Hall A » SBS experiments » SBS-analysis

The purpose of this task is track and summarize the status of the Gain Coefficients for the GEMs in the GMn/nTPE run period. I spent the last 2 weeks or so working on generating gain coefficients and checking output. I used the following version of the Gain Match Script: https://github.com/zwertz/SBS-replay/blob/master/scripts/gems/GEM_GainMatch.C . This version is consistent with the most up-to-date version in the main SBS-replay repo, well at least at the time of writing. The generated gain information can be found here: https://github.com/zwertz/SBS-replay/tree/master/DB_Zeke in the corresponding directory and db_bb.gem.dat file. I will work with Andrew and others in the coming days to figure out the best way to integrate these gain coefficients into the main SBS-replay DB.

All of the useful information for the GEM Gain Match can be found on the DocDB: https://sbs.jlab.org/cgi-bin/DocDB/private/ShowDocument?docid=443 . This includes all of the diagnostic plots for each set of gain coefficients, the output gain coefficient files, and the setup files that I used. There is also some more reference information, particularly correlated to the events that prompt changes in the gains: https://sbs.jlab.org/cgi-bin/DocDB/private/ShowDocument?docid=444 .

In general we concluded that there are only major changes that should affect the gain in between the main production data taking for each kinematic. So I generated 1 set of gain coefficients for each kinematic, generally focusing on acquiring sufficiently high statistics using a reasonable portion of the production data per kinematic.

Moving forward, since I think this calibration is correct, I will have the calibration checked with folks. If everything looks good, then we would just need to add the gain coefficients properly to the main SBS-Replay and then check some small subset of data prior to the beginning of the Pass 2 Replay.