Observation of resonance effects in the relative partial photoionization cross sections of the d bands of M(CO)6, M = Cr, Mo and W

1986 ◽  
Vol 125 (2) ◽  
pp. 97-100 ◽  
Author(s):  
Glyn Cooper ◽  
Jennifer C. Green ◽  
Martin P. Payne ◽  
Barry R. Dobson ◽  
Ian H. Hillier
Keyword(s):  
Cross Sections ◽  
Resonance Effects

RESONANCE EFFECTS OBSERVED IN THE INTERACTION OF LOW-ENERGY ELECTRONS AND INTRAMOLECULAR VIBRATIONS OF SOLID C70

1995 ◽  
Vol 02 (05) ◽  
pp. 557-562 ◽  
Author(s):  
L.-M. YU ◽  
B.-Y. HAN ◽  
K. HEVESI ◽  
P. RUDOLF ◽  
G. GENSTERBLUM ◽  
...  
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Cross Sections ◽  
Negative Ion ◽  
Resonance Effects ◽  
Resolution Electron ◽  
Low Energy Electrons ◽  
Intramolecular Vibrations ◽  
The Impact ◽  
Electron Energy Loss

The intramolecular vibrations of a thick epitaxial C 70(111) film on GeS (001) have been measured by high-resolution electron energy-loss spectroscopy (HREELS). A negative-ion resonant behavior is observed in the energy dependence of the impact scattering differential cross sections. These resonances are described as electronic excitation associated shape resonances, which are coincident with the electron energy loss and free-electron capture experiments. Finally, the effect of charge transfer on the resonance behavior is discussed through the comparison of bulk spectra with those from an adsorbed monolayer of C 70 on Au (110).

scholarly journals Resonance effects in elastic cross sections for electron scattering on pyrimidine: Experiment and theory

2016 ◽  
Vol 144 (2) ◽  
pp. 024301 ◽  
Author(s):  
Khrystyna Regeta ◽  
Michael Allan ◽  
Carl Winstead ◽  
Vincent McKoy ◽  
Zdeněk Mašín ◽  
...  
Keyword(s):  
Electron Scattering ◽  
Cross Sections ◽  
Resonance Effects

scholarly journals PROCESSING RESONANCE SELF-SHIELDING EFFECT OF GADOLINIA BASED ON IMPTOVED SUPERCELL SCHEME

2021 ◽  
Vol 247 ◽  
pp. 02031
Author(s):  
Jikui Li ◽  
Tiejun Zu ◽  
Wen Yin ◽  
Liangzhi Cao
Keyword(s):  
Cross Sections ◽  
Interpolation Method ◽  
Shielding Effect ◽  
Group Method ◽  
Local Effects ◽  
Correction Formula ◽  
Resonance Effects ◽  
Shadowing Effect ◽  
Low Efficiency ◽  
Shielding Effects

An improved supercell scheme has been proposed in this paper to efficiently and accurately process resonance self-shielding effect of gadolinia. Resonance effects are classified into global shadowing effect and local effects involving resonance interference, spatial self-shielding effects. Two categories of effects are decoupled and treated respectively based on different 1-D cylindrical pins. Hyperfine group method is applied to obtain multi-group cross sections for each 1-D pin. Afterwards, two categories of effects are coupled based on a correction formula. Because of the low efficiency for Carlvik method to compute collision probabilities in hyperfine group method, online tabulation and interpolation method is developed to accelerate gaining collision probabilities. The proposed scheme is verified against the problems of 3×3 pins with gadolinia rod, VERA 2O assembly with 12 gadolinia rods and VERA 2P with 24 gadolinia rods. The numerical results suggest promising consistence of multi-group cross sections and eigenvalues between the proposed scheme and reference solutions.

scholarly journals Nonresonant effects in one- and two-photon transitions

2002 ◽  
Vol 80 (6) ◽  
pp. 633-644 ◽  
Author(s):  
U D Jentschura ◽  
P J Mohr
Keyword(s):  
Cross Sections ◽  
Atomic Hydrogen ◽  
Rayleigh Scattering ◽  
Energy Levels ◽  
Experimental Accuracy ◽  
Differential Measurement ◽  
Resonance Effects ◽  
Two Photon ◽  
Scattering Cross ◽  
Scattering Cross Sections

We investigate nonresonant contributions to resonant Rayleigh-scattering cross sections of atoms. The problematic nonresonant contributions set a limit to the accuracy to which atomic spectra determine energy levels. We discuss the off-resonance effects in one-photon transitions. We also show that off-resonance contributions for the 1S–2S two-photon transition in atomic hydrogen are negligible at current and projected levels of experimental accuracy. The possibility of a differential measurement for the detection of off-resonance effects in one-photon transitions in atomic hydrogen is discussed. PACS Nos.: 31.15-p, 12.20Ds

scholarly journals Importance of double-resonance effects in two-photon absorption properties of Au25(SR)18−

2017 ◽  
Vol 8 (6) ◽  
pp. 4595-4601 ◽  
Author(s):  
Zhongwei Hu ◽  
Lasse Jensen
Keyword(s):  
Cross Sections ◽  
Double Resonance ◽  
Photon Absorption ◽  
Absorption Cross ◽  
Absorption Properties ◽  
Resonance Effects ◽  
Two Photon Absorption ◽  
Two Photon

We show that double-resonance effects for Au25(SR)18− are less pronounced and do not lead to significantly enhanced two-photon absorption cross-sections.

scholarly journals Complex angular momentum theory of state-to-state integral cross sections: resonance effects in the F + HD → HF(v′ = 3) + D reaction

2015 ◽  
Vol 17 (28) ◽  
pp. 18577-18589 ◽  
Author(s):  
D. Sokolovski ◽  
E. Akhmatskaya ◽  
C. Echeverría-Arrondo ◽  
D. De Fazio
Keyword(s):  
Angular Momentum ◽  
Cross Sections ◽  
Quantum Mechanical ◽  
Resonance Effects ◽  
Momentum Theory ◽  
Complex Angular Momentum ◽  
Mechanical Resonances ◽  
Angular Momentum Theory

State-to-state reactive integral cross sections (ICSs) are often affected by quantum mechanical resonances, especially in the neighborhood of a reactive threshold.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

An Analysis of Dissociation of Molecules in a High Resolution Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 486-487
Author(s):  
Mihir Parikh
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Sections ◽  
Resolving Power ◽  
Peak Intensity ◽  
Molecular Film ◽  
Resolution Electron ◽  
Dissociation Cross Section ◽  
High Resolution Electron Microscope ◽  
The Stability

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used

Sign in / Sign up

Export Citation Format

Share Document