scholarly journals EXIST: A high sensitivity hard x-ray imaging sky survey mission for ISS

2000 ◽  
Author(s):  
J. Grindlay
Keyword(s):  
High Sensitivity ◽  
X Ray ◽  
X Ray Imaging ◽  
Sky Survey

scholarly journals High-sensitivity high-resolution X-ray imaging with soft-sintered metal halide perovskites

2021 ◽  
Vol 4 (9) ◽  
pp. 681-688
Author(s):  
Sarah Deumel ◽  
Albert van Breemen ◽  
Gerwin Gelinck ◽  
Bart Peeters ◽  
Joris Maas ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Metal Halide ◽  
Detector Arrays ◽  
X Ray ◽  
Carrier Lifetimes ◽  
Sintered Metal ◽  
X Ray Imaging ◽  
Imaging Detector ◽  
High Carrier ◽  
Halide Perovskites

AbstractTo realize the potential of artificial intelligence in medical imaging, improvements in imaging capabilities are required, as well as advances in computing power and algorithms. Hybrid inorganic–organic metal halide perovskites, such as methylammonium lead triiodide (MAPbI3), offer strong X-ray absorption, high carrier mobilities (µ) and long carrier lifetimes (τ), and they are promising materials for use in X-ray imaging. However, their incorporation into pixelated sensing arrays remains challenging. Here we show that X-ray flat-panel detector arrays based on microcrystalline MAPbI3 can be created using a two-step manufacturing process. Our approach is based on the mechanical soft sintering of a freestanding absorber layer and the subsequent integration of this layer on a pixelated backplane. Freestanding microcrystalline MAPbI3 wafers exhibit a sensitivity of 9,300 µC Gyair–1 cm–2 with a μτ product of 4 × 10–4 cm2 V–1, and the resulting X-ray imaging detector, which has 508 pixels per inch, combines a high spatial resolution of 6 line pairs per millimetre with a low detection limit of 0.22 nGyair per frame.

Computer reconstructed X-ray imaging

1979 ◽  
Vol 292 (1390) ◽  
pp. 223-232 ◽  
Keyword(s):  
Spatial Resolution ◽  
Atomic Number ◽  
High Sensitivity ◽  
Precise Determination ◽  
Diagnostic Methods ◽  
X Ray ◽  
X Ray Imaging ◽  
Internal Structures ◽  
Transmission Measurements

Computed tomography is a method for obtaining a series of radiographic pictures of contiguous slices through a solid object such as the human body. Each picture is computed from a set of X-ray transmission measurements and represents the distribution of X-ray attenuation in the slice. The high sensitivity of the method to changes in both density and atomic number has resulted in the development of new diagnostic methods in medicine. The limitations of the method are discussed in terms of two particular kinds of application. First, those applications in which a very precise determination of density or atomic number is required, but at low spatial resolution; an example would be the determination of the uniformity of mixture of plastics or metals. The second kind of application is that requiring high spatial resolution as in the detection of cracks and the visualization of internal structures in complicated objects.

Characteristics of a New High-Sensitivity X-Ray Imaging Tube for Video Topography

1993 ◽  
Vol 32 (Part 1, No. 5A) ◽  
pp. 2142-2146 ◽  
Author(s):  
Fumio Sato ◽  
Hirotaka Maruyama ◽  
Katsuyuki Goto ◽  
Isao Fujimoto ◽  
Keiichi Shidara ◽  
...  
Keyword(s):  
High Sensitivity ◽  
X Ray ◽  
X Ray Imaging

Instantaneous Display of X-Ray Diffraction using a Diode Array Camera Tube

1968 ◽  
Vol 12 ◽  
pp. 165-173 ◽  
Author(s):  
Arthur N. Chester ◽  
Fred B. Koch
Keyword(s):  
Low Cost ◽  
High Sensitivity ◽  
Photon Flux ◽  
Diode Array ◽  
High Quantum Efficiency ◽  
X Ray ◽  
X Ray Imaging ◽  
Counting Statistics ◽  
Electron Imaging ◽  
Array Camera

AbstractThe silicon diode array camera tube, recently developed for PICTURFPHONE® service, was modified to permit X-ray imaging. High quantum efficiency is attained without the use of a phosphor screen, since each photon absorbed in the silicon target generates several hundred hole-electron pairs for each keV of its energy, most of which can he usefully collected. The sensitivity and resolution are adequate to allow a continuous television display of the diffracted intensity as a crystal is oriented. Particular advantages of this technique include; high resolution (< 25 μm); electronically variable magnification; direct oscilloscope measurement of X-ray spot Intensity profiles and relative spot intensities because signal current is directly proportional to photon flux; high sensitivity in the range of 0.6 to 5.0 Å, potentially limited only "by counting statistics; integration times variable from < 1/60 second to minutes; and expected low cost, since the camera tube has no complicated electron imaging, and is directly interchangeable Mith a standard television vidicon. Applications which are described include crystal orientation and X-ray topography.

