Going Nondispersive

1998 ◽  
Vol 4 (6) ◽  
pp. 552-558
Author(s):  
Kurt F.J. Heinrich ◽  
Ray Fitzgerald ◽  
Klaus Keil
Keyword(s):  
Solid State ◽  
Energy Range ◽  
Atomic Number ◽  
Energy Resolution ◽  
Electron Probe ◽  
Emission Lines ◽  
Crystal Spectrometer ◽  
X Ray ◽  
State Detection ◽  
The One

The energy-dispersive Si(Li) X-ray spectrometer, introduced 30 years ago into electron probe mi-croanalysis (EPMA) by R. Fitzgerald et al., has profoundly affected the development of microanalysis. It offers many advantages over the wavelength-dispersive crystal spectrometer. It has no moving parts and covers the full energy range of interest in EPMA. There is no defocusing over large distances on the specimen, the efficiency of the device is high, varies slowly and continuously with atomic number, and can be predicted fairly accurately, and, most importantly, all emission lines are detected and can be observed simultaneously. The one remaining disadvantage of the Si(Li) spectrometer is its poorer energy resolution. Solid-state detection devices now under development promise to achieve resolution comparable to that of the crystal spectrometer.

scholarly journals ASCA Observations of Supernova Remnants

1996 ◽  
Vol 145 ◽  
pp. 369-379
Author(s):  
Hiroshi Tsunemi ◽  
Keyword(s):  
Energy Range ◽  
Energy Resolution ◽  
Supernova Remnants ◽  
Emission Lines ◽  
X Ray ◽  
Preliminary Results ◽  
Hot Plasma

We present here preliminary results of the ASCA satellite. ASCA is equipped with X-ray telescopes that can observe the energy range up to 12 keV. There are two types of detector systems: GIS and SIS. The energy resolution of the SIS is 130 eV (FWHM at 6 keV) and can resolve emission lines clearly. For the PV phase, we planned to observe about 150 sources. Among them, there are 23 SNR's, some of which are presented here. We will be able to study the evolution of thin hot plasma in the SNRs.

Design of an ultrahigh-energy-resolution and wide-energy-range soft X-ray beamline

2013 ◽  
Vol 21 (1) ◽  
pp. 273-279 ◽  
Author(s):  
L. Xue ◽  
R. Reininger ◽  
Y.-Q. Wu ◽  
Y. Zou ◽  
Z.-M. Xu ◽  
...  
Keyword(s):  
Energy Range ◽  
Energy Resolution ◽  
Wide Energy Range ◽  
Ultrahigh Energy ◽  
Exit Slit ◽  
Shanghai Synchrotron Radiation Facility ◽  
X Ray ◽  
Variable Line ◽  
Line Spacing ◽  
Wide Energy

A new ultrahigh-energy-resolution and wide-energy-range soft X-ray beamline has been designed and is under construction at the Shanghai Synchrotron Radiation Facility. The beamline has two branches: one dedicated to angle-resolved photoemission spectroscopy (ARPES) and the other to photoelectron emission microscopy (PEEM). The two branches share the same plane-grating monochromator, which is equipped with four variable-line-spacing gratings and covers the 20–2000 eV energy range. Two elliptically polarized undulators are employed to provide photons with variable polarization, linear in every inclination and circular. The expected energy resolution is approximately 10 meV at 1000 eV with a flux of more than 3 × 1010 photons s−1at the ARPES sample positions. The refocusing of both branches is based on Kirkpatrick–Baez pairs. The expected spot sizes when using a 10 µm exit slit are 15 µm × 5 µm (horizontal × vertical FWHM) at the ARPES station and 10 µm × 5 µm (horizontal × vertical FWHM) at the PEEM station. The use of plane optical elements upstream of the exit slit, a variable-line-spacing grating and a pre-mirror in the monochromator that allows the influence of the thermal deformation to be eliminated are essential for achieving the ultrahigh-energy resolution.

scholarly journals Techniques for improving the sensitivity of proportional counters used in X-ray astronomy

1970 ◽  
Vol 37 ◽  
pp. 35-40 ◽  
Author(s):  
P. W. Sanford ◽  
A. M. Cruise ◽  
J. L. Culhane
Keyword(s):  
Energy Range ◽  
Energy Resolution ◽  
X Ray ◽  
Large Window ◽  
Proportional Counters

The discovery and measurement of cosmic X-ray sources has almost invariably been performed with proportional counters which have large window areas. In the energy range from 1 to 50 keV, proportional counters have advantages over other types of detectors; they provide energy resolution and they can be made relatively easily with very large window areas.

