glast lat projectpeer review, march 24-25, 2003 7e2 1 gamma-ray large area space telescope 7e2: em...

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

7E2 1

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

7E2: EM test plans

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

Nicola MazziottaUniversity and INFNBari - [email protected]


7E2 2

OutlineOutlineTest strategiesFirst resultsPanel vib planTray thermal

planTower vib planTower thermal

planEM Matrix planReference 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-01004, EM Tray Vibration Test Plan 7. LAT-TD-01037, EM Tray Thermal Test Plan


7E2 3

Tray assembly&test sequenceTray assembly&test sequence

Tray factory (panels)

Vibration test

Ladder factory

Tray assembly: ladders and MCMs on trays

Thermal cycles

Stacked cosmic rays*

Electrical test

Fast electrical test*

Tower assembly* Live trays


7E2 4

Tray vib levelsTray vib levels

Frequency (Hz)

ASD QualLevel

(g2/Hz)

ASD AcceptLevel

(g2/Hz)

ASD LaunchLevel(g2/Hz)

20 0.026 0.013 0.0065

20-50 +6 dB/oct +6 dB/oct +6 dB/oct

50-800 0.16 0.08 0.04

800-2000 -6 dB/oct -6 dB/oct -6 dB/oct

2000 0.026 0.013 0.0065

Overall 14.0 grms 10.0 grms 7 grms

Duration 2 min 1 min 1 min

Random vibration

Frequency

(Hz)

ASD WN Level(g2/

Hz)

Overall

grms

Duration

(min)

20 ÷ 2000 10-4 0.45 1

White NoiseFrequency

range20 2000 Hz

Sweep rate 2 oct/min

Target Amplitude

0.5 g0-pk

Sine sweep


7E2 5

Tray vib set upTray vib set up

Accelerometers position:

•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 accelerometer in the middle TP5

Centrotecnica set up:

- 1 LDS V864LT shake table

- 2 fixtures

- 9 read out channels

- 4 trays/day test rate capability

W side on the top


7E2 6

Tray vib sequence thrust Tray vib sequence thrust axisaxis

Step Description Test Level

1 Fixture, tray and accelerometers

mounting

2 Fixture calibration and tray resonance

searchSine sweep 0.5 g 0-pk

3 Pre-random vibration White noise 0.45 grms

4 Random vibration Random vibration

Launch

5 Post/Pre-random vibration

White noise 0.45 grms


Acceptance

7 Post/Pre-random vibration

White noise 0.45 grms


Qualification

9 Post-random vibration White noise 0.45 grms

10 Normal mode check Sine sweep 0.5 g 0-pk

11 Dismounting

12 Test completion


7E2 7

First results – TG07 (1)First results – TG07 (1)

Sine sweep before/after random Random vibration + White noise

Resonance search:

0= 815 Hz, Q 51

Resonance check:

0= 809 Hz, Q 49

Z accelerometer response

X accelerometer response

Y accelerometer response


7E2 8

Light

≈ 1000Hz

≈ 800Hz Heavy tray

Mid tray

Last Vib Runs (Mar, 17-19) (1)Last Vib Runs (Mar, 17-19) (1)

≈ 660Hz


7E2 9

Last Vib Runs (Mar, 17-19) (2)Last Vib Runs (Mar, 17-19) (2)

“Watch-dog”Input-notched: 13.6 grms

Output-notched: 59.6 grms

Applied notching on qual ASD: output ≤ 16 g2/Hz ( Q=10) “Watch-dog”

Heavy tray (TS05) Q=100 @ 660Hz Output-expected: 140.4 grms


7E2 10

EM Vib Runs Summary (16 trays)EM Vib Runs Summary (16 trays)

All trays first mode › 500 Hz

No relevant changes in the resonance frequency after the

random


7E2 11

Thermal tests on pre-EM trays: set-Thermal tests on pre-EM trays: set-upup

Wheatstone bridge

configuration(Labview)

Si Strain gauge

Reference Strain gauge on quartz

1 m3

Procedures: LAT-TD-1037; Pre-EM Results: LAT-TD-1249

Service box


7E2 12

Thermal tests on pre-EM trays: some Thermal tests on pre-EM trays: some resultsresults

Silicon temperature delay 45 min

Stability @ plateau: dT/dt < 3°C/hrTchamber

Tsilicon

plateau 5 hr


7E2 13

Tray thermal levelsTray thermal levelsAcceptance 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‹ 10-5 Torr T-V

1 atm T-C‹ 10-5 Torr T-V

Duration @ T extreme

5 hr 5 hr

Total Duration 62 + 2 hr 72 + 2 hr

T-C: Thermal cycle (dummy trays)

T-V: Thermal vacuum (live tray)

