NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Optical Analysis of an Ultra-High resolution Two-Mirror Soft X-Ray MicroscopeThis work has summarized for a Schwarzschild microscope some relationships between numerical aperture (NA), magnification, diameter of the primary mirror, radius of curvature of the secondary mirror, and the total length of the microscope. To achieve resolutions better than a spherical Schwarzschild microscope of 3.3 Lambda for a perfectly aligned and fabricated system. it is necessary to use aspherical surfaces to control higher-order aberrations. For an NA of 0.35, the aspherical Head microscope provides diffraction limited resolution of 1.4 Lambda where the aspherical surfaces differ from the best fit spherical surface by approximately 1 micrometer. However, the angle of incidence varies significantly over the primary and the secondary mirrors, which will require graded multilayer coatings to operate near peak reflectivities. For higher numerical apertures, the variation of the angle of incidence over the secondary mirror surface becomes a serious problem which must be solved before multilayer coatings can be used for this application. Tolerance analysis of the spherical Schwarzschild microscope has shown that water window operations will require 2-3 times tighter tolerances to achieve a similar performance for operations with 130 A radiation. Surface contour errors have been shown to have a significant impact on the MTF and must be controlled to a peak-to-valley variation of 50-100 A and a frequency of 8 periods over the surface of a mirror.
Document ID
19970002939
Document Type
Reprint (Version printed in journal)
Authors
Shealy, David L.
(Alabama Univ. Birmingham, AL United States)
Wang, Cheng
(Alabama Univ. Birmingham, AL United States)
Hoover, Richard B.
(NASA Huntsville, AL United States)
Date Acquired
August 17, 2013
Publication Date
January 1, 1994
Publication Information
Publication: Journal of X-Ray Science and Technology
Volume: 4
ISSN: 0895-3996
Subject Category
Instrumentation And Photography
Report/Patent Number
NASA-TM-112178
NAS 1.15:112178
Meeting Information
Soft X -rays in the 21st Century Conference(Provo, UT)
Distribution Limits
Public
Copyright
Public Use Permitted.
Document Inquiry
No Preview Available