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User name V. Sulkosky
Log entry time 10:51:02 on February 2,2009
Entry number 258684
This entry is a followup to: 258581
Followups:
keyword=Gas Cerenkov PMT #6The left gas Cerenkov PMT #6 ADC appears to have started to have
problems with run 5745 (taken on Saturday afternoon). The first
symptom was that the single photoelectron peak shifted from channel
160 to about 110. I looked through most of the production runs
starting from this period and I have seen that the problem is
intermittent. For example, Figure 1 shows the ADC amplitude for this
PMT from run 5792, which matches the golden run very well. Then in
Figure 2 is the spectrum from run 5795, which shows a amplitude
reduction.
I haven't seen any change in the TDC spectrum for this PMT. The
intermittent behavior leads me to believe that the problem might be do
to a flakey cable. During the beam studies tomorrow, I will look
into this possibility.
FIGURE 1
FIGURE 2
