

Science Journals Connector (OSTI)

A conception of Neutron Science Research Project (NSRP) has been proposed in Japan Atomic Energy Research Institute (JAERI) since 1994 for its future big science project. The project aims at exploring new basic science and nuclear energy science by using a high-intensity proton accelerator. NSRP is a complex composed of a powerful superconducting proton linac the target systems which convert the proton beam to neutrons or other particles and the facilities for scientific research programs. The proton linac is required to supply a high-intensity proton beam with an energy up to 1.5 GeV and an average current around 10 mA. The scientific research programs are as follows: In the area of basic science structural biology and material science with slow neutron scattering method neutron nuclear physics and spallation radioisotope physics and in the area of nuclear energy science the experimental feasibility studies of incineration for the nuclear waste transmutation and material developments with a neutron irradiation facility. Other scientific research programs are also proposed such as meson science for meson and muon physics radioisotope production for medical use. Research and development (R&D) have been carried out for the components of the injector system of the proton linac; an ion source an RFQ linac and a part of DTL linac. The conceptual design work and R&D activities for NSRP have started in the fiscal year 1996. The first beam of 1.5 GeV and 1 mA is expected to be extracted from the proton linac by 2004 and finally a 10 mA is to be obtained in 2007 by reflecting the results of technological developments.

Y. Suzuki; Y. Oyama; T. Sasa; K. Suzuki; H. Yasuda; T. Tone; T. Takizuka; M. Mizumoto; N. Watanabe; T. Mukaiyama

1997-01-01T23:59:59.000Z

326

Water Calibration Measurements for Neutron Radiography: Application to Water Content Quantification in Porous Media  

SciTech Connect

Using neutron radiography, the measurement of water thickness was performed using aluminum (Al) water calibration cells at the High Flux Isotope Reactor (HFIR) Cold-Guide (CG) 1D neutron imaging facility at Oak Ridge National Laboratory, Oak Ridge, TN, USA. Calibration of water thickness is an important step to accurately measure water contents in samples of interest. Neutron attenuation by water does not vary linearly with thickness mainly due to beam hardening and scattering effects. Transmission measurements for known water thicknesses in water calibration cells allow proper correction of the underestimation of water content due to these effects. As anticipated, strong scattering effects were observed for water thicknesses greater than 2 mm when the water calibration cells were positioned close to the face of the detector / scintillator (0 and 2.4 cm away, respectively). The water calibration cells were also positioned 24 cm away from the detector face. These measurements resulted in less scattering and this position (designated as the sample position) was used for the subsequent experimental determination of the neutron attenuation coefficient for water. Neutron radiographic images of moist Flint sand in rectangular and cylindrical containers acquired at the sample position were used to demonstrate the applicability of the water calibration. Cumulative changes in the water volumes within the sand columns during monotonic drainage determined by neutron radiography were compared with those recorded by direct reading from a burette connected to a hanging water column. In general, the neutron radiography data showed very good agreement with those obtained volumetrically using the hanging water-column method. These results allow extension of the calibration equation to the quantification of unknown water contents within other samples of porous media.

Kang, Misun [ORNL; Bilheux, Hassina Z [ORNL; Voisin, Sophie [ORNL; Cheng, Chu-lin [University of Tennessee, Knoxville (UTK); Perfect, Edmund [University of Tennessee, Knoxville (UTK); Horita, Juske [Texas Tech University (TTU); Warren, Jeffrey [ORNL

2013-01-01T23:59:59.000Z

327

Neutron Polarization  

Science Journals Connector (OSTI)

The production of polarized neutrons in magnetized iron has been studied, using the intense neutron beams available at the Argonne heavy water pile. The theoretical work of Halpern et al., used as a guide in the experiments, has been checked in many respects, with the exception that the polarization cross section p has a measured value of 3.15 barns compared to the theoretical 1 barn. The application of neutron polarization to the measurement of the approach to saturation in ferromagnets is described and preliminary results are reported.

D. J. Hughes; J. R. Wallace; R. H. Holtzman

1948-06-01T23:59:59.000Z

328

Thermal neutron detection system  

DOE Patents (OSTI)

According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

Peurrung, Anthony J. (Richland, WA); Stromswold, David C. (West Richland, WA)

2000-01-01T23:59:59.000Z

329

Educational Programs  

NLE Websites -- All DOE Office Websites (Extended Search)

Program Program The program of the school focuses on the following areas: The fundamentals of the interaction of X-rays and neutrons with matter X-ray and neutron production and experimental instrumentation Theory and practical application of various X-ray and neutron experimental techniques Hands on experience gained through experiments at the Advanced Photon Source (APS), Spallation Neutron Source (SNS), and High Flux Isotope Reactor (HFIR). Lectures are given by prominent scientists drawn from universities, several national laboratories, and industry. Subjects for lectures include: Interactions of X-rays and Neutrons with Matter Neutron Generation and Detection Neutron Instrumentation X-ray Generation and Detection X-ray Instrumentation Single-Crystal and Surface Diffraction

330

Neutron Checkup  

Science Journals Connector (OSTI)

Neutron activation analysis is yet another technique in the arsenal of diagnostic methods that physicians can draw on to examine the health of their patients. The University of Washington's school of medicine in Seattle is the first facility in the ...

1969-11-10T23:59:59.000Z

331

Neutron Reflectometry  

Science Journals Connector (OSTI)

Neutron reflectometry is a relatively new technique [1,2]. In the last years, it has been extensively used for solving soft matter problems like polymer mixing [3,4] or the structure of liquids at the surface [5,

Claude Fermon; Frdric Ott; Alain Menelle

1999-01-01T23:59:59.000Z

332

Neutron Tomography and Space  

E-Print Network (OSTI)

Kevin Shields, Optimization of neutron tomography for rapidNEUTRON TOMOGRAPHY AND SPACE Hal Egbert, Ronald Walker, R.industrial applications[1]. Neutron Computed Tomography was

Egbert, Hal; Walker, Ronald; Flocchini, R.

2007-01-01T23:59:59.000Z

333

Neutron range spectrometer  

DOE Patents (OSTI)

A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are colliminated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. 1 fig.

Manglos, S.H.

1988-03-10T23:59:59.000Z

334

OPERATIONAL RESULTS OF THE SPALLATION NEUTRON SOURCE (SNS) POLYPHASE CONVERTER-MODULATOR FOR THE 140 KV KLYSTRON RF SYSTEMS  

SciTech Connect

This paper describes the first operational results of the 140 kV, 1 MW average, 11 MW peak, zero-voltage-switching, 20 kHz polyphase bridge, boost converter-modulator for klystron pulse application. The DC-DC converter derives the buss voltages from a standard 13.8 kV to 2100 Y substation cast-core transformer. Energy storage and filtering is provided by self-clearing metallized hazy polypropylene traction capacitors. Three ''H-Bridge'' Insulated Gate Bipolar Transistor (IGBT) switching networks are used to generate the polyphase 20 kHz transformer primary drive waveforms. The 20 kHz drive waveforms are chirped the appropriate duration to generate the desired klystron pulse width. Pulse-Width Modulation (PWM) of the individual 20 kHz pulses is utilized to provide regulated output waveforms with adaptive feedforward and feedback techniques. The boost transformer design utilizes amorphous nanocrystalline material that provides the required low core loss at design flux levels and switching frequencies. Resonant shunt peaking is used on the transformer secondary to boost output voltage and resonate transformer leakage inductance. With the appropriate transformer leakage inductance and peaking capacitance, zero-voltage-switching of the IGBT's is attained, minimizing switching losses. Reviews of these design parameters and an examination of the first operational results will be performed.

W.A. REASS; J.D. DOSS; ET AL

2001-06-01T23:59:59.000Z

335

Overview of the US-Japan collaborative investigation on hydrogen isotope retention in neutron-irradiated and ion-damaged tungsten  

SciTech Connect

Plasma-facing components (PFCs) will be exposed to 14 MeV neutrons from deuterium-tritium (D-T) fusion reactions, and tungsten, a candidate PFC for the divertor in ITER, is expected to receive a neutron dose of 0.7 displacement per atom (dpa) by the end of operation in ITER. The effect of neutron-irradiation damage has been mainly simulated using high-energy ion bombardment. While this prior database of results is quite valuable for understanding the behavior of hydrogen isotopes in PFCs, it does not encompass the full range of effects that must be considered in a practical fusion environment due to short penetration depth, damage gradient, high damage rate, and high PKA energy spectrum of the ion bombardment. In addition, neutrons change the elemental composition via transmutations, and create a high radiation environment inside PFCs, which influence the behavior of hydrogen isotope in PFCs, suggesting the utilization of fission reactors is necessary for neutron irradiation. Therefore, the effort to correlate among high-energy ions, fission neutrons, and fusion neutrons is crucial for accurately estimating tritium retention under a neutron-irradiation environment. Under the framework of the US-Japan TITAN program, tungsten samples (99.99 at. % purity from A.L.M.T. Co.) were irradiated by neutron in the High Flux Isotope Reactor (HFIR), ORNL, at 50 and 300C to 0.025, 0.3, and 1.2 dpa, and the investigation of deuterium retention in neutron-irradiation was performed in the INL Tritium Plasma Experiment (TPE), the unique high-flux linear plasma facility that can handle tritium, beryllium and activated materials. This paper reports the recent results from the comparison of ion-damaged tungsten via various ion species (2.8 MeV Fe2+, 20 MeV W2+, and 700 keV H-) with that from neutron-irradiated tungsten to identify the similarities and differences among them.

Masashi Shimada; Y. Hatano; Y. Oya; T. Oda; M. Hara; G. Cao; M. Kobayashi; M. Sokolov; H. Watanabe; B. Tyburska; Y. Ueda; P. Calderoni

2011-09-01T23:59:59.000Z

336

Spallation process with simultaneous multi-particle emission in nuclear evaporation  

SciTech Connect

High energy probes have been used currently to explore nuclear reaction mechanism and nuclear structure. The spallation process governs the reaction process around 1 GeV energy regime. A new aspect introduced here to describe the nuclear reaction is the in-medium nucleonnucleon collision framework. The nucleon-nucleon scattering is kinematically treated by using an effective mass to represent the nuclear binding. In respect to the evaporation phase of the reaction, we introduce the simultaneous particles emission decay. This process becomes important due to the rise of new channels at high excitation energy regime of the compound nucleus. As results, the particles yields in the rapid and evaporation phases are obtained and compared to experimental data. The effect and relevance of these simultaneous emission processes in the evaporation chain is also discussed.

Santos, B. M. [Instituto de Fisica/UFF - Av. Gal. Milton Tavares de Souza, Praia Vermelha, Niteroi - RJ (Brazil); Goncalves, M. [Comissao Nacional de Energia Nuclear/CNEN - Rua Gal Severiano, nr. 90, Botafogo - RJ (Brazil); Assis, L. P. G. de; Duarte, S. B. [Centro Brasileiro de Pesquisas Fisicas/CBPF - Rua Dr. Xavier Sigaud, nr.150, Urca - RJ (Brazil)

2013-05-06T23:59:59.000Z

337

Neutron Halo Isomers in Stable Nuclei and their Possible Application for the Production of Low Energy, Pulsed, Polarized Neutron Beams of High Intensity and High Brilliance  

E-Print Network (OSTI)

We propose to search for neutron halo isomers populated via $\\gamma$-capture in stable nuclei with mass numbers of about A=140-180 or A=40-60, where the $4s_{1/2}$ or $3s_{1/2}$ neutron shell model state reaches zero binding energy. These halo nuclei can be produced for the first time with new $\\gamma$-beams of high intensity and small band width ($\\le$ 0.1%) achievable via Compton back-scattering off brilliant electron beams thus offering a promising perspective to selectively populate these isomers with small separation energies of 1 eV to a few keV. Similar to single-neutron halo states for very light, extremely neutron-rich, radioactive nuclei \\cite{hansen95,tanihata96,aumann00}, the low neutron separation energy and short-range nuclear force allows the neutron to tunnel far out into free space much beyond the nuclear core radius. This results in prolonged half lives of the isomers for the $\\gamma$-decay back to the ground state in the 100 ps-$\\mu$s range. Similar to the treatment of photodisintegration of the deuteron, the neutron release from the neutron halo isomer via a second, low-energy, intense photon beam has a known much larger cross section with a typical energy threshold behavior. In the second step, the neutrons can be released as a low-energy, pulsed, polarized neutron beam of high intensity and high brilliance, possibly being much superior to presently existing beams from reactors or spallation neutron sources.

