Back up stave test program status

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Back up stave test program status

• Pre production status
• Assembling phase comments
• Geometrical control
• Stave Qualification
• Tube pressure tests
• Tube pressure cycles
• Stave thermal conduction
• Stave thermal distortion
• Stave thermal stability
• Stave connection
• Stave insulation
• Schedule and budget

Eric VIGEOLAS Pixel week December 2000
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Pre Production status
Up to now 5 back up staves was assembled. One
have been fully tested for the June mechanical
review. One stave was broken during the shipment
(but one half was tested to confirm the thermal
distortions observed on the previous stave) Three
additional stave was manufactured two with an
aluminium tube without parylene, the last one was
manufactured with Parylene coated tube.
This pre production have confirmed that the
assembling tools foreseen for the baseline stave
was suitable for the Back up stave. Only one
additional sequences is needed during the
assembling phase (the grease deposition on the
tube which take a few minutes). One Sequence in
the baseline assembling was changed, the Omega
glue deposition. An manual deposition which
consist to wet the two wings of the Omega was
chosen in order to reduce the amount of Glue.
Eric VIGEOLAS Pixel week December 2000
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Assembling phase Comments

• One important result of the stave assembling
  technique is that due to the pressure applied on
  the Omega in the gluing phase, the thickness of
  Omega glue is bellow the expected 0.1mm.
• 0.1 mm was the nominal grease thickness foreseen.
  This amount of grease was foreseen to permit to
  the tube to have a degree of freedom to avoid
  thermal mismatch. Therefor the tube is in contact
  with the C-C.
• The main effects of this observation is
• More thermal deformations due to CTE mismatch,
  but those deformations are reduced by the use of
  5 supports points (presented later), and stays in
  the requirements
• Better thermal efficiency of the cooling pipe
• The tube grease layer is less determining is the
  stave reliability.

0.1mm
0.1mm
Pressure applied during the assembling on the
Omega
The tube is in contact with the C-C
Eric VIGEOLAS Pixel week December 2000
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Geometrical Control (June stave)

• Each tilted plan of the stave was measured in
  order to estimate the accuracy reached after the
  machining and the assembling.
• The individual plan geometry accuracy is listed
  in the table bellow.
• The relative plan location (in R an Z direction )
  accuracy is
• Z 50?m
• R 100?m
• The R location inaccuracy is mainly due to the
  natural bowing if the stave (composite material,
  thermal curing)

Eric VIGEOLAS Pixel week December 2000
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Geometrical Control (2 November staves)

• On the new staves received at CPPM the planarity
  of the Tilted plan was measure
• each plans presented the same S shape
• The average planarity on 24 plan is 41 ?m
• The sigma is 13 ?m
• The best planarity was 19 ?m
• The worst one was 67 ?m
• The main risk of a poor planarity is the
  difficulty to deposit a module on the surface
  with the required glue thickness. Two
  consequences are suspected
• Silicon temperature dispersion if the glue
  thickness is not controlled
• Impossibility to reduce the remaining force to 0
  grams during the deposition.
• Two stave was equipped with Si by using the CPPM
  module assembling tool. The main results are
• During the thermal test no important temperature
  dispersion was shown
• Remaining forces on Si was existing on a minority
  of plan (lt 100 grams), The consequences of such
  parameter have to be understood (not yet done).

Eric VIGEOLAS Pixel week December 2000
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Stave QualificationTube pressure tests

• The Aluminium Tube was individually pressurised
  in order to control it pressure stiffness. The
  tube flat edge deformation was measured to
  control eventual remaining distortions.
• The tube has resist to an internal pressure of 15
  bar without remaining deformations.
• At 4 Bars absolute the tube have a flat face
  bowing of 15 ?m.
• At 8 Bars the flat face bowing is about 25 ?m.

F
Eric VIGEOLAS Pixel week December 2000
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Stave QualificationTube pressure Cycles

• 500 Pressure cycles was applied from 1 Bar to 7.5
  Bar in order to control if any creep appear. The
  creep rate observed after the full tests was 0.1
  which is negligible.
• By maintaining the pressure in the tube after the
  tests no leaks was observed. Further leak tests
  will be done with He.

Eric VIGEOLAS Pixel week December 2000
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Stave QualificationStave Thermal Cycles
Thermal Chock -35C
Eric VIGEOLAS Pixel week December 2000
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Stave QualificationStave Thermal Cycles

• The Thermal cycles was performed with full power
  on the stave (134W), by just switching on and off
  the power supply. The main variation in the
  temperature are driven by the inertia of the
  cooling system (stabilisation of the intern stave
  pressure, flow rate stabilisation) than by any
  effect of the stave thermal conduction changes.
• Before this test thermal chocks was also applied
  (power on on one side of the stave and power off
  on the other side and vice and versa (temperature
  decrease up to -35C) switch off of the cooling
  with an immediate switch on (temperature goes up
  to 60C) ).
• Moreover during these tests the stave was handle
  on two points, with allows the mobility of this
  one. This was the worst conditions (high
  displacements) to test the reliability of the
  thermal conduction.
• Finally this test gave precious informations
  about the reliability of the NEA123 UV Glue
  CGL7018 Grease for the module attachment.

Eric VIGEOLAS Pixel week December 2000
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Stave QualificationStave Thermal conduction
(June stave)

• The Temperature measured at full power was
  uniform along the stave. The average Silicon
  temperature is -12C.
• The pressure drop was lt 0.05 bar, this involve a
  very low ?T along the tube lt 2C.
• The temperatures measured on the C-C shows a low
  ?T in the cross section of the silicon lt3C. The
  ?T between the fluid and the silicon is lt 12C
• The Back up stave meet perfectly the thermal
  requirements.

