xBSM Analysis - Dan Peterson 2011-02-18 At previous meetings: 2011-01-28 CesrTA general meeting 2011-02-01 Collaboration meeting reported on progress on xBSM data analysis using all 3 optics : GAP. FZP, CA, using parameterized fitting in all cases. 2011-02-18 an update modifications to the functions comparison of results from optics, for same conditions comparison with the template-based fitting

4 parameters: gaussian + flat background New fits: GAP - unchanged, using a gap size of 21μm referred to the source. 4 parameters: gaussian + flat background FZP - out-of-focus width and fraction have been calibrated using the smallest beam size available. Introduced a slope to the background. 4 parameters: narrow gaussian + background slope CA - adjusted peak positions ( 2) and strengths (3) . There were changes to 5 of the 36 constants. Intrinsic widths at σ=0 μm beam size are derived from the sum: ∑ exp(i 2π P(x) /λ T(x) ) For this approach to work, it is necessary only to have a function for σ=0 μm beam size and parameterization for σ≠0 μm beam size . Remember, it does not matter how I obtain the function. 3 parameters: width, position, height D. Peterson 2011-02-18 ( Wide gaussian position, width, and fractional area are fixed. Constant background is fixed in a preliminary fit. ) The position motion is now reported at the source.

GAP FZP CA J. Flanagan template fitting D. Peterson parameterized fitting GAP FZP CA

FZP 16 μm 20 μm 30 μm 40 μm 50 μm “57 μm” The out-of-focus part is has a width of σ=84 μm, and is 87% of the signal. Precision is lost when the beam size exceeds about σ=45 μm.

Coded Aperture 16 μm 20 μm 45 μm When the beam size exceeds about σ=55 μm, the dip between the two major peaks has less influence on the fit relative to trying to fit the wings. Even though the fit range is cut off with larger beam motion (so that non-pixels are not added to the average), the fit is not good on the wings. 50 μm “60 μm”