D. Habs; M. Gross; P. G. Thirolf; P. Bni

2010-09-30T23:59:59.000Z

338

Neutron Repulsion  

E-Print Network (OSTI)

Earth is connected gravitationally, magnetically and electrically to its heat source - a neutron star that is obscured from view by waste products in the photosphere. Neutron repulsion is like the hot filament in an incandescent light bulb. Excited neutrons are emitted from the solar core and decay into hydrogen that glows in the photosphere like a frosted light bulb. Neutron repulsion was recognized in nuclear rest mass data in 2000 as the overlooked source of energy, the keystone of an arch that locked together these puzzling space-age observations: 1.) Excess 136Xe accompanied primordial helium in the stellar debris that formed the solar system (Fig. 1); 2.) The Sun formed on the supernova core (Fig. 2); 3.) Waste products from the core pass through an iron-rich mantle, selectively carrying lighter elements and lighter isotopes of each element into the photosphere (Figs. 3-4); and 4.) Neutron repulsion powers the Sun and sustains life (Figs. 5-7). Together these findings offer a framework for understanding how: a.) The Sun generates and releases neutrinos, energy and solar-wind hydrogen and helium; b.) An inhabitable planet formed and life evolved around an ordinary-looking star; c.) Continuous climate change - induced by cyclic changes in gravitational interactions of the Sun's energetic core with planets - has favored survival by adaptation.

Oliver K. Manuel

2011-02-08T23:59:59.000Z

339

Fast-Neutron Handbook  

Science Journals Connector (OSTI)

... FAST neutron physics, in the present context, concerns the study of interactions of atomic nuclei with neutrons ...

J. H. MONTAGUE

1961-06-10T23:59:59.000Z

340

Advanced neutron source reactor probabilistic flow blockage assessment  

SciTech Connect

The Phase I Level I Probabilistic Risk Assessment (PRA) of the conceptual design of the Advanced Neutron Source (ANS) Reactor identified core flow blockage as the most likely internal event leading to fuel damage. The flow blockage event frequency used in the original ANS PRA was based primarily on the flow blockage work done for the High Flux Isotope Reactor (HFIR) PRA. This report examines potential flow blockage scenarios and calculates an estimate of the likelihood of debris-induced fuel damage. The bulk of the report is based specifically on the conceptual design of ANS with a 93%-enriched, two-element core; insights to the impact of the proposed three-element core are examined in Sect. 5. In addition to providing a probability (uncertainty) distribution for the likelihood of core flow blockage, this ongoing effort will serve to indicate potential areas of concern to be focused on in the preliminary design for elimination or mitigation. It will also serve as a loose-parts management tool.

Ramsey, C.T.

1995-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Ultracold Neutrons Jeff Martin  

E-Print Network (OSTI)

in beam power. Cyclotron operates ~ 8 months/yr. CANADA'S NATIONAL LABORATORY FOR PARTICLE AND NUCLEAR Manitoba Research & Innovation Fund Japan Society for the Promotion of Science #12;International Spallation funded in Canada and Japan. #12;Outline UCN production and source ­ Technical progress at TRIUMF

Martin, Jeff

342

Ultracold Neutrons Jeff Martin  

E-Print Network (OSTI)

power. Cyclotron operates ~ 8 months/yr. CANADA'S NATIONAL LABORATORY FOR PARTICLE AND NUCLEAR PHYSICS Manitoba Research & Innovation Fund Japan Society for the Promotion of Science #12;International Spallation funded in Canada and Japan. #12;Outline UCN production and source ­ Technical progress at TRIUMF

Martin, Jeff

343

Neutron Scattering User Program | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

User Program SHARE Neutron Scattering Can Benefit Your Research Neutron scattering has applications in almost every technical and scientific field, from biology and chemistry to...

344

Neutron Polarization  

Science Journals Connector (OSTI)

Experiments for the determination of the polarization cross section p of iron with monochromatic and non-monochromatic neutrons are described. The absolute value of p as well as its dependence on the neutron velocity is found to be in good agreement with the recent calculations of Steinberger and Wick and also with other experiments. For a complex neutron spectrum originating from a paraffin moderator p is found to be (2.350.1)10-24 cm2 in agreement with previous investigations. It is shown that the larger value of 3.1510-24 cm2 found by Hughes, Wallace, and Holtzman must be due to spectral differences. The approach of the magnetization of iron towards saturation is also investigated.

J. Fleeman; D. B. Nicodemus; H. H. Staub

1949-12-15T23:59:59.000Z

345

Novel Boron-10-based detectors for Neutron Scattering Science  

E-Print Network (OSTI)

Nowadays neutron scattering science is increasing its instrumental power. Most of the neutron sources in the world are pushing the development of their technologies to be more performing. The neutron scattering development is also pushed by the European Spallation Source (ESS) in Sweden, a neutron facility which has just started construction. Concerning small area detectors (1m^2), the 3He technology, which is today cutting edge, is reaching fundamental limits in its development. Counting rate capability, spatial resolution and cost-e?ectiveness, are only a few examples of the features that must be improved to ful?fill the new requirements. On the other hand, 3He technology could still satisfy the detector requirements for large area applications (50m^2), however, because of the present 3He shortage that the world is experiencing, this is not practical anymore. The recent detector advances (the Multi-Grid and the Multi-Blade prototypes) developed in the framework of the collaboration between the Institut Laue...

Piscitelli, Francesco

2015-01-01T23:59:59.000Z

346

Additive Manufacturing: Technology and Applications  

Energy Savers (EERE)

name Neutron scattering: SNS and HFIR * World's most intense pulsed neutron beams * World's highest flux reactor-based neutron source Leadership-class computing: Titan...

347

Microsoft Word - Project Mgt Working Group Report  

Energy Savers (EERE)

APM. 5.1.3 CASE STUDY: SCIENCE SPALLATION NEUTRON SOURCE The Spallation Neutron Source, a neutron scattering research facility at Oak Ridge National Laboratory, exemplifies a large...

348

The Neutron  

Science Journals Connector (OSTI)

The writers point out that the postulation of the existence of the "neutron," a combination of an electron and a proton, of small size and low energy would be very useful in explaining a number of atomic and cosmic phenomena. They find that a mathematical treatment based on existing theory leads to indications of such a state but no definite proof.

R. M. Langer and N. Rosen

1931-06-15T23:59:59.000Z

349

NEUTRON ELECTRIC-DIPOLE MOMENT, ULTRACOLD NEUTRONS  

E-Print Network (OSTI)

NEUTRON ELECTRIC-DIPOLE MOMENT, ULTRACOLD NEUTRONS AND POLARIZED 3He R. GOLUB~and Steve K REPORTS (Review Section of Physics Letters) 237, No. 1(1994)1--62. PHYSICS REPORTS North-Holland Neutron electric-dipole moment, ultracold neutrons and polarized 3He R. Goluba and Steve K. Lamoreauxb a

350

Neutron reflecting supermirror structure  

DOE Patents (OSTI)

An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. 2 figs.

Wood, J.L.

1992-12-01T23:59:59.000Z

351

Neutron reflecting supermirror structure  

DOE Patents (OSTI)

An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources.

Wood, James L. (Drayton Plains, MI)

1992-01-01T23:59:59.000Z

352

IConUSAS 2003 - Past Events - Calendar - Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Past Events Saturday, January 11, 2014 Past Events Saturday, January 11, 2014 Go Click on image for larger PDF version, which contains links to additional information. Program with Presentations Abstracts Registration Information Registration Form Speaker Information Hotel Reservations Airline Transportation Airline Ground Transportation Weather in Oak Ridge Workshop Venue What to Do in Oak Ridge Organization Chart Local Contacts Workshop Photos Registration Information The registration fee for the workshop is $150.00 paid on or before June 1; the fee is $200.00 if paid between June 2 and June 26. Registration closes on June 26, 2003. The registration form may be submitted electronically, faxed, or mailed to Al Ekkebus Spallation Neutron Source 701 Scarboro Road Oak Ridge, TN 37830 Fax No.: 865-241-5177

353

Neutron Sciences - Electrode Material for Solid-oxide Fuel Cells  

NLE Websites -- All DOE Office Websites (Extended Search)

Theory meets experiment: structure-property relationships in an electrode Theory meets experiment: structure-property relationships in an electrode material for solid-oxide fuel cells Research Contact: Ana B. Munoz-Garcia December 2012, Written by Agatha Bardoel Fuel cell technology is one potentially very efficient and environmentally friendly way to convert the chemical energy of fuels into electricity. Solid-oxide fuel cells (SOFCs) can convert a wide variety of fuels with simpler, cheaper designs than those used in liquid electrolyte cells. Using the Powder Diffractometer at the Spallation Neutron Source, researchers experimentally characterized the promising new SOFC electrode material strontium iron molybdenum oxide─Sr2Fe1.5Mo0.5O6-δ (SFMO). Combining the experimental results with insights from theory showed that the crystal structure is distorted from the ideal cubic simple perovskite

354

The effects of shockwave profile shape and shock obliquity on spallation in Cu and Ta: kinetic and stress-state effects on damage evolution(u)  

SciTech Connect

Widespread research over the past five decades has provided a wealth of experimental data and insight concerning shock hardening and the spallation response of materials subjected to square-topped shock-wave loading profiles. Less quantitative data have been gathered on the effect of direct, in-contact, high explosive (HE)-driven Taylor wave (or triangular-wave) loading profile shock loading on the shock hardening, damage evolution, or spallation response of materials. Explosive loading induces an impulse dubbed a 'Taylor Wave'. This is a significantly different loading history than that achieved by a square-topped impulse in terms of both the pulse duration at a fixed peak pressure, and a different unloading strain rate from the peak Hugoniot state achieved. The goal of this research is to quantify the influence of shockwave obliquity on the spallation response of copper and tantalum by subjecting plates of each material to HE-driven sweeping detonation-wave loading and quantify both the wave propagation and the post-mortem damage evolution. This talk will summarize our current understanding of damage evolution during sweeping detonation-wave spallation loading in Cu and Ta and show comparisons to modeling simulations. The spallation responses of Cu and Ta are both shown to be critically dependent on the shockwave profile and the stress-state of the shock. Based on variations in the specifics of the shock drive (pulse shape, peak stress, shock obliquity) and sample geometry in Cu and Ta, 'spall strength' varies by over a factor of two and the details of the mechanisms of the damage evolution is seen to vary. Simplistic models of spallation, such as P{sub min} based on 1-D square-top shock data lack the physics to capture the influence of kinetics on damage evolution such as that operative during sweeping detonation loading. Such considerations are important for the development of predictive models of damage evolution and spallation in metals and alloys.

Gray, George T [Los Alamos National Laboratory

2010-12-14T23:59:59.000Z

355

Fermilab Project X nuclear energy application: Accelerator, spallation target and transmutation technology demonstration  

SciTech Connect

The recent paper 'Accelerator and Target Technology for Accelerator Driven Transmutation and Energy Production' and report 'Accelerators for America's Future' have endorsed the idea that the next generation particle accelerators would enable technological breakthrough needed for nuclear energy applications, including transmutation of waste. In the Fall of 2009 Fermilab sponsored a workshop on Application of High Intensity Proton Accelerators to explore in detail the use of the Superconducting Radio Frequency (SRF) accelerator technology for Nuclear Energy Applications. High intensity Continuous Wave (CW) beam from the Superconducting Radio Frequency (SRF) Linac (Project-X) at beam energy between 1-2 GeV will provide an unprecedented experimental and demonstration facility in the United States for much needed nuclear energy Research and Development. We propose to carry out an experimental program to demonstrate the reliability of the accelerator technology, Lead-Bismuth spallation target technology and a transmutation experiment of spent nuclear fuel. We also suggest that this facility could be used for other Nuclear Energy applications.

Gohar, Yousry; /Argonne; Johnson, David; Johnson, Todd; Mishra, Shekhar; /Fermilab

2011-04-01T23:59:59.000Z

356

Improved design of proton source and low energy beam transport line for European Spallation Source  

SciTech Connect

The design update of the European Spallation Source (ESS) accelerator is almost complete and the construction of the prototype of the microwave discharge ion source able to provide a proton beam current larger than 70 mA to the 3.6 MeV Radio Frequency Quadrupole (RFQ) started. The source named PS-ESS (Proton Source for ESS) was designed with a flexible magnetic system and an extraction system able to merge conservative solutions with significant advances. The ESS injector has taken advantage of recent theoretical updates and new plasma diagnostics tools developed at INFN-LNS (Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare). The design strategy considers the PS-ESS and the low energy beam transport line as a whole, where the proton beam behaves like an almost neutralized non-thermalized plasma. Innovative solutions have been used as hereinafter described. Thermo-mechanical optimization has been performed to withstand the chopped beam and the misaligned focused beam over the RFQ input collimator; the results are reported here.

