Etude de l'Excitation du Néon par Spectrométrie Electronique

1973 ◽  
Vol 51 (15) ◽  
pp. 1597-1601 ◽  
Author(s):  
D. Roy ◽  
A. Delâge ◽  
J. D. Carette
Keyword(s):  
Energy Loss ◽  
Electron Source ◽  
Electron Spectrometer ◽  
Energy Analyzer ◽  
Monoenergetic Electron ◽  
Scattering Angle ◽  
Scattering Chamber

This paper presents the description of an electron spectrometer involving a monoenergetic electron source, a scattering chamber, and an energy analyzer. The results presented are the measurements which have been done over energy loss spectra of exciting electrons in neon, as a function of their energy of incidence and the scattering angle.

Scattering-angle dependence of signal/background ratio of inner-shell electron excitation loss in EELS

1983 ◽  
Vol 41 ◽  
pp. 390-391
Author(s):  
T. Oikawa ◽  
M. Inoue ◽  
T. Honda ◽  
Y. Kokubo
Keyword(s):  
Energy Loss ◽  
Electron Excitation ◽  
Heavy Elements ◽  
Background Intensity ◽  
Light Elements ◽  
Energy Analyzer ◽  
High Background ◽  
Scattering Angle ◽  
Angle Dependence ◽  
Shell Electron

EELS allows us to make analysis of light elements such as hydrogen to heavy elements of microareas on the specimen. In energy loss spectra, however, elemental signals ride on a high background; therefore, the signal/background (S/B) ratio is very low in EELS. A technique which collects the center beam axial-symmetrically in the scattering angle is generally used to obtain high total intensity. However, the technique collects high background intensity together with elemental signals; therefore, the technique does not improve the S/B ratio. This report presents the experimental results of the S/B ratio measured as a function of the scattering angle and shows the possibility of the S/B ratio being improved in the high scattering angle range.Energy loss spectra have been measured using a JEM-200CX TEM with an energy analyzer ASEA3 at 200 kV.Fig.l shows a typical K-shell electron excitation edge riding on background in an energy loss spectrum.

Sections efficaces différentielles relatives de diffusion des électrons lents (15 à 100 eV) par le krypton

1977 ◽  
Vol 55 (21) ◽  
pp. 1835-1841 ◽  
Author(s):  
A. Delâge ◽  
J.-D. Carette
Keyword(s):  
Energy Loss ◽  
Electron Impact ◽  
Cross Sections ◽  
Differential Cross ◽  
High Energy ◽  
Differential Cross Sections ◽  
Electron Spectrometer ◽  
Scattering Angle ◽  
Resolution Electron

A high energy and angle resolution electron spectrometer has been used to study the electroexcitation of krypton. The energy of the incident electrons considered, 15–100 eV, is in a range about which there is little or nothing known at the present time. The relative differential cross sections of excitation by electron impact are calculated from the energy loss spectra of scattered electrons for angles ranging from 0 to 90°. Some conclusions are drawn from the values of these cross sections as a function of the energy of incident electrons and of the scattering angle.

Simple and efficient monoenergetic electron source

1982 ◽  
Vol 53 (6) ◽  
pp. 778-780 ◽  
Author(s):  
M. Proulx ◽  
P. Marmet ◽  
R. Dutil
Keyword(s):  
Electron Source ◽  
Monoenergetic Electron

Small-Sized Technological Electron Spectrometer with Magnetic Energy-Analyzer

2018 ◽  
pp. 237-244
Author(s):  
Yu. G. Manakov ◽  
I. N. Shabanova ◽  
V. A. Trapeznikov ◽  
Ye. A. Morozov
Keyword(s):  
Magnetic Energy ◽  
Electron Spectrometer ◽  
Energy Analyzer

Le spectre des états électroniques de Kr I mesuré par spectrométrie électronique

1975 ◽  
Vol 53 (19) ◽  
pp. 2079-2084 ◽  
Author(s):  
A. Delage ◽  
J.-D. Carette
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Inelastic Scattering ◽  
Electronic States ◽  
Resolving Power ◽  
Electron Spectrometer ◽  
Energy Incident ◽  
First Time ◽  
Electron Energy Loss ◽  
Electron Energy Loss Spectra

The spectrum of electronic states of krypton I has been measured by inelastic scattering of monoenergetic electrons with the aid of an electron spectrometer which has a high resolving power, ΔE/E = 0.02. Electron energy loss spectra have allowed us to detect and identify numerous electronic states of krypton I for the first time by the means of this experimental method. The relative heights of the peaks corresponding to an energy loss, which are related to the probability of excitation of the atom by electron impact to a given state, have been measured from experimental data as a function of the energy incident electrons and as a function of the scattering angle.

