Relative Abundances and Recoil Energies of Fragment Ions Formed from the X‐Ray Photoionization of N2, O2, CO, NO, CO2, and CF4

1972 ◽  
Vol 56 (7) ◽  
pp. 3206-3209 ◽  
Author(s):  
Thomas A. Carlson ◽  
Manfred O. Krause
Keyword(s):  
X Ray ◽  
Fragment Ions ◽  
Relative Abundances

Delorenzite is tanteuxenite

1959 ◽  
Vol 32 (247) ◽  
pp. 308-313
Author(s):  
J. R. Butler ◽  
P. G. Embrey
Keyword(s):  
Rare Earths ◽  
Reasonable Doubt ◽  
Type Locality ◽  
Chemical Analyses ◽  
X Ray ◽  
Relative Abundances

SummarySpecimens of delorenzite from the type locality, Craveggia, Val Vigezzo, Piemont, have been examined and found to be close to tanteuxenite from Australia. The X-ray powder patterns are virtually the same, and the chemical analyses (including the relative abundances of the rare earths) are closely similar.Zambonini's original (1908) specimens have not been re-examined, but are without reasonable doubt the same as the specimens now described; the considerable discrepancies between the old and new analyses can be explained by the difficulty of the separations. It is suggested that the name delorenzite be abandoned despite its priority because of its association with an incorrect analysis.

scholarly journals Auger Electron?Ion Coincidence Studies to Determine the Pathways in Soft X-ray Induced Fragmentation of Isolated Molecules

1986 ◽  
Vol 39 (5) ◽  
pp. 633 ◽  
Author(s):  
W Eberhardt ◽  
EW Plummer ◽  
In Whan Lyo ◽  
R Reininger ◽  
R Carr ◽  
...  
Keyword(s):  
Auger Electron ◽  
Core Hole ◽  
Final State ◽  
Auger Electrons ◽  
X Ray ◽  
Fragment Ions ◽  
Valence Electrons ◽  
Molecular Bond ◽  
Doubly Charged ◽  
Insight Into

We report a coincidence .experiment between energy selected Auger electrons and the ions produced in the events following the absorption of a soft X-ray photon by a CO molecule. This study allows us to correlate specific double hole final state configurations of the Auger decay of a core hole in this molecule with the production of fragment ions, thus giving new experimental insight into the potential energy curves of the doubly charged molecular ion and the involvement of individual valence electrons into the molecular bond in general.

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Iron K-Line Emission from X-Ray Binaries

1988 ◽  
Vol 102 ◽  
pp. 47-50
Author(s):  
K. Masai ◽  
S. Hayakawa ◽  
F. Nagase
Keyword(s):  
Accretion Disk ◽  
Radiative Recombination ◽  
Characteristic Temperature ◽  
Line Emission ◽  
Ionization Front ◽  
Continuum Radiation ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx> 10 keV is likely due to fluorescence outside the He II ionization front.

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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