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.

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.

scholarly journals Absorption coefficients for Al, Cu and Ag in the X-ray region from 13 to 24 A

1937 ◽  
Vol 161 (905) ◽  
pp. 284-298 ◽  
Keyword(s):  
Wave Length ◽  
Grazing Incidence ◽  
Absorption Coefficients ◽  
X Ray ◽  
Mass Absorption ◽  
Long Wave

It may be seen from Table I that there is only one determination in the X-ray region above 10 A, a fact which is probably due to the experimental difficulties attached to the measurements in this region. The difficulties of vacuum technique and of using a grating at grazing incidence involved in isolating the homogeneous X-radiations in the long wave-length region are well known. Furthermore, because of the highly absorbable character of these radiations the metal absorbing laminae must be extremely thin, and homogeneous laminae, so essential for absorption investigations, are not readily obtainable in these thicknesses. Bandopadhyaya and Maitra (1936) found that the mass absorption coefficients for Al in the region 8-25 A do not vary with wave-length according to the generally accepted relation μ / p = Cλ n , (1) where C and n are constants. They observed a decrease in the value of n as the wave-length increased.

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.

X-Ray Spectra of Long Wave-Length

1927 ◽  
Vol 30 (5) ◽  
pp. 567-573 ◽  
Author(s):  
T. H. Osgood
Keyword(s):  
Wave Length ◽  
X Ray ◽  
Long Wave

scholarly journals A vacuum spectrometer for long wave-length X-rays

1931 ◽  
Vol 133 (821) ◽  
pp. 266-274
Keyword(s):  
High Intensity ◽  
Focal Spot ◽  
Photographic Plate ◽  
Wave Length ◽  
X Rays ◽  
Coincidence Method ◽  
X Ray ◽  
Long Wave ◽  
Angular Measurements

The instrument described was designed to give a high intensity of radiation at the photographic plate and to be capable of accurate angular measurements of crystal reflection. The Seeman form of spectrometer, in which a single slit is placed between the crystal (or ruled grating) and the photographic plate, was used together with a method of measuring angles on a single accurate circle. Both spectrometer and X-ray tube were placed in a common vacuum to allow the focal spot to be brought close to the crystal. The instrument has been used with a method similar to Rowland’s coincidence method to measure the wave-length of the AlKα 12 line relative to the fifth and sixth orders of the CuKα 12 doublet, using a sugar crystal. The result obtained, after correction for deviation from the Bragg law, is 8315 X.U. relative to 1539·23 X.U. for the copper doublet, the results being reproducible to 1 X. U.

scholarly journals Luminescence Centers in Thin Films of ZnGa2O4

2015 ◽  
Vol 16 (1) ◽  
pp. 74-78 ◽  
Author(s):  
O. M. Bordun ◽  
I. Y. Kukharskyy ◽  
B. O. Bordun
Keyword(s):  
Thin Films ◽  
Energy Level ◽  
Luminescence Band ◽  
Oxygen Vacancies ◽  
Energy Level Diagram ◽  
Electronic Transitions ◽  
Luminescence Spectra ◽  
X Ray ◽  
Luminescence Centers

Photoexcitation spectra and luminescence of thin films of ZnGa2O4 under photo-, cathode and X-ray excitation were investigated. Luminescence spectra were factorized on ultimate constituents using Alentsev-Fock method. Emission bands with maximums at 3.35, 2.85, 2.50 and 2.38 eV were referred to the luminescence at the expense of electronic transitions between 4Т2, 4Т1, 2Е and 4А2 terms in octahedral complexes (GaO6)9–. It was proposed an energy level diagram with corresponding electronic transitions in such structure. Luminescence band with maximum at 1.75 eV is attributed to oxygen vacancies.

scholarly journals A new maser effect in plasma turbulence

1983 ◽  
Vol 1 (4) ◽  
pp. 427-454 ◽  
Author(s):  
M. Nambu
Keyword(s):  
Wave Length ◽  
Magnetic Confinement ◽  
Plasma Turbulence ◽  
Turbulent Plasma ◽  
Inertial Confinement ◽  
X Ray ◽  
Radiation Losses ◽  
Long Wave ◽  
Maser Effect ◽  
Laser Effect

The present state of understanding of a new maser effect is reviewed. The new maser effect, the idea that the resonant electrons in a turbulent plasma can radiate amplified electromagnetic radiation, does not require population inversion of electrons. The new maser effect always coexists with Landau (or cyclotron) damping; thus it is a fundamental effect in plasma turbulence. In nuclear fusion, magnetic confinement will be at a disadvantage due to the enhanced radiation losses in the long wave length region, while inertial confinement will be improved by the laser effect in the X-ray region

LEED studies on modulated surface structures

2015 ◽  
Vol 230 (1) ◽  
Author(s):  
Wolfgang Moritz
Keyword(s):  
Multiple Scattering ◽  
Fourier Coefficients ◽  
Wave Length ◽  
Computational Effort ◽  
Unit Cell ◽  
Surface Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modulation Function ◽  
Long Wave

AbstractThe problems occurring in structure analyses of modulated surfaces by LEED or X-ray diffraction are briefly discussed. In previous LEED studies of modulated surfaces a commensurate unit cell and Fourier coefficients to describe the modulation function has been used. The wave length of the modulation and the size of the supercell are limited in this way by the computational effort of the multiple scattering calculations. To overcome this problem an approximation is proposed allowing the analysis of commensurate or incommensurate surface modulations with long wave lengths.

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