Evidence for dust contamination on the VETA-1 mirror surfaceRelative surface brightness data from the VETA-1 test displayed an energy dependence which was inconsistent with models which assume surface roughness is the only cause of scattering. A means of separating an in-plane component of scattering caused by surface roughness from an azimuthally symmetric component, which is expected from dust, was afforded by images taken while only single quarters of the mirror surface were exposed. In this case, in-plane scattered X-rays should populate only opposing 90 deg azimuthal quadrants of an image centered on the focal point. As such, this approach is a novel, high sensitivity test for detecting extremely small (about 10 exp -5) fractional dust coverage on X-ray optics. Comparison of in-plane and out-of-plane quadrants in these tests indicated that most of the scattered data were azimuthally symmetric, and that the symmetric component was enhanced at lower energies. Both results support a model which invokes the wing scan results with a combination of dust and surface roughness induced scattering. The extent to which parameters such as the mirror surface roughness, dust size distribution, spatial distribution, and density may be determined using this approach is also discussed.
Document ID
19930055618
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Kolodziejeczak, J. J. (NASA Marshall Space Flight Center Huntsville, AL, United States)
O'Dell, S. L. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Elsner, R. F. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Weisskopf, M. C. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 16, 2013
Publication Date
January 1, 1993
Publication Information
Publication: In: Multilayer and grazing incidence X-ray(EUV optics for astronomy and projection lithography; Proceedings of the Meeting, San Diego, CA, July 19-22, 1992 (A93-39601 15-74)
Publisher: Society of Photo-Optical Instrumentation Engineers
IDRelationTitle19930055604Collected WorksMultilayer and grazing incidence X-ray/EUV optics for astronomy and projection lithography; Proceedings of the Meeting, San Diego, CA, July 19-22, 1992