Measured reflectance of graded multilayer mirrors designed for astronomical hard X-ray telescopes
| Autor: | Fiona A. Harrison, Charles J. Hailey, Mario A. Jimenez-Garate, William W. Craig, James M. Chakan, David L. Windt, Peter H. Mao, Veijo Honkimäki, Finn Erland Christensen, Eric Ziegler |
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| Rok vydání: | 2000 |
| Předmět: |
Physics
Nuclear and High Energy Physics business.industry Astrophysics::High Energy Astrophysical Phenomena Bremsstrahlung Synchrotron radiation X-ray telescope Electromagnetic radiation Particle detector Semimetal law.invention Telescope Optics Stack (abstract data type) law business Instrumentation |
| Zdroj: | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 451:572-581 |
| ISSN: | 0168-9002 |
| DOI: | 10.1016/s0168-9002(00)00332-6 |
| Popis: | Future astronomical X-ray telescopes, including the balloon-borne High-Energy Focusing Telescope (HEFT) and the Constellation-X Hard X-ray Telescope (Con-X HXT) plan to incorporate depth-graded multilayer coatings in order to extend sensitivity into the hard X-ray ( 10≲E≲80 keV ) band. In this paper, we present measurements of the reflectance in the 18–170 keV energy range of a cylindrical prototype nested optic taken at the European Synchrotron Radiation Facility (ESRF). The mirror segments, mounted in a single bounce stack, are coated with depth-graded W/Si multilayers optimized for broadband performance up to 69.5 keV (WK-edge). These designs are ideal for both the HEFT and Con-X HXT applications. We compare the measurements to model calculations to demonstrate that the reflectivity can be well described by the intended power law distribution of the bilayer thicknesses, and that the coatings are uniform at the 5% level over the mirror surface. Finally, we apply the measurements to predict effective areas achievable for HEFT and Con-X HXT using these W/Si designs. |
| Databáze: | OpenAIRE |
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