Kinetic effects in the propagation of ion-acoustic negative solitons in plasmas with negative ions
Description
The existence of ion-acoustic negative (rarefactive) solitons in plasmas was experimentally verified and explained by means of the Korteweg-de Vries equation, obtained from a fluid model. The experimental results obtained in a double-plasma machine of the Institute for Space Research, however, have provided values of Mach number larger than predicted by this simple model. In order to improve the analysis of the phenomenon, Kinetic effects resultant from the occurrence of reflected electrons and trapped ions in the soliton potential were considered, using the theory of Sagdeev potential. For the description of the negative ion dynamics the fluid model treatment was preserved. It was verified that the effects of the finite temperature and trapping of the positive ions modify the results predicted by the simple KdV model in such a way that the Mach number is reduced as the ion temperature increases. It was shown that reflection of electrons is consistent with the large experimental values of Mach number. (Author)
Availability note (English)
MF available from INIS under the Report Number.Abstract (Portuguese)
A existencia de solitons acusticos-ionicos negativos (rarefativos) em plasmas com ions negativos foi verificada experimentalmente e, explicada atraves da equacao simples de Korteweg-de Vries, obtida do modelo de fluidos. Os resultados experimentais obtidos na maquina de plasma duplo do Instituto de Pesquisas Espaciais, porem, forneceram valores de numero de Mach muito maiores do que os previstos por este modelo. Para melhorar a analise do fenomeno foram considerados os efeitos cineticos que resultam da ocorrencia de eletrons refletidos e ions positivos aprisionados no potencial do soliton, usando a teoria do potencial de Sagdeev. Para a descricao da dinamica do ions negativos foi mantido o modelo de fluidos. Verificou-se que os efeitos de temperatura finita e aprisionamento de ions positivos modificam os resultados previstos pelo modelo simples de KdV no sentido de diminuir o numero de Mach a medida que aumenta a temperatura. Foi mostrado que a reflexao de eletrons e compativel com os altos valores encontrados para o numero de Mach no experimento realizado na maquina de plasma duplo do Instituto de Pesquisas Espaciais. (Autor)Files
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Additional details
Additional titles
- Original title (Portuguese)
- Efeitos cineticos na propagacao de solitons acustico-ionicos negativos em plasmas com ions negativos
Publishing Information
- Imprint Pagination
- 174 p.
- Report number
- INPE--4092
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 18075027
- Subject category
- S70: PLASMA PHYSICS AND FUSION TECHNOLOGY; S70: PLASMA PHYSICS AND FUSION TECHNOLOGY;
- Descriptors DEI
- ANIONS; COMPUTER CALCULATIONS; ION ACOUSTIC WAVES; ION TEMPERATURE; KINETIC EQUATIONS; KORTEWEG-DE VRIES EQUATION; MACH NUMBER; PLASMA; PLASMA SIMULATION; SOLITONS
- Descriptors DEC
- CHARGED PARTICLES; DIFFERENTIAL EQUATIONS; EQUATIONS; ION WAVES; IONS; PARTIAL DIFFERENTIAL EQUATIONS; PLASMA WAVES; QUASI PARTICLES; SIMULATION; VELOCITY