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Updated: Jun 15, 2026

Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating
Published on: October 11, 2016
Efficiency and resolution measurements of x-ray transmission gratings between 7.1 and 304 A
Abstract:
Efficiency and resolution measurements are reported of an x-ray transmission grating to be flown on board the European X-ray Observatory Satellite (EXOSAT). By optimizing the thickness of the grating bars, very high efficiencies can be obtained over a limited energy range. An absolute efficiency of 20% at 7.1 A decreasing to 10% above 15 A has been achieved, including all effects of support structure and mounting necessary to withstand space qualification. This means that 10% of the incoming radiation at 7.1 A results in the minus first spectral order and 10% in the plus first order. The measured resolution at the short wavelength end of the range (lambda > 20 A) is determined by the mirror resolution; at the longer wavelengths (300 A), the effects of coma and astigmatism dominate. The measured resolution at 304 A for the EXOSAT-mirror-grating system is 4.5 A in agreement with theoretical predictions.
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