Minutes of the Tracker
Meeting
October 16, 2003
Action Items
Darren said that he wants to
see an NCR for the honeycomb core issue.
Sandro reported on the core
inspection. They measured the weight of
each honeycomb core and inspected them in Pisa before shipping to Plyform. The defect was noticed there. At Plyform Sandro looked at it for the first
time and made the photos. Each core has
a serial number. Sandro will write an
NCR with all the info, and then Tom will approach the vendor about the issue.
Erik reported on the flexure
qualification static test. They pulled
at 45 degrees to 100%. No issues were
seen, and the data are clean. They only
pulled in one direction, which puts some flexures in compression, others in
tension. Two flexures have shear load
with tension and 2 with compression. This
satisfies the requirements, but the other case will be done for completeness.
Jack will meet with Jeff
Wang before next Thursday to go over the thermal-vacuum issues. Nanda said that we need to include
considerations of temperature control requirements of the TEM/PS (not an issue
for the EM, which will not have a TEM/PS).
Sandro needs the instrumentation plan soon to give to Alenia. Also, we need a list of test cases (power
levels, etc). Nanda will be back at the
end of the week after next. In the
meantime, Jack will make a first cut at the instrumentation and test plan.
Erik said that he had talked
to Steve about predictions for the vibration test plan. We want to have response curves at each
accelerometer location. For that Steve
has to re-run the analysis. First they
will review the accelerometer plan. They
also need to define the strain-gauge locations.
There was a discussion of
support of the flex-circuit cables in the EM, especially during vibration. The plan has long been to put 3M transfer
adhesive between the cable and structural closeouts, such that the cable gets
clamped tightly between sidewall and closeout.
Sandro will evaluate how to add tape between the cables and closeouts in
the already assembled EM tower.
Then there was a discussion
of insert preparation for bonding into closeouts. Tom worried that primer on the inserts would add about 100
microns to the insert diameter. Sanding
is another possibility. A higher
strength adhesive might also be used.
Sandro said that inserts were sanded during installation in all the EM
closeouts, and curing was done at 85C for several hours. Inserts are checked after the 85C cure. Sandro needs to check that this procedure is
documented in the procedure. A
completely new procedure document will be made for the bottom trays.
The discussion moved to
coordination of test-script development for Tracker towers. Hiro said that he had talked to Johann about
the problems, and they came up with list of things to correct. The worst problem is a lot hard-coded
parameters. Code cannot be changed during
testing of flight hardware, so parameters that might need changing cannot be
hard coded. Each parameter should have
a default in an XML file and a GUI should be available by which to change the parameters
during testing. The program must log
all such changes automatically. Another
problem is widespread duplication of code fragments. Hiro wants to eliminate these by coding them as subroutines. Also, there are different scripts for layers
versus towers. These should be able to
use the same code, with capability to choose between testing a tray versus a
whole tower. It was decided to have a
kick-off meeting at 8:00 am Monday, October 27. Luca Baldini will do the
minutes.
Luca Baldini reported that Pisa
has a working TEM and mini-tower cables now, so they are able to do some code
testing there.
Sidewall fabrication status:
COI has cut out all of the panels and coupons.
They have drilled several full size panels and done CMM, with good
results. They just received inserts for
coupons this morning, plus screws. They
will do all the mechanical tests.
Thermal test coupons will be sent to Hytec. COI will have tension and compression tests on panel material
done by the end of the day Friday.
Insert coupon testing will be done next week. There are not enough inserts for the short panels. Plyform does have enough inserts and the
tool for installation, so we will wait for Plyform to provide the short
sidewalls for the static test. Plyform
is still waiting on the aluminum and primer.
Nothing arrived as of today.
Plyform can supply the mini-sidewalls 2 weeks after receiving the
material. Jeff will track shipments.
Tray panel status: Plyform
has machined the first group of 40 CC closeouts. They will measure them and then send them to Pisa for
crosscheck. Tools for assembly are
practically ready for mid trays.
Robert reported that we have
been holding daily meetings with Teledyne.
The boards have finally been machined successfully to specifications, by
an outside machine shop. All the
remaining parts will be shipped Friday from SLAC to Teledyne, so Teledyne can
start making up the kits for assembly.
Teledyne is modifying the flex-circuit trimming tool to account for the
offset caused by addition of Kapton to the backside of the board. They have also successfully tested a method
of trimming the two short ends of the flex circuit. The new method is to trim them to length before gluing. Teledyne is making a die and fixture to make
this cut during production. It looks
like the earliest start date to have all of this together to begin production
is next Thursday.
Robert reported that the
present GTRC cannot operate at 20 MHz without skipping clocks. As high as 18 MHz looks possible if the
voltage is raised up to about 3V. A new
GTRC design is in progress and will be done next week.
Darren said that he needs an
NCR on the GTRC issues.
Tom reported that the M55J
pieces are made at COI and cut to raw size.
The next step is to laminate the CC.
They resawed the CC to make 2 from 1.
They will make 98 assemblies to have spares. The remaining CC arrived from Italy and is ready to ship to COI. Purchasing is awaiting release of the
drawings.
The order for corner
brackets and flexures is sitting on Jerry's desk. It is waiting for drawing release.
SLAC needs to know the resin
used for passivation of the carbon on closeouts and trays. This is holding up release of assembly
drawings. SLAC also needs to know
exactly where the resin is applied.
Nanda will find out and send email.
Samples of M55J and CC are
needed for outgassing tests.
Shipping container status:
assembly of a mass model is in progress at SLAC to simulate the tower in its
inner shipping container.
Humidity/temp/shock monitor will be put in, and they will do some drop
tests of the shipping container with mass model at SLAC. They will then ship it to Italy with the
monitor and mass model. The timescale
is a few weeks. BJ will send the
container drawings to Nanda.