An in-situ long trace profiler developed at Brookhaven National Laboratory under the auspices of a CRADA with Continental Optical Corporation has successfully measured thermal distortion on a side-cooled mirror in a beam line at the Advanced Photon Source. The instrument scanned the central 90 mm of the 200 mm long mirror through a vacuum window while the mirror was subjected to heat loading from the synchrotron beam. Results clearly show transient effects occurring when the mirror is first illuminated that relax after about 15 minutes, in accord with finite element thermal calculations. The steady state curvature of the surface is measured to be slightly concave with an additional 5 km radius relative to the initial nominal curvature of about 1 km. The magnitude of this steady state condition was not expected and was not predicted by the calculations.

Date Published: 13 November 1998
PDF: 8 pages
Proc. SPIE 3447, Advances in Mirror Technology for Synchrotron X-Ray and Laser Applications, (13 November 1998); doi: 10.1117/12.331124

Published in SPIE Proceedings Vol. 3447:
Advances in Mirror Technology for Synchrotron X-Ray and Laser Applications
Ali M. Khounsary, Editor(s)