Neri, L., E-mail: neri@lns.infn.it; Celona, L.; Gammino, S.; Mascali, D.; Castro, G.; Ciavola, G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy)] [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy); Torrisi, G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy) [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Ingegneria dellInformazione, delle Infrastrutture e dellEnergia Sostenibile, Universit Mediterranea di Reggio Calabria, Via Graziella, 89122 Reggio Calabria (Italy); Cheymol, B.; Ponton, A. [European Spallation Source ESS AB, Lund (Sweden)] [European Spallation Source ESS AB, Lund (Sweden); Galat, A. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Viale dell'universit 2, 35020 Legnaro (Italy)] [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Viale dell'universit 2, 35020 Legnaro (Italy); Patti, G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy) [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy); Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Viale dell'universit 2, 35020 Legnaro (Italy); Gozzo, A.; Lega, L. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy) [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Ingegneria Informatica e delle Telecomunicazioni, Universit degli Studi di Catania, Viale Andrea Doria 6, 95123 Catania (Italy)

2014-02-15T23:59:59.000Z

357

Neutron Scattering Facilities 1982  

NLE Websites -- All DOE Office Websites (Extended Search)

NEUTRON SOURCES NEUTRON SOURCES Types of Sources U.S. Sources Available for Users Plans for the Future The Neutron Scattering Society of America (NSSA) SNS/ANL School on Neutron and x-Ray Scattering, June 2011 Jim Rhyne Lujan Neutron Scattering Center Los Alamos National Lab. What do we need to do neutron scattering? * Neutron Source - produces neutrons * Diffractometer or Spectrometer - Allows neutrons to interact with sample - Sorts out discrete wavelengths by monochromator (reactor) or by time of flight (pulse source) - Detectors pick up neutrons scattered from sample * Analysis methods to determine material properties * Brain power to interpret results Sources of neutrons for scattering * Nuclear Reactor - Neutrons produced from fission of 235 U - Fission spectrum neutrons

358

Neutron Polarization  

Science Journals Connector (OSTI)

The neutron polarization cross section of iron has been measured as a function of energy from 0.7 to 3.3A by two methods: using the single transmission effect in a block of polycrystalline iron at energies selected by a quartz crystal monochromator; and using a single crystal of magnetized magnetite to analyze the beam emerging from the iron polarizer, the magnetite crystal itself serving as monochromator. The measured values are compared with those of other observers and the theoretically expected values. These are found to agree fairly well within the limits of accuracy of the measurements and existing knowledge of the wave function of the iron 3d shell. The two techniques were used also to determine the average polarization (32 percent) as seen by a 1v detector in a beam of reactor neutrons emerging from a 4-cm thick polarizing block of iron. Problems and techniques associated with the measurement of the average polarization of a continuous spectrum are discussed. A simplified experimental treatment of the problem of beam "hardening" is described. A description is given of the use of the magnetic resonance method in conjunction with a single-crystal magnetite analyzer for the measurement of neutron polarization.

C. P. Stanford; T. E. Stephenson; L. W. Cochran; S. Bernstein

1954-04-15T23:59:59.000Z

359

Neutron Gas  

Science Journals Connector (OSTI)

We assume that the neutron-neutron potential is well-behaved and velocity-dependent. We can then apply perturbation theory to find the energy per particle of a neutron gas, in the range of Fermi wave numbers 0.5

J. S. Levinger and L. M. Simmons

1961-11-01T23:59:59.000Z

360

IBIS: An inverse geometry Brillouin inelastic neutron spectrometer for the SNS  

SciTech Connect

The high power target station at the Spallation Neutron Source (SNS) currently has about 20 completed neutron scattering instruments. With a broad coverage of the momentum transfer (Q)-energy (E) space, these instruments serve an extensive user community. In an effort to further expand the scientific capabilities of the SNS instrument suites, we propose a low background, inverse geometry Brillouin inelastic spectrometer for the SNS which will expand the Q-E coverage of the current instrument suite and facilitate the study of inelastic and quasi-elastic scatterings at low Q values. The possible location for the proposed instrument is either beamline 8 which views the decoupled water moderator, or beamline 14A, which views a cold, coupled super critical hydrogen moderator. The instrument parameters, optimizations, and performances at these two beamline locations are discussed.

Zhao, J. K.; Robertson, Lee; Herwig, Kenneth W. [Instrument and Source Development Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Wildgruber, Christoph U. [Chemical and Engineering Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2013-02-15T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Publications | Neutron Science | ORNL  

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Publications SHARE Publications The Neutron Science publications system contains peer-reviewed publications based on research conducted at ORNL's Neutron Science facilities or...

362

Neutron Scattering Facilities  

Science Journals Connector (OSTI)

The past history, present performance and future prospects for neutron scattering facilities will be discussed. Special features of neutron scattering techniques applicable to biological problems will be ... . Th...

D. L. Price

1996-01-01T23:59:59.000Z

363

Calculations of neutron spectra after neutronneutron scattering  

Science Journals Connector (OSTI)

A direct neutronneutron scattering length, ann, measurement with the goal of 3% accuracy (0.5 fm) is under preparation at the aperiodic pulsed reactor YAGUAR. A direct measurement of ann will not only help resolve conflicting results of ann by indirect means, but also in comparison to the protonproton scattering length, app, shed light on the charge-symmetry of the nuclear force. We discuss in detail the analysis of the nn-scattering data in terms of a simple analytical expression. We also discuss calibration measurements using the time-of-flight spectra of neutrons scattered on He and Ar gases and the neutron activation technique. In particular, we calculate the neutron velocity and time-of-flight spectra after scattering neutrons on neutrons and after scattering neutrons on He and Ar atoms for the proposed experimental geometry, using a realistic neutron flux spectrumMaxwellian plus epithermal tail. The shape of the neutron spectrum after scattering is appreciably different from the initial spectrum, due to collisions between thermalthermal and thermalepithermal neutrons. At the same time, the integral over the Maxwellian part of the realistic scattering spectrum differs by only about 6 per cent from that of a pure Maxwellian nn-scattering spectrum.

B E Crawford; S L Stephenson; C R Howell; G E Mitchell; W Tornow; W I Furman; E V Lychagin; A Yu Muzichka; G V Nekhaev; A V Strelkov; E I Sharapov; V N Shvetsov

2004-01-01T23:59:59.000Z

364

Science | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Science Neutron Science Neutron Scattering Science Neutrons are one of the fundamental particles that make up matter and have properties that make them ideal for certain types of research. In the universe, neutrons are abundant, making up more than half of all visible matter. Neutron scattering provides information about the positions, motions, and magnetic properties of solids. When a beam of neutrons is aimed at a sample, many neutrons will pass through the material. But some will interact directly with atomic nuclei and "bounce" away at an angle, like colliding balls in a game of pool. This behavior is called neutron diffraction, or neutron scattering. Using detectors, scientists can count scattered neutrons, measure their energies and the angles at which they scatter, and map their final position

365

Neutron lifetime measured with stored ultracold neutrons  

Science Journals Connector (OSTI)

The neutron lifetime has been measured by counting the neutrons remaining in a fluid-walled bottle as a function of the duration of storage. Losses of neutrons caused by the wall reflections are eliminated by varying the bottle volume-to-surface ratio. The result obtained is ??=887.63 s.

W. Mampe; P. Ageron; C. Bates; J. M. Pendlebury; A. Steyerl

1989-08-07T23:59:59.000Z

366

Neutron-Neutron Quasifree Scattering  

Science Journals Connector (OSTI)

The reaction D(n ,2n)p has been measured at Einc=14.1 MeV, ?n (3)=?n(4)=30?, ?=180?, and the results are compared with the predictions of two separable-potential models. Neutron-proton and proton-proton quasifree scattering from nucleon + deuteron reactions at 14 MeV are also compared with the predictions of the same models. The upper limit of 2 mb/sr2 is determined for the reaction D(n,n?)d.

Ivo Slaus; J. W. Sunier; G. Thompson; J. C. Young; J. W. Verba; D. J. Margaziotis; P. Doherty; R. T. Cahill

1971-03-29T23:59:59.000Z

367

Neutron reflecting supermirror structure  

DOE Patents (OSTI)

An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. One layer of each set of bilayers consist of titanium, and the second layer of each set of bilayers consist of an alloy of nickel with carbon interstitially present in the nickel alloy.

Wood, James L. (Drayton Plains, MI)

1992-01-01T23:59:59.000Z

368

Direct Measurement of Neutron?Neutron Scattering  

Science Journals Connector (OSTI)

In order to resolve long?standing discrepancies in indirect measurements of the neutron?neutron scattering length ann and contribute to solving the problem of the charge symmetry of the nuclear force the collaboration DIANNA (Direct Investigation of ann Association) plans to measure the neutron?neutron scattering cross section ? nn . The key issue of our approach is the use of the through?channel in the Russia reactor YAGUAR with a peak neutron flux of 1018 /cm2/s. The proposed experimental setup is described. Results of calculations are presented to connect ? nn with the nn?collision detector count rate and the neutron flux density in the reactor channel. Measurements of the thermal neutron fields inside polyethylene converters show excellent prospects for the realization of the direct nn?experiment.

E. I. Sharapov; C. D. Bowman; B. E. Crawford; W. I. Furman; C. R. Howell; B. G. Levakov; V. I. Litvin; W. I. Lychagin; A. E. Lyzhin; E. P. Magda; G. E. Mitchell; G. V. Muzichka; G. V. Nekhaev; Yu. V. Safronov; V. N. Shvetsov; S. L. Stephenson; A. V. Strelkov; W. Tornow

2003-01-01T23:59:59.000Z

369

Neutron-Mirror-Neutron Oscillations in a Trap  

E-Print Network (OSTI)

We calculate the rate of neutron-mirror-neutron oscillations for ultracold neutrons trapped in a storage vessel. Recent experimental bounds on the oscillation time are discussed.

B. Kerbikov; O. Lychkovskiy

2008-04-03T23:59:59.000Z

370

Neutronmirror-neutron oscillations in a trap  

Science Journals Connector (OSTI)

We calculate the rate of neutronmirror-neutron oscillations for ultracold neutrons trapped in a storage vessel. Recent experimental bounds on the oscillation time are discussed.

B. Kerbikov and O. Lychkovskiy

2008-06-27T23:59:59.000Z

371

Manuel Lujan Jr. Neutron Scattering Center Los Alamos Neutron...  

NLE Websites -- All DOE Office Websites (Extended Search)

2013 LANSCE School on Neutron Scattering Geosciences & Materials in Extreme Environments Manuel Lujan Jr. Neutron Scattering Center Los Alamos Neutron Science Center Los Alamos...

372

ORNL Guest House  

NLE Websites -- All DOE Office Websites (Extended Search)

The ORNL Guest House is located in the Oak Ridge National Laboratory campus, within 5 minutes by car to any part of the campus, High Flux Isotope Reactor (HFIR), Conference Center and short walk to the Spallation Neutron Source (SNS). The Guest House is a three story, 47 room, 71 bed facility (23 rooms with king beds and 24 rooms with 2 ex-long double beds). All rooms have a flat screen satellite TV, mini fridge, microwave, coffeemaker, iron & ironing board, and hair dryer. The entire Guest House has high speed wireless internet access with printing capabilities. The ORNL Guest House is located in the Oak Ridge National Laboratory campus, within 5 minutes by car to any part of the campus, High Flux Isotope Reactor (HFIR), Conference Center and short walk to the Spallation Neutron Source (SNS). The Guest House is a three story, 47 room, 71 bed facility (23 rooms with king beds and 24 rooms with 2 ex-long double beds). All rooms have a flat screen satellite TV, mini fridge, microwave, coffeemaker, iron & ironing board, and hair dryer. The entire Guest House has high speed wireless internet access with printing capabilities. ORNL Guest House Oak Ridge National Laboratory Address - 8640 Nano Center Drive Oak Ridge, Tn 37830 Phone: 865-576-8101 Fax: 865-576-8102 Operated by Paragon Hotel Company This Convenient and Modern Facility Offers:

373

Neutron crystallography aids drug design  

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Neutron crystallography aids drug design Neutron crystallography aids drug design Researchers have used neutron crystallography for the first time to determine the structure of a...

