ARAMyS – Alignment Reconstruction Software for the ATLAS Muon Spectrometer

The muon spectrometer of the ATLAS detector at the LHC has been designed to measure the momentum of muons up to the TeV range. To reach this goal, a continuously running alignment monitoring system is essential, which consists of several thousands of optical and temperature sensors. The program ARAMyS has been developed to reconstruct from the sensor measurements the spectrometer geometry, i.e. the deformations of individual chambers and their relative positions and rotations, which are input to the detector geometry model and the track reconstruction algorithms. The program can also be used, in the design phase of a detector, to simulate the expected alignment performance of a network of sensors with given resolutions.