GLAST LAT Project Peer Review, March 24-25, 2003

7D 1

Gamma-ray Large Gamma-ray Large Area Space Area Space TelescopeTelescope

7D: Tray test plans

GLAST Large Area GLAST Large Area Telescope:Telescope:Tracker Subsystem

Nicola MazziottaUniversity and INFNBari - Italymazziotta@ba.infn.it

GLAST LAT Project Peer Review, March 24-25, 2003

7D 2

OutlineOutline

OverviewTray test matrixPanel vib planTray thermal planTest scheduleStacked cosmic rays

Reference LAT Documents:1. LAT-MD-00408, LAT Instrument Performance Verification Plan2. LAT-SS-00788, LAT Environmental Specification3. LAT-TD-01005, Thermal Test Results on Thick Converter Mock-up

Trays4. LAT-TD-01249, Thermal Test Results for Pre-Engineering Model

Trays5. LAT-PS-01584, LAT Tracker Tray SSD Ladder Panel Assembly

Procedure6. LAT-TD-00154, Tray Vibration Test Plan 7. LAT-TD-01839, Tray Thermal Test Plan

GLAST LAT Project Peer Review, March 24-25, 2003

7D 3

Tray test matrixTray test matrix

Item

Qu

an

tity

Qu

an

tity to

test

Hig

h fre

q s

ine

Sw

eep

Ran

dom

Vib

e

Sta

cked

cosm

ic ra

ys

Fu

nctio

nal

Th

erm

al C

ycle

Test s

ite

Lot A Panels

19 19 Z axis QualZ 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

GLAST LAT Project Peer Review, March 24-25, 2003

7D 4

OverviewOverview

Tray factory (panels)

Vibration test*

Ladder factory

Tray assembly: ladders and MCMs on trays

Tray thermal cycles*

Stacked cosmic rays*

Electrical test

Tray functional test*

Tower assembly*Environmental tests

Electrical test before MCMs

encapsulation

GLAST LAT Project Peer Review, March 24-25, 2003

7D 5

Panel vib levelsPanel vib levels

Frequency (Hz)

ASD QualLevel

(g2/Hz)

ASD AcceptLevel

(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

Random vibration

Frequency

(Hz)

ASD WN Level(g2/

Hz)

Overall

grms

Duration

(min)

20 ÷ 2000 10-4 0.45 1

White Noise

Frequencyrange

20 2000 Hz

Sweep rate 2 oct/min

Target Amplitude

0.5 g0-pk

Sine sweep

GLAST LAT Project Peer Review, March 24-25, 2003

7D 6

Panel vib set upPanel vib set up

Accelerometers:

•Control: two mono-axial accelerometers positioned on two of the four L-shaped block TP1&TP2

•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

×

W side on the top

GLAST LAT Project Peer Review, March 24-25, 2003

7D 7

Panel vib sequence thrust Panel vib sequence thrust axisaxis

Step Description Test Level

1Fixture, tray and

accelerometers mounting

2Fixture calibration and

tray resonance search

Sine sweep 0.5 g 0-pk

3 Random vibrationRandom vibration

Qual (Lot A)Acc (Lot B &

Flight)

4 Normal mode check Sine sweep 0.5 g 0-pk

5 Dismounting

6 Test completion

GLAST LAT Project Peer Review, March 24-25, 2003

7D 8

Tray thermal levelsTray thermal levels

Acceptance Qualification/Survival

Temperature Range -20°C 35°C -30°C 50°C

# of cycles 4 4

Temperature rate 20°C/hr 20°C/hr

Pressure 1 atm T-C 1 atm T-C

Duration @ T extreme

5 hr 5 hr

Total Duration 62 + 2 hr 72 + 2 hr

On orbit temperature range -15°C 30°C

GLAST LAT Project Peer Review, March 24-25, 2003

7D 9

Tray thermal Tray thermal sequencesequence

Step Description Level

0 Functional test

1 Thermocouple set up

2 Chamber set up

3 Thermal cycles Lot A QualLot B&Flight Acc

4 Dismounting

5 Functional test

6 Test completion

The tray will be tested in its own service box.

GLAST LAT Project Peer Review, March 24-25, 2003

7D 10

Test scheduleTest 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

GLAST LAT Project Peer Review, March 24-25, 2003

7D 11

Cosmic rays testCosmic rays testTray stacked in single view

2 stacks for a whole tower, readout with a single TEM

GLAST LAT Project Peer Review, March 24-25, 2003

7D 12

ConclusionsConclusions• 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.