Results from the test bench of the Geometry Monitoring System of the ALICE Muon Spectrometer

Abstract

We present the results obtained with the test bench of the Geometry Monitoring System (GMS) for the ALICE Muon Spectrometer. It consists in a mock up, reproducing at full scale, three half planes of the chambers 6, 7 and 8 of the spectrometer. We show that the GMS is able to measure transverse displacements with an accuracy of 1.5 microm. We show also that the resolution deteriorates by a factor 3 to 4 when thermal gradients are generated