Possibility of excitation temperature determination by relative deviation plot of line intensities

1998 ◽  
Author(s):  
Alexandre F. Semerok
Keyword(s):  
Excitation Temperature ◽  
Relative Deviation ◽  
Temperature Determination ◽  
Line Intensities ◽  
Deviation Plot

On Temperature Determination from Rotational Raman Line Intensities

1986 ◽  
Vol 40 (6) ◽  
pp. 831-839 ◽  
Author(s):  
Josef Doppelbauer ◽  
Günter Leyendecker
Keyword(s):  
Single Channel ◽  
Experimental Situation ◽  
Random Errors ◽  
Selected Lines ◽  
Channel Detection ◽  
Temperature Determination ◽  
Temperature Range ◽  
Line Intensities ◽  
Linear Molecules ◽  
Selection Of

A theoretical investigation of temperature determination from the pure rotational Raman spectra of diatomic and linear molecules is performed. Calculations are presented on the suitable selection of the lines used to minimize the random error. The problem is formulated in terms of rotational characteristic temperatures. Our results show, for single-channel detection, that temperature determination from the intensity ratio of only two properly selected lines is superior to the evaluation of many lines. Optimum line pairs are calculated for the most widely used molecules, H2 and N2, in the temperature range 300 to 2000 K. The random errors to be expected in this temperature range are given in a form which allows estimates to be made for any particular experimental situation.

Temperature and Self-Absorption in an Atmospheric Chromium Arc, and f Values for Near-Infrared Lines of Chromium I, from Spectrometric Measurements with Refrigerated Photomultiplier Tubes

1966 ◽  
Vol 20 (1) ◽  
pp. 12-17 ◽  
Author(s):  
Joseph W. Hutcherson ◽  
Bill C. Mundy ◽  
Ray Hefferlin
Keyword(s):  
Emission Line ◽  
Near Infrared ◽  
Excitation Temperature ◽  
Photomultiplier Tubes ◽  
Line Intensities ◽  
Spectrometric Measurements ◽  
Pure Chromium

A 5-A dc are was struck between pure chromium electrodes in nitrogen at 1 atm. The chromium I excitation temperature, averaged over atoms in the center of the arc image, determined by relative emission-line intensities in the near infrared, was found to be (4893 ± 190) °K. The extent of self-absorption was determined from the same lines. Relative f values for 63 lines of chromium I, including the 21 used initially, were determined with precision of 0.33 in log gf. Existing instrumentation and current improvements to the experiment are described.

EXCITATION CONDITIONS IN THE UPPER ATMOSPHERE AS DETERMINED FROM A STUDY OF ATOMIC EMISSION LINES IN THE AURORAL SPECTRUM

1947 ◽  
Vol 25a (5) ◽  
pp. 293-301 ◽  
Author(s):  
William Petrie
Keyword(s):  
Oxygen Atom ◽  
Atomic Emission ◽  
Upper Atmosphere ◽  
Emission Lines ◽  
Excitation Temperature ◽  
Auroral Region ◽  
Line Intensities ◽  
Theoretical Line ◽  
Measured Line ◽  
Excitation Conditions

Vegard's identifications of a number of lines appearing in the auroral spectrum are discussed. The conclusion is reached that a good many of these lines may be attributed to the oxygen atom in several stages of ionization. It is shown how measured line intensities and theoretical line strengths are combined to give the excitation temperature of the auroral region. Preliminary results indicate that this temperature is in the range 3000° to 6000° K. The meaning of this result is discussed briefly.

On the Inhomogeneity of Chemical Composition over the Surface of 21 Per

1976 ◽  
Vol 32 ◽  
pp. 343-349
Author(s):  
Yu.V. Glagolevsky ◽  
K.I. Kozlova ◽  
V.S. Lebedev ◽  
N.S. Polosukhina
Keyword(s):  
Chemical Composition ◽  
Spectral Line ◽  
Variable Star ◽  
Radial Velocities ◽  
Crimean Astrophysical Observatory ◽  
Line Intensities ◽  
Magnetic Variable

SummaryThe magnetic variable star 21 Per has been studied from 4 and 8 Å/mm spectra obtained with the 2.6 - meter reflector of the Crimean Astrophysical Observatory. Spectral line intensities (Wλ) and radial velocities (Vr) have been measured.

Valence state analysis of elements by EPMA and its application

1990 ◽  
Vol 48 (2) ◽  
pp. 230-231
Author(s):  
Chen Liqing ◽  
Liu Zuqin ◽  
Zhang Wei
Keyword(s):  
Valence State ◽  
Line Intensities ◽  
Valence States ◽  
Valence Electrons ◽  
Fe And Mn ◽  
Intensity Ratios ◽  
State Analysis

Valence state analyses of Fe and Mn in oxides by EPMA have been reported in literature. In this paper, the effects of valence state on intensity ratios ILα/IKα and ILα/ILβ of Cu, Ni, Co, Fe, Mn, Cr and their oxides, and on intensity ratios ILβ2/ILα1 and ILγ1/ILα1 of Mo, Nb, Zr and their oxides were studied. It was observed that intensity ratios change with valence states in accordance with some regularities, and these effects could be utilized for analyzing the valence states of catalysts.Valence state analysis of elements by EPMA is based on the fact that changes in the states of valence electrons in the outer shells of an atom cause corresponding changes in line intensities. The M electrons of Cu, Ni, Co, Fe, Mn, Cr and the N electrons of Mo, Nb, Zr are valence electrons. Line Kα1,2 and six lines of L are produced from the transitions of K-L2,3 and L-M or L-N respectively.

EELS white line intensities calculated for the 3d and 4d metals

1989 ◽  
Vol 47 ◽  
pp. 388-389
Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
P. Rez ◽  
B. Fultz
Keyword(s):  
Experimental Data ◽  
Line Intensity ◽  
Transition Probabilities ◽  
Initial Increase ◽  
White Line ◽  
Hartree Fock ◽  
Line Intensities ◽  
Integrated Intensity ◽  
X Ray Absorption ◽  
The Continuum

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.

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