Log entry time 02:14:33 on March 17, 2011

Entry number 352226

Followups:

• 352239 03/17/11 04:38 Higinbotham Check for Protons First

I think that we have some hardware issues for BigBite. I think that the
this hardware issue arrise from two points that I need to clarify.
1) retiming for BigBite
2) Data recording for the 1190 TDCs
3) the readout window for F1 TDCs
4) reference channels for BB TDCs

================
1)I will start from the question concernig the point 4.
The reference channel for the TDCs are comming after the retiming or
befor? I mean that is the ref signal is copy of L1A or is it retimed L1A?

2) I have problem with the reference signal for 1190. The BigBite
libraries are built in such way that they deal with specific structure of
the signal and the ref, However both raw TDC and ref signal spectra are
different between 1190 and F1. (plot for ref channel attached. The TDCs
spectra are posted in Halog:  352165   )



3) we have a cut off if we look on the TDC vs ADC spectra that I posted
earlier (halog:  352159   )

1) This is more complicated...
if I look on the DBB.t3[0] distribution (LHRS trigger copyt that comes to
ROC 10, fastbus for wirechambers) I see to peaks. one peak is when we
have retiming from L1A and the second is when we retime from L1A (L1A
carry the time and NOT BB). All the events in middle are from "succeded"
retiming. This distribution is with cut on trigger type 3 (LHRS). The
common stop for this crate is Retimed L1A.

When I plot this distribution VS left TDC + right TDC for 1190 I get NOT
CORRET PATTERN.
I expect to get vertical line (without any slope). 
For 1190 for some reason if I plot raw TDC left+ right I get vericla
line, however, it doesnot make sense becose I didn't substruct ref
channel, this shouldn't work (I think)!
I post same plots for F1 TDCs to compare. However it's clearly seen that
our readout window is to short.


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Due to all of the reasons above I can't be sure that we can identify even
the double coincidence peak for BB.
=================================

1) Why we are using retimed signal for E/ dE TDCs and ADCs? Shouldn't we
use the retimed signal only for wirechambers?

2) Should we send one copy of the E TDCs to 1877 (In ROC 8. ROC that
don't get retimed signal)

3) Why we are sending all our DBB databases to ROC 10 where we have
retiming from BB, while most of the parameter have nothing to do with it?


 

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