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With the advent of both modern X-ray fluorescence (XRF) methods and improved analytical reliability requirements the demand for suitable reference samples has increased. Especially in nanotechnology with the very low areal mass depositions,…

In the context of the LAUE project devoted to build a long focal-length focusing optics for soft $\gamma$-ray astronomy (80 - 600 keV), we present the results of reflectivity measurements of bent crystals in different configurations,…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 V. Liccardo , E. Virgilli , F. Frontera , V. Valsan

It is widely believed that adaptive optics only has a role in correcting turbulent wavefronts on large telescopes using very bright reference stars. Unfortunately these are very scarce and many astronomical targets require wavefront…

Instrumentation and Methods for Astrophysics · Physics 2019-11-19 Craig Mackay

Laue lenses constitute a promising option for concentrating soft gamma rays with a large collection area and reasonable focal lengths. In astronomy they could lead to increased telescope sensitivity by one to two orders of magnitude, in…

Instrumentation and Methods for Astrophysics · Physics 2014-03-05 Nicolas M. Barrière , John A. Tomsick , Steven E. Boggs , Alexander Lowell , Colin Wade , Max Baugh , Peter von Ballmoos , Nikolay V. Abrosimov , Lorraine Hanlon

Wavefront sensing is a widely-used non-interferometric, single-shot, and quantitative technique providing the spatial-phase of a beam. The phase is obtained by integrating the measured wavefront gradient. Complex and random wavefields…

Optics · Physics 2021-07-09 Tengfei Wu , Pascal Berto , Marc Guillon

We present a new method for determining the sensitivity of X-ray imaging observations, which correctly accounts for the observational biases that affect the probability of detecting a source of a given X-ray flux, without the need to…

Astrophysics · Physics 2009-11-13 A. Georgakakis , K. Nandra , E. S. Laird , J. Aird , M. Trichas

Prospects of parametric x-rays (PXR) application for the development of a tuneable quasi-monochromatic x-ray source for medical imaging are discussed. Analysis of basic requirements for electron accelerator shows that it must be relatively…

General Physics · Physics 2007-05-23 Alexander Lobko , Olga Lugovskaya

The presence of a scattering medium in the imaging path between an object and an observer is known to severely limit the visual acuity of the imaging system. We present an approach to circumvent the deleterious effects of scattering, by…

Ground-based direct imaging of exoplanets at high contrast requires precise correction of atmospheric turbulence using adaptive optics (AO). The planet-to-star contrast ratio at small angular separations from the host star is often limited…

We have recently demonstrated a very favorable, inexpensive modernization of lab-based x-ray absorption fine structure (XAFS) and high-resolution x-ray emission spectroscopy (XES) using only commercially-available optics and x-ray tube…

Instrumentation and Detectors · Physics 2016-06-22 Gerald T. Seidler , Devon R. Mortensen , Alexander S. Ditter , Neil A. Ball , Adam J. Remesnik

Differential wavefront sensing is an essential technique for optimising the performance of many precision interferometric experiments. Perhaps the most extensive application of this is for alignment sensing using radio-frequency beats…

Instrumentation and Detectors · Physics 2021-05-26 Daniel D. Brown , Huy Tuong Cao , Alexei Ciobanu , Peter Veitch , David Ottaway

X-ray devices are far superior to optical ones for providing nanometre spatial and attosecond temporal resolutions. Such resolution is indispensable in biology, medicine, physics, material sciences, and their applications. A bright…

High quality, repeatable point-spread functions are important for science cases like direct exoplanet imaging, high-precision astrometry, and high-resolution spectroscopy of exoplanets. For such demanding applications, the initial on-sky…

Instrumentation and Methods for Astrophysics · Physics 2021-07-19 Steven P. Bos , Michael Bottom , Sam Ragland , Jacques-Robert Delorme , Sylvain Cetre , Laurent Pueyo

Fourier ptychography captures intensity images with varying source patterns (illumination angles) in order to computationally reconstruct large space-bandwidth-product images. Accurate knowledge of the illumination angles is necessary for…

Signal Processing · Electrical Eng. & Systems 2018-11-01 Regina Eckert , Zachary F. Phillips , Laura Waller

The limits for adaptive-optics (AO) imaging at high contrast and high resolution are determined by residual phase errors from non-common-path aberrations not sensed by the wavefront sensor, especially for integral field spectrographs, where…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Benjamin Pope , Niranjan Thatte , Rick Burruss , Matthias Tecza , Fraser Clarke , Garret Cotter

This paper provides a framework for the incorporation of the wavefront sensor measurements in the context of observing modes in which the science camera takes millisecond exposures. In this formulation, the wavefront sensor measurements…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Richard A. Frazin

We report an extensive numerical study and supporting experimental results on the spectral characterization of optical aberrations in macroscopic fluidic lenses with tunable focal distance and aperture shape. Using a Shack-Hartmann…

Optics · Physics 2023-12-19 Graciana Puentes , Fernando Minotti

The direct imaging of an Earth-like exoplanet will require sub-nanometric wavefront control across large light-collecting apertures, to reject host starlight and detect the faint planetary signal. Current adaptive optics (AO) systems, which…

The MIT X-ray Polarimetry Beamline is a facility that we developed for testing components for possible use in X-ray polarimetry. Over the past few years, we have demonstrated that the X-ray source can generate nearly 100% polarized X-rays…

Instrumentation and Methods for Astrophysics · Physics 2024-08-22 Sarah N. T. Heine , Herman L. Marshall , Benjamin Schneider , Beverly Lamar , Nithya Kothnur , Alan Garner

The process of differential deposition is currently applied at the ESRF in order to correct figure errors of x-ray optics substrates, prior to multilayer deposition. The substrate is moved at a controlled speed in front of a sputtering…

Applied Physics · Physics 2023-12-05 Patrice Bras , Sylvain Labouré , Amparo Vivo , François Perrin , Christian Morawe