374

Los Alamos Neutron Science Center  

NLE Websites -- All DOE Office Websites (Extended Search)

LINAC Outreach Affiliations Visiting LANSCE Facilities Isotope Production Facility Lujan Neutron Scattering Center MaRIE Proton Radiography Ultracold Neutrons Weapons Neutron...

375

Cold moderators at ORNL  

SciTech Connect

The Advanced Neutron Source (ANS) cold moderators were not an 'Oak Ridge first', but would have been the largest both physically and in terms of cold neutron flux. Two cold moderators were planned each 410 mm in diameter and containing about 30L of liquid deuterium. They were to be completely independent of each other. A modular system design was used to provide greater reliability and serviceability. When the ANS was terminated, upgrading of the resident High Flux Isotope Reactor (HFIR) was examined and an initial study was made into the feasibility of adding a cold source. Because the ANS design was modular, it was possible to use many identical design features. Sub-cooled liquid at 4 bar abs was initially chosen for the HFIR design concept, but this was subsequently changed to 15 bar abs to operate above the critical pressure. As in the ANS, the hydrogen will operate at a constant pressure throughout the temperature range and a completely closed loop with secondary containment was adopted. The heat load of 2 kW made the heat flux comparable with that of the ANS. Subsequent studies into the construction of cryogenic moderators for the proposed new Synchrotron Neutron source indicated that again many of the same design concepts could be used. By connecting the two cold sources together in series, the total heat load of 2 kW is very close to that of the HFIR allowing a very similar supercritical hydrogen system to be configured. The two hydrogen moderators of the SNS provide a comparable heat load to the HFIR moderator. It is subsequently planned to connect the two in series and operate from a single cold loop system, once again using supercritical hydrogen. The spallation source also provided an opportunity to re-examine a cold pellet solid methane moderator operating at 20K.

Lucas, A. T.

1997-09-01T23:59:59.000Z

376

Neutron Assay System for Con?nement Vessel Disposition  

SciTech Connect

Waste will be removed from confinement vessels remaining from 1970s-era experiments. Los Alamos has 9+ spherical confinement vessels remaining from experiments. Each vessel contains {approx} 500 lbs of radioactive debris such as actinide metals and oxides, metals, powdered silica, graphite, and wires and hardware. In order to dispose of the vessels, debris and contamination must be removed. Neutron assay system was designed to assay vessels before and after cleanout. System requirements are: (1) Modular and moveable; (2) Capable of detecting {approx}100g {sup 239}Pu equivalent in a 2-inch thick steel sphere with 6 foot diameter; and (3) Capable of safeguards-quality assays. Initial design parameters arethe use of 4-atm {sup 3}He tubes with length of 6 feet, and {sup 3}He tubes embedded in polyethelene for moderation. This paper describes the calibration of the Confinement Vessel Assay System (CVAS) and quantification of its uncertainties. Assay uncertainty depends on five factors: (1) Statistical uncertainty in the assay measurement; (2) Statistical uncertainty in the background measurement; (3) Statistical uncertainty in the isotopics determination - This should be much smaller than the other uncertainties; (4) Systematic uncertainty due to position bias; and (5) Systematic uncertainty due to fluctuations in cosmic ray spallation. This one can be virtually eliminated by performing the background measurement with an empty vessel - but that may not be possible. We used modeling and experiments to quantify the systematic uncertainties. The calibration assumes a uniform distribution of material, but reality will be different. MCNPX modeling was used to quantify the positional bias. The model was benchmarked to build confidence in its results. Material at top of vessel is 44% greater than amount assayed, according to singles. Material near 19-tube detector is 38% less than amount assayed, according to singles. Cosmic ray spallation contributes significantly to the background. Comparing rates with and without a vessel showed that spallation adds an average of 27.27 singles/s and 5.45 doubles/s to background. Errors in the background rates were estimated at 20%.

Frame, Katherine C. [Los Alamos National Laboratory; Bourne, Mark M. [Los Alamos National Laboratory; Crooks, William J. [Los Alamos National Laboratory; Evans, Louise [Los Alamos National Laboratory; Mayo, Douglas R. [Los Alamos National Laboratory; Miko, David K. [Los Alamos National Laboratory; Salazar, William R. [Los Alamos National Laboratory; Stange, Sy [Los Alamos National Laboratory; Valdez, Jose I. [Los Alamos National Laboratory; Vigil, Georgiana M. [Los Alamos National Laboratory

2012-07-13T23:59:59.000Z

377

SCIENCE HIGHLIGHTS 2008 ANNUAL REPORT ORNL NEUTRON SCIENCES neutrons.ornl.gov  

E-Print Network (OSTI)

studies with brucite will lead to advances in areas such as medicine, geoscience, and industrial technology. Extreme-Pressure Brucite Studies A collaboration using instruments at both SNS and HFIR has of pressure on the compression properties of hydrogenated and deuterated brucite. Brucite, or magnesium

378

Neutron range spectrometer  

DOE Patents (OSTI)

A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are collimnated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. The computer solves the following equation in the analysis: ##EQU1## where: N(x).DELTA.x=the number of neutron interactions measured between a position x and x+.DELTA.x, A.sub.i (E.sub.i).DELTA.E.sub.i =the number of incident neutrons with energy between E.sub.i and E.sub.i +.DELTA.E.sub.i, and C=C(E.sub.i)=N .sigma.(E.sub.i) where N=the number density of absorbing atoms in the position sensitive counter means and .sigma. (E.sub.i)=the average cross section of the absorbing interaction between E.sub.i and E.sub.i +.DELTA.E.sub.i.

Manglos, Stephen H. (East Syracuse, NY)

1989-06-06T23:59:59.000Z

379

Neutron Generator as a Neutron Source for BNCT  

Science Journals Connector (OSTI)

A neutron generator was investigated for a neutron source for BNCT. Neutron generators have some obvious advantages over nuclear reactors for this purpose. The neutron source is the reaction D(d,n)3He. Moderation...

Gad Shani; Lev Tsvang; Semion Rozin; Michael Quastel

1996-01-01T23:59:59.000Z

380

Development of microstructure and irradiation hardening of Zircaloy during low dose neutron irradiation at nominally 358 C  

SciTech Connect

Wrought Zircaloy-2 and Zircaloy-4 were neutron irradiated at nominally 358 C in the high flux isotope reactor (HFIR) at relatively low neutron fluences between 5.8 1022 and 2.9 1025 n/m2 (E > 1 MeV). The irradiation hardening and change in microstructure were characterized following irradiation using tensile testing and examinations of microstructure using Analytical Electron Microscopy (AEM). Small increments of dose (0.0058, 0.11, 0.55, 1.08, and 2.93 1025 n/m2) were used in the range where the saturation of irradiation hardening is typically observed so that the role of microstructure evolution and hai loop formation on irradiation hardening could be correlated. An incubation dose between 5.8 1023 and 1.1 1024 n/m2 was needed for loop nucleation to occur that resulted in irradiation hardening. Increases in yield strength were consistent with previous results in this temperature regime, and as expected less irradiation hardening and lower hai loop number density values than those generally reported in literature for irradiations at 260 326 C were observed. Unlike previous lower temperature data, there is evidence in this study that the irradiation hardening can decrease with dose over certain ranges of fluence. Irradiation induced voids were observed in very low numbers in the Zircaloy-2 materials at the highest fluence.

Cockeram, Brian V [Bechtel-Bettis, Inc.; Smith, Richard W [Bechtel-Bettis, Inc.; Leonard, Keith J [ORNL; Byun, Thak Sang [ORNL; Snead, Lance Lewis [ORNL

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

LOS ALAMOS NEUTRON SCIENCE CENTER CONTRIBUTIONS TO THE DEVELOPMENT OF FUTURE POWER REACTORS  

SciTech Connect

The Los Alamos Neutron Science Center (LANSCE) is a large spallation neutron complex centered around an 800 MeV high-currently proton accelerator. Existing facilities include a highly-moderated neutron facility (Lujan Center) where neutrons between thermal and keV energies are produced, and the Weapons Neutron Research Center (WNR), where a bare spallation target produces neutrons between 0.1 and several hundred MeV.The LANSCE facility offers a unique capability to provide high precision nuclear data over a large energy region, including that for fast reactor systems. In an ongoing experimental program the fission and capture cross sections are being measured for a number of minor actinides relevant for Generation-IV reactors and transmutation technology. Fission experiments makes use of both the highly moderated spallation neutron spectrum at the Lujan Center, and the unmoderated high energy spectrum at WNR. By combininb measurements at these two facilities the differential fission cross section is measured relative to the {sup 235}U(n,f) standard from subthermal energies up to about 200 MeV. An elaborate data acquisition system is designed to deal with all the different types of background present when spanning 10 energy decades. The first isotope to be measured was {sup 237}Np, and the results were used to improve the current ENDF/B-VII evaluation. Partial results have also been obtained for {sup 240}Pu and {sup 242}Pu, and the final results are expected shortly. Capture cross sections are measured at LANSCE using the Detector for Advanced Neutron Capture Experiments (DANCE). This unique instrument is highly efficient in detecting radiative capture events, and can thus handle radioactive samples of half-lives as low as 100 years. A number of capture cross sections important to fast reaction applications have been measured with DANCE. The first measurement was on {sup 237}Np(n,{gamma}), and the results have been submitted for publication. Other capture measurements in progress include {sup 240}Pu and {sup 242}Pu. The United States recently announced the Global Nuclear Energy Partnership (GNEP), with the goal of closing the commercial nuclear fuel cycle while minimizing proliferation risk. GNEP achieves these goals using fast-spectrum nuclear reactors powered by new transmutation fuels that contain significant quantities of minor actinides. The proposed Materials Test Station (MTS) will provide the GNEP with a cost-effective means of obtaining domestic fast-spectrum irradiations of advanced transmutation fuel forms and structural materials, which is an important step in the fuels qualification process. The MTS will be located at the LANSCE, and will be driven by a 1.08-MW proton beam. Th epeak neutron flux in the irradiation region is 1.67 x 10{sup 15} n/cm{sup 2}/s, and the energy spectrum is similar to that of a fast reactor, with the addition of a high-energy tail. The facility is expected to operate at least 4,400 hours per year. Fuel burnup rates will exceed 4% per year, and the radiation damage rate in iron will be 18 dpa (displacements per atom) per year. The construction cost is estimated to be $73M (including 25% contingency), with annual operating costs in the range of $6M to $10M. Appropriately funded, the MTS could begin operation in 2010.

GAVRON, VICTOR I. [Los Alamos National Laboratory; HILL, TONY S. [Los Alamos National Laboratory; PITCHER, ERIC J. [Los Alamos National Laboratory; TOVESSON, FREDERIK K. [Los Alamos National Laboratory

2007-01-09T23:59:59.000Z

382

Neutron producing target for accelerator based neutron source for  

E-Print Network (OSTI)

247 Neutron producing target for accelerator based neutron source for NCT V. Belov1 , S. Fadeev1, Russia Summary Neutron producing targets for novel accelerator based neutron source [1, 2] are presented Neutron producing target is one of the main elements of proposed accelerator based facility for neutron

Taskaev, Sergey Yur'evich

383

Neutron dose equivalent meter  

DOE Patents (OSTI)

A neutron dose equivalent detector for measuring neutron dose capable of accurately responding to neutron energies according to published fluence to dose curves. The neutron dose equivalent meter has an inner sphere of polyethylene, with a middle shell overlying the inner sphere, the middle shell comprising RTV.RTM. silicone (organosiloxane) loaded with boron. An outer shell overlies the middle shell and comprises polyethylene loaded with tungsten. The neutron dose equivalent meter defines a channel through the outer shell, the middle shell, and the inner sphere for accepting a neutron counter tube. The outer shell is loaded with tungsten to provide neutron generation, increasing the neutron dose equivalent meter's response sensitivity above 8 MeV.

Olsher, Richard H. (Los Alamos, NM); Hsu, Hsiao-Hua (Los Alamos, NM); Casson, William H. (Los Alamos, NM); Vasilik, Dennis G. (Los Alamos, NM); Kleck, Jeffrey H. (Menlo Park, CA); Beverding, Anthony (Foster City, CA)

1996-01-01T23:59:59.000Z

384

Pulsed-neutron monochromator  

DOE Patents (OSTI)

In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The waves are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

Mook, H.A. Jr.

