Aligning the CMS muon chambers with the muon alignment system during an extended cosmic ray run Academic Article uri icon


  • The alignment system for the muon spectrometer of the CMS detector comprises three independent subsystems of optical and analog position sensors. It aligns muon chambers with respect to each other and to the central silicon tracker. System commissioning at full magnetic field began in 2008 during an extended cosmic ray run. The system succeeded in tracking muon detector movements of up to 18 mm and rotations of several milliradians under magnetic forces. Depending on coordinate and subsystem, the system achieved chamber alignment precisions of 140-350 m and 30-200 rad, close to the precision requirements of the experiment. Systematic errors on absolute positions are estimated to be 340-590 m based on comparisons with independent photogrammetry measurements. 2010 IOP Publishing Ltd and SISSA.

published proceedings

  • Journal of Instrumentation

altmetric score

  • 7.33

author list (cited authors)

  • Collaboration, C.

citation count

  • 16

complete list of authors

  • Collaboration, CMS

publication date

  • March 2010