Title of article
Monitoring of absolute mirror alignment at COMPASS RICH-1 detector
Author/Authors
Alexeev، نويسنده , , M. and Birsa، نويسنده , , R. and Bradamante، نويسنده , , F. and Bressan، نويسنده , , A. and Chiosso، نويسنده , , M. and Ciliberti، نويسنده , , P. and Dalla Torre، نويسنده , , S. A. Denisov، نويسنده , , O. and Duic، نويسنده , , V. and Ferrero، نويسنده , , A. and Finger، نويسنده , , M. and Finger Jr.، نويسنده , , M. and Gayde، نويسنده , , J.Ch. and Giorgi، نويسنده , , M. and Gobbo، نويسنده , , B. and Levorato، نويسنده , , S. and Maggiora، نويسنده , , A. and Martin، نويسنده , , A. and Menon، نويسنده , , G. and Panzieri، نويسنده , , D. and Pesaro، نويسنده , , G. and Polak، نويسنده , , J. and Rocco، نويسنده , , E. and Sbrizzai، نويسنده , , G. and Schiavon، نويسنده , , P. and Slunecka، نويسنده , , M. and Sozzi، نويسنده , , F. and Steiger، نويسنده , , L. and Sulc، نويسنده , , M. and Takekawa، نويسنده , , S. and Tessarotto، نويسنده , , F.، نويسنده ,
Pages
4
From page
208
To page
211
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 0.1 mrad.
Keywords
Mirror alignment , Cherenkov radiation , rich , photogrammetry
Journal title
Astroparticle Physics
Record number
2009395
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