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    User name Armstrong

    Log entry time 16:10:48 on November 25, 2009

    Entry number 302564

    keyword=Shift Summary - day shift

    Shift Summary   Day Shift   November 25 2009   (PVDIS)

    D. Armstrong   (SL)
    N. Muangma   (TO)
    C.-M. Jen  (3rd)

    8:00   Status at start of shift:
    - Beam on, 109 µA, 6.067 GeV, Production data-taking underway
    - Slug 8 in progress, IHWP=IN
    - Dithering is ON, FastFeedback ON, beam positions nominal, Raster=4x4
    - RHWP=1200, Pockels Cell(+) = 8.15, Pockels Cell(-)=6.55, PITA slope=21202
    - P0 for Left arm = 3.660 GeV, negative polarity
    - P0 for Right arm = 2.630 GeV, negative polarity
    - Target 20 cm lD2 (loop 1) fan speed = 60 Hz

    - Alexandre seems to be running Compton DAQ remotely, but background is high (2 KHz/µA).
    - Dead time on the HRS DAQs is very high (order 90%) for runs since 5291(right arm) and 25747(left arm) because the FADC readout was turned on by Kai Pan (see Halog entry 302452).

    10:05  RF trip rate over the last couple of hours is about 15/hour. Seems rather high.
    10:40   Bob Michaels calls: he will do expert analysis check-out. He also suggests that we try increasing prescale factors to reduce the deadtime while the FADC is being readout. Kai Pan will try this.

    After a couple of junk runs (problems resetting the pre-scale factors and a CODA crash), we have adjusted the prescales as follows,
    for runs 5298 (right arm) and 25755 (left arm) while run 14207 (HAPPEx) continues:

          Left arm    Right arm

    ps1  4000      1200
    ps2  2800       800 
    ps3     2        60
    ps4     2         4
    ps5    10        80
    ps6  2800        80
    ps7 40000      8000
    ps8   200       200
    
    The effect is that the deadtime at 110 µA goes from 80-90% down to 30-40% for left arm and to 50% for right arm.
    So we have improved, but maybe not gone as far as one might like.

    11:15   MCC calls - they lost an IOC for the RF; beam will be off for at least 15 minutes.

    11:43   Beam returns.

    12:55   MCC calls - beam will be off for 30 minutes or so, for orbit and pathlength checks - goal is to improve rates for the Compton.

    While beam is off, we turn the FADC readout off again and reset prescalers to appropriate values for no FADC.
    See: halog entry 302534

    13:30   Beam returns. Start new runs. Compton rates look much improved!

    14:30   HAPPEx run hangs up. 81.6K events - ROC 23 in disconnected state. KCODA and restart. It is important for shiftcrew to stay vigilant to ensure HAPPEx DAW continues running. I find keeping Runbird on a monitor screen is up a convenient way to monitor this.

    14:50   Alex calls, and says Compton tuning is completed. We have been taking that data regardless during the tuning.
    At present, we see about 60 Hz/µA for Compton Photon Detector - was 1000-2000 Hz/µA before tuning began.

    15:35   Xiaochao and Ramesh turn on 1 KHz tagger at start of runs 14213, 5301, 25757. Will be a 20 minute run, should not count these pairs as "good pairs".

    16:00   Shift ends Happy Turkey Day everyone!


    Runs Taken

    DAQ     Run Number  Events or Good Pairs
    ---     ----------  --------------------
    
    HAPPEx   14204                 39.4 K
    HRS(R)    5292       0.91 M
    HRS(L)   25749       0.70 M
    
    HAPPEx   14205                 36.3 K
    HRS(R)    5293       0.24 M
    HRS(L)   25750         ??
    
    HAPPEx   14206                 31.3 K
    HRS(R)    5294       0.90 M
    HRS(L)   25751       1.20 M
    
    HAPPEx   14207                 (continues) 
    HRS(R)    5295       0.17 M
    HRS(L)   25752       0.19 M
    
    HAPPEx   14207                  (continues) 
    HRS(R)    5296,  5297  (JUNK)
    HRS(L)   25753, 25754  (JUNK)
    
    HAPPEx   14207                 29.5 K     
    HRS(R)    5298       0.20 M
    HRS(L)   25755       0.19 M
    
    HAPPEx   14208                 42.4 K        
    HRS(R)    5299      (continues)
    HRS(L)   25756      (continues)
    
    HAPPEx   14209                 11.8 K        
    HRS(R)    5299       0.59 M
    HRS(L)   25756       0.59 M   
    
    HAPPEx   14210                 16.7 K
    HRS(R)    5300     (continues) 
    HRS(L)   25756     
    
    HAPPEx   14211       (JUNK)
    
    HAPPEx   14212                 32.4 K
    HRS(R)    5300       1.23 M
    HRS(L)   25757       1.41 M
    
    HAPPEx   14213       (underway)             (1.109 kHz tagger on)
    HRS(R)    5301       (underway)
    HRS(L)   25758       (underway)