Abstract:
The silicon-tungsten calorimeter LumiCal, located in very forward region of the future detector at the International Linear Collider, is proposed for precisely luminosity measurement. One of the requirements to fulfil this task is available information on the actual position of the calorimeter relative to the beam interaction area which should be known with accuracy of a few micrometers. In this paper we discuss the possible solutions for the positioning of the LumiCal electron detector by optical method. The results of the displacement measurement using a laser beam and a CCD camera are described. The measurements were performed on a proof-of-principle basis and achieved the accuracy of about ± 1 μm in x, y and ± 3 μm in z direction.
