Optical Tests of a 3.7-m diameter Liquid Mirror: Behavior under External Perturbations
Abstract
We have built and tested a 3.7-m diameter liquid mirror that rotates on a ball bearing. We have carried out extensive optical tests. We find that although the ball bearing has a poor quality, the quality of the mirror, with mercury layers 1-mm thick, is surprisingly good. Taken at face values the instantaneous Strehl ratios indicate a mirror, that is not quite diffraction limited but usable for astronomical applications. However, the large coning error of the bearing (1.5 arcseconds P-V) induces an excessive wobble, considerably worsening the time averaged PSF. The most interesting result of the interferometry is that we do not see any evidence of the strong astigmatism that may have been expected from Coriolis forces.
Cite
@article{arxiv.astro-ph/0102433,
title = {Optical Tests of a 3.7-m diameter Liquid Mirror: Behavior under External Perturbations},
author = {Gregoire Tremblay and Ermanno F. Borra},
journal= {arXiv preprint arXiv:astro-ph/0102433},
year = {2009}
}
Comments
PDF format, 34 pages, 12 figures, (some figures reduced, full size figures in Applied Optics, Vol. 39, No 36, 5651)