Neutrons
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NEUTRONS. Build EAR user/student community and enhance access to neutron facilities Coordinate activities within COMPRES - high P-T calibrations, cell development, etc. Coordinate with global high-P neutron community Support new EAR initiatives at neutron facilities.

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NEUTRONS

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Neutrons

NEUTRONS

  • Build EAR user/student community and enhance access to neutron facilities

  • Coordinate activities within COMPRES - high P-T calibrations, cell development, etc.

  • Coordinate with global high-P neutron community

  • Support new EAR initiatives at neutron facilities


Neutrons

COMPRES: Budget for Neutrons

  • 5/1/02* - 4/30/03: $70,000

  • 5/1/03 - 4/30/04: $70,000

  • Virginia Tech (NL Ross)

  • Constructed webpage: (www.crystal.vt.edu/compres)

* funds not available until August 2002


Compres neutrons

COMPRES Neutrons:

  • Ross Angel (Virginia Tech): High-pressure ferroelastic phase transition in lead phosphate, a model compound for high-pressure improper ferroelastics (travel support to ISIS)

    RJ Angel, U. Bismayer, W.G. Marshall (2003) Dynamism or Disorder at High Pressures? Eos Trans. AGU, 83: F620.

    RJ Angel, U. Bismayer, W.G. Marshall (2003)Local and long range order in ferroelastic lead phosphate at high pressure, Acta Cryst C, submitted.

  • Peter Chupas (Stony Brook): The local structure of “amorphous” FeS (travel support to LANSCE)

  • Aaron Celestian (Stony Brook): Origin of ionic conductivity in Cs14 6Li24[Si72 7Li18O172]: exchange between 7Li and 6Li in channel and framework sites, respectively at high temperature using PDF (travel support to LANSCE)

  • Wendy Mao (Univ. Chicago): support to present results of neutron experiments at 2002 Fall AGU Meeting

    WL Mao, Y Zhao, R J Hemley, H Mao (2002) Hydrogen Storage in Clathrate Hydrate. Trans. AGU, 83:F620-21.


Neutrons

Special Session: Applications of Neutron Scattering in Earth Sciences Convenors: N Ross, Virginia Tech; J Parise Stony Brook

  • Invited lectures: S. Redfern, R. Wenk, H-K Mao, B. Winkler, M. Welch, P. Dera) (thanks Ji Lie!)

  • + Poster Session


Neutrons

NeutronsIn solid stateChemistry and the EarthSciencesToday and tomorrow(March 12–16, 2003)Co-chairs: A. Wilkinson (Georgia Tech), N. Ross (Virginia Tech)

  • Christopher Holl, Univ. Colorado

  • Wendy Mao, Univ. Chicago

  • Philip Neuhoff, Univ. Florida

  • Kinson Kam, UC Santa Barbara

  • Charles Martin, SUNY Stony Brook

  • Meghan Kamp, Ohio State Univ.

  • Yang Ding, Geophysical Laboartory

  • Darren Locke, Arizona State Univ.


Contacts at neutron facilities in u s

Contacts at Neutron Facilities in U.S.

  • Intense Pulsed Neutron Source (IPNS) Argonne National Laboratory: Chris Tulk ([email protected])

  • Los Alamos Neutron Scattering Center (LANSCE): Yusheng Zhao ([email protected]) development of TAP high-pressure cell +ZAP press

  • National Institute of Standards and Technology (NIST) Center for Neutron Research: Brian Toby ([email protected])

  • High Flux Isotope Reactor (HIFR), Oak Ridge National Laboratory (ORNL): Bryan Chakoumakos ([email protected])

  • HIPPO: High Pressure Preferred Orientation: Rudy Wenk (UC Mat. Res. Project, LANSCE) ([email protected])

  • Spallation Neutron Source (SNS) & opportunities for high pressure research: John B. Parise ( [email protected])

  • McClellan Nuclear Radiation Center (MNRC) & UC Davis: Chip Lesher ([email protected])


Neutron sites worldwide

Neutron Sites Worldwide

  • Institut Laue-Langevin (ILL) Grenoble (reactor source)

  • ISIS, Didcot, UK (spallation source)


Neutrons

Bryan Chakoumakos


Spallation neutron source sns

Spallation Neutron Source (SNS)

  • The Spallation Neutron Source (SNS) is an accelerator-based neutron source being built in Oak Ridge, Tennessee, by DOE (www.sns.gov).

