Minutes-5-20-2010

May 20, 2010 FDC meeting

Tentative Agenda

1. Production
   • 727 B.C. status
   • production planning
2. Electronics
   • fADC125 status (Fernando)
   • PCB status (Kim, Fernando)
   • grounding (Fernando, Lubomir)
3. Cathode redesign Bill's changes proposed on the last meeting (Bill, Roger)
4. Full-scale prototype test results
   • tests with fADC125: FDC Log Book, pages 456 and 457; one event using fADC125 (Lubomir)
   • cosmics tests (Beni)
5. Other

Minutes

Participants: Bill, Mark, Casey, Simon, Eugene, Glenn, Fernando, Beni, Lubomir, and Gerard on the phone

Production

- Bill has given updated drawings with our requirements for the off-site space to Ron Lauze. Ron will work on the infrastructure of that building.

- Bill has reviewed the production planing document linked above. There were several questions regarding the testing of the FDC layers and packages with cosmics. What we want to do will depend on the available time. For now we assume one day-night for testing per layer. We will come to this again after creating the production flowchart (Bill will take care about the latter). Fernando explained us the procedures related the the PCB inspections/tests. We need to set-up a place for testing, preferably in 117, and have one person trained for that. Bill mentioned that (from mechanical point of view) the most important is the quality of the PCB edges.

Electronics

- Fernando and Gerard informed us about the last week fADC125 tests. The module was installed in the VXS crate in 126 and connected to three FDC cards (top, bottom cathode and an anode). The tests were done using Gerard's code to configure the module and read the data into a file. Beni wrote a code to read the file from root. The DAQ group will work on incorporating the fADC125 into CODA system. For the beginning, they promised us (within two weeks) to write a simple interface to the module so that Beni can include it in the cosmics set-up. We discussed the heating issues we had with the modules in the VXS crate. Beni said there were problems with the F1TDCs there. Gerard asks us to be cautious and not have the fADC powered for long time (hours).

- Kim received the third quotation for the PCBs from TriLab; the price is more than $200K, which is factor of 5 higher than the CEM's price. Fernando generated the step files for the PCBs, Bill checked for consistency with his 3D model: three holes had to be modified and Kim did it. Kim will submit the PR for the PCBs.

- We discussed the noise bursts we observed on the FDC signals. Beni identified the source: the CAEN HV crate used for the scintillator PMTs. At the same time we discussed why the noise on the bottom cathode is stronger than on the top (see FDC logbook page 457, linked above). Possible explanantions: additional ground plane on the top, different grounding on the different cathodes. Bill, Fernando, Mark and Lubomir looked at the prototype after the meeting. It is also strange that the bursts are correlated with the trigger (seen from the same picture); Beni's explanation: the noise is induced also on the trigger input.

Cathode redesign

Roger is working on the Bill's modifications, will have the cathode design ready soon.

Full-scale prototype test results

- Lubomir is analyzing the data from the fADC125 tests and showed two pictures. The firs one (linked as "one event using fADC125" above) shows

- Beni:

Other

- Bill had a good news: the workshop is getting a CNC horizontal milling machine