January 12, 2009 Tracking CDC/FDC
Meeting Time and Place
Monday January 12, 2009 at 1:30pm At Jefferson Lab, the meeting will be held in room F326
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Agenda
- Announcements
- Status of FDC
- Status of CDC
- Discuss decisions required to complete CDC design:
- straw configuration (Geometry C from David)
- length of straws (optimization study)
- current gas leak
- electronic hookup
- AOT
Minutes
Present at the meeting: Curtis Meyer and Yves VanHaarlem (CMU),
David Lawrence, Elton Smith, Simon Taylor, Mark Ito, Tim Witlach, Beni
Zihlman, Jim Stewart and Elke Aschenauer (JLab)
Dan reported that the frames for the full-scale FDC prototype are presently in the shop. They are supposed to be ready by the end of the week, and then they can be sent off to IUCF for stringing.
Curtis Reported that the new high-voltage board was tested on the 2nd CDC prototype in mid December. Information, including some scope traces are on the CDC page of the wiki. He also reported that the first parts of the electrical connection for the CDC were done, with the longest wire being about 4.5 inches. Still to be done is Slava's plate with holes in it. We also have setup some tests on the glue joints to see if we can identify where the leaks are occurring in the new prototype. This is curing at the moment, and we hope to run ethane through it later this week. Finally, work will continue with the new prototype.
David gave us a status report on where things stand with the length studies of the CDC/FDC. Unfortunately, the combined tracking is currently not working and he is trying to get that back to where it was in mid 2008. Until this is done, it is difficult to carry out the needed studies. He also presented some information on the 30-degree tracks in the CDC. They appear to have fewer hits than track of larger angles, even though they have been generated with the same number of hits. David speculated that this may be due to the non-uniform B field, and perhaps the pattern recognition needs to have a loosened crietria. Jim suggested that if he were to replace the field with a uniform one, that he should be able to see if the field is the problem.
Simon then presented a status report on the Kalman filter. He has now got it working for FDC alone, and combined FDC/CDC tracks. He does not fully understand some of the comparisons at this point, but what he has looks very encouraging.
Finally, there was discussion on what needs to be done to be able to order parts for the CDC. We believe that the straw layout is that from geomerty C, with a 4-4-4 close-pack layout. This was based on all the studies from 2008. The final length (which actually also determines where the holes are drilled in the endplate) is awaiting the results of David's studies.
For the gas leaks, we have studies going on now, but it seems that we need to make sure that the tracking volumes is sealed by the inside and outside shells of the CDC. We expect to know something more later this week. Finally, the electrical connection studies will continue.
We then tried to identify what can be ordered. The major items are as follows:
- Endplates -- awaiting Monte Carlo study.
- Strawtubes -- can be ordered, JLab will do this.
- Wire -- can be ordered but should be combined with the FDC and possibly HallB
- crimp pins -- can be ordered. Can these be coupled to the HallB order?
- donuts -- awaiting final glue studies.
- glue -- will be ordered closer to when we need it (shelf life).