X-Ray Spectrometric Properties of Potassium Acid Phthalate Crystals

1969 ◽  
Vol 13 ◽  
pp. 373-381 ◽  
Author(s):  
R. J. Liefeld ◽  
S. Hanzgly ◽  
T. B. Kirby ◽  
D. Mott
Keyword(s):  
Oxygen Atom ◽  
Energy Range ◽  
Energy Resolution ◽  
Reflection Coefficients ◽  
X Ray ◽  
First Order ◽  
Coefficient Of Reflection ◽  
Potassium Acid Phthalate ◽  
Order Parallel ◽  
Acid Phthalate

The results of two crystal measurements of potassium acid phthalate crystal first order parallel position rocking curves, percent reflections, and reflection coefficients are presented. They cover the 4-24 Ǻ wavelength range and are typical of results with cleaved crystals illuminated over areas of one-half to two square inches. The energy resolution available with these crystals is shown to be nearly constant at about two-thirds of an electron volt over most of the energy range studied and the coefficient of reflection is also nearly constant at about 1 x 10-4 radians. A pronounced line-like reflectivity structure at 23.3 Ǻ is exhibited which is probably associated with oxygen atom K-shell absorption.

A new and versatile computer program for correcting EPMA data

1992 ◽  
Vol 50 (2) ◽  
pp. 1658-1659
Author(s):  
I Farthing ◽  
G Love ◽  
VD Scott ◽  
CT Walker
Keyword(s):  
Chemical Composition ◽  
Computer Program ◽  
Programming Language ◽  
Atomic Number ◽  
Processing Speed ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Epma Data ◽  
X Ray ◽  
X Ray Absorption

A new computer program has been developed to convert electron probe microanalysis data into accurate measurements of chemical composition. It is menu-based and designed to operate off-line using any IBM PC compatible computer. As shown in the flowchart, fig. 1, the architecture is modular and the programming language adopted is a compilable version of BASIC which possesses much of the processing speed associated with FORTRAN or C. Specimens containing up to fifteen elements, with 4 ≤ Z ≤ 96, can be handled and all the major x-ray lines (Kα, Kβ, Lα, L(β, Mα and Mβ) are available for analysis purposes.The procedure itself is based upon the classical ZAF approach in which corrections for atomic number (Z), x-ray absorption (A), characteristic fluorescence (Fl) and continuum fluorescence (F2) are treated independently. The factors dealing with fluorescence are essentially those of Reed (characteristic) and Springer (continuum) although both contain minor updates. However, the atomic number and absorption factors are the authors' own and the latter, developed from a quadrilateral representation of the x-ray distribution with depth in a solid, distinguishes this program from others.

Electron probe x-ray microanalysis with energy-dispersive x-ray spectrometry: The basics of x-ray spectrum interpretation

1994 ◽  
Vol 52 ◽  
pp. 376-377
Author(s):  
Dale E. Newbury
Keyword(s):  
Atomic Number ◽  
Electron Probe ◽  
Energy Dispersive ◽  
X Ray ◽  
Linear Dimensions ◽  
Specimen Volume ◽  
Spectrum Interpretation ◽  
The Rich ◽  
Source Of Information ◽  
Basic Level

Electron probe x-ray microanalysis (EPMA) with energy dispersive x-ray spectrometry (EDS) provides the capability for detecting elements with atomic number ≥ 4 (beryllium) from an excited specimen volume with linear dimensions of micrometers and a mass in the picogram range. To maximize the utility of EPMA/EDS, the analyst needs to understand the rich source of information that is potentially available in the x-ray spectrum. At its most basic level, interpretation of the spectrum consists of recognizing and identifying the various components of the spectrum as recorded by the EDS system: characteristic peaks, artifacts, and continuum background. While a modern EDS system is capable of making this interpretation in an automatic fashion, the careful analyst will always check the computer’s interpretation, which of course demands that the analyst be at least as "smart" as the computer! A systematic examination of spectra from pure elements or simple compounds is a good way to develop the necessary working knowledge.

Eight-channel x-ray spectrometer for 0.2–1.5 keV energy range with high time and energy resolution

2000 ◽  
Vol 71 (1) ◽  
pp. 82-87 ◽  
Author(s):  
A. V. Bessarab ◽  
S. V. Grigorovitch ◽  
V. V. Intyapin ◽  
V. I. Kundicov ◽  
A. V. Kunin ◽  
...  
Keyword(s):  
Energy Range ◽  
Energy Resolution ◽  
High Time ◽  
X Ray ◽  
Time And Energy

scholarly journals Features in the Soft X-ray Background

1990 ◽  
Vol 115 ◽  
pp. 146-155
Author(s):  
R. Rothenflug
Keyword(s):  
Energy Resolution ◽  
Line Emission ◽  
Spatial Variations ◽  
Emission Lines ◽  
X Ray ◽  
Hot Gas ◽  
The North ◽  
North Polar ◽  
X Ray Background ◽  
Japanese Group

AbstractThe soft X-ray background is explained in terms of emission coming from hot gas. Most of these soft X-ray data were obtained by proportional counters with a poor energy resolution. Instruments having the capability to resolve lines were only flown by two groups: a GSPC by a Japanese group and a SSD by a french-american collaboration. They both detected the 0 VII line emission coming from the soft X-ray background and so proved the thermal nature of the emission. The implications of these results on possible models for the local hot medium will be discussed. The same detectors observed part of the North Polar Spur. They detected emission lines coming from different species (0 VII,Fe XVII,Ne IX). Spatial variations of line ratios for this object could be due to non-equilibrium ionization effects.

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