Prototype of a wire scanner for TTF II

Development and test of wire scanners for the Free Electron Laser (FEL) at the Tesla Test Facility phase II are described. The design fulfills the requirements of high precision measurements, of compact and easily exchangeable and referable structures as well as user friendly implementation into the accelerator environment. The basic principle of the measurements consist in detecting the secondary particles created when the wire transverses the electron beam with a constant velocity of up to 1 m/sec. A high resolution measurement system connected with the wire determines the profile and position of the beam with high precision. A reference system connected with the wire scanner components enables the in situ determination of the absolute position of the beam within 20 - 30 $μ$m