Minutes of the BEAST meeting
Friday December 4th 12:00 JST



  • Organization:

    The BEAST shift schedule was revised in accordance with suggestions from Haba-san.
    It is now posted on the BEAST WEB page. The URL is

    http://www.phys.hawaii.edu/~beast

    and is also linked to BELLE Commissioning/Operations page

    http://bsunsrv1.kek.jp/bdocs/belle_ops.html

    which has daily updates on KEK-B status from the 9:00 a.m. meeting.

  • General:

    The DAQ is ready. There is a display which includes drift tube rates that can be accessed in the accelerator control room via the network. It should be updated to include diode rates. The data will be stored in NTUPLES which can be analysed either on-line or on the bwgxx computers. The data storage requirements of BEAST are not yet clear.

    So far, the software for the NSM connection to KEK-B works but it is not yet possible to read out accelerator parameters such as vacuum pressure, beam current or magnet settings.

    We need to monitor integrated radiation doses at the CsI and EFC crystals. This can be done with MOSFETS or simpler devices.

    Sahu and Rosen fixed a grounding problem associated with the shields on cables.


  • Goals:

    We discussed the initial goals for operation and analysis. These goals are:
    1) Establish instantaneous background doses and rates to the accelerator control room
    2) Record data reliably and allow system to be operated by shift personnel
    3) Determine T(Takasaki number). This is the dose (in mrad/sec) at the location of the silicon readout electronics.
    4) Observe correlations of doses and rates with accelerator parameters. Initially, these parameters are I_beam, P(average pressure +-100 m) and magnet parameters.
    5) Measure background distributions versus phi, z.
    6) Determine relative fractions of particle and SR background (T vs I, ratio of diode rates, X-ray lines).
    7) Make detailed comparsions of the simulation and the December BEAST lattice.


  • SR X-ray Detector:

    Varner discussed work on a home-made X-ray detector using silicon PIN diodes. He is able to observe lines with a resolution of around 4-5 keV. A mip corresponds to 80 keV. He has examined a variety of sources (Tb, Rb, Cu, etc...). The X-ray lines shift in energy for different elements but he does not understand the calibration. If there are large SR backgrounds in KEKB, we may expect fluoresence peaks from the tungsten masks and the copper beam pipe.

    An additional power supply will be needed to operate the X-ray detector. We are also investigating buying a non-cryogenic CdZnTe detector.