Stacked depth graded multilayer for hard X-rays, measured up to 130 keV

Carsten P. Cooper-Jensen, Finn Erland Christensen, S. Romaine, R. Bruni, Z. Zhong

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

Abstract

Depth graded multilayer designs for hard x-ray telescopes in the 10 keV to 70-80 keV energy range have had either W or Pt as the heavy element. These materials have been chosen because of reasonable optical constants, the possibility to grow smooth interfaces with the spacer material, and the stability over time. On the flip side both W and Pt have an absorption edge - 69.5 keV (W) and 78.4 keV (Pt) - which is very close to the two Ti-44 lines at 67.9 keV and 78.4 keV that are produced in the envelope of a super nova explosion. Other materials have better optical constants and no absorption edges in this energy range, for example Ni0.93V0.07, but are not used because of high interface roughness. By using a WC/SiC multilayer for the bottom and a Ni0.93V0.07/SiC multilayer for the thicker top layers of a depth graded multilayer we have made a reflector that doesn't have a clear absorption edge. This reflector has been measured at energies between 8 keV and 130 keV. At a graze angle of 0.11 degree there is still nearly the same reflectivity below the W absorption edge as for a traditional W based coating, and above the W absorption edge there is still 48% reflection at 80 keV.
Original languageEnglish
Title of host publicationProceedings of SPIE, the International Society for Optical Engineering
Volume6688
PublisherSpie-int Soc Optical Engineering
Publication date2007
ISBN (Print)978-0-8194-6836-9
DOIs
Publication statusPublished - 2007
EventOptics for EUV, X-Ray, and Gamma-Ray Astronomy III - San Diego, CA, United States
Duration: 29 Aug 200730 Aug 2007

Conference

ConferenceOptics for EUV, X-Ray, and Gamma-Ray Astronomy III
CountryUnited States
CitySan Diego, CA
Period29/08/200730/08/2007

Cite this

Cooper-Jensen, C. P., Christensen, F. E., Romaine, S., Bruni, R., & Zhong, Z. (2007). Stacked depth graded multilayer for hard X-rays, measured up to 130 keV. In Proceedings of SPIE, the International Society for Optical Engineering (Vol. 6688). Spie-int Soc Optical Engineering. https://doi.org/10.1117/12.733911