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A study of some lattice defects with help of channeled {alpha} particles; Etude de quelques defauts cristallins a l'aide de particules {alpha} canalisees

Abstract

A method is described in which a metallic foil is irradiated by isotropic {alpha} particles. The thickness of the foil is such that only channeled particles can traverse it. The emerging flux, a function of the local concentration of defects, falls on a collector where an image of the foil is formed. The influence of grain or twin boundaries, of stacking faults, of dislocations, is observed. A quantitative study of dislocation is presented. The effect of a dislocation is represented by the presence of a coaxial dechanneling-cylinder of diameter: {lambda}-bar = [(b d a E)/({alpha}Z{sub 1}Z{sub 2}e{sup 2})]{sup 1/2}, b is the Burgers vector; d the interatomic distance along the channel; a the screening radius of the interaction between the particles (Z{sub 2}) and the metal (Z{sub 1} ); E the energy of the particles; {alpha} a numerical parameter. There is a reasonable agreement with experimental results. Channeling patterns, observed in all metals, are described. They are more numerous if the metal has been treated some time in gaseous atmospheres. They correspond to zones, on the metal, situated on the side of entrance of particles. It is proposed that in these zones, gaseous atoms strengthen the channels and enhance channeling.  More>>
Authors:
Quere, Y [1] 
  1. Commissariat a l'Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d'Etudes Nucleaires
Publication Date:
Jul 01, 1968
Product Type:
Thesis/Dissertation
Report Number:
CEA-R-3606
Resource Relation:
Other Information: TH: These ES-Sciences; 62 refs; PBD: Jul 1968
Subject:
36 MATERIALS SCIENCE; ALPHA PARTICLES; ALPHA SOURCES; ALUMINIUM; BURGERS VECTOR; CHANNELING; EDGE DISLOCATIONS; FOILS; GRAIN BOUNDARIES; IMAGES; INTERATOMIC DISTANCES; PARTICLE TRACKS; PHOTOMETRY; PHYSICAL RADIATION EFFECTS; QUENCHING; SCREW DISLOCATIONS; STACKING FAULTS; TEMPERATURE DEPENDENCE; TRIANGULAR CONFIGURATION
OSTI ID:
20523389
Research Organizations:
CEA Fontenay-aux-Roses, 92 (France); Faculte des Sciences d'Orsay, Universite de Paris, 91 (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR04R3606091444
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
[75] pages
Announcement Date:
Dec 10, 2004

Citation Formats

Quere, Y. A study of some lattice defects with help of channeled {alpha} particles; Etude de quelques defauts cristallins a l'aide de particules {alpha} canalisees. France: N. p., 1968. Web.
Quere, Y. A study of some lattice defects with help of channeled {alpha} particles; Etude de quelques defauts cristallins a l'aide de particules {alpha} canalisees. France.
Quere, Y. 1968. "A study of some lattice defects with help of channeled {alpha} particles; Etude de quelques defauts cristallins a l'aide de particules {alpha} canalisees." France.
@misc{etde_20523389,
title = {A study of some lattice defects with help of channeled {alpha} particles; Etude de quelques defauts cristallins a l'aide de particules {alpha} canalisees}
author = {Quere, Y}
abstractNote = {A method is described in which a metallic foil is irradiated by isotropic {alpha} particles. The thickness of the foil is such that only channeled particles can traverse it. The emerging flux, a function of the local concentration of defects, falls on a collector where an image of the foil is formed. The influence of grain or twin boundaries, of stacking faults, of dislocations, is observed. A quantitative study of dislocation is presented. The effect of a dislocation is represented by the presence of a coaxial dechanneling-cylinder of diameter: {lambda}-bar = [(b d a E)/({alpha}Z{sub 1}Z{sub 2}e{sup 2})]{sup 1/2}, b is the Burgers vector; d the interatomic distance along the channel; a the screening radius of the interaction between the particles (Z{sub 2}) and the metal (Z{sub 1} ); E the energy of the particles; {alpha} a numerical parameter. There is a reasonable agreement with experimental results. Channeling patterns, observed in all metals, are described. They are more numerous if the metal has been treated some time in gaseous atmospheres. They correspond to zones, on the metal, situated on the side of entrance of particles. It is proposed that in these zones, gaseous atoms strengthen the channels and enhance channeling. (author) [French] On decrit une methode qui consiste a irradier une feuille metallique par des particules {alpha} isotropes. La feuille est assez epaisse pour que seules les particules canalisees emergent. Le flux sortant depend alors fortement de la concentration en defauts. Il est recueilli sur un collecteur ou se forme ainsi une image de l'echantillon. On montre l'influence des joints de grains ou de macle, des fautes d'empilement et des dislocations. Dans ce dernier cas, la methode se prete bien a des etudes quantitatives. On represente l'effet d'une dislocation par la presence d'un cylindre de decanalisation coaxial de diametre: {lambda}-bar = [(b d a E)/({alpha}Z{sub 1}Z{sub 2}e{sup 2})]{sup 1/2} ou b est le vecteur de Burgers, d la distance interatomique du canal considere, a le rayon d'ecran d'interaction particule (Z{sub 2}) - noyau (Z{sub 1}), E l'energie des particules, {alpha} un parametre numerique. L'accord avec les resultats experimentaux, est raisonnable. On decrit les 'figures de canalisation' observees dans tous les metaux, figures geometriques d'autant plus nombreuses que le metal a ete traite plus longuement en atmosphere gazeuse. Ces figures correspondent a des zones situees sur la face d'entree des particules {alpha}. On propose que dans ces zones, les atomes gazeux dissous preferentiellement, renforcent les canaux et accentuent la canalisation. (auteur)}
place = {France}
year = {1968}
month = {Jul}
}