Mechanical and Thermal Tests of the Containers of Liquid Mirrors

Abstract

We give a generic description of a liquid mirror system and summarize some practical information useful to making them. We compare laboratory measurements of deformations, due to the weight of mercury on the container of a 3.7-m mirror and to temperature changes on a 1-m container, to finite element computer simulations. We find that the measurements agree reasonably well with the numerical simulations. The measurements on the 1-m container show no evidence of fatigue after a few thermal cycles. These results validate the computer models of containers described in a companion article.Comment: Experimental Astronomy In Pres

Design of 2-M to 6-M Liquid Mirror Containers

“…The goal is to produce practical recipes that will allow one to build a working LMT container without resorting to his own finite element computations. Measurements on actual containers are presented in a companion paper (Borra et al 2003). They confirm the validity of the calculations in the present paper.…”

“…Measurements on a 3.7-m and a 1-m flat container (see the companion paper: Borra et al 2003) show that theory and experiments are in reasonable agreement. The figures and tables contained in this paper can be used as recipes to build containers having diameters between 2 and 6 meters.…”

“…The main effect is to tilt the container, giving a measurement of the rigidity in tilt. We also studied the effect of putting two bottles on the container, one at each end of a diameter (Borra et al 2003). This is a non-axisymetric problem involving the decomposition in a Fourier series in the azimuthal direction of a local load, then finding the deformations due to each term separately as discussed in the preceding paragraph.…”

Cosmology at low redshifts

“…It is possible to have a smaller, less expensive airbearing bearing custom designed. It is not necessary to design the composite material containers for mirrors smaller than 6-m since they are given by Content (2003) and Borra et al (2003). Tremblay (1999) gives a detailed description of how he built his container, Upper-end: I called the company that built the upper-end of the Canada-France-Hawaii 3.6-m telescope and asked for an estimate.…”