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An Introduction to Neutron Scattering - Spallation Neutron Source

An Introduction to Neutron Scattering - Spallation Neutron Source

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Reflection from Rough Surfaces<br />

z<br />

z = 0<br />

k 1<br />

θ 1<br />

• diffuse scattering is caused by surface roughness or inhomogeneities in<br />

the reflecting medium<br />

• a smooth surface reflects radiation in a single (specular) direction<br />

• a rough surface scatters in various directions<br />

• specular scattering is damped by surface roughness – treat as graded<br />

interface. For a single surface with r.m.s roughness σ:<br />

R<br />

=<br />

Fe R<br />

1<br />

t Izk z<br />

−2k<br />

σ<br />

2<br />

x<br />

θ 2<br />

k 2<br />

k t 1

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