  • The SNS will provide the most intense pulsed neutron beams in the world for scientific research and industrial development.

  • Construction began in 1999 and will be completed in 2006.


Neutrons

The purpose of the SHUG is to:

  • Provide a formal and clear channel for the exchange of information and advice between the investigators who perform neutron scattering and neutron science experiments at the Oak Ridge National Laboratory (ORNL) and the management of the Spallation Neutron Source, the High Flux Isotope Reactor, and the Joint Institute for Neutron Science (JINS).

  • Serve as an advocacy group for the neutron scattering and neutron science activities at SNS and HFIR.

  • Provide a communication channel among users of SNS and HFIR

Membership in the SHUG is open to all users and potential users of the various neutron facilities at the SNS and HFIR and scientists and engineers engaged in the operation and development of these facilities.


Neutrons

A High Pressure Diffractometer for the Spallation Neutron Source

  • John B. Parise, Geosciences/Chemistry & Center for High Pressure Research, State University of New York, Stony Brook

  • Russell J. Hemley, Geophysical Laboratory & Center for High-Pressure Research, Carnegie Institution, Washington, D.C.

  • Chris Tulk, Instrument Scientist, Experimental Facilities Division, Spallation Neutron Source, Oak Ridge National Lab

!!!! June 13, 2003: Fomal approval of DOE funding!!!!


Neutrons

backscattering

spectrometer

SNS

Disordered materials diffractometer

High resolution

chopper spectrometer

proposed location

of high-pressure

diffractometer

SANS

  • other instruments

  • multi-chopper spec

  • hybrid spec

  • liquids reflectometer

  • magnetism reflectometer

  • engineering diffractometer

  • single crystal diffractometer

High resolution

powder diffractometer


Paris edinburgh cell isis pearl

2

0

0

m

m

Hydraulic Ram

sample

Paris-Edinburgh Cell(ISIS - Pearl)

Anvils

  • 100 mm3 to 10 GPa

  • 30 mm3 to 30 GPa


Highest pressure with neutrons

Highest Pressure with Neutrons?

Magnetic neutron diffraction under pressures up to 43 GPa. Study of the EuX and GdX compounds Goncharenko I, Mirebeau I, Ochiai AHYPERFINE INTERACTIONS 128: 225-244 2000 High pressure diffractometer <<MICRO>> at the Laboratoire Léon Brillouin (reactor) Samples 0.01-1 mm3


Compres neutrons 2003 2005

COMPRES Neutrons: 2003-2005?

  • Continue program to facilitate access to neutron facilities

  • Short course or summer school (model IUCr summer school: www.crystalerice.org)

  • Communicate needs of community to advisory groups like SHUG

  • Postdoctoral position(s)

  • Identify needs of the community: Neutron Grand Challenge?

  • Neutrons are EXPENSIVE! Should only be used if it is the right technique (light elements, magnetism, etc.)


Example gas hydrates and planetary mineralogy j loveday r nelmes edinburgh

Example: Gas Hydrates and Planetary MineralogyJ. Loveday, R. Nelmes (Edinburgh)

Ices relevant to large moonsGanymede and Europa (Jupiter), Titan (Saturn), Triton (Neptune), Pluto

Significant fractions of ices (50% by mass)

Titan has a significant atmosphere (nitrogen and methane) Due to be explored by Cassini/Huygens 2004

For Titan ammonia hydrates and methane hydrates are important phases


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