Minutes of the Tracker Meeting
April 24, 2002
Robert discussed the SLAC internal review committee’s recommendation of a 6-month delay of the project schedule. See the attached pdf file for Tom & Robert’s first look at how to revise the Tracker schedule. Note that there is no overlap between ladder and tray assembly. There is also some more time for tray panel fabrication and we take into account a 3-month delay in the flight ASIC submission to allow for adequate testing of the 3rd prototype submission. We use 3 months of the slip to put schedule reserve back in between our completion of tower assembly/test and delivery to I&T.
Tom commented on preparations for a new shake test of the prototype tower. The bottom tray is at GMSI for rework on Friday. Screws and gasket material are on order. The test is scheduled for the week of May 17. SLAC needs the flexures and adapter plate back from Hytec as soon as Erik is finished with them.
Erik said that the thermal cycling tests are in progress at Hytec and should be done next Friday, after which the parts can be shipped back to SLAC.
Sandro said that Pisa has finished measuring the assembly jigs. They found a problem: there is a dimensional error of 100um. Therefore, the jigs need some re-machining. For this we will lose 1 week.
Ladder assembly status: G&A has assembled 100 dummy ladders without wire bonding. Flight assembly should begin May 20 at G&A at a rate of 100 ladders/month. The Mipot line will follow. 1050 wafers have already been tested in Pisa. Robert commented that the flight ladder assembly cannot commence until the procedures have been completely documented, reviewed, and signed off. Sandro said that details of the electrical tests of ladders have to wait until the first few (EM) ladders have been studied. Robert promised to send Sandro comments on the existing procedures document draft.
Erik talked to Alcomp about the final lot of EM closeout material. There is a delay at the high-temperature heat treatment vendor. They will ship next Tuesday at the earliest, Friday at the latest. Erik will talk to Alcomp about the flight material order. SLAC is awaiting a quotation.
Tom reported that 10 MCM closeout walls are completed at GMSI. The rest will be done by the end of next week.
At Plyform the machining status is unknown. Sandro will know more next Monday.
Insert bonding tool: Drawings will be sent on Monday. Two weeks are needed for machining.
Sandro said that Plyform is waiting to have all the parts and jigs in hand, including closeouts with inserts, before starting the panel assembly. They do not want to preassemble parts (such as the face sheets) before hand.
Sandro said that the tungsten assembly tool will follow the insert bonding tool.
Robert said that the ASIC submission is scheduled for Monday (which has now slipped to Wednesday). There will be chips from Tracker, Calorimeter, and ACD in a full wafer run (i.e. lots of parts). For the tracker we will make
- A backup GTRC design with only 32 events of memory, using flip-flops for storage (similar to version 1, which we are using in our current test systems).
- The preferred GTRC design using RAM for storage (64 events), with the design-rule violations fixed. Both versions have a few logic fixes and route the clock neatly to a buffer for each row of cells to fix timing problems in version 2.
- Version 2 of the GTFE64f (AC coupled between shaper and comparator) with the following changes:
o Fix the error in the comparator input baseline restoration circuit
o Fix a couple of logic errors in the digital circuit (plus a couple of improvements to increase timing margin)
o Remove resistors from the I/O pads that were hampering operation at 20 MHz and also contribute noise to the amplifier front end.
o Increase trace with on the I/O driver outputs to reduce delays, particularly in the layer-OR signal.
- Version 2 of the GTFE64e (DC coupled between shaper and comparator), with the design-rule violations fixed. This also includes the last 3 bullets listed under the f version.
This submission will make more than enough chips for the engineering model live trays.