Flat Crystal X-Ray Optics

1957 ◽  
Vol 1 ◽  
pp. 193-206 ◽  
Author(s):  
William J. Campbell ◽  
Melvin Leon ◽  
John Thatcher
Keyword(s):  
Wave Length ◽  
Pulse Height ◽  
Line Profiles ◽  
Line Broadening ◽  
Crystal Surfaces ◽  
X Ray ◽  
Line Intensities ◽  
Long Wave ◽  
On Line ◽  
College Park

AbstractAn investigation was undertaken by the Bureau of Mines at College Park, Md., to determine the effect of various combinations of collimators, analyzing crystals and detectors on line intensities, line-to-backgrouhd ratios, and spectral resolution. The research showed that line broadening due to mosaic crystal surfaces was greatly reduced and line splitting from faults was eliminatedby the use of two fine collimators (0.005 inch, spacing, 4 inch length). Line intensities were reduced, but lineto- background ratios arid line profiles were substantially improved with double collimators. Pulse height discrimination resulted in marked improvement in the line-to-background ratio in the long-wave length region, 2 to 10 A, but was much less effective for shorter wave lengths.

Evaluation of Straight and Curved Braun Position-Sensitive Proportional Counters on a Huber-Guinier X-Ray Diffraction System

1983 ◽  
Vol 27 ◽  
pp. 261-266 ◽  
Author(s):  
R.A. Newman ◽  
P. Moore Kirchhoff ◽  
T.G. Fawcett
Keyword(s):  
Scintillation Counter ◽  
Line Profiles ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
Camera System ◽  
X Ray ◽  
Proportional Counters ◽  
On Line ◽  
Position Sensitive ◽  
Gas Chamber

AbstractThe interfacing of both straight and curved Braun Position- Sensitive Proportional Counters (PSPC's) to a high resolution Huber-Guinier camera system has been accomplished, resulting in a 10 to 100-fold decrease in data collection times when compared to conventional Guinier (film or scintillation counter) detector techniques.Various factors causing line broadening were evaluated for both PSPC Guinier systems. The depth of the PSPC gas chamber was found to Have the greatest influence on line profiles. An R0% increase in peak half-widths was observed for PSPC-Guinier data compared to our highest resolution Guinier film data, but still yielded significantly better resolution than conventional powder diffractometer data obtained in our laboratory.

Measurement in the 10 to 100 Angstrom X-Ray Region*

1960 ◽  
Vol 4 ◽  
pp. 244-279 ◽  
Author(s):  
Burton L. Henke
Keyword(s):  
Proportional Counter ◽  
Low Voltage ◽  
Wave Length ◽  
Pulse Height ◽  
Total Reflection ◽  
Interaction Coefficients ◽  
X Ray ◽  
Long Wave ◽  
Microchemical Analysis ◽  
Pulse Height Analysis

AbstractThe results of recent work of the Millikan Laboratory of Physics on the physics and application of ultra s oft X-radiation s are summarized. These investigations include (1) the compilation of ultrasoft X-ray interaction coefficients. (2) the development of high-intensity, low-voltage X-ray tubes (100 to 1000 v), (3) the application of pulse-height analysis in flow proportional counter measurement of 10 to 100 A radiations, (4) a detailed study of the photographic action of the ultrasoft X-radiations, and (5) the application of these long wave length X-radiations to micromass and microchemical analysis by mïcroradiographïand total-reflection techniques.

Influence of Chemical Heterogeneities on Line Profiles

2014 ◽  
pp. 142-170
Keyword(s):  
Probability Distribution Function ◽  
Lattice Parameter ◽  
Line Profiles ◽  
Line Broadening ◽  
Diffraction Vector ◽  
Composition Fluctuation ◽  
Evaluation Procedures ◽  
Edgeworth Series ◽  
On Line ◽  
Diffraction Peaks

