Evening Shift, Thursday, August 29, 2002 Abdellah/Eugene/Jingtang/Valerie 16:15 Ask for Hall lockup. MCC is trying to send beam to Hall C. After that they will try to give us beam. We have decided to try again to get some HyCal-0 data. Last night's attempt was futile; no beam at all. 16:45 The sweep of the hall is done 17:10 Called MCC to inquire about when they plan to start tuning beam for us, the answer was in 1 hr. 17:22 We've got some premisses of pulsed beam @ 0.6 nA To save time we decided to move the HYCAL to the "home" position. MCC then sent CW beam (around 5 nA). The BIG PROBLEM is that the tagger power supply was OFF because of a water flow fault, and so electron beam was sent on the detector. After some panic we stopped the beam. We did some caculations and it looks like when we were moving down HYCAL the beam was about 37.4 mm away from G11 which is located at the upper-right corner of HYCAL. So thanks God it seems that we are OK. Moreover none of the detectors HVs tripped which is a good sign. IN THE FUTURE, Hall B photon beam should be INTERLOCKED with thw tagger power supply. If we were calibrating one of the detectors and the tagger goes down, tnat can be the end of HYCAL!!. Valerie requested a restricted access to check water leaks. 18:35 Called MCC and ask if they can interlock the beam with the tagger power supply. The suprising answer was yes. Wonder why it wasn't done ?!. 18:44 D. Lawrence - Changed the time window for the tagger TDCs from 10 us to 1us. This is done by changing the link in /usr/local/clas/parms/feconf/csrconf/primex called ROC15.hardcnf to point to the file with the appropriate settings. Now, it is pointing to ROC15_1us_8hit.hardcnf. This only takes affect at the download transition of CODA. Thus, I ended the current run (819), did an Abort, then Downloaded. No water leak was found at the tagger power supply. Eugene reset the power supply and the tagger seems to be OK. Doug Tilles then came and decided to go down and check everything to make sure the tagger power supply is behaving well. Going back to the story of the tagger-beam interlock, it seems that somebody at MCC mistakingly turned the interlock off!!. 19:30 D. Tilles and S. Christer came from the Hall, they checked the tagger power supply, fixed a wire for a temperature sensor of coil # 13 which was diconnected among other checks, now everything is fine. We called for beam permit. Called MCC for beam but they have a problem with beam leakage from Hall C. It is a least 4 nA. Of course we can not with it. Jay Benesch is working on it... 20:55 the leakage problem is fixed. Now MCC needs to work on the beam steering. 21:15 we did a harp scan. Beam profile looks OK. 21:20 we start our 1st HYCAL calibration run: beam = 100 pA, radiator = D (2 x 10^-5), master OR T1-19 = 2.4 KHz There is no trigger from the lead-glass detectors. We asked for access to change the thresholds on HYCAL sum modules. Threshold for HYCAL was set to 50mV. Timing was perfect. 2 channels were also plugged to see the signals at the counting house.