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A prototype ultrahigh resolution spectrograph has been built with an adaptive optics telescope. It provides $250,000$ resolving power, 300 \AA\ wavelength coverage and 0.8\% efficiency.

Astrophysics · Physics 2007-05-23 J. Ge , B. Jacobsen , J. R. P. Angel , N. Woolf , J. H. Black , M. Lloyd-Hart , P. Gray , R. Q. Fugate

Spectroastrometry is a technique which has the potential to resolve flux distributions on scales of milliarcseconds. In this study, we examine the application of spectroastrometry to binary point sources which are spatially unresolved due…

Astrophysics · Physics 2009-11-10 John M. Porter , Rene D. Oudmaijer , Debbie Baines

We investigate the effects of atmospheric dispersion on observations of the Sun at the ever-higher spatial resolutions afforded by increased apertures and improved techniques. The problems induced by atmospheric refraction are particularly…

Astrophysics · Physics 2008-11-26 Kevin P. Reardon

Circular dichroism spectroscopy is an essential technique for understanding molecular structure and magnetic materials, but spatial resolution is limited by the wavelength of light, and sensitivity sufficient for single-molecule…

A fundamental issue that limits the efficiency of many photoelectrochemical systems is that the photon absorption length is typically much longer than the electron diffusion length. Various photon management schemes have been developed to…

High-resolution x-ray microscopy requires a high photon flux to measure the signal from weakly scattering samples. This exposes samples to high radiation doses, potentially damaging or destroying them through radiation damage. In this work,…

Medical Physics · Physics 2024-09-04 Felix Wittwer , Peter Modregger

The use of strongly bent crystals in spectrometers for pulses of a hard x-ray free-electron laser is explored theoretically. Diffraction is calculated in both dynamical and kinematical theories. It is shown that diffraction can be treated…

Instrumentation and Detectors · Physics 2019-05-28 Vladimir Kaganer , Ilia Petrov , Liubov Samoylova

Photonic spectrographs offer a highly miniaturized, flexible, and stable on-chip solution for astronomical spectroscopy and can be used for various science cases such as determining the atmospheric composition of exoplanets to understand…

Instrumentation and Methods for Astrophysics · Physics 2022-03-22 Marcos Perez , Pradip Gatkine , Nemanja Jovanovic , Jeffrey Jewell , J. Kent Wallace , Dimitri Mawet

Stereoscopic spectral imaging is an observing technique that affords rapid acquisition of limited spectral information over an entire image plane simultaneously. Light from a telescope is dispersed into multiple spectral orders, which are…

Astrophysics · Physics 2007-05-23 Craig E. DeForest , Charles C. Kankelborg

The Planet Hunting and Asteroseismology Explorer Spectrophotometer, PHASES, is a concept for a space-borne instrument to obtain flux calibrated spectra and measure micro-magnitude photometric variations of nearby stars. The science drivers…

Instrumentation and Methods for Astrophysics · Physics 2010-01-13 Carlos del Burgo , Carlos Allende Prieto , Tully Peacocke

Polarimetry is widely considered a powerful observational technique in X-ray astronomy, useful to enhance our understanding of the emission mechanisms, geometry and magnetic field arrangement of many compact objects. However, the lack of…

Instrumentation and Methods for Astrophysics · Physics 2010-04-28 Ronaldo Bellazzini , Fabio Muleri

Echelle spectrographs with their high resolution plays important role in determination of characteristics of stellar lines. Wide field of applications is focused mainly on the measurements of precise radial velocity applied in exoplanetary…

Instrumentation and Methods for Astrophysics · Physics 2016-02-16 Romana Grossová

At modern X-ray sources, such as synchrotrons and X-ray Free-Electron Lasers (XFELs), it is important to measure the absolute value of the photon energy directly. Here, a method for absolute spectral metrology is presented. A photon energy…

We investigate the feasibility of detecting extensive air showers via their geo-synchrotron X-ray emission from high-altitude platforms. Starting from first principles, we derive a differential expression for the number of emitted photons…

High Energy Astrophysical Phenomena · Physics 2026-01-14 Rodrigo Alberto Torres Saavedra , Caterina Trimarelli , Roberto Aloisio , John F. Krizmanic , Johannes Eser , Austin Cummings

Point-spread function of the probe forming optics ($PSF_{optics} $) is reported for the first time in an uncorrected (without multipole correctors) scanning electron microscope (SEM). In an SEM, the electron probe information is lost as the…

Materials Science · Physics 2024-07-02 Surya Kamal , Richard K. Hailstone

Entangled two-photon spectroscopy is expected to provide advantages compared with classical protocols. It is achieved by coherently controlling the spectral properties of energy-entangled photons. We present here an experimental setup that…

Quantum Physics · Physics 2021-08-25 Stefan Lerch , André Stefanov

Spectroscopy is a well-established nonintrusive tool that has played an important role in identifying substances and quantifying their compositions, from quantum descriptions to chemical and biomedical diagnostics. Challenges exist in…

Atmospheric and Oceanic Physics · Physics 2020-12-02 S. Yu , Z. Zhang , H. Xia , X. Dou , M. Li , T. Wei , L. Wang , P. Jiang , Y. Wu , C. Zhang , L. You , Y. Hu , T. Wu , L. Zhao , M. Shangguan , L. Tao , J. Qiu

Flows of synchrotron-emitting material can be found in several astrophysical contexts, including extragalactic jets and pulsar-wind nebulae (PWNe). For X-ray synchrotron emission, flow times are often longer than electron radiative…

High Energy Astrophysical Phenomena · Physics 2015-05-13 S. P. Reynolds

X-ray free electron lasers (XFELs) generate sequences of ultra-short, spatially coherent pulses of x-ray radiation. We propose the diffraction focusing spectrometer (DFS), which is able to measure the whole energy spectrum of the radiation…

Optics · Physics 2013-02-22 V. G. Kohn , O. Y. Gorobtsov , I. A. Vartanyants

Electron energy loss spectroscopy is consolidating as a powerful tool to explore electronic (as well as vibrational) excitations of matter, including molecules. Performed in a scanning transmission electron microscope, this technique is…

Chemical Physics · Physics 2021-03-05 Ciro A. Guido , Enzo Rotunno , Matteo Zanfrognini , Stefano Corni , Vincenzo Grillo
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