Minutes of the BEAST meeting
Friday February 5th 12:00 JST

  • KEK-B General:

    Collisions at low current were made at 7:05 a.m Friday. Both horizontal and vertical deflections due to beam-beam interaction were observed. HER problems are getting solved and injection efficiency has improved from 30% to 56%. LER e+ currents up to 60 mA were stored. HER e- currents of up to 26 mA were stored. This weekend, KEK-B plans to store currents up to 100 mA e+ and 50 mA e-.

  • Organization:

    After an NSM crash Thursday night around 1:00 a.m., the BEAST DAQ was stopped until 11:00 a.m. (the BELLE DAQ also crashed). The shifter contacted Bozek but DAQ experts were not called in. BELLE management has now officially requested that cosmic ray shifters maintain BEAST so that this kind of problem does not occur in the future. Expert call list and BEAST operation manuals will be posted in a more promenient location.

  • EFC:

    Minzu Wang reported that the EFC back to back trigger has been improved. Energy thresholds have been turned up to about 1 GeV. This dramatically decreases the fake rate. No signal was seen during collision, but the expected luminosity should give a rate of 10**-3 Hz. Calibration and improvements are continuing.

  • Diodes:

    Some diodes have been killed by injection while others have large leakage currents which are out of range for the IOTECH. 8 new diode boxes were constructed by Marc Rosen and crew. We plan to install these during a shutdown during the week of February 20th. We hope to also install new MOSFETs to replace those that are nearly out of range. Australians will investigate availability of MOSFETs.

  • DAQ:

    Moffitt fixed some problems with NSM KEKB communication, ntuples and auto-repeat mode.

  • BEAST SVD:

    The executive board officially recommended that BEAST SVD ladders be installed. The SVD group should help debug readout and DAQ. At the moment, the spare DOCK will be used for debugging TTM by the Krakow group. The end of February is the earliest time that the BEAST SVD could be installed.

    It is important to understand better the injection loss events that have killed or severely damaged diodes. We should also check for spikes in steady state running. Ways of observing these spikes with CsI(Tl), diodes, Moffitt's injection loss monitor and drift tubes were discussed.