Time of Flight (TOF) tecnique - E21

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Time of Flight (TOF) tecnique - E21

Time of Flight (TOF) techniqueSeminar Methods and experimental scattering of neutronsCoordinator: Prof. Cristoph MorkelStudent: Luca Braglia


Contents• Quasi-elastic neutron scattering (QENS)• TOF technique• Examples


Contents• Quasi-elastic neutron scattering (QENS)• TOF technique• Examples


What information income?• Coherent scatteringInterference phenomena• Incoherent scatteringDiffusional motions


Diffusional motionsH• Translational diffusion• Rotational diffusionHCH


Energy resolution and time scales


Contents• Quasi-elastic neutron scattering (QENS)• TOF technique• Examples


Time of Flight (TOF) spectrometers• Direct-geometryspectrometers• Indirect-geometryspectrometers


countsDirect geometry time-of-flight spectrometer„white“ neutron beammonochromatic beamFermi-ChopperL1neutron pulses: E itime of flightsampleMulti-Channel-AnalyserE fΦL2Schematic diagram of the direct-geometry spectrometer


Direct geometry time-of-flight spectrometer


Direct geometry time-of-flight spectrometerEnergy transferWhich becomes for E i fixed:


Direct geometry time-of-flight spectrometer


Examples Direct geometry• TOFTOF• MAPS• IN5


TOFTOF


TOFTOF


Mode operation


Multi angle position sensitive (MAPS)


IN5


Applications IN5• local and long-range diffusion in disordered systemssuch as liquids, molecular crystals, amorphous solids(superionic glasses, orientational glasses, spin glasses),polymers, hydrogen-metal systems, ionic conductors.• dynamics of ’soft matter’, including gels, proteins andbiological membranes.• Dynamics of quantum liquids.• Rotational tunnelling in molecular crystals.• Crystal field splitting.• Spin dynamics in high-TC superconductors• Critical scattering phenomena in dense gases and solids.


Inverted-geometry spectrometers


Inverted-geometry spectrometers


Inverted-geometry spectrometers


Examples Inverted geometry• IN10• IN13


IN10


IN13


Applications IN13• Membranes and protein dynamics ; Protein/membraneinteractions ; Extreme environmental conditions inbiosciences and biotechnology ; In-vivo studies• Polymers and saccharides• Saccharides and trehalose dynamics ; Main chain andside chain motions in polymers ; Conducting acid-dopedpolymers ; Rotator phases• Confined media and inclusion compounds


Contents• Quasi-elastic neutron scattering (QENS)• TOF technique• Examples


ApplicationDetermination of the diffusion in nano-sized emulsiondroplets


QENS spectra of sample Q10D at 150K for 3 different momentum transfers Q.


References• www.ill.eu• Slides Prof. Morkel• Slides Prof. Böni• Neutron Diffraktion, 3rd EditionG.E. Bacon, Clarendon Press, Oxf. 1962• Introduction to the Theory of Thermal Neutron ScatteringG.L. Squires, Dover. Publications, N.Y. 1966• Experimental Neutron Scattering, B.T.M Willis, C.J Carlile, Oxford• Neutron Scattering, Thomas Bruckel, Gernot Heger, Dieter Richter andReiner Zorn, Forschungszentrum Julich• Neutron Scattering in Novel Materials, Albert Furrer• Frontiers of Neutron scattering, Albert Furrer• Molecular dynamics in pharmaceutical drug delivery systems, TobiasUnruh, Cristoph Smuda, Gerd Gemmecker, Heike Bunjes


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