scholarly journals PHEMTO: the polarimetric high energy modular telescope observatory

2021 ◽  
Author(s):  
P. Laurent ◽  
F. Acero ◽  
V. Beckmann ◽  
S. Brandt ◽  
F. Cangemi ◽  
...  
Keyword(s):  
Black Holes ◽  
Energy Range ◽  
High Performance ◽  
Angular Resolution ◽  
High Energy ◽  
Thermal Processes ◽  
Scientific Performance ◽  
X Ray ◽  
Measurement Capability ◽  
Better Than

AbstractBased upon dual focusing techniques, the Polarimetric High-Energy Modular Telescope Observatory (PHEMTO) is designed to have performance several orders of magnitude better than the present hard X-ray instruments, in the 1–600 keV energy range. This, together with its angular resolution of around one arcsecond, and its sensitive polarimetry measurement capability, will give PHEMTO the improvements in scientific performance needed for a mission in the 2050 era in order to study AGN, galactic black holes, neutrons stars, and supernovae. In addition, its high performance will enable the study of the non-thermal processes in galaxy clusters with an unprecedented accuracy.

scholarly journals Diffractive X-Ray Telescopes

2010 ◽  
Vol 2010 ◽  
pp. 1-17 ◽  
Author(s):  
Gerald K. Skinner
Keyword(s):  
Black Holes ◽  
Angular Resolution ◽  
Supermassive Black Holes ◽  
Active Galaxies ◽  
Optical Elements ◽  
X Ray ◽  
Limited Bandwidth ◽  
Imaging Capability ◽  
Fresnel Lenses ◽  
Better Than

Diffractive X-ray telescopes using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution several orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of microarcseconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the supermassive black holes in the center of active galaxies What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

THE AGILE MISSION AND GAMMA-RAY ASTROPHYSICS

2002 ◽  
Vol 17 (12n13) ◽  
pp. 1799-1808 ◽  
Author(s):  
MARCO TAVANI
Keyword(s):  
Energy Range ◽  
Gamma Ray ◽  
Angular Resolution ◽  
Source Monitoring ◽  
Space Mission ◽  
Quick Response ◽  
Scientific Program ◽  
X Ray ◽  
Imaging Capability ◽  
Gamma Ray Imaging

Gamma-ray astrophysics in the energy range between 30 MeV and 30 GeV is in desperate need of arcminute angular resolution and source monitoring capability. The AGILE Mission planned to be operational in 2004-2006 will be the only space mission entirely dedicated to gamma-ray astrophysics above 30 MeV. The main characteristics of AGILE are the simultaneous X-ray and gamma-ray imaging capability (reaching arcminute resolution) and excellent gamma-ray timing (10-100 microseconds). AGILE scientific program will emphasize a quick response to gamma-ray transients and multiwavelength studies of gamma-ray sources.

scholarly journals Spatial resolution of synchrotron x-ray microtomography in high energy range: Effect of x-ray energy and sample-to-detector distance

2012 ◽  
Vol 101 (26) ◽  
pp. 261901 ◽  
Author(s):  
D. Seo ◽  
F. Tomizato ◽  
H. Toda ◽  
K. Uesugi ◽  
A. Takeuchi ◽  
...  
Keyword(s):  
Energy Range ◽  
Spatial Resolution ◽  
High Energy ◽  
Range Effect ◽  
X Ray ◽  
Detector Distance

Comparative study of X-ray charge-density data on CoSb3

2013 ◽  
Vol 69 (6) ◽  
pp. 570-582 ◽  
Author(s):  
Mette Stokkebro Schmøkel ◽  
Lasse Bjerg ◽  
Finn Krebs Larsen ◽  
Jacob Overgaard ◽  
Simone Cenedese ◽  
...  
Keyword(s):  
Charge Density ◽  
High Performance ◽  
Theoretical Data ◽  
High Energy ◽  
Data Sets ◽  
High Symmetry ◽  
X Ray ◽  
Structure Factors ◽  
Small Crystals ◽  
Density Analysis

