Log entry time 07:33:22 on March 10, 2011

Entry number 351173

This entry is a followup to: 351161

Followups:

• 351174 03/10/11 07:56 rshneor BigBite wirechambers missing wires looks like T0 calibration problem
• 351186 03/10/11 09:42 lselvy Known problems

I replayed run 2658. The errors on out of bound channels started around
event 170000 (see hlog 351172).


Below are plots of u1 for events:
0-170000 - the one with only 1 noisy bunch
170000-240000 - the one with 3 noisy bunches
(I'm showing all hits not only the first one)


1)
It is clear that the noisey bunch around wire 20 is real. From what I see
in Igors log and my tests - its not coming from the first hit but buileds
up, more indications that it's HW?


2)
The more important part is the other two noisy bunches.
They apear to come only with the latter events only.
I know that the statistics is marginal at best but still it is clear.



This might affect the HV\treshold scan that Tai did a few days ago.
I hadn't analysed it yet so I can't say waht's going on there.
(I hope to analyse it today and see where we stand)



We must resulve this isue today - before starting production.

Figure 1

Figure 2