A Comparison of Four Slit Apertures for Selected-Area Analysis with the X-Ray Secondary-Emission Spectrometer

1966 ◽  
Vol 10 ◽  
pp. 462-473
Author(s):  
Eugene P. Bertin
Keyword(s):  
Spectral Line ◽  
Line Width ◽  
Pulse Height ◽  
High Sensitivity ◽  
Secondary Emission ◽  
The Other ◽  
X Ray ◽  
Spectral Line Width ◽  
Fixed Radius ◽  
First Time

AbstractFour types of slit apertures—vertical, horizontal, inclined, and sirtgle-edge—for selected-area analysis with commercial X-ray secondary-emission (fluorescence) spectrometers are described, evaluated, and compared. The vertical and single-edge slits already have been described by the writer and Rizzo. The other two are described here for the first time. The vertical and horizontal slits are secondarybeam apertures; the other two lie in both the primary and secondary beams. AH the slits are mounted on the specimen drawer. No further modification of the spectrometer is required except replacement of the soller collimators with open tunnels or simple slits, and replacement of the flat crystal with a fixed-radius curved crystal to increase sensitivity. The accessories are inexpensive and can be made in even a modest machine shop. They can be installed on or removed from the spectrometer in about 5 min. The accessories are applicable ordy to linear selected areas where composition varies in the direction normal to but not along the line, for example, linear inclusions and sections of plated surfaces, diffusion couples, and interfaces. The four slits were evaluated and compared for resolution, sensitivity, and spectral-line width. Techniques for use, advantages, limitations, and means for improvement are discussed for each of the slits. The horizontal slit is of little value, but each of the others has features which permit analysis of very narrow selected areas for which pinhole apertures would not be sufficiently sensitive. Slit widths as narrow as 0,00012 in. (0.003 mm) have been used in favorable cases. The inclined slit, used with a pulse-height analyzer, is probably the most useful of the four apertures, combining high sensitivity, high resolution, and narrow spectral-line width.

Temperature dependence of the spectral line width for complex europium compounds in solutions

1986 ◽  
Vol 44 (2) ◽  
pp. 156-159
Author(s):  
N. N. Mit'kina ◽  
R. A. Puko ◽  
T. I. Razvina ◽  
V. V. Kuznetsova ◽  
M. R. Posledovich
Keyword(s):  
Spectral Line ◽  
Temperature Dependence ◽  
Line Width ◽  
Spectral Line Width

Study of Garnets by ALCHEMI

2001 ◽  
Vol 7 (S2) ◽  
pp. 358-359
Author(s):  
János L. Lábár ◽  
Lajos Tόth ◽  
István Dόdony ◽  
Jerzy Morgiel
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
High Sensitivity ◽  
Unit Cell ◽  
Previous Literature ◽  
The Other ◽  
Axial Orientation ◽  
Partial Substitution ◽  
X Ray ◽  
Oxygen Atoms

Garnets were one of the first materials in which an occupation of separate lattice sites by different atomic species was determined with an ALCHEMI technique proposed by Spence and Tafto in l982. The reason of so much interest in this material was twofold, i.e. first its known high sensitivity of X-ray generation depending on orientation especially in the axial orientation and second its complicated crystal structure allowing different atomic arrangements in the unit cell depending on its chemical composition. The dodecahedral (X), octahedral (Y) and tetrahedral (Z) sites between the relatively large oxygen atoms can be filled with a variety of small cations in accordance with the formula X3Y2Z3O12. Partial substitution of one cation with another is common in this structure. The results presented in the previous literature indicated that ALCHEMI can only separate the Y-sites from the sum of the other two (X+Z), while the latter has to remain unresolved.

Wavelength stabilized ns-MOPA diode laser system with 16 W peak power and a spectral line width below 10 pm

2014 ◽  
Vol 29 (3) ◽  
pp. 035012 ◽  
Author(s):  
Thi Nghiem Vu ◽  
Andreas Klehr ◽  
Bernd Sumpf ◽  
Hans Wenzel ◽  
Götz Erbert ◽  
...  
Keyword(s):  
Spectral Line ◽  
Diode Laser ◽  
Line Width ◽  
Peak Power ◽  
Laser System ◽  
Spectral Line Width

scholarly journals Localisation of intracellular calcium in the neutrophil through the selective precipitation with the antimonate ion

2001 ◽  
Vol 20 (1) ◽  
pp. 4-8
Author(s):  
A. M. Koorts ◽  
A. N. Hall ◽  
M. Viljoen Viljoen
Keyword(s):  
Intracellular Calcium ◽  
The Other ◽  
Precipitation Reaction ◽  
Sodium Ions ◽  
Selective Precipitation ◽  
X Ray ◽  
Transmission Electron ◽  
Microscopy Method ◽  
Electron Microscopy Method ◽  
First Time

The antimonate ion was used for the first time in 1962 by Komnick for the precipitation of intracellular sodium ions. The antimonate ion can, however, also precipitate other cations and can be employed in subcellular calcium localisation studies. The greatest difficulty encountered with such subcellular calcium localisation studies is the selectivity of the antimonate ion for calcium in the presence of the other intracellular cations. Various x-ray analyses and chelation studies have shown that the antimonate precipitation reaction can be specific for calcium under appropriate conditions. A transmission electron microscopy method for the selective localisation of intracellular calcium in the neutrophil with the antimonate ion is discussed. It is indicated that the antimonate ion can specifically precipitate calcium in the presence of the other intracellular cations.

scholarly journals Multiple cyclotron line-forming regions in GX 301−2

2018 ◽  
Vol 620 ◽  
pp. A153 ◽  
Author(s):  
F. Fürst ◽  
S. Falkner ◽  
D. Marcu-Cheatham ◽  
B. Grefenstette ◽  
J. Tomsick ◽  
...  
Keyword(s):  
Relativistic Effects ◽  
Resonant Scattering ◽  
The Other ◽  
High Mass ◽  
Good Resolution ◽  
Gaussian Shape ◽  
X Ray ◽  
Cyclotron Line ◽  
First Time ◽  
The Continuum

We present two observations of the high-mass X-ray binary GX 301−2 with NuSTAR, taken at different orbital phases and different luminosities. We find that the continuum is well described by typical phenomenological models, like a very strongly absorbed NPEX model. However, for a statistically acceptable description of the hard X-ray spectrum we require two cyclotron resonant scattering features (CRSF), one at ∼35 keV and the other at ∼50 keV. Even though both features strongly overlap, the good resolution and sensitivity of NuSTAR allows us to disentangle them at ≥99.9% significance. This is the first time that two CRSFs have been seen in GX 301−2. We find that the CRSFs are very likely independently formed, as their energies are not harmonically related and, if the observed feature were due to a single line, the deviation from a Gaussian shape would be very large. We compare our results to archival Suzaku data and find that our model also provides a good fit to those data. We study the behavior of the continuum as well as the CRSF parameters as function of pulse phase in seven phase bins. We find that the energy of the 35 keV CRSF varies smoothly as a function of phase, between 30 and 38 keV. To explain this variation, we apply a simple model of the accretion column, taking into account the altitude of the line-forming region, the velocity of the in-falling material, and the resulting relativistic effects. We find that in this model the observed energy variation can be explained as being simply due to a variation of the projected velocity and beaming factor of the line-forming region towards us.

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