CoSb3is an example of a highly challenging case for experimental charge-density analysis due to the heavy elements (suitability factor of ∼0.01), the perfect crystallinity and the high symmetry of the compound. It is part of a family of host–guest structures that are potential candidates for use as high-performance thermoelectric materials. Obtaining and analysing accurate charge densities of the undoped host structure potentially can improve the understanding of the thermoelectric properties of this family of materials. In a previous study, analysis of the electron density gave a picture of covalent Co–Sb and Sb–Sb interactions together with relatively low atomic charges based on state-of-the-art experimental and theoretical data. In the current study, several experimental X-ray diffraction data sets collected on the empty CoSb3framework are compared in order to probe the experimental requirements for obtaining data of high enough quality for charge-density analysis even in the case of very unsuitable crystals. Furthermore, the quality of the experimental structure factors is tested by comparison with theoretical structure factors obtained from periodic DFT calculations. The results clearly show that, in the current study, the data collected on high-intensity, high-energy synchrotron sources and very small crystals are superior to data collected at conventional sources, and in fact necessary for a meaningful charge-density study, primarily due to greatly diminished effects of extinction and absorption which are difficult to correct for with sufficient accuracy.

scholarly journals ON ESTIMATING THE HIGH-ENERGY CUTOFF IN THE X-RAY SPECTRA OF BLACK HOLES VIA REFLECTION SPECTROSCOPY

2015 ◽  
Vol 808 (2) ◽  
pp. L37 ◽  
Author(s):  
Javier A. García ◽  
Thomas Dauser ◽  
James F. Steiner ◽  
Jeffrey E. McClintock ◽  
Mason L. Keck ◽  
...  
Keyword(s):  
Black Holes ◽  
High Energy ◽  
Reflection Spectroscopy ◽  
X Ray ◽  
Energy Cutoff

scholarly journals NuSTAR observations of rotation-powered pulsars and magnetars

2012 ◽  
Vol 8 (S291) ◽  
pp. 331-336
Author(s):  
V. M. Kaspi ◽  
H. An ◽  
M. Bachetti ◽  
E. Bellm ◽  
A. M. Beloborodov ◽  
...  
Keyword(s):  
Point Source ◽  
Angular Resolution ◽  
Focal Length ◽  
Effective Area ◽  
X Ray ◽  
Large Effective Area ◽  
Better Than

AbstractNASA's NuSTAR observatory is the first focusing hard X-ray telescope. Launched in June 2012, NuSTAR is sensitive in the 3–79 keV range with unprecedented ~17″ FWHM angular resolution above 12 keV, a result of its multilayer-coated optics and 10-m focal length. With its large effective area (900 cm2 at 10 keV), NuSTAR has point-source sensitivity ~100 times better than previous hard X-ray telescopes. Here we describe NuSTAR and its planned work on rotation-powered pulsars and magnetars during its nominal 2-yr baseline mission that has just commenced.

Silicon Carbide for Alpha, Beta, Ion and Soft X-Ray High Performance Detectors

2005 ◽  
Vol 483-485 ◽  
pp. 1015-1020 ◽  
Author(s):  
Giuseppe Bertuccio ◽  
Simona Binetti ◽  
S. Caccia ◽  
R. Casiraghi ◽  
Antonio Castaldini ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Collection Efficiency ◽  
High Energy ◽  
Beta Particle ◽  
High Energy Resolution ◽  
Charge Collection Efficiency ◽  
X Ray ◽  
Current Densities ◽  
Full Charge

High performance SiC detectors for ionising radiation have been designed, manufactured and tested. Schottky junctions on low-doped epitaxial 4H-SiC with leakage current densities of few pA/cm2 at room temperature has been realised at this purpose. The epitaxial layer has been characterised at different dose of radiations in order to investigate the SiC radiation hardness. The response of the detectors to alpha and beta particle and to soft X-ray have been measured. High energy resolution and full charge collection efficiency have been successfully demonstrated.

