Photon Beam Position Stability Mike Grissom UNCW July 29,2005

Task Analyze PrimEx Gamma Profiler (PGP) EPICS data to study photon beam position stability during the fall 2004 data run EPICS Data consists of two 64- dimensional arrays, one in x and one in y

Process 1. Extract all arrays from all skim files 2. Make histograms of the x and y distributions 3. Gaussian fit 4. Log EPICS event number, means, sigmas, and integral of number of events in a data file

Data Storage Book keeping DB: means, sigmas, and integral of number of events for each EPICS event (x and y) Calibration DB: average means and sigmas for each run (x and y) Note: First ~200 and last ~100 runs (calibration snake runs) show bad position data

Summary Created histograms using EPICS skim files Fit all distributions Put means, sigmas, integral for all events in book_keeping DB Put ave. means and sigmas for all runs in Cal DB

Future Use survey data to find absolute position of photon beam Analyze electron beam stability (position and current)

Thanks Liping Gan Ashot Gasparian Dustin McNutly Mike Wood Mark Ito Vasily Mochalov