X-Ray CCD Setup for Large-Area Wire Chamber Calibration.

An X-ray setup has been developed to measure wire positions of straw tube drift chambers of the COMPASS experiment with a charge-coupled device. In an automatic scanning procedure wire positions can be determined with an accuracy better than 30 μm inside an area of 3.6 × 3.6 m2. This accuracy is achieved by means of multiple stereo recordings of the detector wires and external reference wires. Within small distances of several centimeters the achieved accuracy is on the order of a few micrometers. [ABSTRACT FROM AUTHOR]