Pixel R

1
Pixel RD

• The useful lifetime of the innermost pixel layer
  is expected to be limited to a few years at
  design luminosity.
• However, there are substantial uncertainties in
  the actual radiation levels and realistic
  operating voltages gt plan on replacing at least
  this layer(possibly more) early, since pixels are
  essential for tracking and required for all
  b-tagging, which is critical for high Pt physics.
• On a somewhat longer timescale, luminosities
  beyond 1034 will require major upgrades to the
  tracking system eg. replacement of gas detectors
  by silicon(or something else), replacement of
  silicon strip detectors by pixels and increased
  radiation hardness(beyond the current 25MRad) for
  pixel detectors.
• RD for gt1034 is very challenging(its taken us
  about 20 years to be comfortable with 1034).

2
Pixel RD Areas

• Electronics
• Increase/understand radiation hardness gt 100
  MRad. This looks promising but much more study
  needed.
• Follow the technology from 0.25? to smaller
  feature sizes. Work on 0.17 ? or 0.13? can begin
  very soon.
• Reduce pixel size below 50x400?. There is already
  significant confusion in at least innermost pixel
  layer.
• Sensors
• A follow on to the successful ROSE collaboration
  is starting to address the 1035 challenge.
• Hybridization
• Reduce the pitch of bump bonding to allow smaller
  pixels, or use redistribution in electronics.
• Development of MCM-D technology to mostly
  eliminate kapton hybrids has been ongoing for
  some time and needs further development.
• Mechanics and systems issues
• Reduce material and complexity of the
  mechanics/cooling. Material reduction directly
  improves electron and photon energy resolution
  and tracking performance.
• Complexity of current cabling/cooling is
  formidable. Reliability will be problem.
• Radioactivation of pixel elements is already
  significant at 1034. There are as yet no good
  ideas about how to handle this for higher
  luminosities.

3
Replacement Funding Profile
4
Replacement Costs

• Silicon RD in past years received substantial
  non-project support, which will be largely absent
  for replacement.
• Pixel Replacement RD(2.5M)
• For comparison, past project costs for pixel RD
  were about 2.5M(AY). Costs including other
  support were 2-3 times this value.
• Pixel Replacement Costs(5M)
• For comparison, current project baseline project
  costs(TPC) are 6.7M. Including non-project
  support would raise this to about 11M.
• SCT Replacement RD Costs(0.9M)
• Covers only US part of electronics design and
  prototype costs for silicon strip IC replacement.
• ReadOut Driver RD and Replacement Costs(2.3M)
• Covers RD related to replacement of pixel RODs
  to match pixel replacement. Current ROD
  TPC(including pixel RODs in management
  contingency) is about 3.5M.