8 Accelerator Engineering and Technology: Accelerator Technology
501
Fig. 8.102 Survey galleries
Fig. 8.103 The HLS and WPS around an LHC experiment
the quadrupoles. To link both sides, a “long” (120 m) wire has been installed in
dedicated Survey galleries and goes through the experimental cavern (Fig. 8.103).
The distances between the “long” and the “shorts” wires are measured by invar
rods and proximity sensors in six locations to have redundant measurements. The
accuracy obtained is in the range of several microns for the quadrupole magnets
located along the same “short” wire and 0.1 mm between both sides of the
experiment.
In addition, a motorized system has been installed to enable a remote readjustment for the improvement of the beam trajectory. This is not an active alignment
system, the alignment is allowed only when the beam is off.
501
Fig. 8.102 Survey galleries
Fig. 8.103 The HLS and WPS around an LHC experiment
the quadrupoles. To link both sides, a “long” (120 m) wire has been installed in
dedicated Survey galleries and goes through the experimental cavern (Fig. 8.103).
The distances between the “long” and the “shorts” wires are measured by invar
rods and proximity sensors in six locations to have redundant measurements. The
accuracy obtained is in the range of several microns for the quadrupole magnets
located along the same “short” wire and 0.1 mm between both sides of the
experiment.
In addition, a motorized system has been installed to enable a remote readjustment for the improvement of the beam trajectory. This is not an active alignment
system, the alignment is allowed only when the beam is off.