Neutron Diffraction Neutron Diffraction Studies at the IBR2 Studies at the IBR2

ReactorReactorStatus and FutureStatus and Future

Geologisches Institut, Universität Freiburg, Albertstr. 23b, 79104 Freiburg, GermanyGeologisches Institut, Universität Freiburg, Albertstr. 23b, 79104 Freiburg, Germany

J.H. BehrmannJ.H. Behrmann

Status and FutureStatus and Future

Experimental facilities availableExperimental facilities available

Possible ventures into new Possible ventures into new equipmentequipment

Examples of current studiesExamples of current studies

Future experimental activities Future experimental activities

SKAT - Neutron texture SKAT - Neutron texture diffractometerdiffractometer

Experimental facilities:

Parameters of SKATParameters of SKAT

Total flight path (moderator – detector) 103.81 m

Range of wavelengths 0.8 ~ 7.6 Å

Range of d-spacings 0.6 ~ 5.6 Å

Detectors up to 21 3He single tube, Ø: 60mm, unique scattering angle 2=90°

Collimators two sets of Gd-coated soller collimators, angular dispersion: 18’ and 45’, cross section: 55 x 55 mm

Resolution d/d ~ 0.55 % at d =2 Å(18’ collimation)~ 0.7 % at d = 2 Å (45‘ collimation)

Beam cross section 50 x 85 mm

Typical sample volume 20 ~ 50 cm3

Experiment control VME-based measuring system running OS-9 and X WINDOW

Main advantages of SKATMain advantages of SKAT

low absorption of neutrons in matter: large sample low absorption of neutrons in matter: large sample volumes accessiblevolumes accessible

TOF: complete diffraction patterns can be recordedTOF: complete diffraction patterns can be recorded

application of multiple detectorsapplication of multiple detectors:: measurements are measurements are fastfast

excellent spectral resolution: suitable for excellent spectral resolution: suitable for polyphase geological samples with many polyphase geological samples with many diffraction linesdiffraction lines

unique scattering angle 2unique scattering angle 2 of all detectors of all detectors:: minimum of intensity corrections requiredminimum of intensity corrections required

Polyphase rock sample: calcite + quartz Polyphase rock sample: calcite + quartz +/- dolomite+/- dolomite

EPSILON - EPSILON - Experimental facilities:

Parameters of EPSILONParameters of EPSILON

Main advantages of EPSILONMain advantages of EPSILON

Excellent spectral resolution because of long Excellent spectral resolution because of long flight path (> 100 m)flight path (> 100 m)

Intensity gain by operation of radial collimators Intensity gain by operation of radial collimators and multi-detector systemand multi-detector system

Simultaneous detection of nine different Simultaneous detection of nine different directions on Debye-Scherrer cone offers directions on Debye-Scherrer cone offers possibility for strain tensor estimationspossibility for strain tensor estimations

Detection of lattice strains by Bragg peak shift Detection of lattice strains by Bragg peak shift and broadeningand broadening

Uniaxial pressure device (max. load 150 Uniaxial pressure device (max. load 150 MPa) for MPa) for in situin situ deformation of samples deformation of samples

Laser extensometer for Laser extensometer for in-situin-situ determination of macroscopic sample straindetermination of macroscopic sample strain

Temp. cabin for thermal stability (Temp. cabin for thermal stability (T = +/- 0.5 K)T = +/- 0.5 K)

Possible ventures into new Possible ventures into new equipmentequipment

Construct new Construct new neutron guide neutron guide (curved)(curved)

Achieve approx. Achieve approx. 10x increase in 10x increase in available available proportion of proportion of thermal thermal neutronsneutrons

Examples of current Examples of current studiesstudies

Anisotropic thermal expansion of Anisotropic thermal expansion of rocks/minerals,rocks/minerals,

Fabric destruction of building stones by Fabric destruction of building stones by weatheringweathering

Bent marble facade panelsBent marble facade panels

Compressional wave velocity anisotropy Compressional wave velocity anisotropy in rocksin rocks

quartz single crystalsquartz single crystals

Texture-related compressional wave Texture-related compressional wave anisotropy in Quartzites, Naxos Island, anisotropy in Quartzites, Naxos Island,

GreeceGreece

Comparison of texture-inducedComparison of texture-inducedand microcrack-induced Vp and microcrack-induced Vp

anisotropyanisotropy

Texture-induced,quartzite, Naxos

microcrack-induced,quartz-rich gneiss,Austrian Alps

Studies of relation between textures Studies of relation between textures and acoustic anisotropy are vital for the and acoustic anisotropy are vital for the understanding of understanding of seismic reflectorsseismic reflectors in in

the deep Earth´s crustthe deep Earth´s crust

Residual lattice strains in crystals and Residual lattice strains in crystals and rocksrocks

Bragg peak shift as residual lattice strain Bragg peak shift as residual lattice strain indicatorindicator

Future experimental Future experimental activitiesactivities

Future projects should either contain a component Future projects should either contain a component of instrument development, to be carried out when of instrument development, to be carried out when reactor is being reconstructedreactor is being reconstructed

or have close relation to measurement of other or have close relation to measurement of other physical properties of geo-materials (elastic, physical properties of geo-materials (elastic, plastic, magnetic, thermal, strain state), not using plastic, magnetic, thermal, strain state), not using neutron radiationneutron radiation

or address fundamental questions in applied geo-or address fundamental questions in applied geo-materials researchmaterials research

or emphasize on development of novel methods of or emphasize on development of novel methods of data analysisdata analysis

Expressions of interestExpressions of interest Rock anisotropyRock anisotropy- elastic (Behrmann, Freiburg; Kern, Kiel; elastic (Behrmann, Freiburg; Kern, Kiel;

Nikitin/Ivankina, Dubna)Nikitin/Ivankina, Dubna)- thermal (Siegesmund, Göttingen)thermal (Siegesmund, Göttingen)- magnetic (de Wall, Würzburg)magnetic (de Wall, Würzburg)- strain state (Frischbutter, Potsdam)strain state (Frischbutter, Potsdam)

Texture for kinematic analysisTexture for kinematic analysis- (Kroner, Freiberg; Behrmann, Freiburg)(Kroner, Freiberg; Behrmann, Freiburg)

Mathematical background (Schaeben, Freiberg; Mathematical background (Schaeben, Freiberg; Nikolayev, Dubna)Nikolayev, Dubna)