Minutes of the March 7 Tracker Technical Meeting

 

Erik said that the inserts for the end screws on the MCM interfere with the closeout walls by ½ mm.  Either flats must be cut on the inserts or else the MCM layout must be modified.  Gwelen will look into modifying the layout to shift the hold by ¾ mm.

 

Tom (in Pisa) reported that they are discussing assembly issues.  He is also going over environmental testing with Bari.  He received a quote for the Cristek connectors: $39.75 for the socket and $39.25 for the plug.  This is for molded parts.  The lead time is 14 weeks.

 

Sandro reported that a ladder was made with HPK detectors.  The maximum error was 17 microns end to end and 8 microns wafer to wafer, with less than 20 microns vertical step wafer to wafer.  Preliminary drawings are ready for the tray service box and will be put on the web.  We need at least 5 cm length for the connector savers. 

 

Sandro said that they have made an FEM of the Agile tray and found good agreement with measurements.  They are now running the GLAST tray.  He said that CERN will measurement modulus of the silicone adhesive.  He said that he put on the web some drawings of his ideas for tray assembly.

 

Erik reported that Steve has written up his study of tolerance stackup in the tower.  Erik will review it and then distribute it.  The face sheets have been cut.  Pull tests will be run by the vendor this week before shipping.  The tooling for panel assembly is being machined.  A test closeout frame (with some detailed features left out) is due Monday from the machine shop.  The closeout drawings are being finalized, with an RFQ to be done next week.  Tests were done on inserts to test the aluminum strength.  The results look favorable for the use of aluminum: the carbon-fiber will fail before the aluminum would.

 

Robert reported that the deadline for first drafts of PDR documents is May 9, for a dry run, with final drafts due May 16.

 

SLAC is still working on setting up the glue dispenser, with some problems.  The syringes are on order.

 

John said that there is some delay of the EDM of the tungsten wafers, because the staff is out for one week.

 

Gwelen said that the MCM layout is nearly complete and that the 1.6 mm screws worked out okay.  The pitch-adapter layout is also nearly complete, but the work on assembly tooling is a little behind.  There are some issues with the tooling for precision adhesive application.  Glass beads are going to be tried out for spacing, to ensure uniform adhesive thickness.

 

There will be a meeting with Q-Flex on Friday about cable fabrication.  BJ said that Nanonics could make a vertical-mount plug; he will send the drawing to UCSC.  However, the preference is to make the cable with no bend at the top.  Tom will contact Martin about stay-clear issues in that region.

 

Erik said that he would like to have the closeout drawings checked by BJ and Gwelen before the RFQ.  He will have them on the web by Monday.

 

Action Items:

1.     Gwelen: get the MCM layout modified to shift the outermost screw holes inward by ¾ mm.

2.     Tom: talk to Martin about the stay-clear at the top of the tower and whether some more space could be had for the readout cable.