On orbit temperature range -15°C 30°C


7E2 14

Tray thermal Tray thermal sequencesequence

Step Description Level

0 Strain gauges and thermocouple set

up

1 Chamber set up

2 Strain gauges calibration

3 Thermal cycles Qualification

4 Dismounting

5 Test completion

The EM dummy trays will be tested at ambient pressure into the service

boxes


7E2 15

Tower vib levelsTower vib levels

Frequency(Hz)

ASD Acceptance

Level (g2/Hz)

ASD Qualification Level (g2/Hz)

20 0.01 0.02

20-50 +5.9 dB/oct +5.9 dB/oct

50-800 0.06 0.12

800-2000 -5.9 dB/oct -5.9 dB/oct

2000 0.01 0.02

Overall 8.7 grms 12.3 grms

Duration 1 min/axis 2 min/axis

Low frequency sine sweep

Frequencyrange

20 2000 Hz

Sweep rate 2 oct/min

Target Amplitude

0.5 g0-pk

High frequency sine sweep

Frequency

(Hz)

ASD WN Level(g2/

Hz)

Overall

grms

Duration

(min)

20 ÷ 2000 10-4 0.45 1

White Noise

Random vibration


7E2 16

Tower vib set upTower vib set up

Accelerometers set up (TBR):1. 3 axial on the shaker table (control accelerometer) 2. 3 axial on the center of the bottom tray lower surface 3. 3 axial on the center of the top tray upper surface 4. 3 axial accelerometer +X sidewall center of the thermal

boss tray number 12;5. 3 axial accelerometer +Y sidewall near the center of the

tray number 10;6. 3 axial accelerometer +Y sidewall center of the thermal

boss of the tray number 1;7. 3 axial accelerometer +Y sidewall center of the thermal

boss of the tray number 19;8. 3 axial accelerometer -X sidewall center of the thermal

boss of the tray number 10;9. 3 axial accelerometer -Y sidewall near the center of the

tray number 10, on the center plane;


7E2 17

Tower vib sequence X,Y,Z Tower vib sequence X,Y,Z axisaxis

For each axisStep Description Test Level

1 Fixture, tower and accelerometers mounting

2 Fixture calibration High frequency sine sweep

0.5 g 0-pk

3 Normal mode search High frequency sine sweep

0.5 g0-pk

4 Pre-random vibration White noise 0.45 grms

5 Random vibration Random vibration -6 dB Qual

6 Post/Pre-random vibration White noise 0.45 grms

7 Random vibration Random vibration -3 dB Qual

8 Post/Pre-random vibration White noise 0.45 grms

9 Random vibration Random vibration 0 dB Qual

10 Post-random vibration White noise 0.45 grms

11 Normal mode check High frequency sine sweep

0.5 g0-pk

12 Low frequency test Low frequency sine sweep

Qual

13 Dismounting

14 Test completion


7E2 18

Tower thermal levelsTower thermal levels

Thermal-Vacuum cycling/Qual-Surv level

Ranges -30°C 50°C

# of cycles 8 (12)

Temp. rate 20°C/hr

Pressure 10-5 Torr

Duration @ extreme 12 hr

Total Duration 256 (384) hr + stabilization


7E2 19

Tower thermal set upTower thermal set up

Additional thermocouples (TBR):1.+Y sidewall center of the thermal boss of the tray number 1;2.+X sidewall center of the of the tray number 1, on the center plane;

3.+Y sidewall center of the thermal boss of the tray number 19;4.+X sidewall center of the of the tray number 19, on the center plane;

5.-X sidewall center of the thermal boss of the tray number 10;6.-Y sidewall near the center of the tray number 10, on the center plane

The tower has a large number of thermocouples in the read out cables that can be acquired by using the TKR DAQ system.

The temperature control point for the cold part of the cycle will be the coldest thermocouple, while

the control point for the hot part of the cycle will be the hottest one.

Tower covered with a thermal blanket during T-V cycles.


7E2 20

Tower thermal Tower thermal sequencesequence

Step Description Level

0 (Strain gauges and) Thermocouple set up

1 Chamber set up

2 (Strain gauges calibration)

3 Thermal vacuum cycles Qualification/Survival

4 Dismounting

5 Test completion


7E2 21

EM matrixEM matrix

Item

Qu

an

tity

Qu

an

tity to

test

Hig

h fre

q s

ine

Sw

eep

20-2

000 H

z

Ran

dom

Vib

e

Wh

ite n

ois

e

Low

freq

sin

e

Sw

eep

5-5

0 H

z

Fu

nctio

nal

Th

erm

al C

ycle

Th

erm

al V

acu

um

Test s

ite

Panels

24 24 QualZ axis

QualZ

axis

Centrotecnica (vib)

Live Trays

5 1 QualZ axis

QualZ

axis

Qual Centrotecnica (vib)

Alenia (thermal-vac)

Dummy Trays

19 5 vib19 ther

QualZ axis

Qual Z

axis

Qual Centrotecnica (vib)

INFN Perugia (in Terni) (thermal)

Tower 1 1 QualX,Y,Z

QualX,Y,Z

Qual Alenia