HIGH PRECISION SURVEY AND ALIGNEMENT OF LARGE LINEAR COLLIDERS- VERTICAL ALIGNMENT-

Abstract. Future linear colliders of 1 TeV energy like TESLA at DESY require new techniques of precise alignment. The planned 33km long accelerator facility will be established in a subterraneous tunnel, which follows an equipotential expanse. The required accuracy for the vertical alignment of the accelerator components is 0.2mm per 600m. To fulfill this demand, a HLS with a free surface ("half filled pipe") has been developed. For scanning the fluid surface ultrasonic measurement equipment is used. A new concept of “in-situ ” calibration which eliminates drifts of the sensor as well as temperature effects is presented, supported by results of a HLS-test installation of up to 1 km in length. An accuracy estimation for the adjustment of the accelerator components is made