From: Frank Geurts (geurts_at_rice.edu)
Date: Wed May 14 2003 - 16:53:13 EDT
W.J. Llope wrote:
[...]
>
> the caveat (comments?):
> the one thing that makes me wonder though is that the number of
> "adc hits" is also a factor of very roughly ~2 "low" (evaluated
> by eye from the generic hit patterns)... this is what
> lead me to believe earlier that this was a fee or det problem (so
> i'm still thinknig about this too)...
>
> given the intermittent nature of the effect, and assuming the
> problem is indeed not inside the pole tip,
> it's possible that simply carefully reseating this tdc could
> stabilize this... i see no harm whatsoever in trying this
> if there is an access...
> this i bring up since this unit generally works fine -
> i.e. it was fine through all of the dAuTOF running...
>
agree
btw. no trace in the daq log files of any problems with TOFr TDCs,
although we still see on the average of 6x/day TOFp ADC DMA errors show up.
> otherwise (and assuming we can indeed isolate it to the tdc)
> we could consider replacing this tdc but
> we have to decide if just reseating it is worth an attempt...
> that's becuase if we just replace it we'll have to time-calibrate
> both this tdc and the replacement separately during the offline
> analyses if we want to use all the p+p data ...
unless the module really dies, I wouldn't go and make calibration even
harder by changing this module. Any news on today's data?
>
> but by the next real spill these channels may come alive again
> just by themselves if history is any guide... sigh.
>
> we have to decide what action we want to take here... comments?
> suggestions? thanks, regards
> bill
>
> _________________________________________________________
> W.J. Llope, Ph.D. Res. Assoc. Professor
> http://wjllope.rice.edu/default.html
> llope_at_physics.rice.edu
> T.W. Bonner Nuclear Lab.
> Rice University, MS-315
> 6100 S. Main phone: 713-348-4741
> Houston, TX 77005-1892 fax: 713-348-5215
>
>
>
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