Pixel Support Tube Introduction

1
Pixel Support TubeIntroduction

• October 2001

2
Since the Last Review

• FEA calculations to evaluate different design
  options for the PST were completed and
  documented(see note of Neal Hartman).
• The impact on the barrel SCT of potential
  movements of the forward part of the PST has been
  evaluated via FEA calculations by Joel Cugnoni
  and partially validated by the pixel team(also
  note of Neal Hartman)
• This led to a design change to reduce the
  stiffness of the forward sections of the PST. We
  now propose to make the forward sections from
  glass fiber rather than carbon fiber to reduce
  the stiffness and thus impact on the SCT barrel.
• In addition, the z-stiffness of the PST
  mounts(flexures) has been evaluated(E. Anderssen)
  to also reduce the impact on the SCT from PST
  longitudinal motions.

3
Since the Last Review(2)

• At the last review, our baseline design had a
  single thermal barrier for the barrel SCT and
  barrel pixel regions. A detailed interface
  drawing was prepared under this assumption
• Recently(last few weeks), the ID community has
  proposed to have an independent SCT-barrel
  thermal barrier ie. two thermal barriers in the
  barrel region, one for the SCT and one for
  pixels.
• A preliminary interface between the barrel
  SCT(interlinks) and the PST has been worked out
  but there has been insufficient time to create
  detailed interface drawings.
• Although not yet formally approved by ATLAS, we
  are proceeding under the assumption that an
  independent thermal barrier for the SCT will
  become the new baseline.
• A conceptual design for the mounts attaching the
  pixel detector to the PST(barrel flanges) has
  been completed and will be presented today.

4
Since the Last Review(3)

• Our current baseline design is that the VI
  section of the beampipe is supported by the PST,
  and that X-Y adjustment of the beampipe is
  included in these supports. A conceptual design
  for this will be presented today.
• A concept for attaching the pixel detector to the
  service panel/beampipe support structures will
  also be presented.
• The area needed for service connections at the
  end of the PST - Patch Panel 1(PP1) - has been
  sized in a preliminary way and a very early
  layout completed.
• Tests of potential slider materials have just
  begun but there are no conclusions. And
  alternatives(rollers) remain to be evaluated.
• Feasibility of delivery to pit of pixel package
  has been studied and will be presented.

5
Final Introductory Remarks

• Although considerable work has been done, much,
  much more remains to be done.
• A critical point is that much of the PST design
  is interface driven.
• I will attempt to summarize after talks by Eric
  the critical interfaces, issues and plans for
  near-term work to be done.