| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 8175529 | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | 2014 | 4 Pages |
Abstract
The gaseous COMPASS RICH-1 detector uses two spherical mirror surfaces, segmented into 116 individual mirrors, to focus the Cherenkov photons onto the detector plane. Any mirror misalignment directly affects the detector resolution. The on-line Continuous Line Alignment and Monitoring (CLAM) photogrammetry-based method has been implemented to measure the alignment of individual mirrors which can be characterized by the center of curvature. The mirror wall reflects a regular grid of retroreflective strips placed inside the detector vessel. Then, the position of each mirror is determined from the image of the grid reflection. The images are collected by four cameras. Any small mirror misalignment results in changes of the grid lines' positions in the image. The accuracy limits of the CLAM method were checked by laser interferometry and are below 0.1Â mrad.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Instrumentation
Authors
M. Alexeev, R. Birsa, F. Bradamante, A. Bressan, M. Chiosso, P. Ciliberti, S. Dalla Torre, O. Denisov, V. Duic, A. Ferrero, M. Finger, M. Jr., J.Ch. Gayde, M. Giorgi, B. Gobbo, S. Levorato, A. Maggiora, A. Martin, F. Tessarotto,