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User name Kai
Log entry time 04:22:56 on November 11, 2009
Entry number 298915
keyword=BCM noncorrelated problem basiclly solvedIt's my first time to check the bcm correlation after I installed a new 757 module to fanout the bcm in the counting house. Right now, we are missing only right arm d3 in our daq. However, I don't think it is a big problem. First of all, I can read out the d3 scaler cnt in R-HRS which is a fan out of our right arm d3 on 2nd floor detector hut. Secondly, in all of my bcm test before the experiment starts, d3 path works well. So it might be just a "cable unpluged" problem. Last, and most importantly, I got a very good result after I let the bcm d3 signal go through original bcm d10 path in the counting house side.
Fig 1 is the comparison between left and right arm PVDIS bcm asymmetry of u1,u3,d1,d3. The raw scaler counting is even convincing that there is just one scaler counting diff at most between left and right in all u1,u3,d1,d3.
Fig 2 is the comparison between the asymmetry of happex u1 and our left u1,u3,d1,d3. The result shows the clear correlation already, and it is because we haven't done pedestal subtraction of bcm scaler yet that leads to a little fat pattern you see here. Usually, when there is no beam, it will still have several hundred hz reading from scaler, and u3,d3 is roughly three times as large as u1 and d1.
So I think the previous noncorrelation problem is basically solved. It is because the bcm 740 fanout in the counting house that brought us trouble. After I set up the new module to fanout them, both test pulse result and real beam result is consistent and good.
PS: I plug back the d3 to its original d3 path, and restore the d10 path
to avoid confusion. Please, Xiaochao decide we should find reason of
missing d3 on right arm in next access which is probably just cable
unpluged or we use original d10 path, which is not very useful, to go
through d3 signal.
A copy of this log entry has been emailed to: xiaochao, rom, rsubedi, deng, dwang, pkpan
Figure 1
Figure 2
