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User name R. Michaels
Log entry time 11:11:26 on December 21,1999
Entry number 31686
keyword=RE: SPOT vs MCC beam size
There are two reasons why MCC's spot size don't
agree with spot++. One is that the MCC software doesn't
know about the quad optics, the other is a miscalibration
that spot++ shows a spot too big by a factor 1.25 (also it has
a shift of ~0.5 mm). To account for optics one must
measure what one has, then ask MCC what they are setting
and ask them to change, if necessary, using an empirical
scale factor. Don't make MCC think about it, just give the
setting. To calibrate spot++ better, someone can follow
the procedure described by Luminita Todor at
www.jlab.org/~luminita/bpm_rast.ps
If someone gets the offsets and scale factors we can
put them into spot.