Tracker Status Report
March 26, 2004
1. Thermal Vacuum Testing (N. Mazziotta)
a. A meeting was held in Bari to review the test results. See the Bari web page for presentations.
b. The 3 goals of the test were accomplished:
1. thermistor vs thermocouple correlation
2. evidence that the design is reasonable, with gradients less than predicted (parasitics still need to be accounted for in the analysis)
3. 7 cases of thermal-balance data to correlate with models
c. The thermocouples and thermistor data are available in electronic text and Excel formats on the Bari web page.
d. A test report will be available in a couple of weeks, and a report on the model correlations will be available in 4 weeks.
2. SSD Procurement (A. Brez)
a. 9500 tested, 46 rejected
b. 1000 recently received from the ASI order
c. 1000 more coming soon, to complete the procurement
3. Ladder Assembly (A. Brez)
a. 967 assembled and tested (16 rejected)
4. Mid Tray Production
a. Plyform is completing assembly of the honeycomb sandwiches and the closeouts.
b. Next week the bare panels will be assembled (about 20).
5. Bottom Tray Closeouts
a. The drawings should go out for release today.
b. The PO is being prepared for the machining at COI.
c. LAT QA will travel to COI for their inspection.
6. Bottom Tray Titanium Parts and Flexures
a. The machining is in progress at Advanced Machining, with a delivery date of April 9.
7. Tracker-Grid Interface Components
a. Drawings are nearly ready to go out for review by everybody.
b. Planning is in progress to machine some engineering evaluation parts at Advanced Machining.
c. A qualification plan and schedule was prepared.
8. Bottom Tray Static Test
a. A SLAC/Hytec team is gearing up to fly to Pisa in April to make the system operational.
b. Work is starting on design modifications needed on the base frame, to accommodate the new interface.
9. Tray Vibration Testing (N. Mazziotta)
a. The procedure is ready for release. The document LAT-TD-00154 is on the Bari web page http://www.ba.infn.it/~glast/repository.htm in the GLAST internal document repository.
10. Stacked Tray Test (N. Mazziotta)
a. The muon trigger rate has been measured in Bari by using three scintillator layers with different trigger layout. The distance between each couple of layers is about 92 cm, while the area of each layer is 40x40 cm2.
b. The trigger rate between the far layers (about 1.8 m distance) is about 0.6 Hz; the trigger rate between near layers (0.92 m distance) is about 2.4 Hz. The trigger rate measured as OR of concidencies between adjacent couples of layers is about 3.5 Hz.
11. Bias Circuit Fabrication
a. 42 bias circuits are on the way to Pisa.
b. 2 of the circuits were measured at SLAC with good, conforming results (within 10 microns).
c. Jerry is working with Parlex today to get the drawings correct with regard to the trace extensions needed for gold plating of the main flight order. Parlex promised delivery of 50 ¼-oz circuits April 13.
12. MCM Test System
a. Two new interface boards were assembled, debugged, and tested. Mutsumi will go to Teledyne on Monday to install them. They replace the previous revision, which had a lot of hand wired corrections.
b. Spare electronics modules for the test system were sent out for calibration.
c. Procurements are in progress at SLAC to obtain some more spare parts, to avoid schedule delays during production.
13. MCM Assembly and Test
a. The preproduction is completed at Teledyne, and the last set of boards should start thermal cycles and burn-in at SLAC in the next days.
b. Hallelujah, the Teledyne PO was finally agreed to by both parties, after a 3 week delay, and flight production started this Tuesday.
14. MCM Burn-In and Acceptance Test System
a. Same as for the MCM test system, spare components are being obtained and calibrated.
15. MCM Integration onto Trays
a. G&A is machining the new tooling
16. Sidewall Manufacture
a. Plyform sent COI an RFQ for the prepreg, and COI is working on an offer.
b. Some issues with the specifications were straightened out this week.
17. Flex Circuit Fabrication and Test (H. Sadrozinski)
a. Non-flight cables C0: Parlex is still working on a reply. One item, the testing of assemblies, is being worked. We supplied all information on how we test the assembled cables. Jerry Clinton is setting up a telecon with their technical people to sort out and solve the issues.
b. Flight: All mechanical drawings are done. C0 and C3 have been electrically laid out and also checked by Martin Nordby. They represent the two different types of cables. The plan is to have Jerry Clinton and Dave Nelson check them, and then have them sent around by Natalie for sign-off. We will then have the PRR, and go to production with these two.
c. The pace of electrical layout is as expected, two per week.