NESE

Setting the scene

Mineralogy Petrology Geochemistry Volcanology

Rock Physics Geomaterials Magnetism

Cryosphere Planetary Solar System Science

Energy Resources Environment

Instruments development

Rock Physics, Geomaterials & Magnetism
Rock textures, stress and strain analysis
Tectonic studies of the European Alps using neutron texture goniometry. Neutron diffraction, combined with other methods, is an extremely powerful tool for retrieving the information registered in deformed rocks. Of the four most important methods for geological texture analysis, (1) optical orientation analysis, (2) X-ray diffraction texture goniometry, (3) electron diffraction, and (4) neutron diffraction, neutrons have the advantage that their low absorption by matter and generally large beam diameter enable true volume measurements. Examples: Results from the Adula nappe (Eastern Swiss-Italian Alps) and the Monte Rosa nappe (Western Swiss-Italian Alps).	Challenges for future work: overpriniting of deformation events, textures of low-symmetry minerals (e.g. feldspar), polymineralic rocks. The potential of neutron diffraction for tectonic studies is at the moment only used by few working groups. One reason is the limited knowledge about this potential among earth scientist. Another reason is the limited number of neutron instruments and restrictions with respect to measuring time, especially when large suites of samples have to be analysed, as is usually the case in tectonic studies. In order to increase neutron application by earth scientists, more, efficient, and easy to access neutron instruments should be made available. Neutron Instruments Diffractometer SV7b at Forschungszentrum Jülich.	Presentation (PDF, 8.3MB)	Nikolaus Froitzheim Geologisches Institut, Rhein. Friedrich-Wilhelms- Universität Bonn, Nußallee 8, D-53115 Bonn, Germany. niko.froitzheim@uni-bonn.de
Results from deformation experiments performed at a range of temperatures and pressures in the ENGIN-X neutron beamline at RAL. Conventional rock deformation experiments are designed primarily to investigate the mechanical properties and behaviour of geological materials at geologically interesting conditions • The type of experiment most widely used for determining material strength involves measuring the load (deviatoric stress) supported during deformation at constant strain-rate, temperature and and confining pressure (± constant pore fluid pressure, pore fluid volume, effective pressure). • Generally, the experiments are performed at • Temperatures < 1200ºC Temperatures < 1200ºC • Confining pressures < 500 Confining pressures < 500 MPa MPa	• Within the general remit of experimental rock deformation, the neutron methods described provide a non non-destructive means of monitoring how the deformation within samples is accommodated at the grain grain-scale scale. • This has particular value for investigating microstructural influences on elastic and inelastic behaviour. • In principle, it also provides a method for calibrating stress-induced crystallographic changes, e.g., mechanical twinning. • The design of an apparatus allowing elevated temperatures and confining pressures to be applied simultaneously would extend the range of materials that could be investigated. Neutron Instruments ENGIN ISIS - Stress measurement for the 21st century .	Presentation (PDF 2.1MB)	Steve Covey-Crump School of Earth, Atmospheric and Environmental Sciences The University of Manchester Williamson Building Oxford Road Manchester M13 9PL Email: s.covey-crump@manchester.ac.uk
TOF Neutron Diffraction to Characterize Polycrystalline Rocks: Quartz Textures as Examples Neutron diffraction is increasingly used to characterize properties of polycrystalline materials. Such properties include microstructure (grain size, grain shape, defect densities), texture (crystallographic preferred orientation) and stress. • Neutron diffraction texture measurements have the advantage of measuring volumes, rather than surfaces and are representative of bulk material properties. • Of particular interest are TOF neutrons (measuring a whole spectrum) and multidetector instruments (each detector recording spectra from differently oriented crystals) • The Rietveld method as implemented in MAUD has become the favorite tool for multispectra data analysis.	Neutron Instruments HIPPO (High Pressure Preferred Orientation) at the Lujan Center at LANSCE D1B at ILL- Two-axis diffractometer. GPPD at IPNS - General Purpose Powder Diffractometer. Sv29 at Jülich - Thermal Time-of-Flight Spectrometer.	Presentation (PDF 1MB)	Hans-Rudolph Wenk University of California Department of Earth & Planetary Science College of Letters and Science 307 McCone Hall Berkeley, CA 94720-4767 wenk@seismo.berkeley.edu
Porous rocks and fractal dimensions
Freezing in Natural Porous Materials Neutrons provide a unique means of examining the processes of freeze-thaw in uncontrolled porous solids that are common materials in the real world, such as rock, sediment and Portland cement paste	• The sensitivity of neutrons to hydrogen and their bulk penetration allows one to independently measure the ice content, via Bragg peaks, and water content, via changes in the background near the first maxima of S(Q) of D2O, of microporous systems as a function of temperature. • This allows test of freeze-thaw hysteresis. • Neutrons provide a method of testing the invasion hypothesis of ice through porous media in predominantly macroporous diatomite and chalk.	Presentation (PDF, 5.2MB)	Ian P Swainson Canadian Neutron Beam Centre Chalk RiverLabs Chalk River ON, Canada
Examples of applications of neutron imaging methods for the study of properties and phenomena in the earth sciences			Eberhard Lehmann
Magnetism
Medium pressure magnetism of natural ferrimagnets: a Martian story of impacts and pyrrhotite To help understanding the demagnetization of the Martian crust around large impact craters (>500 km diameter) we have investigated one candidate ferrimagnetic mineral in martian rocks: monoclinic pyrrhotite (Fe7S8). Neutron scattering study on a pyrrhotite powder under pressure was conducted in ILL	Neutrons experiment -confirms the pressure transition -pinpoints the actual transition pressure Next: PT diagrams; Other minerals: -higher pressure needed! -solid solutions -order-disorder transition, e.g.: FeNi taenite => tetrataenite (Néel, 1964) Neutron Instruments D1B - ILL, CRG - two-axis diffractometer. D20- ILL, High-intensity two-axis diffractometer with variable resolution.	Presentation (PDF 2MB)	Pierre Rochette Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement Europôle Méditerranéen de l'Arbois BP 80 - 13545 AIX EN PROVENCE, France rochette@cerege.fr
Neutron diffraction and atomistic simulation of magnetic and cation ordering in titanohematite: new insight into the mechanism of self-reversed thermoremanent magnetization		NO AVAILABLE	Richard Harrison R.J.Harrison@bris.ac.uk