OT Survey

1
OT Survey Adjustment
06-03-2007

• Outline
• Survey technique at present
• what has been done and what there is to do
• issues to complete OT alignment before pilot run
• possible optimizations
• long-term maintainance

2
Open Position
Modules
Bridge
C-frame OT
Cryo-Platform
Table Cable Trays
3
C Frames
Distribution of cooling and gas
Front-End Electronics Boxes
Detector Modules
Distribution of LV,HV, ECS/TFC, etc.
4
C-Frame Survey
Survey Points 2(X/U) x 2(T/B) x 9 Per point two
targets for position distance 1 day per C-frame
5
C-Frame Adjustment
Long Beams (IPE 300)
Transversal Beams
C-Frame Rails
Wheeled Support, Alignment, and Stop-and-Lock
Blocks
6
Survey Work
All data available at http//www.nikhef.nl/pub/ex
periments/bfys/lhcb/outerTracker/Installation/Surv
ey/Overview.html
7
Achieved so far
8
Problems to be solved

• Completion of OT alignment before pilot run
• Close OT or at least come into the region of the
  alignment blocks
• access magnet area for survey
• access top dowel pins for survey target
  installation
• access alignment mechanism to adjust C-Frame
  position

• Maintain the OT alignment (long-term)
• access magnet area for survey
• access top dowel pins for survey target
  installation
• create possibility of survey from the A side
• A side survey point outside the detector
• C side survey point between A and C halves

9
Optimize the survey targets

• Currently used
• gives good resolution in position and distance
• only one available (plus few spares)
• needs two accesses per dowel pin (distance and
  position)
• does not fit between two C-Frames

• Alternative 1
• gives acceptable resolution in position and
  distance
• can make 2 x 9
• needs one access per dowel pin
• does not fit between two C-Frames

• Alternative 2
• gives good resolution in position and distance
• can make many (432??)
• needs no access
• fits between two C-Frames
• needs two survey stations in the magnet
  (triangulation)

10
Reduce the number of survey points

• Completion of OT alignment before pilot run
• must have all points (2 x 2 x 9 per C-Frame)
• after adjustment can measure less points (1 x 2
  x 5 per C-Frame)

• Maintain the OT alignment (long-term)
• can use a reduced set of points (1 x 2 x 5 per
  C-Frame)

11
Side Survey

• Target Alternative 3 (side view)
• gives good resolution in distance and acceptable
  in position
• can make 18
• needs one access per dowel pin
• does not fit between two C-Frames
• needs survey platforms to be made

• create possibility of survey from the A side
• A side survey point outside the detector
• C side survey point between A and C halves