1984-01-01T23:59:59.000Z

385

The Harwell Neutron Project  

Science Journals Connector (OSTI)

... 2 cm. thick, placed on three sides of the neutron booster. A layer of boron-10 metal placed between these tanks and the uranium-235 core prevents return of slow neutrons ...

M. J. POOLE; E. R. RAE

1960-01-30T23:59:59.000Z

386

Pulsed-neutron monochromator  

DOE Patents (OSTI)

In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The wave are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

Mook, Jr., Herbert A. (Oak Ridge, TN)

1985-01-01T23:59:59.000Z

387

Neutrons - 88-Inch Cyclotron  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutrons Neutron beams are available at the 88-Inch Cyclotron. Available energies range of from 8 to 30 MeV, with fluxes of up to 1E8 neutronscm2sec. For more information,...

388

Thermal Neutron Scattering  

Science Journals Connector (OSTI)

... of its title. It is not for the nuclear physicist, nor even for the neutron physicist, but for the student of solids and liquids. "Thermal ... physicist, but for the student of solids and liquids. "Thermal neutron ...

G. E. BACON

1968-11-09T23:59:59.000Z

389

Neutron activation analysis  

Science Journals Connector (OSTI)

Neutron activation analysis (NAA) is an that relies on the measurement of ?-rays emitted from a sample that was irradiated by neutrons. The rate at which ?-rays are emitted from an element in a sample is dir...

James R. Budahn

1998-01-01T23:59:59.000Z

390

Ultrafast neutron detector  

DOE Patents (OSTI)

A neutron detector of very high temporal resolution is described. It may be used to measure distributions of neutrons produced by fusion reactions that persist for times as short as about 50 picoseconds.

Wang, C.L.

1985-06-19T23:59:59.000Z

391

Coherent neutrino-nucleus scattering detection with a CsI[Na] scintillator at the SNS spallation source  

E-Print Network (OSTI)

We study the possibility of using CsI[Na] scintillators as an advantageous target for the detection of coherent elastic neutrino-nucleus scattering (CENNS), using the neutrino emissions from the SNS spallation source at Oak Ridge National Laboratory. The response of this material to low-energy nuclear recoils like those expected from this process is characterized. Backgrounds are studied using a 2 kg low-background prototype crystal in a dedicated radiation shield. The conclusion is that a planned 14 kg detector should measure approximately 550 CENNS events per year above a demonstrated $\\sim7$ keVnr low-energy threshold, with a signal-to-background ratio sufficient for a first measurement of the CENNS cross-section. The cross-section for the $^{208}$Pb($\

J. I. Collar; N. E. Fields; E. Fuller; M. Hai; T. W. Hossbach; J. L. Orrell; G. Perumpilly; B. Scholz

2014-08-20T23:59:59.000Z

392

Neutron computed tomography  

E-Print Network (OSTI)

to make the Donner Algorithms run. TABLE OF CONTEliiTS CHAPTF. . R I NEI. TRON RADIOGRAPHY . I. 1 Background . I. 2 Theory . l. 3 Neutron Beam Characterization I. 4 Image Detectors . COMPI'TED TOMOGRAPHY . Il I Background . II. 2 Notation II. 3... data which is generated by rays traveling (and being attenuated) in straight lines. However in neutron radiography, what is measured is, to most extents, the levels of neutrons which are not attenuated. Neutrons are particles. They scatter...

Russell, Clifford Marlow

2012-06-07T23:59:59.000Z

393

Neutron scattering and ribosomes  

Science Journals Connector (OSTI)

... the complexity of intra-ribosomal interactions. This is however by no means the case with neutron ...neutronscattering ...

Richard Brimacombe

1977-06-23T23:59:59.000Z

394

High resolution neutron crystallographic studies of the hydration of coenzyme cob(II)alamin  

SciTech Connect

The hydration of coenzyme cob(II)alamin has been studied using high resolution monochromatic neutron crystallographic data collected at room temperature to a resolution of surrounded by flexible side chains with terminal functional groups may be significant for 0.92 on the original diffractometer D19 with a prototype 4o x 64o detector at the high-flux reactor neutron source run by the Institute Laue Langevin. The resulting structure provides H bonding parameters for the hydration of biomacromolecules to unprecedented accuracy. These experimental parameters will be used to define more accurate force-fields for biomacromolecular structure refinement. The presence of a hydrophobic bowl motif efficient scavenging of ligands. The feasibility of extending the resolution of this structure to ultra high resolution was investigated by collecting time-of-flight neutron crystallographic data on diffractometer TOPAZ with a prototype array of 14 modular 21o x 21o detectors at the Spallation Neutron Source run by Oak Ridge National Laboratory.

Jogl, Gerwald [Brown University; Wang, Xiaoping [ORNL; Mason, Sax [Institut Laue-Langevin (ILL); Kovalevsky, Andrey [Los Alamos National Laboratory (LANL); Mustyakimov, Marat [Los Alamos National Laboratory (LANL); Fisher, Zoe [Los Alamos National Laboratory (LANL); Hoffmann, Christina [ORNL; Kratky, Christoph [Institute of Biosciences, University of Graz; Langan, Paul [ORNL

2011-01-01T23:59:59.000Z

395

Phonon characteristics of high {Tc} superconductors from neutron Doppler broadening measurements  

SciTech Connect

Statistical information on the phonon frequency spectrum of materials can be measured by neutron transmission techniques if they contain nuclei with low energy resonances, narrow enough to be Doppler-broadened, in their neutron cross sections. The authors have carried out some measurements using this technique for materials of the lanthanum barium cuprate class, La{sub 2{minus}x}Ba{sub x}CuO{sub 4}. Two samples with slightly different concentrations of oxygen, one being superconductive, the other not, were examined. Pure lanthanum cuprate was also measured. Lanthanum, barium and copper all have relatively low energy narrow resonances. Thus it should be possible to detect differences in the phonons carried by different kinds of atom in the lattice. Neutron cross section measurements have been made with high energy resolution and statistical precision on the 59m flight path of LANSCE, the pulsed spallation neutron source at Los Alamos National Laboratory. Measurements on all three materials were made over a range of temperatures from 15K to 300K, with small steps through the critical temperature region near 27K. No significant changes in the mean phonon energy of the lanthanum atoms were observed near the critical temperature of the super-conducting material. It appears however that the mean phonon energy of lanthanum in the superconductor is considerably higher than that in the non-superconductors. The samples used in this series of experiments were too thin in barium and copper to determine anything significant about their phonon spectra.

Trela, W.J.; Kwei, G.H.; Lynn, J.E. [Los Alamos National Lab., NM (United States); Meggers, K. [Univ. of Kiel (Germany)

1994-12-01T23:59:59.000Z

396

Apparatus for nuclear transmutation and power production using an intense accelerator-generated thermal neutron flux  

DOE Patents (OSTI)

Apparatus for nuclear transmutation and power production using an intense accelerator-generated thermal neutron flux. High thermal neutron fluxes generated from the action of a high power proton accelerator on a spallation target allows the efficient burn-up of higher actinide nuclear waste by a two-step process. Additionally, rapid burn-up of fission product waste for nuclides having small thermal neutron cross sections, and the practicality of small material inventories while achieving significant throughput derive from employment of such high fluxes. Several nuclear technology problems are addressed including 1. nuclear energy production without a waste stream requiring storage on a geological timescale, 2. the burn-up of defense and commercial nuclear waste, and 3. the production of defense nuclear material. The apparatus includes an accelerator, a target for neutron production surrounded by a blanket region for transmutation, a turbine for electric power production, and a chemical processing facility. In all applications, the accelerator power may be generated internally from fission and the waste produced thereby is transmuted internally so that waste management might not be required beyond the human lifespan.

Bowman, C.D.

1992-11-03T23:59:59.000Z

397

Neutronics and Fuel Performance Evaluation of Accident Tolerant Fuel under Normal Operation Conditions  

SciTech Connect

This report details the analysis of neutronics and fuel performance analysis for enhanced accident tolerance fuel, with Monte Carlo reactor physics code Serpent and INLs fuel performance code BISON, respectively. The purpose is to evaluate two of the most promising candidate materials, FeCrAl and Silicon Carbide (SiC), as the fuel cladding under normal operating conditions. Substantial neutron penalty is identified when FeCrAl is used as monolithic cladding for current oxide fuel. From the reactor physics standpoint, application of the FeCrAl alloy as coating layer on surface of zircaloy cladding is possible without increasing fuel enrichment. Meanwhile, SiC brings extra reactivity and the neutron penalty is of no concern. Application of either FeCrAl or SiC could be favorable from the fuel performance standpoint. Detailed comparison between monolithic cladding and hybrid cladding (cladding + coating) is discussed. Hybrid cladding is more practical based on the economics evaluation during the transition from current UO2/zircaloy to Accident Tolerant Fuel (ATF) system. However, a few issues remain to be resolved, such as the creep behavior of FeCrAl, coating spallation, inter diffusion with zirconium, etc. For SiC, its high thermal conductivity, excellent creep resistance, low thermal neutron absorption cross section, irradiation stability (minimal swelling) make it an excellent candidate materials for future nuclear fuel/cladding system.

Xu Wu; Piyush Sabharwall; Jason Hales

2014-07-01T23:59:59.000Z

398

More about neutron - mirror neutron oscillation  

E-Print Network (OSTI)

It was pointed out recently that oscillation of the neutron $n$ into mirror neutron $n'$, a sterile twin of the neutron with exactly the same mass, could be a very fast process with the the baryon number violation, even faster than the neutron decay itself. This process is sensitive to the magnetic fields and it could be observed by comparing the neutron lose rates in the UCN storage chambers for different magnetic backgrounds. We calculate the probability of $n-n'$ oscillation in the case when a mirror magnetic field $\\vec{B}'$ is non-zero and show that in this case it can be suppressed or resonantly enhanced by applying the ordinary magnetic field $\\vec{B}$, depending on its strength and on its orientation with respect to $\\vec{B}'$. The recent experimental data, under this hypothesis, still allow the $n-n'$ oscillation time order 1 s or even smaller. Moreover, they indicate that the neutron losses are sensitive to the orientation of the magnetic field. %at about $3\\sigma$ level. If these hints will be confirmed in the future experiments, this would point to the presence of the mirror magnetic field on the Earth of the order of 0.1 G, or some equivalent spin-dependent force of the other origin that makes a difference between the neutron and mirror neutron states.

Zurab Berezhiani

2008-04-13T23:59:59.000Z

399

Neutron removal cross section as a measure of neutron skin  

Science Journals Connector (OSTI)

We study the relation between neutron removal cross section (?-N) and neutron skin thickness for finite neutron-rich nuclei using the statistical abrasion ablation model. Different sizes of neutron skin are obtained by adjusting the diffuseness parameter of neutrons in the Fermi distribution. It is demonstrated that there is a good linear correlation between ?-N and the neutron skin thickness for neutron-rich nuclei. Further analysis suggests that the relative increase of neutron removal cross section could be used as a quantitative measure for neutron skin thickness in neutron-rich nuclei.

D. Q. Fang (???); Y. G. Ma (???); X. Z. Cai (???); W. D. Tian (???); H. W. Wang (???)

2010-04-07T23:59:59.000Z

400

FCD Instrument Team | ORNL Neutron Sciences  

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The Four-Circle Diffractometer at HFIR The Four-Circle Diffractometer at HFIR HB-3A Four-Circle Diffractometer (HB-3A). The Four-Circle Diffractometer goniometer has a full χ circle with a 4.5-450 K closed-cycle helium refrigerator. The detector is 3He with a 7-anode array in a honeycomb pattern. Currently, only the center anode is used. The upper 2Θ limit is 155°. A multilayer-[110]-wafer silicon monochromator with the reflection from planes of the zone ensures sharp diffraction peaks in specified ranges of detector angles by control of the horizontal radius of curvature. Any plane from the zone can be set in Bragg position, but only the (331), (220) with (440), and (111) with (333) reflections are of practical interest. For the fixed monochromator angle of 48°, these reflections provide principal incident wavelengths of

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

The neutron warhead decision  

Science Journals Connector (OSTI)

The neutron warhead decision ... Nuclear war moved a step closer last week with the U.S.'s decision to move ahead with production of so-called neutron warheads for use on short-range missiles and in artillery shells. ... And neutron weapons would be almost as effective on ... ...

