scholarly journals The Fluctuations of the Cosmic X-Ray Background as a Sensitive Tool to the Universal Source Distribution

1981 ◽  
Vol 94 ◽  
pp. 277-278
Author(s):  
P. Giommi ◽  
G. F. Bignami
Keyword(s):  
Low Energy ◽  
Experimental Results ◽  
Space Distribution ◽  
Source Distribution ◽  
X Ray ◽  
Definite Relation ◽  
Sensitive Tool ◽  
X Ray Background ◽  
Flux Curve

Recent experimental results (Giacconi et al, 79, Tananbaum et al 79) ascribe an increasingly important role to the contribution of discrete sources to the low-energy (few Kev) cosmic X-ray background (CXB). While the astrophysical nature of the objects involved is not yet clear, distant and powerful emitters like QSO play probably an important role (e.g. Setti and Woltjer 1979, Field 1980). For them, often the number-flux curve (LogN-LogS) provides useful hints on such properties as space distribution and/or evolution. For the case of the X-ray sources, moreover, a definite relation exists between their LogN-LogS and the granularity of the sky emission as described by the fluctuations of the X-ray background.

scholarly journals X-ray Constraints on AGN Clustering

1989 ◽  
Vol 134 ◽  
pp. 492-493
Author(s):  
G. De Zotti ◽  
M. Persic ◽  
A. Franceschini ◽  
L. Danese ◽  
G.G.C. Palumbo ◽  
...  
Keyword(s):  
Space Distribution ◽  
Background Intensity ◽  
Additional Contribution ◽  
List Type ◽  
X Ray ◽  
Upper Limit ◽  
Angular Scale ◽  
Sky Survey ◽  
The Mean ◽  
X Ray Background

Studies of the HEAO–1 A2 all–sky survey data have established that the level of anisotropy of the extragalactic X–ray background (XRB) is relatively low: –The cell–to–cell XRB intensity variations can be entirely accounted for by Poisson fluctuations in the space distribution of known classes of sources; the 90% confidence upper limit to any additional contribution on a scale of 26 square degrees is 2.3% (Shafer and Fabian 1983).–No significant correlations of XRB intensity fluctuations appear to be present; the formal 90% confidence upper limit on the amplitude of autocorrelations, relative to the mean background intensity, for an angular scale of 3° is Γ(3°) ≤ 1.9 × 10−2 (Persic et al. 1988).

Experimental results on hard x-ray energy emitted by a low-energy plasma focus device: a radiographic image analysis

2009 ◽  
Vol 51 (12) ◽  
pp. 125003 ◽  
Author(s):  
Marcelo Zambra ◽  
Patricio Silva ◽  
Cristian Pavez ◽  
Denisse Pasten ◽  
José Moreno ◽  
...  
Keyword(s):  
Image Analysis ◽  
Plasma Focus ◽  
Low Energy ◽  
Experimental Results ◽  
Plasma Focus Device ◽  
Radiographic Image ◽  
X Ray

scholarly journals Evidence for a galactic component of the diffuse X-ray background

1970 ◽  
Vol 37 ◽  
pp. 280-288
Author(s):  
B. A. Cooke ◽  
R. E. Griffiths ◽  
K. A. Pounds
Keyword(s):  
Energy Range ◽  
Low Energy ◽  
Galactic Latitude ◽  
X Ray ◽  
Latitude Dependence ◽  
The Galaxy ◽  
X Ray Background

It is widely believed that the diffuse X-ray background, observed on several occasions over the energy range from 0.25 keV to above 1 MeV has an extragalactic origin. Evidence for this comes from the generally reported isotropy above several keV [1, 2, 3] and the observed galactic latitude dependence at 0.25 keV, believed to result from the interstellar attenuation of these low energy photons in passage through the Galaxy [4, 5].

scholarly journals The SHEAL Diffuse X-ray Spectrometer Experiment

1990 ◽  
Vol 115 ◽  
pp. 376-379
Author(s):  
W. T. Sanders ◽  
S. L. Snowden ◽  
R. J. Edgar
Keyword(s):  
Energy Resolution ◽  
Low Energy ◽  
X Ray ◽  
X Ray Background ◽  
Better Than

AbstractThe Diffuse X-ray Spectrometer (DXS) experiment is part of NASA’s SHEAL 2 mission, scheduled to be flown as an attached Shuttle payload in 1992. The DXS is designed to measure the spectrum of the low energy (0.15 to 0.28 keV) diffuse x-ray background with energy resolution better than 0.01 keV. This paper describes the DXS experiment and presents the results of calculations of the anticipated data.

Performance Study of the Anti-Scatter Grid for Sub-Megavolt X-Ray Flash Radiography

2013 ◽  
Vol 275-277 ◽  
pp. 1994-1997
Author(s):  
Wen Jie Liu ◽  
Jun Liu ◽  
Zhi Qiang Xiao
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
State Of The Art ◽  
High Energy ◽  
Optical Component ◽  
Low Energy ◽  
Experimental Results ◽  
Affecting Factors ◽  
Performance Study ◽  
X Ray

In the field of the flash radiography scattering is one of the most important affecting factors in determining the object information. A state-of-the-art optical component called anti-scatter grid has been used in high energy X-ray radiography. But the application for such kind of module in sub-megavolt (100 keV ~ 1MeV) flash radiography has not been mentioned yet. Recently our group has designed a new grid which was different with the products either in high energy X-ray radiography or in low energy mammography. The grid was manufactured and then tested in a 450 keV flash radiography source. The experimental results indicated that the grid’s anti-scatter capability was superexcellent. The Monte Carlo simulation also confirmed the experimental conclusion and the scattered to primary ratios with and without the grid were evaluated quantificationally.

Diagnostics of Gold Laser Plasmas

1988 ◽  
Vol 102 ◽  
pp. 357-360
Author(s):  
J.C. Gauthier ◽  
J.P. Geindre ◽  
P. Monier ◽  
C. Chenais-Popovics ◽  
N. Tragin ◽  
...  
Keyword(s):  
Experimental Results ◽  
Pure Gold ◽  
Electronic Temperature ◽  
X Ray ◽  
Laser Plasmas ◽  
Collisional Radiative Model ◽  
Radiative Model

AbstractIn order to achieve a nickel-like X ray laser scheme we need a tool to determine the parameters which characterise the high-Z plasma. The aim of this work is to study gold laser plasmas and to compare experimental results to a collisional-radiative model which describes nickel-like ions. The electronic temperature and density are measured by the emission of an aluminium tracer. They are compared to the predictions of the nickel-like model for pure gold. The results show that the density and temperature can be estimated in a pure gold plasma.

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