Characterization of a long-focal-length polycapillary optic for high-energy x-rays

2000 ◽  
Author(s):  
Padiyar Cari ◽  
Suparmi ◽  
Sushil D. Padiyar ◽  
Walter M. Gibson ◽  
Carolyn A. MacDonald ◽  
...  
Keyword(s):  
Focal Length ◽  
High Energy ◽  
X Rays

scholarly journals Introducing the HD+B model for pulsar wind nebulae: a hybrid hydrodynamics/radiative approach

2020 ◽  
Vol 494 (3) ◽  
pp. 4357-4370
Author(s):  
B Olmi ◽  
D F Torres
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Theoretical Modelling ◽  
X Rays ◽  
Pulsar Wind Nebulae ◽  
New Approach ◽  
Energy Gamma ◽  
Radiative Model ◽  
Pulsar Wind

ABSTRACT Identification and characterization of a rapidly increasing number of pulsar wind nebulae is, and will continue to be, a challenge of high-energy gamma-ray astrophysics. Given that such systems constitute -by far- the most numerous expected population in the TeV regime, such characterization is important not only to learn about the sources per se from an individual and population perspective, but also to be able to connect them with observations at other frequencies, especially in radio and X-rays. Also, we need to remove the emission from nebulae in highly confused regions of the sky for revealing other underlying emitters. In this paper, we present a new approach for theoretical modelling of pulsar wind nebulae: a hybrid hydrodynamic-radiative model able to reproduce morphological features and spectra of the sources, with relatively limited numerical cost.

Characterization of Cellulosic Biomass Loaded with Iron and Arsenic Using High Energy X-Rays

2007 ◽  
Vol 20-21 ◽  
pp. 643-646 ◽  
Author(s):  
G. Cordeiro Silva ◽  
Regina Pinto de Carvalho ◽  
M. Sylvia S. Dantas ◽  
Virgínia S.T. Ciminelli
Keyword(s):  
Fine Structure ◽  
Arsenic Species ◽  
High Energy ◽  
Cellulosic Biomass ◽  
X Rays ◽  
Iron Ions ◽  
X Ray ◽  
X Ray Absorption ◽  
Exafs Spectra

The biosorption of arsenic species by dried lettuce leaves (L.sativa) was investigated. Arsenic sorption, that is not effective on in natura biomass, was enhanced when the biomass was previously loaded with Fe(III). Analysis of X-ray Absorption Near-Edge Spectroscopy (XANES) spectra showed that iron was incorporated as Fe(III) and arsenic as As(V), regardless the contact with the lowest or highest valence species of these elements. The features of Extended X-ray Absorption Fine-Structure Spectroscopy (EXAFS) spectra suggest that the nearest neighboring atoms of iron ions are the same in all the samples, even in the As-Fe loaded ones. These results indicate the arsenic oxyanions as the sorbed species on the iron-loaded biomass.

In Situ Observation of Oxygen Precipitation in Silicon with High Energy X-Rays

2009 ◽  
Vol 156-158 ◽  
pp. 437-441 ◽  
Author(s):  
Hannes Grillenberger ◽  
Andreas Magerl
Keyword(s):  
High Energy ◽  
Ex Situ ◽  
X Rays ◽  
X Ray Diffraction ◽  
Oxygen Precipitation ◽  
Float Zone ◽  
Diffraction Mode ◽  
Oxygen Precipitates

Oxygen precipitation in silicon has been studied in-situ by high energy X-ray diffraction. A gain of diffracted intensity is expected if an ideal crystal is distorted by growing precipitates as the diffraction mode changes from a dynamical to a more kinematical one. Irreversible changes in the intensity of a 220 and a 400 Bragg peak are detected for Czochralski grown samples only, but not in a float zone grown reference crystal. Thus, these changes are attributed to oxygen precipitation, which is confirmed by a subsequent classical ex-situ characterization. Further, the changes of the intensities of the two measured Bragg peaks are compared to each other to get the level of change in the diffraction mode from a dynamical to a kinematical one. The detection limit of the specific setup is estimated via a simulation of the defect inventory to correspond to a precipitate diameter of 50nm with the density of 6.9•109 1/cm3. The diffraction experiments are done with polychromatic and divergent X-rays generated by a laboratory source, albeit with high energy. This results in a simple and accessible setup for the characterization of oxygen precipitates.

