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Notes on the resolution smearing

The smeared intensity Is(q0) is calculated by knowing the resolution function R(q,q0) for all values of q0 and a model intensity function Resolution Equation 1 by the function

Resolution Equation 3

The resolution function is approximated by a Gaussian given by

Resolution Equation 4

where the shadow factor, fs, the mean scattering vector, Resolution Equation 2, and the variance, Resolution Equation 5, are all functions of q0.

The shadow factor is needed because the tail of the gaussian resolution function is cut off by the beamstop. This factor accounts for the missing intensity due to the beamstop.

For the resolution calculations performed by the SANS simulator applet a 20 point integration is performed to plus and minus three standard deviations of the Gaussian resolution function for each point in q.

Report errors or make inquiries to Alan Munter, <alan.munter@nist.gov>

Last modified 25-March-2003 by website owner: NCNR (attn: Alan Munter)