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Next Generation Science with Inelastic X-ray Scattering . Clement Burns Western Michigan University. Thanks to: Yuri Shyvd’ko, Ercan Alp, Ayman Said (APS) Peter Abbamonte (UIUC) Zahid Hasan (Princeton). Six Challenges for Physics. National Research Council Review of Physics (2001)
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Next GenerationScience with Inelastic X-ray Scattering Clement Burns Western Michigan University Thanks to: Yuri Shyvd’ko, Ercan Alp, Ayman Said (APS) Peter Abbamonte (UIUC) Zahid Hasan (Princeton)
Six Challenges for Physics National Research Council Review of Physics (2001) • Developing quantum technologies • Understanding complex systems • Applying physics to biology • Creating new materials • Exploring the universe • Unifying the forces of nature
Focus with X-ray Mirrors Small Beam • High flux for experiments • IXS flux hungry technique • >1016P=photon/sec-0.1% bandwidth • Small beam size (<4 x 40 mm2) • High pressure work • Nanomaterials • New materials • E.g., MgB2 • Devices • Surfaces • Environmental • But… start 2014 NSLS II http://www.esrf.eu/UsersAndScience/Publications /Highlights/2002/Imaging/IMA8/fig103 http://www.physics.umd.edu/mfuhrer/images/longNT.jpg
Need for Higher Resolution Pilla et al, PRL 85, 2136 (2000) DNA Liu, J. Chem. Phys. 123, 214909 2005 DNA Krisch PRE 73, 061909 2006 DHO Memory Fun.
Science at 0.1 meV • 1 meV resolution does not mean one can study excitations with an energy of 1 meV • Large background from elastic • High resolution and good elastic rejection From Yuri Shvyd’ko
Possible Science • Low energy excitations in polymers • Related to wetting, adhesion.. • Lipid membranes • Mapping superconducting band gap with phonons • Dynamics of glasses Inoue, PRL 95, 056102 (2005) Reinstäder, Phys. Rev. Lett. 93, 108107 (2004)
0.1 meV Science From Ruocco
Some Ideas at 1 meV • Extreme environments – low temperature, high field, ultrahigh pressure • Small samples • Down to nanoparticle size • (High pressure) • Surface phonons • Grazing incidence requires small beam • 10’ yields ~1.5 mm on sample • Most current techniques require high vacuum • Exotic excitations • Orbitons • Resonant scattering? • Pulse probe technique – phonons in excited states
Extreme Environments Levitated Liquids • High pressure • High Temperature • High magnetic fields • Low temperature • Heating issues Sinn, Science 299, 2047 (2003)
Small Samples • New materials – e.g., phonons in MgB2 • Samples/regions in crystals - Pu • Really small ? • 100 nm? Smaller? • Nanotubes? Wong et. al, Science 301, 1071 (2003)
Surface Phonon Scattering • Thin films (need to compare to e.g., He scattering) • Buried interfaces? • Study 2-d behavior liquids Murphy et. al, PRL 95, 256104 (2005)
Science at Medium Resolution • Electronic excitations • Plasmons, excitons, spinons, holons, Mott gap, band transitions, superconducting gap…. • Non-resonant scattering – easy comparison to (q,) • Resonant scattering –site and state selective • Soft x-ray edges at high energy • Time evolution of systems • Study highly correlated electron systems, Mott-Hubbard insulators, organic semiconductors, regular metals, …new systems everyday
Scattering Cross Section From Platzman and Isaacs, PRB 57, 11107 (1998) Non-resonant Scattering
Medium Resolution Work IXS Organic Molecular Crystal Spinon-holon Yang et al., PRL 98, 036404 (2007) Y. Cai, et al, Phys. Rev. Lett. 2006 June et al., PRL 137402 (2004) • www.afrlhorizons.com/Briefs/Jun04/ML0319.html Kodituwakku et al, submitted to PRL
Medium Resolution – Monochromator Improvements • Tom Toellner, APS • Four bounce • High efficiency • Wide energy range
Medium Resolution SpectrometerDetector Improvements • Line detector • Huotari et al., ESRF • Shvyd’ko APS • Improve counts • Larger solid angle • Improve resolution • Reduces geometric effect • Other energies? S. Huotari et al., Journal of Synchrotron Radiation20, 467-472 (2005).
Why do we need NSLS-II? • Smaller samples can be studied • New materials, high pressure • Many, many systems to look at • Higher resolution - necessary for many cases…
Low Resolution Options Important! • Dynamics on attosecond time scales From Peter Abbamonte
Low / Adjustable Resolution • Dipole forbidden d-d excitations Larson et al., PRL 99, 026401 (2007)
Observations • No one cares how good the NSLS-II synchrotron is …. • They care about the quality of science • Many good ideas for IXS • Throw out most of them • Use strengths of NSLS-II • Develop early – detectors, etc. • Room for future ideas • Adjustable resolution • Support • Sample orientation/alignment • Characterization (other departments?)