[Mott] Mott beam systematic TN .... done

[Joseph Grames]

All,

Following our last meeting I've made meaningful updates to the Mott beam systematics TN, please find attached.  The note is meant to be an informative summary for writing the corresponding section of the Mott paper that demonstrates our extrapolation measurement conditions were taken within a stable parameter space.

Notables:

1. I had missed a factor of 1/sqrt(2) when determining beam size with wire scanner, forgetting to account for the 45 deg motion of the wire wrt X or Y.   I fixed this.  The consequence is that measured beam emittance, measured energy spread and calculated spot size at target are now smaller.

2. Brian Freeman collected additional target ladder images vs. known ladder motion.  I used this to refine absolute calibration of beam positions at target during  Run I (see Appendix A). Position don't change much, but are now pretty much final.

3. I looked at statistically suspect Mott runs.  Nothing obvious in plots, asymmetries, rates.   The 6 "bad" spot size runs still remain "bad", i.e. there is a very large background (including bursts early in time) for RMS spot size larger >1.5mm.  

Moving on to detector acceptance...

Joe

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