MICHAEL HEYLIN

1981-08-17T23:59:59.000Z

402

High energy neutron dosimeter  

DOE Patents (OSTI)

A device for measuring dose equivalents in neutron radiation fields is described. The device includes nested symmetrical hemispheres (forming spheres) of different neutron moderating materials that allow the measurement of dose equivalents from 0.025 eV to past 1 GeV. The layers of moderating material surround a spherical neutron counter. The neutron counter is connected by an electrical cable to an electrical sensing means which interprets the signal from the neutron counter in the center of the moderating spheres. The spherical shape of the device allows for accurate measurement of dose equivalents regardless of its positioning. 2 figures.

Rai, K.S.F.

1994-01-11T23:59:59.000Z

403

Principles of neutron reflection  

SciTech Connect

Neutron reflection is perhaps the most developed branch of slow neutrons optics, which in itself is a direct consequence of the undulatory nature of the neutron. After reviewing the basic types of interactions (nuclear and magnetic) between neutrons and matter, the formalism is introduced to calculate the reflectivity from a sample composed of stacked flat layers and, inversely, to calculate the stacking from reflectivity measurements. Finally, a brief survey of the applications of neutron reflection is given, both in technology and in fundamental research. 32 refs., 6 figs.

Felcher, G.P.

1988-08-01T23:59:59.000Z

404

On neutron numbers and atomic masses  

Science Journals Connector (OSTI)

On neutron numbers and atomic masses ... Assigning neutron numbers, correct neutron numbers, and atomic masses and nucleon numbers. ...

R. Heyrovsk

1992-01-01T23:59:59.000Z

405

The Neutron Lifetime  

E-Print Network (OSTI)

The decay of the free neutron into a proton, electron, and antineutrino is the prototype semileptonic weak decay and the simplest example of nuclear beta decay. The nucleon vector and axial vector weak coupling constants G_V and G_A determine the neutron lifetime as well as the strengths of weak interaction processes involving free neutrons and protons that are important in astrophysics, cosmology, solar physics and neutrino detection. In combination with a neutron decay angular correlation measurement, the neutron lifetime can be used to determine the first element of the CKM matrix Vud. Unfortunately the two main experimental methods for measuring the neutron lifetime currently disagree by almost 4 sigma. I will present a brief review of the status of the neutron lifetime and prospects for the future.

Wietfeldt, F E

2014-01-01T23:59:59.000Z

406

The Neutron Lifetime  

E-Print Network (OSTI)

The decay of the free neutron into a proton, electron, and antineutrino is the prototype semileptonic weak decay and the simplest example of nuclear beta decay. The nucleon vector and axial vector weak coupling constants G_V and G_A determine the neutron lifetime as well as the strengths of weak interaction processes involving free neutrons and protons that are important in astrophysics, cosmology, solar physics and neutrino detection. In combination with a neutron decay angular correlation measurement, the neutron lifetime can be used to determine the first element of the CKM matrix Vud. Unfortunately the two main experimental methods for measuring the neutron lifetime currently disagree by almost 4 sigma. I will present a brief review of the status of the neutron lifetime and prospects for the future.

F. E. Wietfeldt

2014-11-13T23:59:59.000Z

407

Cold neutron research facility at the Budapest Neutron Centre  

Science Journals Connector (OSTI)

The new cold neutron research facility has been routinely operated at the Budapest Neutron Centre (BNC) since February 2001. This ... of equipment consists of a liquid hydrogen cold neutron source, an optimised s...

L. Rosta

2002-12-01T23:59:59.000Z

408

Measurement of Thermal Neutron Flux in Photo-Neutron Source  

Science Journals Connector (OSTI)

The Photo-Neutron Source (PNS) project is a study ... design, simulation and construction an accelerator based neutron source for Boron Neutron Capture Therapy (BNCT). The system uses ... medical linear accelerat...

A. Taheri; A. Torkamani; A. Pazirandeh

2013-01-01T23:59:59.000Z

409

Sample Environment | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Home › Instruments › SNS › Sample Environment Home › Instruments › SNS › Sample Environment Sample Environment The Sample Environment Group provides equipment and support for studying materials under controlled conditions (temperature, pressure, magnetic field, chemical environment, etc.). When you come to SNS to conduct an experiment, our front-line teams are there to support you. Although we currently offer a wide range of capabilities, we realize that these capabilities must continually grow. Therefore, we also have a busy research and development team, and we encourage you to partner with them to develop new equipment and techniques. The Sample Environment Equipment Database allows you to search for information about the sample environment equipment available for HFIR and SNS instruments. It will be available in the near future for SNS sample

410

Gamma Irradiation | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Gamma Irradiation Gamma Irradiation Gamma Irradiation Facility Gamma irradiation chamber Gamma irradiation chamber. The HFIR Gamma Irradiation Facility is an experimental facility designed to irradiate materials with gamma radiation from spent fuel elements. The facility chamber is stainless steel and is made of 0.065-thick tubing to maximize the internal dimensions of the chamber. This allows for the largest samples possible that can still fit inside the cadmium post of the spent fuel loading station positions. The interior chamber is approximately 3.75 inches inside diameter and accommodates samples up to 25 inches long. There are two configurations for the chamber assembly, with the only difference being the plugs. The uninstrumented configuration has a top plug that is used for installation of the samples, to support the inert gas

411

Industry - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Industry banner Industry banner Neutron scattering research has applications in practically every field, and neutron research at ORNL is leading to productive partnerships with the industrial and business communities. We welcome proposals for all types of research, including those involving proprietary work. Recent studies have led to discoveries with potential applications in fields such as medicine, energy, and various metals technologies. For more information, please see our recent research highlights. Research Collaborations Industry-Driven Research Benefits Plastics Manufacturing Corning uses VULCAN to test limits of ceramic material for car emission controls, filtration devices Neutrons Probe Inner Workings of Batteries Industry and Neutron Science: Working To Make a Match

412

Neutron wave packet tomography  

E-Print Network (OSTI)

A tomographic technique is introduced in order to determine the quantum state of the center of mass motion of neutrons. An experiment is proposed and numerically analyzed.

G. Badurek; P. Facchi; Y. Hasegawa; Z. Hradil; S. Pascazio; H. Rauch; J. Rehacek; T. Yoneda

2005-03-29T23:59:59.000Z

413

Neutron Science Forum | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

environment for discussion, innovation, and dissemination of information within the neutron scattering community as well as engaging closely related disciplines through...

414

Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

User Office User Program Manager Laura Morris Edwards 865.574.2966 ORNL study uses neutron scattering, supercomputing to demystify forces at play in biofuel production Full...

415

Polarizability of the Neutron  

Science Journals Connector (OSTI)

Experiments on scattering of low-energy neutrons by heavy elements may give information concerning the electric polarizability of the neutron. The relation of the electric polarizability to the low-energy neutron scattering data is developed. One pertinent experiment is discussed and from this an upper bound on the polarizability is obtained. This upper bound to the polarizability ? is an order of magnitude larger than the meson-theoretic estimate of ?. If the value of ? is as small as is predicted by meson theory, or by an analysis of the pion photoproduction data, then it is unlikely to be observed in neutron scattering experiments of the presently achievable accuracy.

R. M. Thaler

1959-05-01T23:59:59.000Z

416

Neutron superfluidity and unusual nuclear shapes in neutron stars crusts  

Science Journals Connector (OSTI)

We calculate in the frame-work of a semiclassical model the neutron superfluidity in the crust of neutron stars, accounting for the presence of unusual....

G. Lazzari; F. V. De Blasio

1994-01-01T23:59:59.000Z

417

Neutron capture cross sections for neutron-rich isotopes  

Science Journals Connector (OSTI)

Average continuum (Hauser-Feshbach) and resonance (Breit-Wigner) neutron capture rates for neutron-rich isotopes, determined on the basis of...

B. Leist; W. Ziegert; M. Wiescher

1985-01-01T23:59:59.000Z

418

Neutron Diffraction Studies of Proteins  

Science Journals Connector (OSTI)

20 November 1980 research-article Neutron Diffraction Studies of Proteins G. A. Bentley S. A. Mason Neutrons interact differently with protein crystals...hydrogen or deuterium atoms diffract neutrons relatively more strongly, but in addition...

1980-01-01T23:59:59.000Z

419

Neutron and Nuclear Science News  

NLE Websites -- All DOE Office Websites (Extended Search)

News Recent news and events related to neutron and nuclear science at LANSCE. Neutron and Nuclear Science News Links Neutron and Nuclear Science News Media Links Profiles Events at...

420

Neutron Scattering Methods in Chemistry  

Science Journals Connector (OSTI)

Starting with basic properties of the neutron, this chapter reviews the most important neutron scattering methods that provide valuable information for a ... wide, from standard methods of crystallography to neutron

L. Pusztai

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Slide 1  

NLE Websites -- All DOE Office Websites (Extended Search)

IPTS Proposal Preparation IPTS Proposal Preparation Procedure November 3, 2008 Welcome to this guide to the Integrated Proposal Tracking System, used by the Neutron Sciences Directorate at Oak Ridge National Laboratory to accept and process proposals submitted by users for beam time at the High Flux Isotope Reactor (HFIR) and the Spallation Neutron Source (SNS). This guide will allow you to: * View the mechanics of the proposal system without having to register * See the format of the proposal, and the information required before you start your proposal creation * View the guidelines for the Statement of Research (SoR) required in the proposal preparation To enter the actual Integrated Proposal Tracking System (IPTS) web page, click on the hyperlink. The following page will appear.

422

Uniformity measurements and new positioning algorithms for wavelength-shifting fiber neutron detectors  

SciTech Connect

Wavelength-shifting (WLS) fiber scintillator detectors were successfully installed at two neutron powder diffractometers at the Spallation Neutron Source (SNS). However, they have the following second-order disadvantages: i). they cannot have both high efficiency and images free of ghosting (position misassignment) concomitantly; ii). the apparent detection efficiency and spatial resolution are not uniform. These issues are related to the diffusion of scintillation photons and the fluctuation in the number of photons (quantum noise) collected by photo-multiplier tubes (PMTs). To mitigate these two issues, we developed two statistics-based positioning algorithms, i.e., a centroid algorithm (CEA) and a correlation algorithm (CA). Compared with the generally used maximum-photon algorithm (MPA), CEA eliminates the ghosting with only about a 10% loss in detection efficiency, and provides better uniformity in detection efficiency and intrinsic background. CA can effectively eliminate ghosting too, but the loss of efficiency at the group boundaries of PMTs is large. The results indicate that both algorithms can reduce the influence of quantum noise on the neutron positioning.

Wang, Cai-Lin [ORNL] [ORNL; Riedel, Richard A [ORNL] [ORNL

2014-01-01T23:59:59.000Z

423

Irradiation hardening in unalloyed and ODS molybdenum during low dose neutron irradiation at 300 and 600?C  

SciTech Connect

Unalloyed molybdenum and oxide dispersion strengthened (ODS) molybdenum were irradiated at 300 C and 600 C in HFIR to neutron fluences of 0.2, 2.1, and 24.3 x 10{sup 24} n/m{sup 2} (E > 0.1 MeV). The size and number density of voids and loops as well as the measured irradiation hardening and electrical resistivity were found to increase sub-linearly with fluence. This supports the idea that the formation of the extended defects that produce irradiation hardening in molybdenum is the result of a nucleation and growth process rather than the formation of sessile defects directly from the displacement damage cascades. This conclusion is further supported by molecular dynamics (MD) simulations of cascade damage. The unalloyed molybdenum had a low impurity interstitial content with less irradiation hardening and lower change in electrical resistivity than is observed for ODS Mo. This result suggests that high-purity can result in slightly improved resistance to irradiation embrittlement in molybdenum at low fluences.

Snead, Lance Lewis [ORNL; Byun, Thak Sang [ORNL; Leonard, Keith J [ORNL; Smith, Richard W [Bechtel-Bettis, Inc.; Cockeram, Brian V [Bechtel-Bettis, Inc.

2008-01-01T23:59:59.000Z

424

Neutron activation experiments in radiochemistry  

Science Journals Connector (OSTI)

Neutron activation experiments in radiochemistry ... Describes experimentation involving the neutron activation of a variety of samples irradiated in a subcritical reactor and a paraffin-moderated source. ...

Karl S. Vorres

1960-01-01T23:59:59.000Z

425

Neutron Stars and Fractal Dimensionality  

E-Print Network (OSTI)

We argue that the material inside Neutron stars behaves anomalously with fractal statistics and that in principle, we could induce mini Neutron stars, with the release of energy.

