June 16, 2008 Tracking CDC/FDC

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Meeting Time and Place

Monday June 16, 2008 at 1:30pm At Jefferson Lab, the meeting will be held in room F228

Connections

To connect from the outside, please use ESNET 1.) ESNET: 8542553

2.) Phone:

+1-800-377-8846 : US

+1-888-276-7715 : Canada

+1-302-709-8424 : International

then enter participant code: 39527048# (remember the "#")

Agenda

  • Announcements

Minutes

  • Curtis reported that the peculiar behavior of the pulses in the CDC when the prototype was tilted (in which the pulse heights seemed to go down) seems to be related to the sagging of the tubes due to gravity, which impacts the gas gain of the tubes. The bottom tube experiences as much as 5 mm sag. Another possible source of problems is gas flow.
  • A sag test of 80 tubes glued in a ring has been completed. The tubes are spot-glued together at 3 points along the 1.5 m length of the tubes. This mockup does not show evidence of any sagging.
  • Curtis and company are in the process of gathering up the parts to build another prototype, which is expected to be completed in the summer. Due to limited readout capability this prototype will probably have 16 instrumented straw tubes.
  • The immediate goal for the CDC is to iron out the dynamic range; Curtis expects studies to continue for another week or so.
  • Simon reported posting a preliminary draft of a report on FDC ASIC studies to the portal. We discussed the noisy multi-peak behavior seen in the sample anode and cathode pulses presented in the report; the origin of some of these peaks is not completely clear. Since those pulses were recorded the grounding situation has been improved, but the preamplifier boards themselves are still exposed. Beni mentioned that most drift chambers have their pre-amplifier electronics shielded in some way in a Faraday cage. Simon will look into the feasibility of implementing that idea for the small-scale prototype.