scholarly journals High Resolution Proton Energy Loss Spectroscopy of High Overtone Levels of Polyatomic Molecules

1991 ◽  
Vol 11 (3-4) ◽  
pp. 247-252 ◽  
Author(s):  
W. Maring ◽  
J. P. Toennies
Keyword(s):  
High Resolution ◽  
Energy Loss ◽  
Inelastic Scattering ◽  
Proton Energy ◽  
Polyatomic Molecules ◽  
High Degree ◽  
Collision Mechanism ◽  
Very High ◽  
High Overtone ◽  
Anharmonicity Constants

In the inelastic scattering of nearly monoenergetic proton beams (≅ 20 e V) from polyatomic molecules such as CF4 sharp peaks are observed corresponding to the excitation of very high overtone levels (n ≤ 14) of the infrared active modes. The collision mechanism leading to the high degree of excitation is described and an example from recent experiments is presented. A fit of the CF4 spectra provides new anharmonicity constants for the ν3-mode.

High resolution proton energy loss spectroscopy of the high overtone vibrations in CF4

1995 ◽  
Vol 103 (4) ◽  
pp. 1333-1352 ◽  
Author(s):  
W. Maring ◽  
J. P. Toennies ◽  
R. G. Wang ◽  
H. B. Levene
Keyword(s):  
High Resolution ◽  
Energy Loss ◽  
Proton Energy ◽  
High Overtone

High-resolution proton energy-loss spectroscopy of the high-overtone levels of the v3 mode in CF4

1991 ◽  
Vol 184 (4) ◽  
pp. 262-266 ◽  
Author(s):  
W. Maring ◽  
J.P. Toennies ◽  
R.G. Wang ◽  
H.B. Levene
Keyword(s):  
High Resolution ◽  
Energy Loss ◽  
Proton Energy ◽  
High Overtone

scholarly journals Very High Resolution Energy Loss Spectroscopy: Applications in Plasmonics

2016 ◽  
Vol 22 (S3) ◽  
pp. 974-975 ◽  
Author(s):  
E.P. Bellido ◽  
I.C. Bicket ◽  
J. McNeil ◽  
G.A. Botton
Keyword(s):  
High Resolution ◽  
Energy Loss ◽  
Very High

Atomic resolution in energy-loss images: fact or artefact?

1995 ◽  
Vol 53 ◽  
pp. 262-263
Author(s):  
Max T. Otten
Keyword(s):  
High Resolution ◽  
Elastic Scattering ◽  
Energy Loss ◽  
Inelastic Scattering ◽  
Main Issue ◽  
Atomic Resolution ◽  
Fine Detail ◽  
Insight Into

Since the introduction of energy-filtered imaging, the ultimate resolution has been a point of debate. Berger and Kohl[1] concluded that resolution is limited to ~1 nm. In contrast, one group of investigators[2,3] has argued that atomic resolution can be achieved. The conclusions from the latter group have been questioned previously [4]. In order to provide more insight into the origin of the fine detail in some energy-loss images, a number of experiments have been performed to try and resolve this issue.The main issue of the high-resolution detail in energy-loss images (i.e., images from electrons that have lost an amount of energy) is whether it comes from elastic or to inelastic scattering. In the former case, a combination of elastic scattering and inelastic scattering, the high-resolution energy-loss image is an artefact. In the latter case, inelastic scattering only, it would be real.On the basis of theory energy-loss images are unlikely to achieve atomic resolution.

Very High Resolution Analysis of the Dynamics of a Coronal Plasmoid

1994 ◽  
Vol 144 ◽  
pp. 593-596
Author(s):  
O. Bouchard ◽  
S. Koutchmy ◽  
L. November ◽  
J.-C. Vial ◽  
J. B. Zirker
Keyword(s):  
High Resolution ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Field Of View ◽  
Small Field ◽  
High Resolution Analysis ◽  
Ccd Observations ◽  
Resolution Analysis ◽  
Very High ◽  
Small Field Of View

AbstractWe present the results of the analysis of a movie taken over a small field of view in the intermediate corona at a spatial resolution of 0.5“, a temporal resolution of 1 s and a spectral passband of 7 nm. These CCD observations were made at the prime focus of the 3.6 m aperture CFHT telescope during the 1991 total solar eclipse.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

Low-workfunction field-emission source for high-resolution EELS

1987 ◽  
Vol 45 ◽  
pp. 132-133
Author(s):  
P. E. Batson
Keyword(s):  
High Resolution ◽  
Energy Loss ◽  
Electron Probe ◽  
Collection Efficiency ◽  
Electron Sources ◽  
Wien Filter ◽  
Half Angle ◽  
Thermal Emitter ◽  
Electron Energy Loss ◽  
Intrinsic Energy

In recent years,instrumentation for electron energy loss spectroscopy (EELS) has been steadily improved to increase energy resolution and collection efficiency. At present 0.40eV at 10mR collection half angle is available with commercial magnetic sectors (e.g. Gatan, Inc. and VG Microscopes, Ltd.), and 70meV at 10mR has been demonstrated by use of a Wien filter within a large deceleration field. When these high resolution spectrometers are coupled to the modern small electron probe instrument, we obtain a tool which promises to reveal local changes in bandstructure and bonding near defects and interfaces in heterogeneous materials.Unfortunately, typical electron sources have intrinsic energy widths which limit attainable spectroscopic resolution in the absence of some monochromation system. For instance, the W thermal emitter has a half width of about 1eV.

Sign in / Sign up

Export Citation Format

Share Document