Burra G. Sidharth

2008-05-06T23:59:59.000Z

426

A history of the neutron  

Science Journals Connector (OSTI)

A history of the neutron ... Describes some of the individuals and the work they did leading to the discovery of the neutron. ...

Vasilis Lavrakas

1952-01-01T23:59:59.000Z

427

Neutron and Nuclear Science Publications  

NLE Websites -- All DOE Office Websites (Extended Search)

Publications Recent publications related to neutron and nuclear science at LANSCE. Neutron and Nuclear Science Publications Chi-Nu Publications DANCE Publications GEANIE...

428

Neutron and Nuclear Science News  

NLE Websites -- All DOE Office Websites (Extended Search)

News Recent news and events related to neutron and nuclear science at LANSCE. Neutron and Nuclear Science News Nuclear science observations and opportunities at the Los Alamos...

429

Neutron Science Research Areas | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Home | Science & Discovery | Neutron Science | Research Areas SHARE Research Areas Neutron scattering research at ORNL covers four broad research areas: biology and soft...

430

LANSCE School on Neutron Scattering:  

NLE Websites -- All DOE Office Websites (Extended Search)

11 th LANSCE School on Neutron Scattering: Materials at the Mesoscale Lujan Center Los Alamos Neutron Science Center Los Alamos National Laboratory lansce.lanl.govneutronschool...

431

Advances in specular neutron reflectometry  

Science Journals Connector (OSTI)

Specular neutron reflectometry provides a depth profile of the scattering ... material. To date, numerous productive applications of neutron reflectometry have been demonstrated. With the new development ... stil...

C.F. Majkrzak; N.F. Berk

2002-12-01T23:59:59.000Z

432

Category:Neutron Log | Open Energy Information  

Open Energy Info (EERE)

Neutron Log page? For detailed information on Neutron Log, click here. Category:Neutron Log Add.png Add a new Neutron Log Technique Pages in category "Neutron Log" This category...

433

Workshop For Analyzing SANS Data  

NLE Websites -- All DOE Office Websites (Extended Search)

HFIR Center for Neutron Scattering HFIR Center for Neutron Scattering Workshop for Analyzing SANS Data April 18 - 20, 2011 SNS Logo Spallation Neutron Source * Oak Ridge National Laboratory * Oak Ridge TN, USA Workshop Home Workshop Agenda Information Contacts Pre-Workshop Installation & Reading filler Workshop summary and purpose Since its inception the BIO-SANS and GP-SANS instruments have supported over 440 unique users and thus a need arose to supply users with additional support via data analysis and reduction to expedite the publication of new science. A continuation of this kind of user support is being done by our upcoming workshop to help past users reduce and analyze data from our SANS instruments using the established data acquisition software. We will be using Igor Pro and our in house routines to do the data reduction and fitting. The goal is that everyone who attends will leave the workshop with completely analyzed data and meaningful results. To accomplish this feat, we will focus the first day on data reduction and the following two days on analysis. We will go over in detail all the different fitting functions that are currently supported in Igor and set-aside time to discuss what other functions need to be inputted into Igor. Finally, there will be a demonstration of the new NSSD data reduction/analysis software, MANTID, that will be implemented in the near future across the SANS beam lines.

434

Neutron Capture Therapy  

Science Journals Connector (OSTI)

... . Only those elements which have a high thermal-neutron capture cross-section, such as boron-10, lithium-6, and uranium-235, are useful. This suggestion was first put forward ... was first put forward in 1936 by Locher. The utilization of thermal neutron capture by boron-10 for the treatment of human-brain tumours, chiefly glioblastoma multiforme, has been under investigation ...

1961-09-23T23:59:59.000Z

435

Neutron capture therapies  

DOE Patents (OSTI)

In one embodiment there is provided an application of the .sup.10 B(n,.alpha.).sup.7 Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

Yanch, Jacquelyn C. (Cambridge, MA); Shefer, Ruth E. (Newton, MA); Klinkowstein, Robert E. (Winchester, MA)

1999-01-01T23:59:59.000Z

436

Neutron calibration facilities  

Science Journals Connector (OSTI)

......shut down. A recent development for a thermal neutron calibration field is a neutron guide used at the research reactor GKSS Geesthacht(35). The result is a high-intensity thermal beam providing a flux of up to 106 s1 with a field size of about 2.5 2......

H. Schuhmacher

2004-08-01T23:59:59.000Z

437

Neutron Scattering Software  

NLE Websites -- All DOE Office Websites (Extended Search)

Software Software A new portal for neutron scattering has just been established at neutronsources.org. The information contained here in the Neutron Scattering Web has been transferred to the new site. We will leave the current content here for archival purposes but no new content will be added. We encourage everyone interested in neutron scattering to take full advantage of this exciting new resource for our community. Neutronsources.org Data Formats NeXus: Neutron and X-ray Data Format Crystallographic Binary Format (CBF/imgCIF) Hierarchical Data Format (HDF) Data Analysis and Visualization Data Analysis for Neutron Scattering Experiments (DANSE): distributed data analysis project Large Array Manipulation Program (LAMP): IDL-based data analysis and visualization

438

Pocked surface neutron detector  

DOE Patents (OSTI)

The detection efficiency, or sensitivity, of a neutron detector material such as of Si, SiC, amorphous Si, GaAs, or diamond is substantially increased by forming one or more cavities, or holes, in its surface. A neutron reactive material such as of elemental, or any compound of, .sup.10 B, .sup.6 Li, .sup.6 LiF, U, or Gd is deposited on the surface of the detector material so as to be disposed within the cavities therein. The portions of the neutron reactive material extending into the detector material substantially increase the probability of an energetic neutron reaction product in the form of a charged particle being directed into and detected by the neutron detector material.

McGregor, Douglas (Whitmore Lake, MI); Klann, Raymond (Bolingbrook, IL)

2003-04-08T23:59:59.000Z

439

Structure of the Neutron  

Science Journals Connector (OSTI)

In an earlier paper, the contribution of the meson current to the electromagnetic structure of the nucleon was calculated by use of the dispersion relations for pion-nucleon scattering. Here the contribution of the nucleon current to the electromagnetic structure of the neutron is obtained analogously by use of the dispersion relations for neutron-proton scattering. Only the contribution from the one-pion and two-pion states of nucleon-nucleon scattering is considered. It is found that both states reduce the neutron-electron potential, i.e., leads to a smaller charge radius of the neutron. The contribution from the deuteron state is shown to be negligible. The resulting mean-square radii of the neutron, including the contributions of both meson and nucleon current, are (0.2310-13cm)2 for the charge distribution and (0.4110-13cm)2 for the magnetic moment distribution with f2=0.08.

Katsumi Tanaka

1959-01-15T23:59:59.000Z

440

THERMAL NEUTRON BACKSCATTER IMAGING.  

SciTech Connect

Objects of various shapes, with some appreciable hydrogen content, were exposed to fast neutrons from a pulsed D-T generator, resulting in a partially-moderated spectrum of backscattered neutrons. The thermal component of the backscatter was used to form images of the objects by means of a coded aperture thermal neutron imaging system. Timing signals from the neutron generator were used to gate the detection system so as to record only events consistent with thermal neutrons traveling the distance between the target and the detector. It was shown that this time-of-flight method provided a significant improvement in image contrast compared to counting all events detected by the position-sensitive {sup 3}He proportional chamber used in the imager. The technique may have application in the detection and shape-determination of land mines, particularly non-metallic types.

VANIER,P.; FORMAN,L.; HUNTER,S.; HARRIS,E.; SMITH,G.

2004-10-16T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Neutron LifetimeNeutron Lifetime IUCF Colloquium April 13,  

E-Print Network (OSTI)

Neutron LifetimeNeutron Lifetime IUCF Colloquium April 13, 2007 Albert Steyerl Department 940 878.5±0.8 885.7±0.8 new result neutronlifetime(),s year world average Neutron lifetime data #12 world average Neutron lifetime data A. Serebrov et al. 2005Storage of ultra-cold neutrons878.5 ±±±± 0

Steyerl, Albert

442

Hyperons in neutron stars  

E-Print Network (OSTI)

Using the Dirac-Brueckner-Hartree-Fock approach, the properties of neutron-star matter including hyperons are investigated. In the calculation, we consider both time and space components of the vector self-energies of baryons as well as the scalar ones. Furthermore, the effect of negative-energy states of baryons is partly taken into account. We obtain the maximum neutron-star mass of $2.08\\,M_{\\odot}$, which is consistent with the recently observed, massive neutron stars. We discuss a universal, repulsive three-body force for hyperons in matter.

Katayama, Tetsuya

2015-01-01T23:59:59.000Z

443

Pulsed Neutron Powder Diffraction  

Science Journals Connector (OSTI)

The nature and scope of powder diffraction with a white, pulsed beam of neutrons is discussed. Analysis of the data by the Rietveld profile technique is described in brief, and a range of applications in solid...

A. K. Cheetham

1988-01-01T23:59:59.000Z

444

Neutron Science Center  

NLE Websites -- All DOE Office Websites (Extended Search)

to have rare opportunity to tour Neutron Science Center May 10, 2011 LANL Rosenfest will celebrate life of LANSCE founder Louis Rosen and offer tour LOS ALAMOS, New Mexico, May 10,...

445

Shifting scintillator neutron detector  

DOE Patents (OSTI)

Provided are sensors and methods for detecting thermal neutrons. Provided is an apparatus having a scintillator for absorbing a neutron, the scintillator having a back side for discharging a scintillation light of a first wavelength in response to the absorbed neutron, an array of wavelength-shifting fibers proximate to the back side of the scintillator for shifting the scintillation light of the first wavelength to light of a second wavelength, the wavelength-shifting fibers being disposed in a two-dimensional pattern and defining a plurality of scattering plane pixels where the wavelength-shifting fibers overlap, a plurality of photomultiplier tubes, in coded optical communication with the wavelength-shifting fibers, for converting the light of the second wavelength to an electronic signal, and a processor for processing the electronic signal to identify one of the plurality of scattering plane pixels as indicative of a position within the scintillator where the neutron was absorbed.

Clonts, Lloyd G; Cooper, Ronald G; Crow, Jr., Morris Lowell; Hannah, Bruce W; Hodges, Jason P; Richards, John D; Riedel, Richard A

2014-03-04T23:59:59.000Z

446

Scattering of Slow Neutrons  

Science Journals Connector (OSTI)

1 September 1937 research-article Scattering of Slow Neutrons M. Goldhaber G. H. Briggs The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to Proceedings...

1937-01-01T23:59:59.000Z

447

Neutron Diffraction Texture Analysis  

Science Journals Connector (OSTI)

...conducted at Chalk River (Canada), Geesthacht (Germany), LLB (France) and NIST...deformed limestone that was measured at Geesthacht with this method. It is also possible...with monochromatic neutrons at GKSS, Geesthacht. Equal area projection, linear contours...

Hans-Rudolf Wenk

448

Neutron stars - thermal emitters  

E-Print Network (OSTI)

Confronting theoretical models with observations of thermal radiation emitted by neutron stars is one of the most important ways to understand the properties of both, superdense matter in the interiors of the neutron stars and dense magnetized plasmas in their outer layers. Here we review the theory of thermal emission from the surface layers of strongly magnetized neutron stars, and the main properties of the observational data. In particular, we focus on the nearby sources for which a clear thermal component has been detected, without being contaminated by other emission processes (magnetosphere, accretion, nebulae). We also discuss the applications of the modern theoretical models of the formation of spectra of strongly magnetized neutron stars to the observed thermally emitting objects.

Potekhin, A Y; Pons, J A

2014-01-01T23:59:59.000Z

449

Clifford G. Shull, Neutron Diffraction, Hydrogen Atoms, and Neutron  

Office of Scientific and Technical Information (OSTI)

Clifford Shull, Neutron Diffraction, and Neutron Scattering Clifford Shull, Neutron Diffraction, and Neutron Scattering Resources with Additional Information Clifford G. Shull was awarded the 1994 Nobel Prize in Physics "for the development of the neutron diffraction technique". 'Professor Shull's prize was awarded for his pioneering work in neutron scattering, a technique that reveals where atoms are within a material like ricocheting bullets reveal where obstacles are in the dark. Clifford Shull Photo Courtesy of Oak Ridge National Laboratory When a beam of neutrons is directed at a given material, the neutrons bounce off, or are scattered by, atoms in the sample being investigated. The neutrons' directions change, depending on the location of the atoms they hit, and a diffraction pattern of the atoms' positions can then be obtained.