The Scattering Distribution from Semiconductors as a Function of Angle and Energy Loss in the Electron Microscope

1996 ◽  
Vol 466 ◽  
Author(s):  
C. B. Boothroyd ◽  
R. E. Dunin-Borkowski ◽  
T. Walther
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Dark Field ◽  
High Angle ◽  
Scattering Angle ◽  
Annular Dark Field ◽  
Insight Into

ABSTRACTWe examine the scattering distribution from thin C, Ge and thick Si specimens as a function of scattering angle and energy loss, in order to gain insight into the relative contributions to both low and high angle annular dark field images from elastically and inelastically scattered elections.

Collision site effect on the radiation dynamics of cytosine induced by proton

2022 ◽  
Author(s):  
Xu Wang ◽  
Zhi-Ping Wang ◽  
Feng-Shou Zhang ◽  
Chao-Yi Qian
Keyword(s):  
Energy Loss ◽  
Incident Energy ◽  
Density Functional ◽  
Degrees Of Freedom ◽  
Site Effect ◽  
Low Energy ◽  
Microscopic Mechanism ◽  
Scattering Angle ◽  
Fragment Mass ◽  
Dynamics Simulations

Abstract By combing the time-dependent density functional calculations for electrons with molecular dynamics simulations for ions (TDDFT-MD) nonadiabatically in real time, we investigate the microscopic mechanism of collisions between cytosine and low-energy protons with incident energy ranging from 150 eV to 1000 eV. To explore the effects of the collision site and the proton incident energy on irradiation processes of cytosine, two collision sites are specially considered, which are N and O both acting as the proton receptors when forming hydrogen bonds with guanine. Not only the energy loss and the scattering angle of the projectile, but also the electronic and ionic degrees of freedom of the target are identified. It is found that the energy loss of proton increases linearly with the increase of the incident energy in both situations, which are 14.2% and 21.1% of the incident energy respectively. However, the scattering angles show different behaviors in these two situations when the incident kinetic energy increases. When proton collides with O, the scattering angle of proton is larger and the energy lost is more, while proton captures less electrons from O. The calculated fragment mass distribution shows the high counts of the fragment mass of 1, implying the production of H+ fragment ion from cytosine even for proton with the incident energy lower than keV. Furthermore, the calculated results show that N on cytosine is easier to be combined with low-energy protons to form NH bonds than O.

A New High Performance Electron Energy Loss Spectrometer for use with Monochromated Microscopes

2001 ◽  
Vol 7 (S2) ◽  
pp. 908-909
Author(s):  
H.A. Brink ◽  
M. Barfels ◽  
B. Edwards ◽  
P. Burgner
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Energy Resolution ◽  
Optical Design ◽  
Electron Source ◽  
High Voltage Power Supply ◽  
Electron Energy Loss Spectrometer ◽  
Electron Microscopes ◽  
Electron Energy Loss ◽  
Better Than

A new type of electron energy loss spectrometer for use with monochromated microscopes is presented. The energy resolution of the spectrometer is better than 0.100 eV. A completely new electron optical design with a number of extra optical elements and advanced tuning software makes it possible to correct spectrum aberrations to 4th order, which increases sensitivity and collection angles. New high-stability electronics make it possible to maintain energy resolution over a period of several minutes in a practical laboratory environment.The energy resolution of Transmission Electron Microscopes (TEMs) equipped with electron energy loss spectrometers is determined by a combination of the energy spread of the electron source, the stability of the microscope’s high voltage power supply, and the energy resolution of the spectrometer. Commercial microscopes usually employ electron sources with an energy distributions of around 0.5 eV or more (FWHM), limiting the energy ultimate energy resolution that can be achieved. Recently FEI constructed a special 200 kV TEM with a built-in monochromator which makes it possible to monochromize the electron source to better than 0.100 eV. A prototype of the presented spectrometer has been installed on this microscope.

Sign in / Sign up

Export Citation Format

Share Document