Minutes of the Tracker Technical Meeting
Wednesday, September 27, 2000

Present: Trieste, Pisa, Perugia (Roberto at CERN), SLAC, UCSC, Hytec

At Robert's request, John agreed to inventory his stock of cores and facesheets left over 
from BTEM fabrication and to send sample cores to Hytec and Pisa.

In response to a question, Erik reported that Hytec so far has only analyzed the cores and 
facesheets for regular (thin converter) trays.  Pisa will investigate the cores and facesheets 
for thick-converter trays.

Andrea reported on Pisa vibration analysis results.  They constrained the trays at the 
corner pins and along the sidewalls and found f0=600 Hz, compared with 529 Hz by the 
earlier Hytec analysis.  The differences probably are in details of the material properties.  
For the tray size they used drawings of the aluminum closeout from BJ.

Erik reported that Hytec is working on transforming their drawings and models to he final 
tray dimension (including 200um spacing between ladders).  BJ will get the latest 
numbers for Erik on the Grid dimensions.  He noted that there is a review of the grid 
design on the coming Monday.  Tom agreed to get the necessary interface information 
transferred to Erik.

There was a discussion of making up prototype panels of aluminum core and carbon-fiber 
face sheets to use as substrate for doing thermal tests.  Panels of the BTEM size can be 
made up from materials already in hand.  For full-size cores and facesheets, we should 
make a combined order with Hytec, when they are ready.  There was some unresolved 
disagreement on whether the closeout is of any importance for such tests.  Erik said that 
in any case, they can probably get the closeout material more quickly than the facesheet 
material.  The facesheets have a lead time of 6 to 8 weeks.

Ossie reported on the availability of tungsten.  A few standard thicknesses are more 
readily available, such 5, 16, and 20 mil, but only in high purity.  The alloys appear to be 
sintered rather than really alloyed, and are hard to make thin.  He handled some pure 
material and found the properties to be acceptable.  The foils can be ordered to size with 
about 6 to 8 weeks lead-time.  There was some discussion of how many we need.  Pisa 
would like to cover up to 8 tray sides (128 wafers) with thick foils (e.g. 20 mil, or 15% 
RL).  SLAC would need a similar number of thin foils (e.g. 5 mil, or 3.6% RL).

Ossie reported that Roman still is working on finalize his report on the thermal tests.  
They went as low as -70C and as high as +50C with Si glued to Al (full epoxy coverage) 
without any breakage.  The next test is to use a dot pattern and to try a more realistic 
substrate.

Alec's drawing of the spring contact test fixture was reviewed (see attachment).  He 
needs at least about 6 mil of vertical space for the spring (Ossie said that thinner material 
can be obtained if necessary).  The point of this concept was to avoid use of silver glue, 
for which many people have expressed concern over silver migration.  This prompted 
some discussion, and nobody could see how silver migration could possibly be an issue 
in our setup.  The glue is in a uniform, nearly field-free region.  It would have to migrate 
very far from our underside contact points before it could get away from the detectors or 
on top of the detectors to cause any problem with shorting.  Hartmut agreed to talk to 
Japanese collaborators about what they think the issues are with silver loaded adhesives.

There was a discussion of the UCSC baby-detector thermal-test coupons that were taken 
to SLAC.  John is needed to add strain gauges, but he is busy with the glue application 
tool for detector edge bonding.  It was thought that the thermal test should take temporary 
priority.  A GPIB card for current monitoring is on order.  Gwelen said that he could go 
to SLAC to help.

Sandro reported on the status of the pitch-adapter prototype.  He expects in about a week 
to have samples with and without cover layers.  On the mechanical side they have in hand 
already a vibration model, and a tray thermal model is in progress.  An engineer from 
Perugia is joining their effort.  They are working on drawing the ladder alignment jig.  On 
the electronics end they should have their VME-PCI card next week and then will be able 
to get the UCSC/Stanford readout going.  Also, next week they have a meeting with a 
local company about building mockup trays for testing.

Hartmut led some discussion on SSD prototyping.  He said that HPK will deliver 
prototypes in December.  Michela reported that STM is making a new design according 
to the new specifications and that from Micron they have a gds2 file of the layout.  She 
can make it into a dxf file for Hartmut to view at UCSC.  Roberto reported that CSEM 
can finalize a design in 1 or 2 weeks.  Hartmut said that he would like to review that 
drawing as well.

Action items:
1.	John: inventory cores and facesheets and send sample cores to Hytec and Pisa 
(done).
2.	Tom: transfer grid-tracker interface information from BJ to Hytec.
3.	Ossie: order tungsten samples for SLAC and Pisa.
4.	Ossie et al: thermal tests with dot patterns.
5.	Hartmut: talk to Japanese collaborators about silver migration.
6.	Gwelen: help SLAC get the baby-detector thermal test going.
7.	Michela and Roberto: send detector layouts to Hartmut to review (dxf format)