NEWS

1
NEWS

• Internal Review
• November 20
• Presentation covering most of the relevant L4 WBS
  activities rf shielding, substrate,Vacuum
  vessel, Position control system, Cooling system,
  Pixel support frame
• 3 hours of presentation
• Discussion with the Reviewers
• Question individual comments from reviewer,
  written report
• Charge to the reviewers

2
ESLI

• 48 glassy carbon tubes delivered
• 1.5mm OD (23), 1.2mm OD (25)
• Four of each being sent to Iowa and WSU
• Properties see attached spreadsheet
• Tests planned impact test of joints, strength
  test of the tubes, solution to manifold,
  irradiation test, corrosion test
• Wall thickness found to be non-uniform

3
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4
RF shielding

• Alex will report on the FEA
• We met with Weiren Chou (BD) to discuss the
  shielding. Chou will do calculation on the beam
  effects impedance, heating, and image current
  return
• Also discussed with Cary and Mark on prototyping
  would like to fabricate a short section
• (welding, stamping, EDM, laser cut etc)

5
Be substrate ( for CM )

• More movies taken with small bump
• Conclusion not much difference
• Proposed to adopt Charles idea make it solid Be
  at the notch
• Had a meeting with Mike H., Mike R., Jim Fast on
  the alignment holes lead to some changes in the
  precision of the holes, ideas on assembly etc
• We should try out the procedure Zeiss 850
  available to us will use it for the thermal
  displacement test but also for the assembly
  practice

6
Be substrate
7
FEA

• Recall that bump bond is the weakest link
  according to FEA
• We can improve the strength by putting in
  underfill around the corners
• Our test using ATLAS 2x8 module with 5 FPIX1
  chips bonded is still OK after a few thermal
  cycles

8
FEA (cont)

• Big stress on the epoxy layer because if CTE
  mismatch between Si and Be
• Factor of 3 larger than strength of any known
  epoxy
• Separate the epoxy layer into