ATLAS Pixel System

1
ATLAS Pixel System
Provides ? 3 his for ??2.5
Three disk layers
Three barrel layers
Pixel size is 50x400?, except for innermost
barrel layer that is 50x300?
2
US Pixel Project

• Pixel production baseline review completed
  earlier this year and Pixels are now part of the
  approved production scope within the US ATLAS
  Project.
• The US baseline scope corresponds to a 2-hit
  system.
• The innermost(B-layer) and outermost barrel
  layers are retained.
• 2x2 disks are retained.
• This corresponds to the current concept for the
  ATLAS initial detector for first operation.
• Upgrade path to full 3-hit system facilitated by
  design change to fully insertable system - see
  next page.

3
Pixel Installation Changed
Transition Radiation Tracker(TRT)
Semiconductor Tracker(SCT)
Pixel Detector
Pixel design modified in last year to allow
insertion from end of Inner Detector.
Support tube
4
Pixel Mechanics

• LBNL now has the lead role in pixel mechanics in
  ATLAS.
• Responsibilities include
• Support tube
• Global pixel support frame
• End(disk) sections
• Power and coolant services support panels
• Other items(actual services, final
  assembly/installation) are shared with European
  collaborators, who will provide barrel section.
• There are still uncovered aspects of the
  mechanics(final installation tooling and others)
  that LBNL could(and should) do, but US funds not
  currently available.
• Production of the first elements of the mechanics
  system will begin by July of this year.

5
Disk Structures

• Disks are composed of sectors(8 per disk) that
  provide mechanical support and cooling and
  support rings.
• Six modules are mounted on each sector.
• Sectors are attached to disk support ring at
  outer radius.
• Disk support ring is mounted in support frame.
• Sectors are ready to begin production in July.
• Final design of support rings is complete and
  design of fabrication tooling started.

6
Support Frame
Disk Sections
Barrel Section

• Frame design advanced.
• Support cone prototype complete next month
• Trial insertion of disk ring into prototype of
  frame started

Barrel Support Cone
7
Support Frame Prototypes
Panel components
Frame prototype
First bonded flat panels with P30 facings for
support cone prototype
8
Support Tube

• Support tube design started - see next page.
• Detector beam vacuum pipe will be held by this
  tube.
• Three-piece composite structure with integrated
  rails to slide in Pixel Detector and all of its
  services.
• Assembly is complex. Practice.
• Constructing complete mockup(located in Bevatron
  building) to understand assembly and installation
  sequence.

Service Rails
Detector Rails
9
Support Tube - Composite Structure
0.44 mm wall
Hoop Hat Stiffeners (section view)
7.5m long
Bolt flanges
Sct mount pads
End Plugs (1 mm equiv. carbon sheet)