SANS Challenges

1. ChallengesforSANS
Ricardo Ferraz Leal
rhf@ornl.gov

2. SANS Beamline scientists requirements
• When Qx/Qy is rebinned, dQx/dQy
changes accordingly
• 2D plot I(Qx, Qy)
• Qx – binned
• Qy – binned
• dQx – binned
• dQy - binned
• I
• Sigma(I)

3. Workpace2D current implementation
• Qx – binned ✓︎
• Qy – binned ✕
• Spectrum number
• dQx – binned ✓︎
• dQy ✕ – binned ✕
• I
• Sigma(I)
• When Qx/Qy is rebinned,
dQx/dQy changes accordingly ✕
• 2D plot I(Qx, Qy) ✓︎

4. Very soon…
• dQxi and dQyi are now a single value representing the standard deviation of a
gaussian distribution (the instrument resolution).
• In the future this will be a convolution of multiple factors affecting the
instrument resolution, e.g., a convolution of multiple functions.
• Because this function is sometimes difficult/impossible to describe
analytically, it will be digitized as 2 arrays (𝑞 = 𝑓 𝑞 ) which can then
interpolated.
• All in one: For every Qx/Qy we need 2 extra arrays.
• SasView will read this format once adopted by canSAS / NXcanSAS.