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    User name P. Monaghan

    Log entry time 08:12:39 on January 8,2005

    Entry number 138490

    keyword=Owl Shift Summary

    Owl Shift - 8th January 2005

    SL: Peter Monaghan
    TO: Aidan Kelleher
    3rd: Eli Piasetsky

    00:00 Shift begins with us waiting on MCC delivering beam to the hall; anytime soon hopefully.

    00:30 MCC call to inform us that they are unable to get beam past the Moeller quadrupoles; the quads are reading zero current despite the setpoint being 41A. MCC are calling there technical support for help.

    01:00 MCC called to tell us that they were sending in 'electrical engineering support' (EES) to work on the Moeller quads. We decided to also take the opportunity to go into the hall to look at our log book and figure out how to get our proton/neutron scaler GUI working.

    01:15 cosmic run 1491, about 180k events, was analyzed.
    anlyzer gives error messages for the 1492-"storing too much varibale size.."

    01:40 Finishing making notes from the logbook in the hall and we now have our scaler GUI back up running again.

    01:45 MCC called and told us that the EES found no current at all in the Moeller quads and they are now contacting the 'Engineer On Call' for help; at least another 30 minute delay.

    02:30 MCC are now trying to ramp up the Moeller quads and we'll see soon if the work was successful or not.

    02:55 MCC are going to try and send tuned beam into the hall.

    03:15 Noticing very high scaler rates on the proton detector at the moment and we decided to turn of the HV to it.

    03:25 MCC asked for a setting of the BCM current limit - for the moment we will have it set to 20uA. When the experiment needs to run higher, this limit must be changed accordingly.

    03:30 Noticed that the neutron detector channel N2-6L high voltage had tripped (reached a current trip limit) so we reset it; the setting was -2600 V and we decided to reduced this a bit and see what happens to the rate when beam is in the hall - currently it is set to -2200 V.

    03:55 MCC have successfully delivered beam into the hall and are now going to try and give us 5uA centered at (0,0) on the BPMs. The overcurrent limit on the BCM has now been set to 25uA.

    04:00 MCC delivers 5uA CW tuned beam to the hall; everything looks good and now we are going to do a harp scan.

    04:10 Harp scan complete; scanner 6 gave horizontal width = 97um and vertical width = 78um. Moving to the BeO target to check the spot size.

    04:20 Discovered that the fileserer had crashed again! Funnily enough it was about the same time yesterday morning that it crashed.

    04:36 Ran spot++ to check the beam spot on the BeO target; spot was 0.5mm wide in x direction and 0.8mm wide in y direction. Position was 0.57 in y and -0.04 in x.

    04:40 Now try powering up the BigBite magnet. Ramp up in 100A steps and look at the beam position monitor. Beam position did not change much at all (see separate log entry) and MCC can correct for the small amount of steering of the beam by BigBite.

    04:45 Noticed that the high voltage for the VDC in the right arm is not working correctly. Will email Jack Segal about it but not try to reset it yet since we are not using the right arm at the moment.

    05:05 Changing targets to the 4cm Hydrogen target and then we will try taking data.

    07:00 Problems with the daq/trigger rate that we are being swamped and seeing only an event rate in coda of 50-60 Hz. Need to talk to the experts about this.

    08:00 Shift Ends with 5uA beam incident on 4cm hydrogen target and we are continuing to investigate why we have such a low event rate despite our attempts to use only certain event types as triggers (for example, T3 and T6).


    Run Summary

    1491 - Cosmic run - ~180000 events

    Neutron Array: -
    No ADC for Veto 1-8 Left and 1-8 Right
    Strange TDC spectrum for veto 1-6 Left.
    Major change in position parameter required for channels N1-28, N2-6, N3-8, N3-19.
    Major high voltage change required for channels N2-6L and N3-19R.

    Proton array: -
    Auxiliary plane channels 10, 28, 54 and 55 have 'weak' ADC spectra. Auxiliary channels 34 and 53 may have too high HV set - according to ADC spectra.
    ADC channels E-2R, E-17R and DE-23R seem 'weak'.
    DE-17L ADC spectrum shifted such that the pedestal is above 300 in the ADC - maybe HV is too high.

    1492 - Cosmic run - ~ 200000 events
    Tried to analyse this run but at some point a repeated error message appeared saying that it was 'storing to much variable size..'.
    Ended up not completing the analysis of this run.

    1493 - Cosmic run - ~ 50000 events

    1494 - Cosmic run - ~ 120000 events; note, the high voltage to the proton detector was switched off during this run (high scaler rates as MCC tuned the beam into the hall).

    ---------------
    1495 - 1505 Runs with 4cm hydrogen target in place where we changed the prescaler values; unfortunately, the event rate was still very low.
    ---------------

    1500 4cm Hydrogen target with everything prescaled out except T3 triggers from left arm; still a low event rate ~ 50 Hz

    1501 Same target but now everything prescaled out except T6; still a small event rate.

    1502-1505 Checking prescalers again.