Minutes of AFE meeting May 8, 2001 ++++++++++++++++++++++++++++++++++++++++++++++++ J. Anderson, G. Blazey, F. Borcherding, A. Bross, G. Ginther, P. Grannis, R. Jesik, M. Johnson, P. Rubinov, 1. Sanmina internal engineering has not released the OK to start stuffing. Calls every other day are being made. Sales sounded unclear on the reason -- perhaps due to being busy with relocations within the company? They still expect to make 73 RHB first, then 73 LHB. All parts seem shipped to them seem to be found -- all MCMs accounted for, and it seems the opamps are there too. John Anderson has given them pick and place files for coordinates and part rotation, relative to a drilled hole. 2. For the extra 54 AFE boards, all but a few passive parts have been located and ordered. Johnny Green is working on the rest, and has established space to collect and box them. The bare board rec went to Data Circuits after Paragon found they could not do the width of gold plating required, and after Data Circuits lowered the quote to be low bidder. We expect 10 day turn around; quote is $18,470 for 54 boards. At present, the longest lead time parts is 7 weeks; Johnny is trying to work on these, but John expects perhaps 6 week delivery. Total parts are estimated at $60K, and stuffing at something like $350/board (perhaps at Manutek or QSM). 3. RevA board 9 (LHB) was modified so that one half of the MCMs 3,4, 5,6 (the CPS locations) have lower input caps to SIFT. Values are 5,6,10,12,15,22,33,47 pF. We also have 100pF on the MCMs 1,2,7,8. The mods are done; testing of the board at DAB3 shows some problems with SVX readout that are being chased. Then we can take the board to Lab 3 to test cold for photopeaks. Fred Borcherding checked Paul G's spreadsheet for AFE performance on CPS and found no errors. We need to measure the cable/stray capacitance with the modified board. From this we can also perhaps determine the SIFT to SVX gain value, though with photopeaks and known cassette gains, we can get it independently. It is possible that Thomas Nunnemnann could get it also from his analysis of photopeaks in SIFT discriminators compared to the SVX photopeaks. This gain is needed to set the desired value to the SIFT input caps. Delivery of caps in the range we expect (~12pF) should be very short and not delay the extra board stuffing. 4. Daniel Mihalcea and Rick Jesik have come on board to supervise production testing at SiDet and DAB3 respectively. SiDet is setting up space for steps 1-4. Daniel and Fred reported progress on finding the necessary hardware for SiDet. Daniel thought finding 1553 was perhaps the most critical problem; we will have a report next week. Firmware for SiDet was reported doing well. Given the slip with Sanmina, the priority this week for engineers and techs shifted to give support for platform work the top spot. The AFE test stand work continues though with Mike Matulik (hardware) and Bob Angstadt (software) devoted to it. We don't see a problem in getting the test stand and documentation by the time boards start to arrive. Manpower identified for testing include Mike Matulik, John Anderson, Fred Borcherding and Pat Shehan as needed to give overall supervision. SiDet gives 3 half techs and two full time techs for steps 1-4. For DAB3 tests, there are about 8 students from NIU, Stony Brook, Cinvestav, Rice, BU, FSU and Saclay that have been promised for all or most of summer; two high school students, and a couple of physicists. We now don't foresee starting training until beginning of June, given stuffing schedule. 5. Cassette testing has neared 99 tested cassettes. One remaining FPS cassette has some problems to fix. No new flex circuits have arrived since our last meeting. We have a hope to put all 99 cassettes in the cryostats during the shutdown, but will have at least 94 (the West cryostat cassettes are in place now). The west cryostat is being cooled down (or being leak fixed for cooling). The east cryostat will probably be warmed this Friday, new cassettes installed and then cooled down before the end of the shutdown. Alan Bross would like to see temperature controlling tests in the platform using LEDs. 6. Paul Rubinov showed plots of DNL and fast fourier analysis of the periodicity. Adding caps to the DVDD or AVDD pins gave roughly a factor of 4-8 improvement in DNL. Tests will be done at Lab 3 using photopeak with enough combinations of (larger) caps on AVDD, AVDD2, DVDD to understand that all should have added caps. Default seems to be to add/increase these capacitor values. These tests (and those of the modified MCM boards for CPS) should occur in about two weeks. 7. Marvin noted discussions on the modified MCM based on the SVX4 design by Yarema, Zimmermann and Abner. He will review the progress and planning at next weeks meeting. The AFE group noted that we need real guidance from the Lab on when the transition to 132 ns could earliest occur. Next meeting will be 4PM on Tuesday, May 15.