1 research outputs found
Alignment of the CMS silicon strip tracker during stand-alone commissioning
The results of the CMS tracker alignment analysis are presented using the
data from cosmic tracks, optical survey information, and the laser alignment
system at the Tracker Integration Facility at CERN. During several months of
operation in the spring and summer of 2007, about five million cosmic track
events were collected with a partially active CMS Tracker. This allowed us to
perform first alignment of the active silicon modules with the cosmic tracks
using three different statistical approaches; validate the survey and laser
alignment system performance; and test the stability of Tracker structures
under various stresses and temperatures ranging from +15C to -15C. Comparison
with simulation shows that the achieved alignment precision in the barrel part
of the tracker leads to residual distributions similar to those obtained with a
random misalignment of 50 (80) microns in the outer (inner) part of the barrel.Comment: 41 pages, 63 postscript figures, submitted to JINS