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Published byAlan Cobb Modified over 9 years ago
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Nuclear Spectroscopy & Imaging Stephen Cramer UC Davis / LBNL
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Nuclear Experiments Nuclear Forward Scattering – NFS SR Perturbed Angular Correlation Nuclear Resonance Vibrational Spectroscopy
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Nuclear Experiments The trick 70 psec 3680 nsec 153 nsec off ~20 ns~133 ns on h Source Signal
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Nuclear Lifetimes & Energies What works
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Nuclear Forward Scattering ferrocene
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Synchrotron Radiation Perturbed Angular Correlation (SRPAC)
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The NRVS Experiment 100 eV … Detector: 1 eV1 meV 70 psec 3680 nsec 153 nsec off ~20 ns~133 ns on h Source Signal
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FeN x H y Models HFe-N 2 DFe-N 2 Fe- 14 N 2 H 2 Fe- 15 N 2 H 2 Fe- 14 N 2 H 4 Fe- 15 N 2 H 4 N2N2 N2H2N2H2 N2H4N2H4
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Fe Protein NRVS [Fe 4 S 4 ] 2+ Any redox level Low frequency modes Quantitative simulation [Fe 4 S 4 ] 1+ [Fe 4 S 4 ] 0
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Nuclear Needs Nuclear Forward Scattering – NFS SR Perturbed Angular Correlation Nuclear Resonance Vibrational Spectroscopy
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X-Ray Microtomography Carolyn Larabell - NIH funded facility at ALS Image of yeast cell
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Diffraction-Enhanced Imaging x http://www.iit.edu/~chapman/AAPM/sld027.htm
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Mössbauer cross sections are 500 x photoelectric c. s. but linewidths are 10 8 smaller ‘Nuclear contrast’ Why do it? less radiation damage zero background
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Nuclear Imaging Fe Kr / Xe Lanthanide nanoparticle tags
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Nuclear Imaging Needs Orders of magnitude more flux Higher energies (30-70 keV) Nano eV (nuclear) monochromators Suitable bunch schemes Better (picosecond) detectors
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Nuclear Future? I dream of things that never were … and say why not ? (RFK) To accomplish great things, we must not only act, but also dream; not only plan, but also believe. (Anatole France)
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