Summary: what you must know about scattering

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Summary what you must know about scattering
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A plane wave
Phase fronts (planes of equal phase)
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Point scatter
Scattering vector
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Point scatters
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Continuous medium
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Form factor scattering
Independent scatterers
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Form factor scatteringAn example a uniform
sphere
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Form factor scatteringAn example a uniform
sphere
In reality
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Form factor scatteringAn example a uniform
sphere
Guinier range I(K) ? exp(-RgK)2/3)
LOG-LOG plot
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Porod range I(K) ? A/K4
total surface area
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experimental Form Factor
4 orders of magnitude variation
Dangerous region
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Form factor scatteringMore examples disks rods
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Form factor scatteringMore examples Dumbbells
R 95 nm
Johnson et al. (Utrecht) published in Langmuir
(2005)
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SANS structure factor effect in dipolar chains
M. Klokkenburg et al., to be published.
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Most popular techniques

• Small-angle x-ray scattering (SAXS)
• Small-angle neutron scattering (SANS)
• Light scattering
• See slides of the other lecture