Application of Imaging Plate for X-Ray Diffractometry

1991 ◽  
Vol 35 (A) ◽  
pp. 407-413 ◽  
Author(s):  
Atsushi Shibata ◽  
Katsunari Sasaki ◽  
Takao Kinefuchi
Keyword(s):  
Structure Analysis ◽  
Dynamic Range ◽  
Imaging System ◽  
High Sensitivity ◽  
Effective Area ◽  
Superior Performance ◽  
Imaging Plate ◽  
X Ray ◽  
X Ray Imaging ◽  
Electric Device

AbstractThe Fuji Imaging Plate (IP) is a 2-dimensional detector in which a latent X-ray image is stored as a distribution of color centers on a photostimulable phosphor (BaFBr:Eu2+) screen. It has a large effective area, wide dynamic range and high sensitivity. Thus it has been widely used not only in medical but also in scientific and industrial fields. Particularly in X-ray structure analysis, mainly of proteins, it has been used extensively and achieved good results.On the other hand, few applications have been reported in the field except for structure analysis, in spite of the superior performance of the IP which will give significant advantages in various measurements which have been done using an X-ray film such as electric device and fiber specimen.Therefore we report here the basic performance of R-AXIS II(Rigaku Automated X-Ray Imaging System II), an IP reader made by Rigaku, and some applications of X-ray diffraction measurements using IP.

High-sensitivity X-ray imaging of a lead halide perovskite single-crystal scintillator

2020 ◽  
Vol 45 (2) ◽  
pp. 355 ◽  
Author(s):  
Qiang Xu ◽  
Wenyi Shao ◽  
Yang Li ◽  
Zhichao Zhu ◽  
Bo Liu ◽  
...  
Keyword(s):  
Single Crystal ◽  
High Sensitivity ◽  
X Ray ◽  
X Ray Imaging ◽  
Crystal Scintillator ◽  
Halide Perovskite ◽  
Lead Halide

scholarly journals ROSAT Observations of Active Galactic Nuclei

1994 ◽  
Vol 159 ◽  
pp. 53-62 ◽  
Author(s):  
W. Brinkmann
Keyword(s):  
Active Galactic Nuclei ◽  
Spectral Properties ◽  
Galactic Nuclei ◽  
High Sensitivity ◽  
Good Energy Resolution ◽  
Ongoing Research ◽  
X Ray ◽  
Sky Survey ◽  
Good Energy ◽  
First Time

The large number of Active Galactive Nuclei detected for the first time through their X-ray emission in the ROSAT All Sky Survey as well as the first measurements of the X-ray emission of many previously known AGN provide a new unprecedented large basis for the statistical and morphological exploration of these objects.The soft energy range of the X-Ray Telescope, the good energy resolution of the PSPC detector, and the high sensitivity of the instrument further allows an investigation of the spectral properties of sources in this energetically important energy band.A short overview is given of the actual ongoing research concentrating on the study of the soft X-ray class properties of the various types of AGN.

scholarly journals Long-term NIR variability in the UKIDSS Ultra Deep Survey: a new probe of AGN activity at high redshift

2020 ◽  
Vol 493 (2) ◽  
pp. 3026-3035 ◽  
Author(s):  
E Elmer ◽  
O Almaini ◽  
M Merrifield ◽  
W G Hartley ◽  
D T Maltby ◽  
...  
Keyword(s):  
Near Infrared ◽  
High Redshift ◽  
Galactic Nuclei ◽  
Host Galaxies ◽  
X Ray ◽  
X Ray Imaging ◽  
Sky Survey ◽  
Deep Survey ◽  
Stellar Masses

ABSTRACT We present the first attempt to select active galactic nuclei (AGN) using long-term near-infrared (NIR) variability. By analysing the K-band light curves of all the galaxies in the UKIRT Infrared Deep Sky Survey (UKIDSS) Ultra Deep Survey, the deepest NIR survey over ∼1 deg2, we have isolated 393 variable AGN candidates. A comparison to other selection techniques shows that only half of the variable sources are also selected using either deep Chandra X-ray imaging or Infrared Array Camera (IRAC) colour selection, suggesting that using NIR variability can locate AGN that are missed by more standard selection techniques. In particular, we find that long-term NIR variability identifies AGN at low luminosities and in host galaxies with low stellar masses, many of which appear relatively X-ray quiet.

scholarly journals Combining Monte Carlo methods with coherent wave optics for the simulation of phase-sensitive X-ray imaging

2014 ◽  
Vol 21 (3) ◽  
pp. 613-622 ◽  
Author(s):  
Silvia Peter ◽  
Peter Modregger ◽  
Michael K. Fix ◽  
Werner Volken ◽  
Daniel Frei ◽  
...  
Keyword(s):  
Monte Carlo ◽  
High Sensitivity ◽  
Wave Optics ◽  
X Rays ◽  
X Ray ◽  
Coherent Wave ◽  
Open Questions ◽  
X Ray Imaging ◽  
Simulation Based ◽  
Phase Sensitive

Phase-sensitive X-ray imaging shows a high sensitivity towards electron density variations, making it well suited for imaging of soft tissue matter. However, there are still open questions about the details of the image formation process. Here, a framework for numerical simulations of phase-sensitive X-ray imaging is presented, which takes both particle- and wave-like properties of X-rays into consideration. A split approach is presented where we combine a Monte Carlo method (MC) based sample part with a wave optics simulation based propagation part, leading to a framework that takes both particle- and wave-like properties into account. The framework can be adapted to different phase-sensitive imaging methods and has been validated through comparisons with experiments for grating interferometry and propagation-based imaging. The validation of the framework shows that the combination of wave optics and MC has been successfully implemented and yields good agreement between measurements and simulations. This demonstrates that the physical processes relevant for developing a deeper understanding of scattering in the context of phase-sensitive imaging are modelled in a sufficiently accurate manner. The framework can be used for the simulation of phase-sensitive X-ray imaging, for instance for the simulation of grating interferometry or propagation-based imaging.

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