RASNIK in LHCb Outer Tracker

This page describes the simplest system of RASNIK lines in LHCb OT.

A more detailed description can be found in this draft note.

An older version of this page can be found here.


RASNIK is a 3 point infrared optical alignment system.

RasNik system

RASNIK for ATLAS (learn more from NIKHEF/ATLAS pages about RASNIK.)

Outer Tracker support structures

Outer Tracker frames

OT Racks

  • Rack_in_tunnel Location of Racks.

  • Slides about RASNIK in Outer Tracker

    There are 3 stations in OT and 4 C-frames in each station. In each corner of C-frame there will be 1 RASNIK line. This makes 48 RASNIK lines. These lines are parallel to the beam (z axis) and short (from 9cm - to about 0.6 m). They measure relative movement of C-frames vs bridge (pilars or rails). Two vertical, 8m long lines will measure displacements of the bridge vs bunker in horizontal directions.

  • RasnikLocations.ppt - x,y of RASNIK on C-frames. Convention for installation of masks inside C-frames.
  • RasnikFocalLengths.xls - z of RASNIK elements.
  • RasnikMiddleScaleTest.ppt Materials shown on the 6th of June 2005. (only part 1 - without cables)
  • RasnikCable.ppt Corrected cable location. (part 2 - cables)
  • RasnikList.xls List of main RASNIK elements.
  • RasnikLongLines.ppt - 2 horizontal lines on top of the bridge could measure if it is bending. (Such lines are not installed, that was just an idea.)

  • RasnikBridge

    Area with RASNIK shelves (green) with lenses and cameras and cables (red) installed on pillars, bridge and tables. Lines monitoring bridge are on the corners of bunker: cameras on L-profiles (orange), mask and lenses inside square tubes (blue).

    Above drawing as .ipt (to see from any side)

    Drawing of old version with Hall probes as .ipt

    RASNIK and IT chain

    Krzysztof Syryczynski

    updated: 1 dec 2007