GEM-TN-92-150 Analysis of an Alignment Scheme for (original) (raw)

An analysis package has been developed to investigate an alignment scheme defined for the GEM muon barrel. Individual chambers can be arbitrarily translated and/or rotated, and sagitta corrections are calculated from a system of alignment monitors. The sagitta error, correction, and residual are plotted (vs. θ and φ) for straight-line tracks arising from the IP. Using this package, intuition may be developed into the accuracy and nature of particular alignment corrections. Several effects have been found to limit the error correction to the percent or permil levels for certain chamber deflections, which may become significant for large misalignments.