Tube sensors
C-C sensors
Eric VIGEOLAS Pixel week December 2000
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Stave QualificationStave Configuration (June
stave)

• The stave configuration was as follow one Pt100
  sensor was glued on each silicon(13 sensors),4
  Pt100 was glued on the edge of the C-C, Two Pt100
  was glued on the tube at the inlet and the
  outlet. The maximum power applied was 107 Watts
  on the full stave.
• This test was done at CERN with C3F8 fluid.

Estimations of Silicon temperature by
calculations shows that the uniformity of the
temperature(?T on Si) is lt 5C
Estimations of C-C temperature by calculations
shows that it is very close to the silicon one
(-11C)
Heaters
Back thermal sensor on C-C
Eric VIGEOLAS Pixel week December 2000
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Stave QualificationStave Configuration
(November stave)

• The stave configuration was as follow one Pt100
  sensor was glued on each silicon(13 sensors), Two
  Pt100 was glued on the tube at the inlet and the
  outlet. The maximum power applied was 134 Watts
  on the full stave.
• This test was done at CERN with C3F8 fluid.

Thermal Sensor
Heaters
Eric VIGEOLAS Pixel week December 2000
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Stave QualificationStave thermal conduction test
(November stave, before pressure cycles)

• The Si temperature average values is -11.07 C on
  the tilted Si, and -7.05C on the middle Si.
• The Pressure drop along the stave is 0.1 Bar.

Eric VIGEOLAS Pixel week December 2000
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Stave QualificationStave thermal conduction test
(November stave, After the Temperature cycles)

• The Si temperature average values is -12.96 C on
  the tilted Si, and -7.34C on the middle Si.
• The Pressure drop along the stave is 0.2 Bar.

Eric VIGEOLAS Pixel week December 2000
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Stave QualificationStave thermal distortion on
three aligned points test (June stave)

• The stave shows an asymmetric behaviour in the
  two configurations. On side stays within the
  requirements with a maximal R displacement of 30
  ?m. The other side get out of the specifications.
  This asymmetry was shown on all the staves
  measured. Phenomena to be studied..

• Two measurements was done in a cold box for a ?T
  of 25C.
• On of the measurement was done without silicon
  glued on the stave, the second one with silicon
  glued on the stave in order to control the module
  influence on the stave deformation.

Eric VIGEOLAS Pixel week December 2000
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Stave QualificationStave thermal distortion on
five aligned points test (November stave)

• The stave shows an asymmetric behaviour. On side
  have a maximal R displacement of 10 ?m. The other
  side have a maximal R displacement of 30 ?m .
  This confirm what was said before about the
  asymmetry shown on every staves.

• This measurement was done in a cold box for a ?T
  of 25C.
• The stave was equipped with Si heaters

Eric VIGEOLAS Pixel week December 2000
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Stave QualificationStave thermal stability on
five aligned points test (November stave)

• This test was done on half of the stave. This
  consist of applying a power on Si to maintain a
  ?T of 10C in between The Si and The Coolant.
• And switch off the power on one and three modules
  in between two support to control the stave
  mobility.
• The Cooling system available at CPPM works at
  constant cooling power (and not at Temperature
  constant as for C3F8). This is a worst condition
  because more parts of the stave will have
  temperature changes, which involve more
  displacements.

• The Maximum displacement after Three modules off
  was 3 ?m (indicative value which is inside the
  tolerance of our CMM)

Module3
Module2
Module1
Supports
Eric VIGEOLAS Pixel week December 2000
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Stave QualificationStave thermal stability on
five aligned points test (November stave)
Eric VIGEOLAS Pixel week December 2000
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Stave Connection

• Connection project still under study. This
  subject have took two months of delay due to the
  use of the induction Power supply by an other
  experiment.
• Meanwhile the first Cupro-Nickel Tests pieces was
  Brazing. The design program is
• Complete the study concerning the Cupro-Nickel
• Study the feasibility of an Aluminium pieces
  brazing

• Each study is split in several qualifications
  tests
• Corrosion inspection (visual inspection after a
  metallurgical polishing)
• Pressure test (leak tests coupled with pressure
  cycles)
• Traction and shear tests coupled with He leak
  tests
• Remaining studies concerns
• The layout of the piping (designed as close as
  possible than the baseline one)
• The scenarios of the the pipes assembling (staves
  connection and deconnection).
• .

Eric VIGEOLAS Pixel week December 2000
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Stave Insulation

• The stave insulation will be handle by the
  Parylene deposition on the tube.
• The insulation resistance is gt 20MOhm (limit of
  our measurement instrument) in between the
  internal face of the tube (non coated) and the
  external one.
• The first stave prototype equipped with a
  Parylene coated tube was assembled a few weeks
  ago, and the thermal conduction of this one
  should be done by January (to verify the effected
  of the additional thermal resistance due to
  Paryelene).

Eric VIGEOLAS Pixel week December 2000
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Schedule and Budget

• Concerning the additional tasks required for the
  Back up stave assembling, this have no influence
  on the schedule of the Baseline stave assembling
  (the additional tasks take a few minutes). All
  these tasks will be done at Plyform Which
  actually is involved in the baseline assembling
  and which have built the three previous backup
  staves.
• The tube delivery is 7 weeks 4 weeks needed for
  the Parylene deposition.
• The tube price plus the Parylene deposition have
  a price of 50000 ChFr.
• The additional cost due the the new tasks needed
  at Plyform is not known.

Eric VIGEOLAS Pixel week December 2000