70 likes | 208 Views
Alignment systems for GlueX. Courtesy of Dimos Sampsonidis, Aristotle University of Thessaloniki. Presented by Zisis Papandreou, University of Regina. GlueX Collaboration Meeting Bloomington, Indiana May 20-22, 2004. NIKHEF Web Page. Pattern used to measure x- and y-axis, size for z-axis.
E N D
Alignment systems for GlueX Courtesy of Dimos Sampsonidis, Aristotle University of Thessaloniki Presented by Zisis Papandreou, University of Regina GlueX Collaboration Meeting Bloomington, Indiana May 20-22, 2004
NIKHEF Web Page Pattern used to measure x- and y-axis, size for z-axis Range of several cm with accuracy less than 1m
Y X The infrastructure - RASNIK systems The main element used in chamber alignment and QA/QC during chamber construction •Three point relative alignment measurement systems (RASNIK) with accuracy ± 1μm. CCD camera 400000 pixels pixel size 7x7μm2 Mask and light source Lens adapted to layout Original system used a bright dot
RASNIK specs Y X Infrared LED Performance, in terms of Image Position on Sensor: x = 0.05 µm y = 0.05 µm scale = 2 x 10-5 RotZ = 20 µrad Coded Mask Alignment information from image pattern recognition
Online Quality Assurance Temperature variation Effect on RASNIK monitoring for tube layer position (z coordinate) Temperature variation at Stiffback The height of the clean room is limited (2,65 m). The stiffback is heated from the lights while it is suspended. Temperature variation at Rasnik Tower 6m shift of stiffback visible!
What’s required • RasNik components: camera, mask, lens • PC with FrameGrabber: data translation • Rasmux: a custom multiplexer • For use with camera and mask • Suitable cables • Software: free from NIKHEF • AUTH will contact NIKHEF for a system or could participate in system development
BCAM: another option • Boston CCD Angle Monitor • ATLAS forward muon chambers • Camera electronics is radiation resistant • 10 mrad field view • At 16m 3rad accuracy • Minimum effect of turbulence on resolution