Re: [BLAST_TOF] TOF gains

From: Tancredi Botto (tancredi@mitlns.mit.edu)
Date: Wed Apr 09 2003 - 18:26:26 EDT


Dear all,
I think we need a little better than that (not to blame adrian, indeed
he ran out of time also due to the many discussions about db).

There is a number of channels that are consistently off. They were off
also last fall but it'd beat the point of gain matching if they stay off.

On a first pass I count 8 tubes which are off target by more than 200
channels. I think that is more than what you would expect from the fit
errors. A few of these 8 actually changed since then, some stayed stable
but are/were off and, true, the results depend somewhat on what you call
the reference run. Which makes me think we may want another reference run.

other opinions ?

-- 
________________________________________________________________________________
Tancredi Botto,  		phone: +1-617-253-9204  mobile: +1-978-490-4124
research scientist		MIT/Bates, 21 Manning Av    Middleton MA, 01949
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On Wed, 9 Apr 2003, Adrian T Sindile wrote:

> Hi! > The goal today was to check the TOF gains and adjust the voltages if > needed, then to take a new flasher run with the new voltages and compare > the timing with the one from the runs taken on Monday. > > Unfortunately, I needed to spend some time troubleshooting, as CODA was > not getting any events... Tancredi helped me and we found that the > retiming OR was not properly connected. > > I took runs 3682 (magnet was ON by that time) and 3683 (field OFF). > I compared runs 2999 (last gain-matching run from November) and 3683. > Plots are included (green is the target, red is the actual value). > Both TOFs and CCs were in the trigger. > > We can see that the gains did not change almost at all. However, there are > a few channels that could be improved: LTOF 13, 14 bottom; RTOF 8, 10, 15 > bottom. They are off target now, and they were off target in November, as > you can see from the plots (that was the best we could do at that time). > Plots are also in the "BLAST trigger and flasher logbook". > > The macro I used for the plots was: > > /home/blast/blast/commis/phase2/macros/raw_macros/raw_ped_gain.C > > Tomorrow the few HV channels mentioned above should be adjusted, then a > quick flasher run should be taken to compare the timing. > In conclusion, the TOFs are as ready for beam as they were last fall, > with a few channels that will be improved by Friday. > > Adrian > > ------------------------------- > Adrian Sindile > Research Assistant > Nuclear Physics Group > University of New Hampshire > phone: (603)862-1691 > FAX: (603)862-2998 > email: asindile@alberti.unh.edu > http://einstein.unh.edu/~adrian/ >



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