Low-energy x-ray interaction coefficients: Photoabsorption, scattering, and reflection

Henke, Burton L.; Lee, P.; Tanaka, Takaho; Shimabukuro, Riki; Fujikawa, B. K.

doi:10.1016/0092-640x(82)90002-x

Cited by 1,146 publications

(319 citation statements)

References 30 publications

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“…with τ(E) the absorption depth for silicon for X-ray photon energy E as derived from Henke et al (1982). At the spot of the X-ray photon absorption, an amount of electric charge is released proportional to the incident energy of the photon.…”

Section: Detector Modelmentioning

confidence: 99%

Calibration and in-orbit performance of the reflection grating spectrometer onboardXMM-Newton

Vries

Herder

Gabriel

et al. 2015

A&A

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Context. XMM-Newton was launched on 10 December 1999 and has been operational since early 2000. One of the instruments onboard XMM-Newton is the reflection grating spectrometer (RGS). Two identical RGS instruments are available, with each RGS combining a reflection grating assembly and a camera with charge-coupled devices to record the spectra. Aims. We describe the calibration and in-orbit performance of the RGS instrument. By combining the preflight calibration with appropriate inflight calibration data including the changes in detector performance over time, we aim at profound knowledge about the accuracy in the calibration. This will be crucial for any correct scientific interpretation of spectral features for a wide variety of objects. Methods. Ground calibrations alone are not able to fully characterize the instrument. Dedicated inflight measurements and constant monitoring are essential for a full understanding of the instrument and the variations of the instrument response over time. Physical models of the instrument are tuned to agree with calibration measurements and are the basis from which the actual instrument response can be interpolated over the full parameter space. Results. Uncertainties in the instrument response have been reduced to <10% for the effective area and <6 mÅ for the wavelength scale (in the range from 8 Å to 34 Å). The remaining systematic uncertainty in the detection of weak absorption features has been estimated to be 1.5%. Conclusions. Based on a large set of inflight calibration data and comparison with other instruments onboard XMM-Newton, the calibration accuracy of the RGS instrument has been improved considerably over the preflight calibrations.

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Section: Detector Modelmentioning

confidence: 99%

Calibration and in-orbit performance of the reflection grating spectrometer onboardXMM-Newton

Vries

Herder

Gabriel

et al. 2015

A&A

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“…It can be seen that the X-ray induced signal is about a factor of five larger than the background gas ionisation rate. Absorption of high energy X-rays in molecules and solids is in fact atomic-like for energies greater than 50 eV (Henke et al 1982). This means that one can take the cross section for absorption by individual elemental atoms and sum over the number of such atoms in the target.…”

Section: Resultsmentioning

confidence: 99%

Nanoparticle destruction by X-ray absorption

Mitchell

Rebrion-Rowe

LeGarrec

et al. 2002

A&A

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“…After a scattering, the new photon energy is just given by = 0 /(1 + 0 mc 2 (1 − cos θ s )). The absorption of X-ray photons, which is the dominant process below ∼10 keV was modeled using modern solar photospheric abundances (Asplund et al 2009) and cross-sections (Henke et al 1982;Balucinska-Church & McCammon 1992) for the most important elements H, He, C, N, O, Ne, Na, Mg, Al, Si, S, Cl, Ar, Ca, Cr, Fe and Ni. For X-ray energies >10 keV, photoelectric absorption was approximated as σ a ( 0 ) ∼ −3 0 (Magdziarz & Zdziarski 1995).…”

Section: Spatial Characteristics Of the Primary Backscattered And Obmentioning

confidence: 99%

Positions and sizes of X-ray solar flare sources

Kontar¹,

Jeffrey²

2010

A&A

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Aims. The positions and source sizes of X-ray sources taking into account Compton backscattering (albedo) are investigated. Methods. Using a Monte Carlo simulation of X-ray photon transport including photo-electric absorption and Compton scattering, we calculate the apparent source sizes and positions of X-ray sources at the solar disk for various source sizes, spectral indices and directivities of the primary source. Results. We show that the albedo effect can alter the true source positions and substantially increase the measured source sizes. The source positions are shifted by up to ∼0.5 radially towards the disk centre and 5 arcsec source sizes can be two times larger even for an isotropic source (minimum albedo effect) at 1 Mm above the photosphere. The X-ray sources therefore should have minimum observed sizes, and thus their FWHM source size (2.35 times second-moment) will be as large as ∼7 in the 20−50 keV range for a disk-centered point source at a height of 1 Mm (∼1.4 ) above the photosphere. The source size and position change is greater for flatter primary X-ray spectra, a stronger downward anisotropy, for sources closer to the solar disk centre, and between the energies of 30 and 50 keV. Conclusions. Albedo should be taken into account when X-ray footpoint positions, footpoint motions or source sizes from e.g. RHESSI or Yohkoh data are interpreted, and we suggest that footpoint sources should be larger in X-rays than in either optical or EUV ranges.

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Low-energy x-ray interaction coefficients: Photoabsorption, scattering, and reflection

Cited by 1,146 publications

References 30 publications

Calibration and in-orbit performance of the reflection grating spectrometer onboardXMM-Newton

Calibration and in-orbit performance of the reflection grating spectrometer onboardXMM-Newton

Nanoparticle destruction by X-ray absorption

Positions and sizes of X-ray solar flare sources

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