Energy Distribution of Energetic Atoms in a Gaseous Medium. II. Elastic Scattering by a Spherical Two‐Term Potential Composed of a Hard and a Soft Term

1968 ◽  
Vol 48 (6) ◽  
pp. 2786-2799 ◽  
Author(s):  
M. Baer
1957 ◽  
Vol 12 (12) ◽  
pp. 947-955 ◽  
Author(s):  
P. Mittelstaedt

The elastic and inelastic scattering of K--Mesons by complex nuclei are described by means of a phenomenological optical model. The real and the imaginary parts of the optical potential are determined by a comparison with the experimental results of the Goettingen and of the Bern plate group from the angular distribution of the elastic scattering and also from the energy distribution of the inelastically scattered K--Mesons by means of the GoLDBERGER-method.


1975 ◽  
Vol 53 (6) ◽  
pp. 628-636 ◽  
Author(s):  
A. Delage ◽  
D. Roy ◽  
J.-D. Carette

The influence of thermal energy of atoms and molecules and of the energy distribution of electrons on results obtained from electronic impact experiments are analyzed. Special attention is devoted to the width of the peaks found in the spectra of elastically and inelastically scattered electrons. Results are presented in the convenient form of tables, graphs, and a nomogram in order that they may be easily accessible to researchers in the field of electronic collisions. The method used to calculate the influences of the experimental factors has also been used in the case of resonant elastic scattering of electrons in helium. These experimental factors are the thermal energy of the particles of the target and the spread of the electron energy.


2002 ◽  
Vol 16 (28n29) ◽  
pp. 4405-4412 ◽  
Author(s):  
Z. J. DING ◽  
X. D. TANG ◽  
H. M. LI

The full energy distribution of backscattered electrons from elastic peak down to true secondary electron peak has been calculated by a Monte-Carlo simulation method by including cascade secondary electrons production. The simulation method is based on the use of a dielectric function for describing electron inelastic scattering and secondary excitation, and the use of Mott cross section for electron elastic scattering. This calculation reproduces well the backscattering background observed in the direct mode of AES. The calculated absolute electron yields have been compared with the available experimental data. The simulation has indicated that, due to the effect of the elastic scattering differential cross section and detection solid angles, the shape of the energy distribution measured with a cylindrical mirror analyzer may differ from the overall energy spectrum of emitted electrons.


2001 ◽  
Vol 16 (supp01b) ◽  
pp. 715-717
Author(s):  
◽  
Mark S. Neubauer

The first solar neutrino observations from the Sudbury Neutrino Obervatory are presented. SNO is a water Cerenkov detector which uses heavy water (D2O) as both the interaction and detection medium. Based on the angular distribution of events with respect to the solar direction and the radial and energy distribution of events in the detector, it is concluded that data in the region of interest is dominated by 8 B solar neutrinos detected via the charged current and elastic scattering reactions.


1969 ◽  
Vol 22 (6) ◽  
pp. 663 ◽  
Author(s):  
GJ Clark ◽  
PB Treacy ◽  
SN Tucker

The {l-decay of 8B has been investigated by measuring the energy distribution of the <x-particles from subsequent breakup of 8Be. The data have been analysed, in conjunction with data from <X-o< elastic scattering, in a three-level R-matrix formalism. Consistent fits are obtained for a channel radius of 6�0�0�5 fm, and the existence of a broad 2+ state of 8Be near 12�0 MeV, of width 14 MeV, is confirmed.


Author(s):  
J. Langmore ◽  
M. Isaacson ◽  
J. Wall ◽  
A. V. Crewe

High resolution dark field microscopy is becoming an important tool for the investigation of unstained and specifically stained biological molecules. Of primary consideration to the microscopist is the interpretation of image Intensities and the effects of radiation damage to the specimen. Ignoring inelastic scattering, the image intensity is directly related to the collected elastic scattering cross section, σɳ, which is the product of the total elastic cross section, σ and the eficiency of the microscope system at imaging these electrons, η. The number of potentially bond damaging events resulting from the beam exposure required to reduce the effect of quantum noise in the image to a given level is proportional to 1/η. We wish to compare η in three dark field systems.


Author(s):  
D. L. Misell

In the electron microscopy of biological sections the adverse effect of chromatic aberration on image resolution is well known. In this paper calculations are presented for the inelastic and elastic image intensities using a wave-optical formulation. Quantitative estimates of the deterioration in image resolution as a result of chromatic aberration are presented as an alternative to geometric calculations. The predominance of inelastic scattering in the unstained biological and polymeric materials is shown by the inelastic to elastic ratio, I/E, within an objective aperture of 0.005 rad for amorphous carbon of a thickness, t=50nm, typical of biological sections; E=200keV, I/E=16.


Author(s):  
Yasushi Kokubo ◽  
Hirotami Koike ◽  
Teruo Someya

One of the advantages of scanning electron microscopy is the capability for processing the image contrast, i.e., the image processing technique. Crewe et al were the first to apply this technique to a field emission scanning microscope and show images of individual atoms. They obtained a contrast which depended exclusively on the atomic numbers of specimen elements (Zcontrast), by displaying the images treated with the intensity ratio of elastically scattered to inelastically scattered electrons. The elastic scattering electrons were extracted by a solid detector and inelastic scattering electrons by an energy analyzer. We noted, however, that there is a possibility of the same contrast being obtained only by using an annular-type solid detector consisting of multiple concentric detector elements.


Author(s):  
J. P. Langmore ◽  
N. R. Cozzarelli ◽  
A. V. Crewe

A system has been developed to allow highly specific derivatization of the thymine bases of DNA with mercurial compounds wich should be visible in the high resolution scanning electron microscope. Three problems must be completely solved before this staining system will be useful for base sequencing by electron microscopy: 1) the staining must be shown to be highly specific for one base, 2) the stained DNA must remain intact in a high vacuum on a thin support film suitable for microscopy, 3) the arrangement of heavy atoms on the DNA must be determined by the elastic scattering of electrons in the microscope without loss or large movement of heavy atoms.


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