Log entry time 10:38:31 on February 12, 2011

Entry number 346517

This entry is a followup to: 346516

I plot the ADC&TDC for S1 2nd Scin. Bar, and I also plot another PMT channel 3L for comparation.

We can see clearly from the scope that S1-2L is very noisy and some of noise have comparable peak with Cosmic ray signals. They distribute randomly after the real signal. Too bad that I don't know how to save a graphic to demonstrate this problem. Alex will show me how next time.

Then I checked the S1-2R PMT and found that it is also very noisy. However, the case is different with S1-2L, that the noise forms a broad peak that stay a certain distance from the real signal peak. And in between this two peaks, the signals of noise are quite small by comparing with those two peaks.

We might guess that there is a light leak for the S1-2 Scin. bar, but it does not explain what we saw on S1-2R.

Figure 1