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User name Kai Pan
Log entry time 17:09:12 on November 07, 2009
Entry number 298138
keyword=PVDIS DAQ: swapping cable, delay timing, threshold, offset, width1. swapping cable: To solve the problem described in halog 297915, we go to check the prl1, prl2 cable map meticulously. We do find the problem: the cables are all right before going to the sum8, however, the output of sum8 doesn't agree with its input. For example, in group1 "PS(prl1)" sum8, the input is prL17,18,19,20 and prR17,18,19,20 which in fact are SH(prl2) signal. The same mistake was also found in the "SH(prl2)"sum8. So what we cut on "PS" is actually cut on "SH", and what we cut on "PS+SH" is actually "SH+PS" which doesn't hurt. In addition, it also doesn't affect the HRS ADC of which the signal goes from the back of the sum8 separately and independently. It basically can explain the problem in halog 297915. After finding this, we just swap the output cables of those sum8 between "PS" and "SH". So currently, the left side sum8 is the real true "PS" which was mistaked as "SH" before. The right side is the real true "SH" which was mistaked as "PS" before. The labeling there is a little confusing. But PVDIS students know what it is. In addition, there are three labeling conventions on the left arm prion rejectors, I went with Vince yesterday and made the following map which is useful:
http://hallaweb.jlab.org/experiment/E05-007/vasulk/document/PionRejectorHVmap_v3.html
2. delay timing: Bob and Vince bring us 26 56ns cables, and 5 124ns cable. We combined 2 56ns cable together to form 13 113ns long cables, which also means those 5 124ns cables is unusable, because we want precise timing on all groups there. I will go to find more those 56ns cables with Vince.
3. current discriminator threshold: Left narrow: DH:88,DM:25,DL:20, and all "wide" set to 100 Right narrow: DH:91,DM:20,DL:20, and all "wide" set to 100
4. Phillips 740, Lecroy 428F offset is tuned to 0 yesterday.
5. VETO width is 150ns on both arms.
Attached is a very preliminary 2D PID histograms to show that it is
pretty promising on the left arm now.
A copy of this log entry has been emailed to: reimer, xiaochao, rom, dwang, deng, rsubedi, pkpan,
Figure 1
