HIREX Mirror Fabrication and Metrology

The HIREX mirror fabrication and metrology study is being performed in several locations. We are working with Hughes Danbury Optical Systems (HDOS), Bauer Assoc., and Goddard Space Flight Center (GSFC) to completely review the state-of-the-art of mirror fabrication and metrology.

Fabrication:

The underlying plan is to follow the mirror requirements that have been laid out by the XUV lithography industry in their goal of achieving the next generation of computer chip manufacturing equipment. Their requirements closely match what our initial estimates suggest that we need. Bauer Associates has begun working on a complete mirror system specification, and a determination of the surface figure precision and optical positioning tolerance. The initial on--axis design, based on spherical optical components, initial optical design was laid out by Leon Golub and analyzed by Andrew Szentgyorgyi. The current off-axis baseline design consists of an aspheric primary mirror and a spherical secondary mirror, a change made to improve image quality and release valuable error budget to other portions of the system design.

This more complex aspherical design was established by Bauer Assoc. and is given here. To view the complete Bauer report on the HIREX optical system click here.

HDOS will be examining the feasibility of fabricating optics of this quality, size and focal length.

Metrology:

Metrology methods are being examined here and at Bauer Assoc.

Bauer will be examing the feasibility of various metrology techniques, both exisiting and new, for use in the various phases of the mirror processing: fabrication, coating and mounting.

We (SAO) are looking at the requirements placed on the mirror support during the metrology process to ensure that un-accounted for support or gravitationally induced deflections are not misinterpreted as real figure errors and their negative polished into the mirror.

We (SAO) are looking at the requirements placed on the mirror support during operations to ensure that the mirror support does not distort the primary mirror.

Preliminary SAO efforts concentrated on the earlier on-axis design. We have looked at the effect of the the primary back shape on the front surface deflection under a 1 g load.
 

Questions, comments pcheimets@cfa.harvard.edu
Last Modified Monday, 20-Oct-2008 11:05:21 EDT