You need JavaScript to view this

Contribution to the experimental study of wave particle interactions in a plasma having a two-population electronic distribution function; Contribution a l'etude experimentale de l'interaction ondes-particules dans un plasma presentant une fonction de distribution electronique a deux populations

Abstract

The aim of this work is the experimental study of the interaction between electrostatic waves and electrons in a plasma characterized by a so called 'bump in tail' distribution function. To study experimentally the mechanism of this interaction it is necessary to measure precisely the electron distribution and its evolution in space or in time. This was performed with an electrostatic separation probe which was designed especially. We measured also the evolution in space and time of the noise spectrum. We studied this mechanism in two different regimes of our discharge: - In the first case the distribution function is very close to that describing the interaction of a semi-infinite plasma with a cold beam injected at its edge. We showed that the instability resulting from this interaction is convective and that the growth of the waves results in a very important modification of the distribution function. The ionization due to the electric field related to the waves is also important. This modification is similar to that described by the quasi linear theory. The mechanism described by this theory remains then qualitatively valid in a strongly non linear case. - In the second case the conditions necessary for the quasi  More>>
Authors:
Frank, R [1] 
  1. Commissariat a l'Energie Atomique, Saclay (France). Centre d'Etudes Nucleaires
Publication Date:
Jul 01, 1969
Product Type:
Thesis/Dissertation
Report Number:
CEA-R-3720
Resource Relation:
Other Information: TH: These ingenieur; PBD: 1969
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; BUMP-IN-TAIL INSTABILITY; DISTRIBUTION FUNCTIONS; ELECTROSTATIC PROBES; ELECTROSTATIC SEPARATION; PLASMA; PLASMA WAVES
OSTI ID:
20547219
Research Organizations:
CEA Saclay, 91 - Gif-sur-Yvette (France); Paris-11 Univ., Faculte des Sciences, 91 - Orsay (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR04R3720002826
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
[72] pages
Announcement Date:
Feb 01, 2005

Citation Formats

Frank, R. Contribution to the experimental study of wave particle interactions in a plasma having a two-population electronic distribution function; Contribution a l'etude experimentale de l'interaction ondes-particules dans un plasma presentant une fonction de distribution electronique a deux populations. France: N. p., 1969. Web.
Frank, R. Contribution to the experimental study of wave particle interactions in a plasma having a two-population electronic distribution function; Contribution a l'etude experimentale de l'interaction ondes-particules dans un plasma presentant une fonction de distribution electronique a deux populations. France.
Frank, R. 1969. "Contribution to the experimental study of wave particle interactions in a plasma having a two-population electronic distribution function; Contribution a l'etude experimentale de l'interaction ondes-particules dans un plasma presentant une fonction de distribution electronique a deux populations." France.
@misc{etde_20547219,
title = {Contribution to the experimental study of wave particle interactions in a plasma having a two-population electronic distribution function; Contribution a l'etude experimentale de l'interaction ondes-particules dans un plasma presentant une fonction de distribution electronique a deux populations}
author = {Frank, R}
abstractNote = {The aim of this work is the experimental study of the interaction between electrostatic waves and electrons in a plasma characterized by a so called 'bump in tail' distribution function. To study experimentally the mechanism of this interaction it is necessary to measure precisely the electron distribution and its evolution in space or in time. This was performed with an electrostatic separation probe which was designed especially. We measured also the evolution in space and time of the noise spectrum. We studied this mechanism in two different regimes of our discharge: - In the first case the distribution function is very close to that describing the interaction of a semi-infinite plasma with a cold beam injected at its edge. We showed that the instability resulting from this interaction is convective and that the growth of the waves results in a very important modification of the distribution function. The ionization due to the electric field related to the waves is also important. This modification is similar to that described by the quasi linear theory. The mechanism described by this theory remains then qualitatively valid in a strongly non linear case. - In the second case the conditions necessary for the quasi linear theory to be valid are satisfactorily fulfilled. It is then possible to measure, simultaneously, and precisely, the evolution of the distribution function and of the noise spectrum. From these measurements one can deduce the mechanism of the energy exchange between waves and particles and show that it is in good agreement with that described by the quasi linear theory. (author) [French] On presente ici l'etude experimentale detaillee du mecanisme de l'echange d'energie entre les oscillations e la frequence plasma des electrons et des electrons energetiques dans un plasma presentant une fonction de distribution du type a 'double bosse'. Pour realiser cette etude on a mis au point, une 'sonde a separation electrostatique' qui permet de mesurer avec precision la fonction de distribution en energie des electrons et son evolution dans l'espace ou dans le temps. On a pu ainsi, dans un plasma d'hydrogene cree dans une decharge a cathode chaude, etudier le mecanisme de l'interaction entre les ondes et les particules dans deux cas: - dans le premier cas, les conditions necessaires pour l'application de la theorie quasi lineaire sont sensiblement verifiees. On a pu dans ce cas suivre avec precision le developpement de l'instabilite et la deformation de la fonction de distribution qui en resulte. On a montre que dans ce cas le mecanisme decrit par la theorie quasi lineaire etait qualitativement et quantitativement verifie; - dans le second cas, l'interaction entre les ondes et les electrons est beaucoup plus forte que celle qui est decrite par la theorie quasi lineaire et se traduit en particulier par une ionisation assez importante du gaz neutre. On a pu montrer cependant que dans ce cas encore le mecanisme decrit par la theorie quasi lineaire reste qualitativement valable. (auteur)}
place = {France}
year = {1969}
month = {Jul}
}