The design and the construction of the scintillating fiber detector for the UA2 experiment

The scintillating fiber detector (SFD) is a key part of the upgraded UA2 experiment. It includes 60000 scintillating fibers 1 mm in diameter and 2 m long, arranged in 24 coaxial layers fitting in a cylindrical space from 760 to 880 mm in diameter around pp intersection. The fiber layers are arranged in eight stereo triplets. Each one contains one fiber set parallel to the axis and two others inclined at an angle of +or-20 degrees on the average. The SFD has two separate functions: The inside layers give a precise localization of the particles; the outside layers initiate the electromagnetic showers by conversion in a lead sheet 1.5-radiation-lengths thick. Each fiber is optically tested; when not rejected, its scintillating efficiency and attenuation length are recorded. The position of every fiber is measured and recorded, and each fiber is individually read out.<
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