Spectral distribution of a thin window rhodium target x-ray spectrographic tube

1971 ◽  
Vol 43 (7) ◽  
pp. 934-936 ◽  
Author(s):  
J. V. Gilfrich ◽  
P. G. Burkhalter ◽  
R. R. Whitlock ◽  
E. S. Warden ◽  
L. S. Birks
Keyword(s):  
Spectral Distribution ◽  
X Ray

scholarly journals Spectral Index Versus Frequency and Models for the Continua of AGN and QSOs

1989 ◽  
Vol 134 ◽  
pp. 201-202
Author(s):  
Wayne A. Stein
Keyword(s):  
Accretion Disk ◽  
Spectral Index ◽  
Power Law ◽  
Spectral Distribution ◽  
Secondary Electron ◽  
Low Frequency ◽  
Spectral Indices ◽  
Ultraviolet Continuum ◽  
Electron Synchrotron ◽  
X Ray

The observed spectral index as a function of frequency of QSO continua must be explained in models. It is generally increasing (F(ν) ∝ ν−α, α increasing) with higher frequency in the infrared (downward curvature). The visual to ultraviolet continuum has been shown to be a broken power law with F(ν) ∝ ν−0.5 at low frequency and a break to larger α at νo ∼ 3×1015 Hz. X-ray observations frequently exhibit a flat continuum with α < 1. One prominent example is 3C273 for which α1–3μm → 2, αvis ∼ 0.5 and αx ∼ 0.5. These spectral indices arise naturally in Secondary Electron Synchrotron Self-Compton (SESSC) models. Some accretion disk models approach these spectral indices for the visual-ultraviolet portion of the spectral distribution.

Spectra of X-Ray Tubes with Transmission Anodes for Fundamental Parameter Analysis

1992 ◽  
Vol 36 ◽  
pp. 81-88
Author(s):  
Horst Ebel ◽  
Maria F. Ebel ◽  
Christian Pöhn ◽  
Bernd Schoßmann
Keyword(s):  
Energy Distribution ◽  
Penetration Depth ◽  
High Voltage ◽  
Spectral Distribution ◽  
Narrow Band ◽  
Typical Feature ◽  
Parameter Analysis ◽  
Fundamental Parameter ◽  
X Rays ◽  
X Ray

AbstractThe approach for the description of the emission of white and characteristic x-rays from standard x-ray tubes is modified for an application to transmission anodes. This modification is based on the assumption of a negligible penetration depth of the electrons in comparison to the thickness of the anode. The results of our considerations are presented for Cu, Mo and W anodes with two different thicknesses. For comparison, the spectra of standard anodes which have been operated with identically high voltages and anode currents are given. A typical feature of transmission anodes is their spectral hardening of the energy distribution of emitted photons. A further interesting detail is the development of narrow band excitation anodes as can be seen from the results for Mo. With anode thicknesses of approximately 200 μm and a high voltage of 30 kv the spectral distribution is restricted to an energy ranging from 15 to 20 keV.

Calculating the spectral distribution of X-ray tubes with grounded cathode

2001 ◽  
Vol 62 (2-3) ◽  
pp. 207-213 ◽  
Author(s):  
G.V. Pavlinsky ◽  
A.Yu. Portnoy
Keyword(s):  
Spectral Distribution ◽  
X Ray

scholarly journals Experimental Determination of Scan-truncation Losses from Low-temperature (16 K) Single-crystal X-ray Measurements

1988 ◽  
Vol 41 (3) ◽  
pp. 503 ◽  
Author(s):  
Riccardo Destro
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Experimental Determination ◽  
Least Squares ◽  
Spectral Distribution ◽  
Experimental Measurements ◽  
Fourier Methods ◽  
X Ray ◽  
Least Squares Fitting

Model intensity profiles have been obtained for biscarbonyl[ 14]annulene by convoluting the Mo Ka spectral distribution with two functions derived from experimental measurements at 16(1) K, up to 26Mo = 110�, of a spherical crystal mounted on a four-circle diffractometer equipped with the Samson low-temperature apparatus. The process includes accurate measurement of the inherent background, treatment of the profiles by numerical Fourier methods, and least-squares fitting. Owing to the instrumental configuration of the diffractometer used in this investigation, the first step of the process has required a careful determination of the X dependence of the background, besides the usual 26 dependence. Truncation losses for the crystal under study, evaluated for several scan ranges, are far larger than usually assumed or predicted.

scholarly journals Evaluation of Estimation Method of X-ray Spectral Distribution by Attenuation Data

RADIOISOTOPES ◽  
1980 ◽  
Vol 29 (5) ◽  
pp. 215-220
Author(s):  
Shoji TOMINAGA ◽  
Yasuyuki IBARAKI ◽  
Shojiro NAGATA
Keyword(s):  
Spectral Distribution ◽  
Estimation Method ◽  
X Ray

scholarly journals The Spectral Distribution of Be/X-ray Transients Implies Supernova Kicks

2000 ◽  
Vol 175 ◽  
pp. 709-712
Author(s):  
Ignacio Negueruela
Keyword(s):  
Mass Transfer ◽  
Binary System ◽  
Spectral Distribution ◽  
Alternative Model ◽  
Large Fraction ◽  
Supernova Explosion ◽  
X Ray ◽  
Massive Component ◽  
X Ray Binaries ◽  
Orbital Solution

AbstractBe/X-ray binaries are generally assumed to have formed as the result of the evolution of moderately massive binaries in which mass is transferred semi-conservatively from the originally more massive component on to its companion. An alternative model proposes a binary system with a very massive component which loses a large fraction of its mass via very unconservative mass transfer. This scenario allows the formation of Be/X-ray binaries without requiring an asymmetric supernova explosion. We show that the observed properties of most Be/X-ray binaries for which an orbital solution has been found are incompatible with this model.

scholarly journals An Automatic Stabilized Detection System for Measuring Soft Celestial X-Rays

1971 ◽  
Vol 41 ◽  
pp. 211-212
Author(s):  
A. J. F. Den Boggende ◽  
H. F. Van Beek ◽  
A. C. Brinkman ◽  
H. Th. J. A. Lafleur
Keyword(s):  
Normal Mode ◽  
Spectral Distribution ◽  
Detection System ◽  
X Rays ◽  
X Ray

In order to observe celestial X-ray sources an instrument is under development to be launched in the Astronomical Netherlands Satellite (ANS) in 1974. The aim of the experiment is to measure the spectral distribution of the sources. If there is some evidence that a source should be a pulsar the instrument can be switched from the normal mode to the pulsar mode. In this latter mode the detected photons are labeled in time using an on board clock. The ANS will have a pointing mode and a slow scanning mode. The maximum observing time per orbit for one object will be about 2000 s.

Theoretical Calculation of Background in X-Ray Spectrometry for the Determination of Some Heavy Trace Elements

1991 ◽  
Vol 35 (B) ◽  
pp. 755-756
Author(s):  
Jean-Jacques Gruffat
Keyword(s):  
Trace Elements ◽  
Theoretical Calculation ◽  
Spectral Distribution ◽  
Geological Samples ◽  
X Ray ◽  
Correct Calculation ◽  
The Continuum

AbstractThe Kulenkampff-Kramers formula giving the spectral distribution of the continuum as a function of wavelength allows a correct calculation of background under the peak. It is only necessary to measure two backgrounds, one on each side of the peak, The true background under the peak is given by multiplying them by adequate coefficients and adding them up. This method has been applied to the determination of low amounts of Ce, La, Ba and Cs in geological samples.

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