Minutes of the BEAST meeting
Friday August 28 12:00 JST

  • Schedule:

    The base of the concrete shield was installed. EFC installation is beginning. At the end of next week, Haba and Rosen will begin beampipe installation and alignment. An updated BELLE/IR installation schedule is now available.

  • Structure and Construction:

    Sahu and Rosen reviewed BEAST construction status. The beast bed, beampipe support, and CsI(Tl) shelves were shipped to KEK on August 24th.

    All 3 sets of drift tubes are finished. The outer drift tubes are being conditioned. The SVX mechanical support structure is finished. All the diode preamp boxes are complete. The diode boxes have been made. The MOSFET modules are complete.The mechanical design of the diode/MOSFET layer is complete and is being machined this week. A system test of all the detectors began on Saturday.

    The BEAST detector components will be taken by Sahu to KEK on September 9th.

  • Diode readout:

    Gary Varner reported on tests of the diode readout PC boards. The DC output works well. After considerable effort, the AC output works but the sensitivity is poor. With a source, the minimum detectable signal for the AC part is 6 mips. It is unclear whether the AC part is useful. Since the rate sensitivity of the DC part is about 2.5 mRad/s, Gary proposed converting the components of the AC part into a higher gain (higher sensitivity) DC monitor. The existing DC part has a gain of 10 mV/nA while the proposed high gain part would have a gain of 10 mV/pA. It will take about 2 weeks to modify the existing boards with this all-DC scheme. Making a new board with desired AC capability would take on the order of two months.

  • KEK resources:

    Haba reviewed the KEK resources available for BEAST operation. He has now procured 9 x 12 channel scalers, 2 x 2249 ADC, 2 x NIM scalers, a large number of lemo cables, as well as +-5 V, +-15 V, and 600 V power supplies. He has ordered the HRS gas needed for drift tube operation and is investigating bubblers and flow controllers. Special small electronics racks were ordered since the BEAST "cave" has a very low ceiling. A precise ramp generator will be needed for the new diode readout circuit.

  • CsI(Tl):

    The CsI(Tl) crystals will not be available until the end of September.

  • DAQ:

    An additional IOTECH module will be purchased to fulfill the DC channel requirements. This is necessary even if the CsI group does not add additional monitoring channels.