Anti-Friction Effect of Ball-Milled and Subsequently Annealed Expanded Graphite/Iron Powder Mixture

2012 ◽  
Vol 182-183 ◽  
pp. 319-322
Author(s):  
Yu Shan Li
Keyword(s):  
Size Range ◽  
Expanded Graphite ◽  
High Energy ◽  
X Ray Diffraction ◽  
Iron Powders ◽  
X Ray ◽  
Friction Effect ◽  
Air Atmosphere ◽  
Vacuum Atmosphere ◽  
Better Than

A mixture of expanded graphite (EG) and iron powders was ball-milled in a high-energy mill under an air atmosphere and subsequently annealed under a vacuum atmosphere. The products were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), and their anti-friction effect used as lubricating additive was investigated by using a tribo-tester. On the surface of the products, graphite encapsulated iron nanoparticles with a size range of 50-150 nm were formed. Compared with only milled EG/Fe powders, the products exhibit a higher crystallinity of graphite and iron. The products have a marked anti-friction effect, and this effect is better than that of the only milled EG/Fe powders.

Quantitative analysis with the transition edge sensor microcalorimeter X-ray detector

2007 ◽  
Vol 22 (2) ◽  
pp. 138-141 ◽  
Author(s):  
Terrence Jach ◽  
Nicholas Ritchie ◽  
Joel Ullom ◽  
James A. Beall
Keyword(s):  
Quantitative Analysis ◽  
Transition Edge Sensor ◽  
High Energy ◽  
Standard Reference Materials ◽  
High Energy Resolution ◽  
Chemical Methods ◽  
X Ray ◽  
Transition Edge ◽  
Direct Measurements ◽  
Better Than

We report on the use of a microcalorimeter X-ray detector with a transition edge sensor in an electron probe to perform quantitative analysis. We analyzed two bulk samples of multielement glasses that have been previously characterized by chemical methods for use as standard reference materials. The spectra were analyzed against standards using three different correction schemes. In one of the standards, the reference line was easily resolved despite its proximity within 45 eV of another line. With the exception of direct measurements of oxygen (a particularly challenging element), the results are in agreement with the certified characterization to better than 1% absolute or 8% relative. This demonstrates the potential of microcalorimeter detectors as replacements for conventional energy dispersive detectors in applications requiring high energy resolution.

A focusing X-ray telescope for use in the study of extraterrestrial X-ray sources in the energy range 20–140 keV

1968 ◽  
Vol 46 (10) ◽  
pp. S1103-S1106 ◽  
Author(s):  
T. R. Llndquist ◽  
W. R. Webber
Keyword(s):  
Energy Range ◽  
Rock Salt ◽  
Angular Resolution ◽  
X Rays ◽  
Effective Energy ◽  
Optimum Thickness ◽  
Bragg Condition ◽  
X Ray ◽  
Area Efficiency ◽  
Salt Crystals

We have designed and tested a focusing X-ray telescope with an angular resolution (FWHM) of 1.0° for the study of extraterrestrial X-ray sources in the energy range 20–140 keV. The telescope's lens is an array of rock salt crystals (each of which is approximately one inch square), mounted on a 6-ft-diameter paraboloidal frame. The lens is located 9.5 ft above a 2-in.-diameter NaI crystal and PM tube (which measures the energy of the incident X ray). X rays passing through the salt crystals undergo a 2θ deflection if the Bragg condition for reflection, nλ = 2d sin θ, is approximately satisfied. Optimum thickness and effective energy bandwidths for such reflections have been determined for energies in the telescope's operating range. The area-efficiency product of the lens is approximately 8 times the NaI crystal area from 20 to 40 keV, giving a real improvement in the signal-to-background ratio. Crystals more nearly perfect than rock salt offer the possibility of increased gain over narrow energy intervals. Polarization measurements of the incident X rays may also be made.

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