DIRC Operations Report

Wednesday 2007/7/11 to Wednesday 2007/8/15

Oncall: Rolf Andreassen, Justine Serrano
Fast Monitoring: Rolf Andreassen, Justine Serrano, Jose Benitez


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Luminosities this week

PEP peak lumi: ~1.08 x 1034 (last week: ~1.05 x 1034)

PEP delivery: 3.82 fb-1 (last weeks: 3.66 fb-1)

BaBar integrated lumi:3.68 fb-1 (last weeks: 3.21 fb-1)

Run 6 total delivery: 76.27 fb-1

Run 6 total BaBar recorded: 73.34 fb-1 total, including 6.21 fb-1 off-peak data

PEP activities/issues since last DIRC meeting

  • 07/10: ROD. They fixed a vacuum leak that was causing a lot of background in the DIRC
  • 07/17: A test to remove the abort gap in the beams was unsuccesful due to beam instabilities when filling the gap.
  • 07/20: HER Beam-current monitor (BCM) broke so no trickling was possible until ~July 27. In the meantime the HER was operated on a fill-coast-fill mode.
  • 08/01: Another leak in HER ring (IR2 7035) is causing vacuum spikes => Install helium lines to look for vacuum leak. Leak is far from the DIRC so background conditions are OK. Leak has not been found to this day.
  • 08/02: No beam during most of the day to fix a water leak in the Linac which shorted a magnet.
  • 08/03: Starting to have problem with the RF station 4-3, this is now limiting LER current. Possibly not fixable during this run, but they will replace it with a PS from the HER.
  • 08/10: Switched to Offpeak running.

    BaBar activities/issues since last DIRC meeting

  • 07/17: DCH chiller broke. Karl replaced the filter and the pump. Didn't cause any down time.
  • 08/11: BaBar magnet tripped causing a few hours downtime.
  • 08/13: Since last week DCH has several LV drops in one FEA. They need a 1 shift long access to replace this FEA. This will probably happen next week.

    DIRC activities/issues since last DIRC meeting

  • Integrated scaler saturation seen recently was due to a small gate in Jerry's electronics. Jerry fixed it.
  • 07/19 : Matt disabled SOB dump valve for the UPS battery replacement, but the replacement did not happen, it will happen today.
  • 07/31: Neutron counters' power supply tripped.
  • 08/02: One christmas tree showed up in sector 5 during cosmic data taking. We turn off channel 6 in sector 5 (Set V0 and V1 at 110V) to avoid trip. There was another in sector 11, but it disappeared after turn off and on the high voltage (channels 5 and 10).
  • 08/02: Masked out a noisy channel in sector 10.
  • 08/03: We put scaler alarm thresholds back to their original values before July 11 vacuum leak.
  • 08/06: Neutron counters' power supply tripped again, Matt replaced the power supply.

    See DIRC logbook for details

    Lumi and Background this month