450

Science Education Programs | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

with Neutrons Graduate & Post-doctoral Programs Student & Teacher Programs Science Forum Neutron Scattering Tutorials Kids' Corner NScD Careers Supporting Organizations Neutron...

451

Fast Pulsing Neutron Generators for Security Application  

E-Print Network (OSTI)

FAST PULSING NEUTRON GENERATORS FOR SECURITY APPLICATION* Q.time/fast pulsing neutron generator is needed primarily forA compact neutron generator, currently being developed in

Ji, Q.

2010-01-01T23:59:59.000Z

452

Leading neutron spectra  

E-Print Network (OSTI)

It is shown that the observation of the spectra of leading neutrons from proton beams can be a good probe of absorptive and migration effects. We quantify how these effects modify the Reggeized pion-exchange description of the measurements of leading neutrons at HERA. We are able to obtain a satisfactory description of all the features of these data. We also briefly discuss the corresponding data for leading baryons produced in hadron-hadron collisions.

A. B. Kaidalov; V. A. Khoze; A. D. Martin; M. G. Ryskin

2006-02-23T23:59:59.000Z

453

Deformation and Fracture Properties in Neutron Irradiated Pure Mo and Mo Alloys  

SciTech Connect

The effect of neutron irradiation on the mechanical properties of select molybdenum materials, pure low carbon arc-cast (LCAC) Mo, Mo-0.5% Ti-0.1% Zr (TZM) alloy, and oxide dispersion-strengthened (ODS) Mo alloy, was characterized by analyzing the temperature dependence of mechanical properties. This study assembles the tensile test and analysis data obtained through multiple series of irradiation and post-irradiation experiments. Tensile specimens in stress-relieved conditions with longitudinal (LSR) and transverse (TSR) directions were irradiated in high flux isotope reactor (HFIR) at temperatures ranging 270 to 1100oC to 0.6 -13.1 dpa. Also, the recrystallized LCAC Mo specimens in the longitudinal direction (LR) were also irradiated up to 0.28 dpa at ~80oC. Tensile tests were performed at temperatures ranging from -194 oC to 1400oC. Analysis results indicate that the irradiation at temperatures below 700oC increased strength significantly, up to 170%, while the increase of yield stress by irradiations at higher temperature was not significant. The plastic instability stress was strongly dependent on test temperature but was nearly independent of irradiation dose and temperature. The true fracture stress was dependent on test temperature to a lesser degree than was the yield stress and plastic instability stress. It was also slightly impacted by irradiation, depending on both irradiation and test temperatures. Brittle fracture often occurred in the LSR specimens tested at room temperature or lower after low temperature irradiation, while it was observed in many irradiated TSR specimens over the whole test temperature range. The ODS-LSR specimens showed the highest resistance to irradiation embrittlement due to relatively higher fracture stress. The critical temperature for shear failure (CTSF) was defined and evaluated for the materials, and the CTSF values were compared with the ductile to brittle transition temperatures (DBTT) based on ductility data.

Byun, Thak Sang [ORNL; Li, Meimei [ORNL; Cockeram, Brian V [Bechtel-Bettis, Inc.; Snead, Lance Lewis [ORNL

2008-01-01T23:59:59.000Z

454

MAGNETIC NEUTRON SCATTERING  

SciTech Connect

Much of our understanding of the atomic-scale magnetic structure and the dynamical properties of solids and liquids was gained from neutron-scattering studies. Elastic and inelastic neutron spectroscopy provided physicists with an unprecedented, detailed access to spin structures, magnetic-excitation spectra, soft-modes and critical dynamics at magnetic-phase transitions, which is unrivaled by other experimental techniques. Because the neutron has no electric charge, it is an ideal weakly interacting and highly penetrating probe of matter's inner structure and dynamics. Unlike techniques using photon electric fields or charged particles (e.g., electrons, muons) that significantly modify the local electronic environment, neutron spectroscopy allows determination of a material's intrinsic, unperturbed physical properties. The method is not sensitive to extraneous charges, electric fields, and the imperfection of surface layers. Because the neutron is a highly penetrating and non-destructive probe, neutron spectroscopy can probe the microscopic properties of bulk materials (not just their surface layers) and study samples embedded in complex environments, such as cryostats, magnets, and pressure cells, which are essential for understanding the physical origins of magnetic phenomena. Neutron scattering is arguably the most powerful and versatile experimental tool for studying the microscopic properties of the magnetic materials. The magnitude of the cross-section of the neutron magnetic scattering is similar to the cross-section of nuclear scattering by short-range nuclear forces, and is large enough to provide measurable scattering by the ordered magnetic structures and electron spin fluctuations. In the half-a-century or so that has passed since neutron beams with sufficient intensity for scattering applications became available with the advent of the nuclear reactors, they have became indispensable tools for studying a variety of important areas of modern science, ranging from large-scale structures and dynamics of polymers and biological systems, to electronic properties of today's technological materials. Neutron scattering developed into a vast field, encompassing many different experimental techniques aimed at exploring different aspects of matter's atomic structure and dynamics. Modern magnetic neutron scattering includes several specialized techniques designed for specific studies and/or particular classes of materials. Among these are magnetic reflectometry aimed at investigating surfaces, interfaces, and multilayers, small-angle scattering for the large-scale structures, such as a vortex lattice in a superconductor, and neutron spin-echo spectroscopy for glasses and polymers. Each of these techniques and many others offer exciting opportunities for examining magnetism and warrant extensive reviews, but the aim of this chapter is not to survey how different neutron-scattering methods are used to examine magnetic properties of different materials. Here, we concentrate on reviewing the basics of the magnetic neutron scattering, and on the recent developments in applying one of the oldest methods, the triple axis spectroscopy, that still is among the most extensively used ones. The developments discussed here are new and have not been coherently reviewed. Chapter 2 of this book reviews magnetic small-angle scattering, and modern techniques of neutron magnetic reflectometry are discussed in Chapter 3.

ZALIZNYAK,I.A.; LEE,S.H.

2004-07-30T23:59:59.000Z

455

Neutron Radii in Nuclei and the Neutron Equation of State  

Science Journals Connector (OSTI)

The root-mean-square radius for neutrons in nuclei is investigated in the Skyrme Hartree-Fock model. The main source of theoretical variation comes from the exchange part of the density-dependent interaction which can be related to a basic property of the neutron equation of state. A precise measurement of the neutron radius in 208Pb would place an important new constraint on the equation of state for neutron matter. The Friedman-Pandharipande neutron equation of state would lead to a very precise value of 0.160.02 fm for the difference between the neutron and the proton root-mean-square radius in 208Pb.

B. Alex Brown

2000-12-18T23:59:59.000Z

456

Spin-Assisted Layer-by-Layer Assembly: Variation of Stratification as Studied with Neutron Reflectivity<xref ref-type="fn" rid="end1"><sup></sup></xref>  

NLE Websites -- All DOE Office Websites (Extended Search)

21/la9014042 21/la9014042 14017 Langmuir 2009, 25(24), 14017-14024 Published on Web 07/06/2009 pubs.acs.org/Langmuir © 2009 American Chemical Society Spin-Assisted Layer-by-Layer Assembly: Variation of Stratification as Studied with Neutron Reflectivity † Eugenia Kharlampieva, ‡ Veronika Kozlovskaya, ‡ Jennifer Chan, ‡ John F. Ankner, § and Vladimir V. Tsukruk* ,‡ ‡ Department of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, and § Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 Received April 20, 2009. Revised Manuscript Received June 10, 2009 We apply neutron reflectivity to probe the internal structure of spin-assisted layer-by-layer (SA-LbL) films composed of electrostatically assembled polyelectrolytes. We find that the level of stratification and the degree of layer

457

Neutron-Neutron Scattering at Low Energies  

Science Journals Connector (OSTI)

This paper investigates the information contained in a neutron-neutron scattering experiment at low energies which could be performed by colliding beams coming from an underground nuclear explosion. The significance of such an experiment is discussed from the point of view of a check on charge symmetry and charge independence, and it is found that because of the electromagnetic complications in proton-proton scattering, and because of the proton-neutron mass difference, the knowledge of neutron-neutron scattering would be of considerable value. The functional form of the experimental data which is most convenient for analysis and the approximate relative magnitude of the terms is investigated, and it is concluded that for the kind of experiment which is envisaged (measuring cross sections to 10% from 20 keV to 2 MeV) only two parameters should be kept in the effective-range expansion. The connection between the number and distribution of energies at which the cross section is measured and the error on the individual measurements, on the one hand, and the accuracy of the effective-range parameters deduced from the experiments, on the other, is given explicitly and is found also to depend on the absolute magnitude of the scattering length. The results show that ten 10% measurements, suitably distributed between 20 keV and 2 MeV, can determine the sign of the scattering length to four standard deviations, the magnitude of the effective range to 50-70%, and the magnitude of the scattering length to about 3%. Finally, the relationship between the variation of the effective-range parameters and the corresponding variation in the parameters of the scattering potential is studied, and it is found that, while this relationship is strongly shape-dependent, a small change in the potential parameters, in any case, results in a large change in the scattering length, but a small one in the effective range. Numerical relationships show that, even in the worst case, the variation in the scattering length is about eight times the variation in the potential parameter. It is concluded that a 10% experiment at 20 energies between 20 keV and 2 MeV would be able to get information on the potential parameters sufficiently accurately so that charge-dependent or charge-symmetry violating effects could be detected.

Michael J. Moravcsik

1964-11-09T23:59:59.000Z

458

Baseline Design of a Solid Neutron Converter Driven by 160 MeV Protons  

E-Print Network (OSTI)

The European Isotope Separation On-Line Radioactive Ion Beam Facility Design Study (EURISOL DS) aims at the design of several spallation and fission targets for the production of radioactive isotopes. Namely, direct targets, where high-energy protons interact directly with the fission targets, as well as the design of a Multi-MW proton-to-neutron converter coupled with a fission target. For the later, several options have been proposed, including the use of a relatively low energy (in the hundreds of MeV) high intensity proton beam. In this scope, the neutronic characteristics of a tantalum n-converter/fission-target system have been established (although not yet optimised) for a reference proton energy of 160 MeV. A set of simulations has been carried out for different design requirements and different characteristics of the proton beam. An extensive comparison of the main physical parameters has also been carried out, in order to allow the optimal engineering design of the whole target station.

Herrera-Martnez, A

2006-01-01T23:59:59.000Z

459

Neutron degeneracy and plasma physics effects on radiative neutron captures in neutron star crust  

Science Journals Connector (OSTI)

We consider the astrophysical reaction rates for radiative neutron capture reactions (n,?) in the crust of a neutron star. The presence of degenerate neutrons at high densities (mainly in the inner crust) can drastically affect the reaction rates. Standard rates assuming a Maxwell-Boltzmann distribution for neutrons can underestimate the rates by several orders of magnitude. We derive simple analytical expressions for reaction rates at a variety of conditions with account for neutron degeneracy. We also discuss the plasma effects on the outgoing radiative transition channel in neutron radiative capture reactions and show that these effects can also increase the reaction rates by a few orders of magnitude. In addition, using detailed balance, we analyze the effects of neutron degeneracy and plasma physics on reverse (?,n) photodisintegration. We discuss the dependence of the reaction rates on temperature and neutron chemical potential and outline the efficiency of these reactions in the neutron star crust.

P. S. Shternin; M. Beard; M. Wiescher; D. G. Yakovlev

2012-07-24T23:59:59.000Z

460

Neutron-deuteron breakup reaction as a tool for studying neutron-neutron interactions  

SciTech Connect

An analysis of the most recent data on the reaction nd {yields} pnn revealed a serious discrepancy between theoretical predictions and cross sections measured for this reaction in various configurations where the role of neutron-neutron interactions is important. In view of this, it seems necessary both to develop theoretical approaches and to obtain new experimental data. For this purpose, a setup for studying the neutron-deuteron breakup reaction was created at the Institute for Nuclear Research on the basis of the neutron beam in the RADEX channel and deuterium targets. This facility makes it possible to perform experiments over a broad region of primary-neutron energies (10-60 MeV) and in various (final-state interaction, quasifree scattering, and spatial-star) configurations. Preliminary results of the respective experiment were obtained for configurations of final-state neutron-neutron interaction and quasifree neutron-neutron scattering.

Konobeevski, E. S., E-mail: konobeev@inr.ru; Zuyev, S. V.; Mordovskoy, M. V.; Potashev, S. I.; Sharapov, I. M. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)] [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

2013-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "hfir spallation neutron" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.