Local Orientation Measurements in 3D

2005 ◽  
Vol 105 ◽  
pp. 49-54 ◽  
Author(s):  
Dorte Juul Jensen
Keyword(s):  
Tensile Deformation ◽  
High Energy ◽  
X Rays ◽  
X Ray Diffraction ◽  
3 Dimensional ◽  
Grain Structures ◽  
Individual Grains ◽  
Kinetics Of

The 3 Dimensional X-Ray Diffraction (3DXRD) method is presented and its potentials illustrated by examples. The 3DXRD method is based on diffraction of high energy X-rays and allows fast and nondestructive 3D characterization of the local distribution of crystallographic orientations in the bulk. The spatial resolution is about 1x5x5 µm but diffraction from microstructural elements as small as 100 nm may be monitored within suitable samples. As examples of the use of the 3DXRD method, it is chosen to present results for complete 3D characterization of grain structures, in-situ “filming” of the growth of one interior grain during recrystallization, recrystallization kinetics of individual grains and crystallographic rotations of individual grains during tensile deformation.

Characterization of amorphous selenium alloy detectors for x-rays and high energy nuclear radiation detection

2013 ◽  
Author(s):  
Krishna C. Mandal ◽  
Abhinav Mehta ◽  
Sandeep K. Chaudhuri ◽  
Yunlong Cui ◽  
Michael Groza ◽  
...  
Keyword(s):  
Radiation Detection ◽  
High Energy ◽  
Amorphous Selenium ◽  
Nuclear Radiation ◽  
X Rays

scholarly journals Physical Characterization of Breast Implants Submitted to High Energy X-Rays

TECCIENCIA ◽  
2019 ◽  
Vol 14 (26) ◽  
pp. 65-71
Author(s):  
Sandra Johana Patiño Leiva ◽  
María Cristina Plazas ◽  
Lisette Barreto
Keyword(s):  
Breast Implants ◽  
High Energy ◽  
Mechanical Tests ◽  
Prosthetic Material ◽  
X Rays ◽  
X Ray ◽  
Before And After ◽  
The Impact ◽  
Radiotherapy Treatment

Based on clinical experience and various studies, it has been found that breast prostheses present failures that are related to a radiotherapy treatment. However, there are currently few studies that analyze the impact of radiotherapy on the material of the prosthesis. Accordingly, the aim of this paper is to characterize the material of silicone breast implants with high cohesiveness. In order to carry out the research a characterization based on mechanical tests, rheology, and spectrophotometry and scanning electron microscopy. This was done with the objective of identifying changes in the prosthesis before and after being irradiated with high energy x-ray photons. To perform the study, 4 breast implants were used. These implants were subjected to the aforementioned tests. The researcher repeated the observation in the second and the third month. Finally, when comparing the results, the mechanical changes are shown in the coating. In the internal material small changes were generated in the elastic and viscous modules. To conclude, effective changes were observed after radiotherapy treatment in the prosthetic material.

Characterization of the sputtered-sliced zone plate for high energy X-rays

2001 ◽  
Vol 467-468 ◽  
pp. 868-871
Author(s):  
N. Kamijo ◽  
Y. Suzuki ◽  
M. Awaji ◽  
A. Takeuchi ◽  
K. Uesugi ◽  
...  
Keyword(s):  
High Energy ◽  
Zone Plate ◽  
X Rays

Tracking: a method for structural characterization of grains in powders or polycrystals

2001 ◽  
Vol 34 (6) ◽  
pp. 744-750 ◽  
Author(s):  
E. M. Lauridsen ◽  
S. Schmidt ◽  
R. M. Suter ◽  
H. F. Poulsen
Keyword(s):  
High Energy ◽  
X Rays ◽  
Rotation Method ◽  
Euler Space ◽  
On Line ◽  
The Individual ◽  
Individual Grains ◽  
Non Destructive ◽  
Non Destructive Characterization

A method is presented for fast and non-destructive characterization of the individual grains inside bulk materials (powders or polycrystals). The positions, volumes and orientations of hundreds of grains are determined simultaneously. An extension of the rotation method is employed: a monochromatic beam of high-energy X-rays, focused in one dimension, impinges on the sample and the directions of the diffracted beams are traced by translation of two-dimensional detectors. Algorithms suitable for on-line analysis are described, including a novel indexing approach, where the crystal symmetry is used directly by scanning in Euler space. The method is verified with a simulation of 100 grains.

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