You need JavaScript to view this

Results obtained from the 'Bille en tete A' Experiment. Part 1. Collisions in homogeneous magnetic field. Part 2. Collisions in magnetic mirror bottle; Resultats experimentaux sur bille en tete 'A'. Partie I: Collisions en champ magnetique homogene. Partie II: Collisions en bouteille magnetique a miroir

Abstract

Collisions of plasma puffs, whose characteristics (density and velocity) were varied in a broad domain are studied in a homogeneous longitudinal magnetic field. It has been verified that the puffs meet head on. We show that collisions of dense (n{sub i} {>=} 4.10{sup 14} cm{sup -3}) and relatively slow (V{sub 0} {<=} 10{sup 7} cm. s) puffs are 'efficient', i.e. the initial kinetic energies of the puffs are converted into thermal energy of the ions in the resulting plasma. Faster and less dense puffs interact little: incomplete conversion of kinetic into thermal energy. The limit between efficient and inefficient collisions corresponds to that which is expected from the test particle model. The slowing down of our puffs is thus ensured mainly by particle-particle interactions. The use of electric probes and the examination of the evolution of the plasma produced by the collision show that this plasma does not exhibit any rapid radial-motion. In the magnetic bottle of Bille-en-tete A (mirror ratio 4000/2000- G), the collision of two low density puffs leads to the capture of one liter of plasma with a density n{sub i} {approx} 2,10{sup 13} cm{sup -3} and an ionic temperature T{sub i} {approx} 10{sup 6}. The e-folding  More>>
Publication Date:
Jul 01, 1966
Product Type:
Technical Report
Report Number:
CEA-R-3000
Resource Relation:
Other Information: 21 refs; PBD: 1966
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANISOTROPY; ELECTRON-ION COLLISIONS; ION-ION COLLISIONS; KINETIC ENERGY; MAGNETIC FIELD CONFIGURATIONS; PLASMA; THERMAL CONDUCTIVITY
OSTI ID:
20468546
Research Organizations:
Commissariat a l'Energie Atomique, Centre d'Etudes Nucleaires de Fontenay-aux-Roses, 92 (France)
Country of Origin:
France
Language:
French
Other Identifying Numbers:
TRN: FR04R3000044256
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
[107] pages
Announcement Date:

