7D: Tray test plans

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7D Tray test plans
GLAST Large Area TelescopeTracker Subsystem

Nicola MazziottaUniversity and INFNBari -
Italymazziotta_at_ba.infn.it
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Outline

• Overview
• Tray test matrix
• Panel vib plan
• Tray thermal plan
• Test schedule
• Stacked cosmic rays

• Reference LAT Documents
• LAT-MD-00408, LAT Instrument Performance
  Verification Plan
• LAT-SS-00788, LAT Environmental Specification
• LAT-TD-01005, Thermal Test Results on Thick
  Converter Mock-up Trays
• LAT-TD-01249, Thermal Test Results for
  Pre-Engineering Model Trays
• LAT-PS-01584, LAT Tracker Tray SSD Ladder Panel
  Assembly Procedure
• LAT-TD-00154, Tray Vibration Test Plan
• LAT-TD-01839, Tray Thermal Test Plan

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Tray test matrix
Item Quantity Quantity to test High freq sine Sweep Random Vibe Stacked cosmic rays Functional Thermal Cycle Test site
Lot A Panels 19 19 Z axis Qual Z axis Italy factory
Lot A Trays 19 19 ? ? Qual INFN Perugia (in Terni) (thermal)
Lot B Flight panels 323 spares 323 spares Z axis Acc Z axis Italy factory
Lot B Flight trays 323 spares 323 spares ? ? Acc INFN Perugia, Bari, Pisa, RomaII
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Overview
Environmental tests
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Panel vib levels
White Noise
Sine sweep
Frequency (Hz) ASD WN Level(g2/Hz) Overall grms Duration (min)
20 2000 10-4 0.45 1
Frequency range 20 ? 2000 Hz
Sweep rate 2 oct/min
Target Amplitude 0.5 g0-pk
Random vibration
Frequency (Hz) ASD Qual Level (g2/Hz) ASD Accept Level (g2/Hz)
20 0.026 0.013
20-50 6 dB/oct 6 dB/oct
50-800 0.16 0.08
800-2000 -6 dB/oct -6 dB/oct
2000 0.026 0.013
Overall 14.0 grms 10.0 grms
Duration 2 min 1 min
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Panel vib set up
W side on the top

• Accelerometers
• Control two mono-axial accelerometers
  positioned on two of the four L-shaped block
  TP1TP2
• Fixture three mono axial accelerometers placed
  on a corner on one of the four L-shaped block TP6
• Tray one three-axial accelerometers in the
  middle of panel TP5

• Centrotecnica set up
• - 1 LDS shake table
• 2 fixtures
• 9 read out channels
• 4 tested trays/day rate

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Panel vib sequence thrust axis
Step Description Test Level
1 Fixture, tray and accelerometers mounting
2 Fixture calibration and tray resonance search Sine sweep 0.5 g 0-pk
3 Random vibration Random vibration Qual (Lot A) Acc (Lot B Flight)
4 Normal mode check Sine sweep 0.5 g 0-pk
5 Dismounting
6 Test completion
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Tray thermal levels
Acceptance Qualification/Survival
Temperature Range -20C ? 35C -30C ? 50C
of cycles 4 4
Temperature rate 20C/hr 20C/hr
Pressure 1 atm T-C 1 atm T-C
Duration _at_ T extreme 5 hr 5 hr
Total Duration 62 2 hr 72 2 hr
On orbit temperature range -15C ? 30C
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Tray thermal sequence
The tray will be tested in its own service box.
Step Description Level
0 Functional test
1 Thermocouple set up
2 Chamber set up
3 Thermal cycles Lot A Qual Lot BFlight Acc
4 Dismounting
5 Functional test
6 Test completion
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Test schedule
Vib test rate 4 panels/day (Centrotecnica-Milano
) Thermal test lot 4 trays/cycle in 4 climatic
chambers (2 ready by Pg in Terni, 1 foreseen in
Pi, 1 foreseen in Ba) Test rate/climatic chamber
1 tower/month
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Cosmic rays test
Tray stacked in single view
2 stacks for a whole tower, readout with a single
TEM
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Conclusions

• The thermal and vibe tests on trays are well
  understood
• The vibe test rate in Centrotecnica is adequate
• The thermal test rate with the Perugia equipment
  in Terni is just sufficient, but the test lines
  will be doubled
• The mechanics to perform cosmic rays tests is
  under construction. The flux allows a test in
  realistic time. The mini-tower experience will be
  the ground base to define the cosmic rays test.