Tagger timing calibrations

The tagger timing calibrations are very mature at this point in time.

To date, all T counters are timing to within 1 ns of each other. The spurious T channel 17 is well timed, but a significant trigger cable discrepancy length pushes non-overlap events in T counter 9 farther in time. However, this doesn't affect overlap Tchannels 16 and 18, since the `faster' T counters 8 and 10 determine the timing of those overlap regions.

Tagger Energy map corrections from G10

Last week, Stepan gave me the corrections to the Tagger E channel energy map.

A few days ago, I created the calibration database E_correction _factor, and filled it with the g10 values. I also checked code into CVS that reads in and applies these correction factor to the original map.

Tagger Overlap Timing Windows

It became obvious to the collaboration that our EE, TT, and ET timing windows were not sufficiently developed when Aram noticed that there were too many multiple hits in the tagger during a TAC runs. One would normally expect <1% multiplicity in the tagger during a TAC run. He was seeing around 3%. Also these multiple hits were in adjacent counters and close in time, suggesting a poor timing cut. I adjusted, by the rigorous method of 'eye-balling' the overlap peaks, the timing windows. The EE window was widened to 22 ns, the TT window to 13ns, and the ET window to 14 ns.

A more rigorous study (more rigorous than eyeballin', at least) has been done suggesting that the new values above are not perfect, but very good.

This study, which will probably become a PrimEx Note, is located here.

This note is essentially complete, and I submit it to the collaboration for consideration.