Iridium optical constants for the Chandra X-ray Observatory from reflectance measurements of 0.05-12 keV

Graessle, Dale E.; Soufli, Régina; Aquila, Andrew; Gullikson, Eric M.; Blake, R. L.; Burek, A. J.

doi:10.1117/12.506132

Cited by 17 publications

(17 citation statements)

References 6 publications

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“…Therefore, we fixed the density parameter. All in all, our results are in good agreement with the reported ∼ 1.0 nm thick with density of 1.0 g/cm 3 overlayer on iridium mirrors 15 .…”

Section: Overlayer Investigationsupporting

confidence: 92%

X-ray reflectometry of a platinum coating as reference sample for the ATHENA coating development

Jafari

Christensen

Massahi

et al. 2019

Optics for EUV, X-Ray, and Gamma-Ray Astronomy IX

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X-ray reflectivity (XRR) characterization of X-ray mirrors is an essential step for designing space telescopes and instruments. We report on production and characterization of platinum thin films coated onto a flat thick glass substrate for evaluating measurement results obtained using several XRR systems. The main objective of this study is to compare the XRR results measured using facilities at the Technical University of Denmark, DTU Space, and BESSY II for the Advanced Telescope for High-ENergy Astrophysics (ATHENA) mission funded by the European Space Agency, ESA. This sample will be used as a reference sample for testing and calibrating similar measurements at relevant X-ray facilities. This information demonstrates the stable performance of the platinum mirror as a reference sample. Also, the overlayer effect on mirror performance is investigated.

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“…Therefore, we fixed the density parameter. All in all, our results are in good agreement with the reported ∼ 1.0 nm thick with density of 1.0 g/cm 3 overlayer on iridium mirrors 15 .…”

Section: Overlayer Investigationsupporting

confidence: 92%

X-ray reflectometry of a platinum coating as reference sample for the ATHENA coating development

Jafari

Christensen

Massahi

et al. 2019

Optics for EUV, X-Ray, and Gamma-Ray Astronomy IX

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“…In the previous work, ground calibration was performed, and the x-ray properties of x-ray mirrors were clarified. Specifically, iridium optical constants for the Chandra x-ray observatory were measured in the energy band from 50 to 12000 eV 8 to tabulate the iridium optical constants over the full range for this observatory. Kikuchi et al 9 measured the atomic scattering factors around the gold L-edges for the ASTRO-H (Hitomi) 10 telescope with a sub-eV energy pitch matching the spectral resolution (∼5 eV) of the microcalorimeter soft x-ray spectrometer.…”

Section: Introductionmentioning

confidence: 99%

Measuring the atomic scattering factors near the iridium L-edges for the Athena silicon pore optics reflector

Awaki

Maeda

Matsumoto

et al. 2021

J. Astron. Telesc. Instrum. Syst.

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Athena, a future high-energy mission, is expected to consist of a large aperture x-ray mirror with a focal length of 12 m. The mirror surface is to be coated with iridium and a low Z overcoat. To define the effective area of the x-ray telescope, the atomic scattering factors of iridium with an energy resolution less than that (2.5 eV) of the x-ray integral field unit are needed. We measured the reflectance of the silicon pore optics mirror plate coated with iridium in the energy range of 9 to 15 keV and that near the iridium L-edges in steps of 10 and 1.5 eV, respectively, at the synchrotron beamline SPring-8. The L3, L2, and L1 edges were clearly detected around 11,215, 12,824, and 13,428 eV, respectively. The measured scattering factors were ∼3% smaller than the corresponding values reported by Henke et al., likely due to the presence of an overlayer on the iridium coating, and were consistent with those measured by Graessle et al. The angular dependence of the reflectivity measured indicates that the iridium surface was extremely smooth, with a surface roughness of 0.3 nm. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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“…4 It is well beyond the scope of this article to describe these calibration activities and results; the reader is instead referred elsewhere for detailed descriptions relevant to ACIS-S. [4][5][6][7][8][9][10] The adopted "1σ" uncertainties in the different energy ranges for the different subassemblies used in our truncated normal distribution Monte Carlo perturbation vectors, together with edge constraints (described above in Sect. 3.2) are listed in Table 1.…”

Section: Assessment Of Subassembly Response Uncertaintiesmentioning

confidence: 99%

Monte Carlo processes for including Chandra instrument response uncertainties in parameter estimation studies

et al. 2006

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Instrument response uncertainties are almost universally ignored in current astrophysical X-ray data analyses. Yet modern X-ray observatories, such as Chandra and XMM-Newton, frequently acquire data for which photon counting statistics are not the dominant source of error. Including allowance for performance uncertainties is, however, technically challenging in terms of both understanding and specifying the uncertainties themselves, and in employing them in data analysis. Here we describe Monte Carlo methods developed to include instrument performance uncertainties in typical model parameter estimation studies. These methods are used to estimate the limiting accuracy of Chandra for understanding typical X-ray source model parameters. The present study indicates that, for ACIS-S3 observations, the limiting accuracy is reached for ∼ 10 4 counts.

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Iridium optical constants for the Chandra X-ray Observatory from reflectance measurements of 0.05-12 keV

Cited by 17 publications

References 6 publications

X-ray reflectometry of a platinum coating as reference sample for the ATHENA coating development

X-ray reflectometry of a platinum coating as reference sample for the ATHENA coating development

Measuring the atomic scattering factors near the iridium L-edges for the Athena silicon pore optics reflector

Monte Carlo processes for including Chandra instrument response uncertainties in parameter estimation studies

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