I looked at the ET screen that Adrian left. Full of messages:
"Error writing events... Cancel ET read loop!"
Did a df on dblast07. Found that /scratch/dblast07 has no free space.
The ET error message is not very helpful, but lack of disk space was the
problem, not CODA per se.
Need to clean /scratch/dblast07. I'll consult with Tancredi, make sure
any good runs from the last 3 months are on the spuds, then delete lots
of files.
Karen
Adrian T Sindile wrote:
>
> --------------------------------------------------------------------
> Systems looked at: TOFs, Cherenkovs
> Methods: cosmics, flasher
> Problems: CODA - crapped out at high rate and never recovered
> ---------------------------------------------------------------------
>
> Since there was no beam tonight, I chose to work with cosmics and the
> flasher on the TOFs - starting the gain fine-tuning. TOF voltages are
> the same now - so no worry for the WC group!
> First, following John's suggestion, I took a flasher run (1975) to have as
> reference for TOF timing, before playing with voltages.
> I created then cosmicLTOF.settings and cosmicRTOF.settings - trying to
> avoid CODA problems created by high rate from both sectors simultaneosly.
>
> Still, CODA gave me trouble all night - the ROCs were sleeping and I
> barely managed to take two runs (1985 - both cosmics and flasher and 1986
> - only cosmics) switching between ROC, ROCr and ER modes every 5
> seconds... At least this is a starting point for future fine-tuning.
>
> I dropped the TOF tuning since it required CODA and I turned to the
> Cherenkovs, at Tancredi's plea for help with this system.
> I recorded all the signals from the right sector in the TOF logbook, page
> 104 - in the D-tunnel I triggered on the photodiode, setting the scope in
> "average" mode (last week I had done this triggering on the individual
> PMTs and it was nearly impossible to tell the amplitude - signals were
> jumping etc.)
> In short, signals are everywhere between 0.1 V to 1.3 V, varying by a
> factor of 3 on the same box even - but most of the tubes on the same box
> are pretty matched.
> Anyway, they need fine-tuning and this can be used as a starting point.
>
> Tancredi told me he had discovered light leaks on one left Cerenkov, I
> suspect light leaks on the right too, judging by the funny scaler rates
> and the crappines of the signals when triggered directly on the PMTs (not
> on the photodiode - by the way, even triggering on the photodiode gives
> you a flaky signal, Tancredi's suggestion to put the scope on "average"
> mode really helped).
>
> 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/
This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:28 EST