PRECISE MEASURING METHOD FOR DETECTING THE IN-SITU DISTORTION PROFILEOF A HIGH-HEAT-LOAD MIRROR FOR SYNCHROTRON-RADIATION BY USE OF A PENTAPRISM LONG TRACE PROFILER

A precise measuring method for detecting the in situ distortion profil e of a high-heat-load mirror for synchrotron radiation by use of a pen taprism long trace profiler (LTP) is presented. A maximum distortion o f 0.47 mu m across a length of 180 mm was measured for an internally w ater-cooled mirror on an undulator beam line at ELETTRA while exposed to a total emitted power of 600 W. This first successfully tested in s itu distortion profile points out the importance and need for this met hod. Two configurations for performing in situ LTP tests are discussed . For this measurement the configuration with all the equipment extern al to the vacuum chamber was used. The experiment has an accuracy and a repeatability of 0.04 mu m. Suggestions for improving the accuracy a nd stability are presented. (C) 1997 Optical Society of America.