Beam Pipe Support

1
Beam Pipe Support
Composite support tube with integrated rails
TRT
TRT
SCT
Side C
Side A
LBNL responsible for support tube and services
structures
2
Beam Pipe Integration

• Beam pipe is integrated with pixel detector on
  surface building. All then lowered.
• Design requirements from CERN for beam pipe
  support have evolved over last year but now
  appear to be nearly final.
• Design of support and adjustment mechanism being
  done by E. Anderssen, N. Hartman and D. Uken at
  LBNL

3
Beampipe Support Frame
Wire Adjustors
Longerons
Service panel Attachment points
Fixed Adjustors (no spring) Top and Side
Reinforcing Longerons
Wires at Z-800,800
Sprung Adjustors Side and bottom (tension
limiters)
Cruciform supports
4
Geometry at Pixel Detector End
Longerons
Wire Guide
Cruciform Support
No BP Collar Shown
Beampipe
Beampipe shown in extreme off-center position
5
Adjustor/Tension Limiter
Wire Guide
Preload Adjustor Barrel
Wire
Wire Adjustor Nut
Wire Collet Nut
Tension Limiter Plunger
Limiter Spring
Wire Adjustor Screw
6
Assembly of Adjustor/Limiter Unit
Tension Limiter Assembled, Spring Compressed
Wire Fed Through, Clamped into Collet
Wire Adjustor Seated in Tension Limiter
Max IN Adjustment
Max OUT Adjustment
7
Tension Limiter
During Operation, Spring Holds Limiter Plunger
Against Preload Adjustment Barrel
When Tension Limit is Exceeded, Plunger Moves,
Allowing Wire to Extend Under Reduced Stiffness
of Spring
Electrical Contact Between Plunger and Adjustment
Barrel (not shown) signals when Tension Limit is
Exceeded.
8
Next Steps

• Design will be reviewed internally by CERN next
  month.
• Assuming this is OK, immediate next step is to
  make prototype of adjustment mechanism that would
  include short version of support frame.
• Test out adjustment
• After that would proceed to final design and then
  fabrication of the composite support frame and
  multiple adjustment mechanisms.