Constellation-X Spectroscopy X-Ray Telescope Segmented Optic Alignment Using Piezoelectric Actuators
Abstract
The main instrument for the NASA Constellation-X x-ray observatory is the Spectroscopy X-Ray Telescope (SXT). The SXT is comprised of many thin foil closely nested segmented mirror segments. The mission design requires precise mirror alignment. The contribution of this research is towards the development of the alignment and assembly methods for the SXT optics. The method of alignment uses piezoelectric bending actuators at ten actuation points along the mirror to correct non-rigid body deformations and align the mirror segment. The design considerations of an alignment system for thin foil segmented optics using piezoelectric actuators are detailed, leading to the development of two alignment assemblies for the alignment of a single mirror segment and a mirror segment pair. The analysis of flexure design, contact stresses, piezoelectric performance, and stiffness models relating to the alignment of thin foil segmented optics is presented. The thin foil segmented optic alignment methods utilizing piezoelectric actuators are presented, including coordinate measuring machine (CMM) placement, collimated light testing, Centroid Detector Assembly (CDA) alignment, and axial interferometry. The experimental results of precise alignment using Centroid Detector Assembly feedback and piezoelectric actuators for a single mirror segment are presented. Axial interferometry is used to demonstrate the minimization of installation induced axial sag errors near the actuation points for a single mirror segment.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 18, 2005
- Accession Number
- ADA442250
Entities
People
- Thomas F. Meagher
Organizations
- George Washington University