Citation Formats

Evrard, P, Jacquinot, J, Leloup, C, Poffe, J -P, and Waelbroeck, F. Results obtained from the 'Bille en tete A' Experiment. Part 1. Collisions in homogeneous magnetic field. Part 2. Collisions in magnetic mirror bottle; Resultats experimentaux sur bille en tete 'A'. Partie I: Collisions en champ magnetique homogene. Partie II: Collisions en bouteille magnetique a miroir. France: N. p., 1966. Web.
Evrard, P, Jacquinot, J, Leloup, C, Poffe, J -P, & Waelbroeck, F. Results obtained from the 'Bille en tete A' Experiment. Part 1. Collisions in homogeneous magnetic field. Part 2. Collisions in magnetic mirror bottle; Resultats experimentaux sur bille en tete 'A'. Partie I: Collisions en champ magnetique homogene. Partie II: Collisions en bouteille magnetique a miroir. France.
Evrard, P, Jacquinot, J, Leloup, C, Poffe, J -P, and Waelbroeck, F. 1966. "Results obtained from the 'Bille en tete A' Experiment. Part 1. Collisions in homogeneous magnetic field. Part 2. Collisions in magnetic mirror bottle; Resultats experimentaux sur bille en tete 'A'. Partie I: Collisions en champ magnetique homogene. Partie II: Collisions en bouteille magnetique a miroir." France.
@misc{etde_20468546,
title = {Results obtained from the 'Bille en tete A' Experiment. Part 1. Collisions in homogeneous magnetic field. Part 2. Collisions in magnetic mirror bottle; Resultats experimentaux sur bille en tete 'A'. Partie I: Collisions en champ magnetique homogene. Partie II: Collisions en bouteille magnetique a miroir}
author = {Evrard, P, Jacquinot, J, Leloup, C, Poffe, J -P, and Waelbroeck, F}
abstractNote = {Collisions of plasma puffs, whose characteristics (density and velocity) were varied in a broad domain are studied in a homogeneous longitudinal magnetic field. It has been verified that the puffs meet head on. We show that collisions of dense (n{sub i} {>=} 4.10{sup 14} cm{sup -3}) and relatively slow (V{sub 0} {<=} 10{sup 7} cm. s) puffs are 'efficient', i.e. the initial kinetic energies of the puffs are converted into thermal energy of the ions in the resulting plasma. Faster and less dense puffs interact little: incomplete conversion of kinetic into thermal energy. The limit between efficient and inefficient collisions corresponds to that which is expected from the test particle model. The slowing down of our puffs is thus ensured mainly by particle-particle interactions. The use of electric probes and the examination of the evolution of the plasma produced by the collision show that this plasma does not exhibit any rapid radial-motion. In the magnetic bottle of Bille-en-tete A (mirror ratio 4000/2000- G), the collision of two low density puffs leads to the capture of one liter of plasma with a density n{sub i} {approx} 2,10{sup 13} cm{sup -3} and an ionic temperature T{sub i} {approx} 10{sup 6}. The e-folding time of the plasma diamagnetism reaches 50 to 150 {mu}s; no flute instabilities are detected. The T{sub i} evolution was measured by the Doppler broadening of the 4680 angstrom line of the He{sup +} (added to the injected D{sup +} in the proportion of 5 per cent and the relative evolution of n{sub i} by the intensity of the spectral continuum. T{sub i} decreases rapidly, reaches 5.10{sup 5} to 10{sup 5} deg. K respectively 15 and 120 {mu}s after the maximum of the collision diamagnetic signal. n{sub i} increases slowly, 25 per cent during the first 100 {mu}s after the collision. The presence of cold plasma beyond the mirrors of the bottles allows one to justify the energy losses (thermal conductivity) and the apparent stability of the plasma column. (authors) [French] Partie I: Collisions en champ magnetique homogene. Nous etudions, dans un champ magnetique longitudinal et uniforme, la collision de bouffees de plasma dont les caracteristiques de vitesse et de densite couvrent un large domaine. Apres avoir verifie que les bouffees se rencontrent de plein fouet, nous montrons que les collisions de bouffees denses (n{sub i} >= 4.10{sup 14} cm{sup -3}) et relativement lentes (V{sub 0} <= 10{sup 7} cm.s{sup -1}) sont efficaces et qu'on retrouve pratiquement toute l'energie cinetique initiale des bouffees en energie thermique ionique du plasma arrete. Les bouffees plus rapides et moins denses interagissent peu: conversion incomplete d'energie cinetique en energie thermique. La limite entre collisions efficaces et inefficaces correspond a celle qu'on attend en utilisant le modele des particules temoins. Ce sont donc les collisions entre particules qui assurent le freinage des bouffees. L'emploi des sondes electriques et l'etude de l'evolution du plasma forme par collision montrent que ce dernier ne manifeste pas de mouvements radiaux importants. Partie II: Collisions en bouteille magnetique a miroir. Dans la bouteille magnetique de Bille-en-Tete A (B{sub c}entre = 2000 G, R = 2), la collision de 2 bouffees peu denses a permis de pieger un litre de plasma dont la densite n{sub i} vaut 2.10{sup 13} cm{sup -3} et la temperature ionique Ti = 106 K. Le diamagnetisme de ce plasma persiste pendant 50 a 150 {mu}s et on ne decele pas d'instabilites en flutes. L'evolution de T{sub i} a ete mesuree par effet Doppler sur la raie 4686 Angstrom de He'+ (melange a 5 pour cent au D{sup +} injecte) et l'evolution relative de n{sub i} par l'intensite du fond continu spectral T{sub i} decroit rapidement, atteint 5.10'5 et 10'5 K, respectivement 15 et 120 {mu}s apres le maximum du signal diamagnetique de la collision. n{sub i} croit lentement de 25 pour cent pendant les 100 premieres {mu}s apres la collision. La presence de plasma froid exterieur, mais proche des extremites de la bouteille, permet de justifier les pertes d'energie par conductibilite thermique et l'apparente stabilite de la colonne. (auteurs)}
place = {France}
year = {1966}
month = {Jul}
}