Weight reduction on TCS Electronic crates

1
Weight reduction on TCS Electronic
crates Geneva, 12/01/2004 M. Molina
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Open actions since last meeting

• RICH Thermal verification
• Increased power
• Crates accomodation
• On main radiators
• On the Lower USS (LMSO checks needed)
• Zenith radiator thermal influence on the TRD

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Thermal control structure mass budget
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RICH Requirements

• Operative Temperature Range
• -30C50C
• Storage Temperature Range
• -30C50C
• Maximum temperature gradient among the PMTs
• 15C

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AMS-02 Thermal model

• ECAL crates and bricks on USS02
• RICH bricks on USS02
• RichEcal crates radiators removed due to mass
  saving activity
• RICH outer panels covered by MLI

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RICH dissipation

• PMTs 680 x 26mW17.7W
• Boards (RLVPP, Rich Low Voltage Patch Panel)4 x
  2W 4 x 0.45W9.8W
• Mass saving activity 1st step
• FEE on the detector (1.7W0.3W) x 48W
• Mass saving activity 2nd step
• boards on the detector
• 1W 1W2W

37.5W
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HOT cases
B-75_MPA_hot Operative
55.2C is the maximum PMT temperature
prediction (out of nominal range)
DT18.4C
Grid Temperatures
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HOT cases
B-75_MPA_hot Non Operative (RICH is OFF while the
other AMS-02 detectors are ON)
36.8C is the maximum PMT temperature
prediction (13.2C margin)
DT13.2C
Grid Temperatures
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HOT cases
B-60_MPA_hot Operative
42.4C is the maximum PMT temperature
prediction (7.6C margin)
DT14.3C
Grid Temperatures
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COLD cases
B_0_MPA_cold Non Operative
-27.1C is the minimum PMT temperature
prediction (2.9C margin tests ongoing to extend
lower temperature limit)
DT2.9C
Grid Temperatures
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Conclusions (RICH, thermal)

• HOT cases
• The detector (when the ISS atitude is the MPA)
  works for
• 60 ? b?75
• operating for 95 of the time.
• COLD cases
• A test campaign is ongoing to qualify PMTs at
  40C.
• Max continuous heaters power needed in the cold
  cases, when RICH is switched OFF, is 25W.

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Crates on the lower USS
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03/11/2003 1st step

• ECAL crates and bricks on USS02
• RICH crates and bricks on USS02

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1st step CRATES LAYOUT on main radiator
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1st step LMSO COMMENTS 1/6
Summary of Interferences and Issues
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1st step LMSO COMMENTS 2/6
EVA Handrail Interference (X, -Y quadrant)
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1st step LMSO COMMENTS 3/6
Lower USS Shipping Fixture Interferences
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1st step LMSO COMMENTS 4/6
Weldment Interferences
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1st step LMSO COMMENTS 5/6
Weldment Interferences
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1st step LMSO COMMENTS 6/6
Shipping Cover upper horizontal support beam
Close-out panel
Shipping Cover lower horizontal support beam
(upper hidden from view)
Crates Protrude between cover support structure,
interfering with installation and removal of
cover
Cover Interferences
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27/11/2003 2nd step

• ECAL crates and bricks on USS02
• RICH bricks on USS02
• RICH boards moved to RICH detector

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2nd step CRATES LAYOUT on main radiator
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2nd step LMSO COMMENTS 1/2
Must not violate 8 dia x 3.2 tall handrail
access envelope. This includes cabling.
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2nd step LMSO COMMENTS 2/2
Need access here to ¼ handrail bracket screws
(not shown)
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AMS-02 crates current configuration 1/3

• ALL LMSO comments implemented

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ECAL crates and bricks
AMS-02 crates current configuration 2/3

• No changes with respect to the 2nd step

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RICH bricks
AMS-02 crates current configuration 3/3

• Now free access to the handrail brackets screws
• Cables routing must be compliant with stay-out
  zone

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CURRENT CRATES LAYOUT 09/01/2004
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ECAL group request (9th Jan 2004)

• To equally space the ECAL bricks around the ECAL
  itself
• New approval from LMSO needed!

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Conclusion (crates on the lower USS)

• In the current locations crates and bricks
  located on the USS are thermally working fine.
• Current position is compliant with EVA
  requirements and shipping envelope constraints.

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Zenith Radiator Attachment StudyF.Bodendieck
OHB-system
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(No Transcript)
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(No Transcript)
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Summary The present design baseline is identified
by a concept, where the Zenith radiators (to cool
the Cryo-Coolers) are mounted on the top TRD
panel by a combination of spokes and brackets. A
MLI blanket is located between radiators and TRD
in order to thermally decouple both parts. This
study has been performed to investigate the
thermal behavior of a solution, where the
radiators are directly mounted (i.e. glued) to
the upper TRD panel. The idea is that the
ROHACELL foam material, presently used to build
up the radiator sandwich, could serve as a
sufficient isolation to provide the mentioned
thermal decoupling of the two parts. Advantages
of the new concept would be a possible mass
decrease due to the deletion of spokes, brackets
and MLI as well as the deletion of the lower
radiator panel aluminum face-sheet (the foam
radiator panel assembly would be directly glued
to the TRD panel).
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Summary (2) The analysis results, which are
detailed on the next pages, can be summarized as
follows Thermal decoupling between radiator and
TRD is (as expected) less effective with the
direct mounting (gluing) concept and depends
strongly on the foam thickness. The less
effective decoupling is especially pronounced in
the extreme cold case (b 75, YPR
-151515). The TRD temperature for this case is
at about 12C for the spokes version, but at
about -40C for the 45 mm Foam version and at
about 50C for the 10 mm Foam version. The
temperature gradient within the TRD increases
from 0.6C (spokes) to 1.4C (45 mm foam) to 2C
(10 mm foam). It shall be noted that the extreme
low temperatures, calculated for the radiators ,
could not get the Cryo-Cooler requirements
fulfilled (To be verified). The described
temperature effects are less pronounced in the
extreme warm case (b 75, YPR -15-20-15) due
to the more benign temperatures of the radiators
(between around 1C and 3C average for all
cases). This is the reason that the TRD
temperatures favorably decrease from a relatively
high temperature of about 35C (spokes) to about
16C (45 mm foam) to around 7C av. (10 mm foam).
The change in gradient is also less pronounced
from 0.37C (spokes) to 1.5C (45 mm foam) to
2.8C (10 mm foam) A considerable mass decrease
of about 8 kg can be reached when going from the
spokes version to the 10 mm foam case (due to
deletion of spokes, brackets, lower face-sheet
and MLI). For the 45 mm foam case the thicker
foam layer is compensating this advantage.
Actually this case results in a calculated mass
increase of about 0.5 kg
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TRD - Cryo Radiator Assembly
Cryo Radiator
TRD upper cover
Side panel upper part
Side panel lower part
TRD lower cover
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Thermal Analysis Results (1/2)
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Thermal Analysis Results (2/2)
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Maximum Dt between TRD upper cover and lower
cover during 10 orbits
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Mass budget comparison
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Conclusions (zenith radiator)

• The direct mounting of the Cryo-radiator to the
  TRD results in a stronger thermal coupling
  between radiator and TRD. Therefore the extreme
  environments will affect more directly the TRD
  absolute temperature and gradients.
• A 45 mm foam solution could be close to
  feasibility but there is no mass saving advantage
  with respect to the baseline spoke version.
• Another point, which has not been mentioned, is
  the more complex integration sequence and
  responsibility sharing of the direct bonding
  solution.
• As consequence OHB recommends therefore to retain
  the spoke version as baseline.