FDC Weekly Meeting
Date: October 3, 2007
Participants: Daniel, Simon, Brian, Chuck, Tim, Roger, Kim, Fernando, Bill
Next Meeting: October 17, 2007
News of Interest
- Bill Crahen has joined the Hall D group as a mechnical engineer. He attended his first FDC meeting and was duly impressed. He will have some role on the FDC project T.B.D.. - Elke announced at this morning's Hall D meeting that there will be another official drift chamber review that will take place before spring. The main purpose is to address the issues raised during the March 2007 review. More details to come.
Composite Wire Frame
- No work done yet on performing the stress test. Brian will work this into his schedule as soon as he can. He has a two week trip coming up this month at some point, but is not quite sure when. - We agreed that the basic stress test should be completed before construction of the three FNAL test wind planes.
- No work done yet. Brian will get to this soon. - We discussed a plan to butt the neighboring cathode pieces up against each other and to seal the joint with kapton tape. This would eliminate the overlap that was used in the last prototype.
- We reviewed progress by Kim on the layout of the STB boards. Chuck has completed the layout and positioning of the daughter board connectors on the cathode frames and the STBs. He will pass this information on to Kim to include in her design. Her plan is to work primarily on the STB layout before turning full attention to the HVTBs (which are much simpler to design).
Magnetic Field Tests
- Progress on the ongoing Hall B magnetic field test of the small-scale prototype was discussed. In the last few days we completed a reconfiguration of the test setup to move two MWDCs into the magnet gap and to add the PRIMEX photon profiler below the magnet. This was done to reduce the affects of multiple scattering of muons in the magnet steel on our computed residuals at the small-scale prototype location. - Simon is now taking data to calibrate the MWDC chambers to define their geometries. - We are still awaiting delivery of shielding power and signal cables for the MWDCs. However at present, we are able to operate with a 2.0 V threshold on the LeCroy 2735Bs due to some cable rearrangement. However, the noise levels are very sensitive to cable placement. Even the slightest move can bring on the noise, bring on the funk. - Simon has also replaced some of the MWDC preamp cards that seemed to be noisier than the others. - The photon profiler is in place and essentially cabled up. Working to deal with problems with the HV power supply. Other than that, everything else is ready to read out this device. The device consists of orthogonal planes of 64 2-mm square scintillating fibers. We will read these channels out through F1 TDCs to give us another space point below the magnet (where the resolution is not super critical).
- Brian has not gotten to the mounting of the +/-75 deg cathode boards. He has everything he needs to do this work, but has not had time. He will get to this soon.
Cathode Rough Out
- Roger reported more details on the cathode layout redesign due to the central beam hole. We confirmed channel counts and cathode pitch. This number is 5-mm, with a 1-mm gap between neighboring strips.
Cathode Board Readout
- No progress yet. Stay tuned for an update from Roger on a design and the construction of a mechanical prototype.
- Brian will contact Karen Kephart at FNAL to begin discussions on when she will be ready for us to send up the 3 wire frames for the winding test. The plan is that some contingent of FDC folks will drive the frames up to FNAL and stay there for the course of the test wind (hopefully just a few days). - This test wind will allow us to better normalize and baseline the costs of the FNAL test wind in terms of time per plane.
Daughter Boards/Transition Boards
- Fernando will deliver pictures of the front and back of both of these boards.
- The Spectrastrip cable has arrived sans connectors (which are still more than a month away from arriving). However, Gerard Visser can already start doing some tests with the bare cable. - Simon will get in touch with Joe Beaufait about contacting Gerard and finding out what he needs. Joe will then ship the cable up to IU.
- The FDC short-term work list has been posted on the FDC web site (see http://www.jlab.org/Hall-D/detector/fdc/). This is continually being updated and DSC welcomes any feedback or comments from the group.
Minutes prepared by Daniel. Send any comments or corrections along.