The chemical composition fluctuation in a material may cause line broadening due to the variation of the lattice parameter, which yields a distribution of the profile centers scattered from different volumes of the material. The nature of line broadening induced by chemical heterogeneities is similar to a microstrain-like broadening in the sense that the peak width increases with the magnitude of the diffraction vector. However, the dependence of compositional broadening on the orientation of diffraction vector (i.e. the anisotropic nature of this effect) differs very much from other types of strain broadening (e.g. from that caused by dislocations). The anisotropic line broadening caused by composition fluctuation is parameterized for different crystal systems and incorporated into the evaluation procedures of peak profiles. This chapter shows that the composition probability distribution function can be determined from the moments of the experimental line profiles using the Edgeworth series. The concentration fluctuations in decomposed solid solutions can also be determined from the intensity distribution in the splitted diffraction peaks.

scholarly journals X-ray spectroscopic diagnosis of laser-produced plasmas, with emphasis on line broadening

1980 ◽  
Vol 22 (6) ◽  
pp. 2746-2760 ◽  
Author(s):  
J. D. Kilkenny ◽  
R. W. Lee ◽  
M. H. Key ◽  
J. G. Lunney
Keyword(s):  
Line Broadening ◽  
X Ray ◽  
On Line

Chemical Bond Effects on Line Intensities in Arsenic X-Ray Emission Spectrum

2003 ◽  
Vol 44 (3) ◽  
pp. 410-419 ◽  
Author(s):  
T. A. Kupriyanova ◽  
M. N. Filippov ◽  
O. I. Lyamina
Keyword(s):  
Emission Spectrum ◽  
Chemical Bond ◽  
X Ray ◽  
Line Intensities ◽  
On Line

scholarly journals Distorted Wave Calculations: Application to Astrophysics and Tokamak Plasma

1984 ◽  
Vol 86 ◽  
pp. 92-99
Author(s):  
A.K. Bhatia
Keyword(s):  
Physical Properties ◽  
Spectral Resolution ◽  
Spectroscopic Data ◽  
Solar Maximum ◽  
Tokamak Plasma ◽  
Line Profiles ◽  
Distorted Wave ◽  
Solar Maximum Mission ◽  
X Ray ◽  
Line Intensities

During the last few years, observations of solar phenomena have been carried out by rocket flights, manned satellites like Skylab, unmanned satellites like Orbiting Solar Observatories and more recently Solar Maximum Mission. The wavelengths, line intensities and line profiles in UV and X-ray regions of the solar spectra have been measured. The spectroscopic data obtained are of high spatial and spectral resolution. The goal is to understand the physical properties of the emitting plasma and determine the electron temperatures, densities and volume of the emitting plasma from UV and X-ray spectra.

scholarly journals The interpretation of protoplanetary disc wind diagnostic lines from X-ray photoevaporation and analytical MHD models

2020 ◽  
Vol 496 (1) ◽  
pp. 223-244 ◽  
Author(s):  
Michael L Weber ◽  
Barbara Ercolano ◽  
Giovanni Picogna ◽  
Lee Hartmann ◽  
Peter J Rodenkirch
Keyword(s):  
Trace Gas ◽  
Line Profiles ◽  
Line Broadening ◽  
Low Velocity ◽  
X Ray ◽  
Double Peaks ◽  
Multiple Components ◽  
Spectral Profiles ◽  
Extended Mhd ◽  
Gaussian Decomposition

ABSTRACT High-resolution spectra of typical wind diagnostics ([O i] 6300 Å and other forbidden emission lines) can often be decomposed into multiple components: high-velocity components with blueshifts up to several 100 km s−1 are usually attributed to fast jets, while narrow (NLVC) and broad (BLVC) low-velocity components are believed to trace slower disc winds. Under the assumption that the line broadening is dominated by Keplerian rotation, several studies have found that the BLVCs should trace gas launched between 0.05 and 0.5 au and correlations between the properties of BLVCs and NLVCs have been interpreted as evidence for the emission tracing an extended magnetohydrodynamics (MHD) wind and not a photoevaporative wind. We calculated synthetic line profiles obtained from detailed photoionization calculations of an X-ray photoevaporation model and a simple MHD wind model and analysed the emission regions of different diagnostic lines and the resulting spectral profiles. The photoevaporation model reproduces most of the observed NLVCs but not the BLVCs or HVCs. The MHD model is able to reproduce all components but produces Keplerian double peaks at average inclinations that are rarely observed. The combination of MHD and photoevaporative winds could solve this problem. Our results suggest that the Gaussian decomposition does not allow for a clear distinction of flux from different wind regions and that the line broadening is often dominated by the velocity gradient in the outflow rather than by Keplerian rotation. We show that observed correlations between BLVC and NLVC do not necessarily imply a common origin in an extended MHD wind.

