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

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:• 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 MeetingWL Mao, Y Zhao, R J Hemley, H Mao (2002) Hydrogen Storage in Clathrate Hydrate.

Trans. AGU, 83:F620-21.

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 In solid state Chemistry and the Earth SciencesToday 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.

• Intense Pulsed Neutron Source (IPNS) Argonne National Laboratory: Chris Tulk (CTulk@anl.gov)

• Los Alamos Neutron Scattering Center (LANSCE): Yusheng Zhao (yzhao@lanl.gov) development of TAP high-pressure cell +ZAP press

• National Institute of Standards and Technology (NIST) Center for Neutron Research: Brian Toby (brian.toby@nist.gov)

• High Flux Isotope Reactor (HIFR), Oak Ridge National Laboratory (ORNL): Bryan Chakoumakos (kou@ornl.gov)

• HIPPO: High Pressure Preferred Orientation: Rudy Wenk (UC Mat. Res. Project, LANSCE) (wenk@seismo.berkeley.edu)

• Spallation Neutron Source (SNS) & opportunities for high pressure research: John B. Parise ( jparise@notes.cc.sunysb.edu)

• McClellan Nuclear Radiation Center (MNRC) & UC Davis: Chip Lesher (lesher@geology.ucdavis.edu)

Neutron Sites Worldwide

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

• ISIS, Didcot, UK (spallation source)

Bryan Chakoumakos

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.

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.

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!!!!

High resolution powder diffractometer

backscatteringspectrometer

High resolutionchopper spectrometer

SANS

Disordered materials diffractometer

proposed locationof high-pressurediffractometer

other instruments-multi-chopper spec-hybrid spec-liquids reflectometer-magnetism reflectometer-engineering diffractometer-single crystal diffractometer

SNS

Anvils

2 00 mm

sample

Hydraulic Ram • 100 mm3 to 10 GPa• 30 mm3 to 30 GPa

Paris-Edinburgh Cell(ISIS - Pearl)

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?

• 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)

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