Nuclear Resonant Filtering of Synchrotron Radiation by Grazing-Incidence Antireflection Films

Abstract

Coherent nuclear diffraction of synchrotron radiation has been observed from grazing-incidence antireflection films (GIAR films) containing 57Fe. These films, which consisted of polycrystalline S7FeCrNi on a Pd backing, reduced the electronic reflectivity to 7 .Nuclear reflection of the resonant photons led to a counting rate of = 0.05 Hz of delayed quanta. The measurements show that nuclear resonant filtering of synchrotron radiation by GIAR films is possible.

<title>Coherent nuclear resonant optics for third-generation synchrotron radiation sources</title>

“…Such materials have been proposed,(17) synthesized, (18) and tested. (19) The large difference in electronic and nuclear absorption cross sections (more than two orders of magnitude) provide an opportunity to design the thickness of the thin film layers so that x-rays reflected from electron charge interfere destructively at a given angle, and there is still appreciable reflectivity for x-rays resonantly scattered by nuclei.…”

Advanced X-ray polarimeter design for nuclear resonant scattering

“…The time filtering method alone is not adequate for discrimination and has to be combined with an improvement of the signal-to-noise ratio, in general by highresolution monochromators (Faigel et al, 1987;Toellner, 2000;Shvyd'ko, 2013). Other methods which are used to suppress the nonresonant background are: grazing-incidence antireflection (GIAR) films (Grote et al, 1991;Alp et al, 1993), multilayer structures (Trammell & Hannon, 1978;Rö hlsberger et al, 1993), high-speed shutters (Toellner et al, 2011), the nuclear lighthouse effect (Rö hlsberger et al, 2001) and polarization filtering (Toellner et al, 1995;Alp et al, 2000;Siddons et al, 1995). The last one is a technique that makes use of the strong optical activity that is inherent to the nuclear scattering process.…”