HIREX

On-Axis Mirror Analysis

There two main areas of concern that are being examined here:

The results of mounting studies are outlined below, while the effect of solar illumination is discussed elsewhere.

On-Axis Mirror Mounting Plan:

The SAO study team has examined the effects of mounting an on-axis mirror in a mounting system similar to that used on the TRACE telescope. A much lower preload would be used, for the initial models the preload was only 44.5 N (10#). Two models were run, the first looked at the effect of a preload applied directly to the mirror seat. In the second model an initial mount design was modeled as well.

The resulting predicted surface is shown below:

Pure Clamping (no mount):

With the defect of focus removed, again pure clamping:

It is clear that this method has promise so a mount was added to understand its effect on the mirror surface.

Mounted Clamping:

With the addition of the mount to the FEA model yielded the following surface error:

With the focus error removed the surface deflection is given below:

The mount bending results in a >10x increase in the surface deflection, even after the focus error is removed. A mount design based on a stiffer clamp will be examined.

Questions, comments pcheimets@cfa.harvard.edu