X-Ray Diffraction Study of Ordering in Two Sigma Phases

1966 ◽  
Vol 10 ◽  
pp. 213-220 ◽  
Author(s):  
R. W. Spor ◽  
H. Claus ◽  
Paul A. Beck
Keyword(s):  
Scintillation Counter ◽  
Pulse Height ◽  
X Ray Diffraction ◽  
Measured Intensity ◽  
Atomic Size ◽  
X Ray ◽  
Line Intensities ◽  
Ordering Schemes ◽  
Intensity Ratios ◽  
Pattern Line

AbstractX-ray powder pattern line intensities were measured for the (Cr, Re)σ and (Re, Fe)σ phases by a step-scanning diffractometer, using CrKα radiation, scintillation counter, and a pulse height analyzer. The measured intensity ratios for all available pairs of adjacent lines were compared by means of a computer with the corresponding calculated intensity ratios based on approximately 1800 different ordering schemes for each alloy. The results showed ordering in both alloys, and indicated that the ordering was based on atomic size. These results are different from those obtained previously by Kasper and Waterstrat (no ordering), and by Ageyev et al. [In (Cr, Re)σ the Cr atoms are preferentially in large coordination number positions.]

scholarly journals Some investigations in Röntgen spectra. Part I.─X-ray spark lines

1931 ◽  
Vol 131 (818) ◽  
pp. 633-647 ◽  
Keyword(s):  
Energy Level ◽  
Wave Length ◽  
The State ◽  
Energy Level Diagram ◽  
Selection Rules ◽  
X Ray ◽  
Long Wave ◽  
Chemical Combination ◽  
Close Study ◽  
Principal Lines

As is now well known there are certain lines in Röntgen spectra which cannot be fitted up into the usual energy level diagram even after violating the selection rules ∆ j = ± 1, 0, and ∆1 = ±1. These are called “non-diagram” lines or “spark” lines although the latter designation is somewhat anomalous in as much as the usual diagram lines are, regularly, lines due to transitions in an atom deprived of one of the electrons of the completed groups. They are found on the short as well as on the long wave-length side of the principal diagram lines, and consequently it has been customary to describe them as “satellites” of the principal lines. After their first discovery by Siegbahn and Stenström their number has rapidly grown large. Recently Beuthe has measured the β‴ line for elements V (23) to Y (39) and has also discovered a new line η for some of these elements. The problem of X-ray spark lines is little understood, and it is desirable to study closely the satellites of the principal lines for many elements in the several series. As a first step towards the achievement of this end a close study of Kα and Kβ satellites of the elements Si (14) to Cl (17) was undertaken. The results obtained go to show that the structure of the satellites is complex and that their nature is highly dependent upon the state of chemical combination of the atom which emits them.

scholarly journals Spectroscopic analysis of hot dense plasmas: A focus on ion dynamics

1996 ◽  
Vol 14 (4) ◽  
pp. 713-730 ◽  
Author(s):  
C.F. Hooper ◽  
D.A. Haynes ◽  
D.T. Garber ◽  
R.C. Mancini ◽  
Y.T. Lee ◽  
...  
Keyword(s):  
Spectroscopic Analysis ◽  
Standard Theory ◽  
Combined Effects ◽  
Ion Dynamics ◽  
Line Profiles ◽  
Line Broadening ◽  
Dense Plasmas ◽  
Plasma Line ◽  
On Line ◽  
The University

A brief discussion of the standard theory of line broadening is presented together with an analysis of selected laser-driven implosion experiments. The effect of improved theoretical procedures on experimental analysis is discussed. In particular, we consider the combined effects of ion dynamics and opacity on line profiles used in the analysis of these plasmas. The experiments discussed were performed at the University of Rochester Laboratory for Laser Energetics (LLE). The results presented in this paper illustrate the usefulness of plasma line broadening in diagnosing hot dense plasmas and in understanding fundamental plasma processes.

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