Energy coupling among the degrees of freedom in an electron–positron plasma

Abstract

Abstract. Nonlinear coupling of the motion in the three spatial degrees of freedom of a cold fluid electron-positron plasma is investigated. Exact solutions describing expanding flows with oscillations are obtained. It is found that the energy in the irrotational flow component is in general transferred to the rotational components, but not in the reversed direction. Furthermore, since the density evolution need not be related to all the three flow components, oscillations in one or two of the flow fields can be purely electromagnetic and are not accompanied by density oscillations.

Coupled azimuthal modes propagating in current-carrying plasma waveguides

“…Studied power transfer between these modes is characterized only by nonlinear dependence upon small parameter of the problem, κ = B 0ϑ /B 0z Ӷ 1. As it was proved in [28], cylindrically symmetric nonlinear flows and oscillations in rotating and expanding electron-positron plasma also tended to concentrate their energy just into the azimuthal flow component. It was found in [27] that disturbances of azimuthal gaseous plasma flows didn't affect other components of the flow.…”

“…Thus, energy of azimuthal flow oscillations could not be converted into radial and axial degrees of freedom, but the energy of latter could be transferred into azimuthal component. As it was proved in [28], cylindrically symmetric nonlinear flows and oscillations in rotating and expanding electron-positron plasma also tended to concentrate their energy just into the azimuthal flow component. The results obtained in [27,28] can be applied for describing the experiments with rotating plasma in fusion devices, understanding solar dynamos, observing the plasma crystal formation, etc.…”

“…In spite of this fact, it is similar to such strongly nonlinear effect as coupled plasma flows studied in [27,28], which were studied numerically by the aid of choosing suitable spatial vari-ations for plasma particle velocities and electromagnetic fields without application of the method of successive approximations. Studied power transfer between these modes is characterized only by nonlinear dependence upon small parameter of the problem, κ = B 0ϑ /B 0z Ӷ 1.…”

“…In spite of this fact, it is similar to such strongly nonlinear effect as coupled plasma flows studied in [27,28], which were studied numerically by the aid of choosing suitable spatial vari-ations for plasma particle velocities and electromagnetic fields without application of the method of successive approximations. The results obtained in [27,28] can be applied for describing the experiments with rotating plasma in fusion devices, understanding solar dynamos, observing the plasma crystal formation, etc. Thus, energy of azimuthal flow oscillations could not be converted into radial and axial degrees of freedom, but the energy of latter could be transferred into azimuthal component.…”

“…Studied power transfer between these modes is characterized only by nonlinear dependence upon small parameter of the problem, κ = B 0ϑ /B 0z Ӷ 1. In spite of this fact, it is similar to such strongly nonlinear effect as coupled plasma flows studied in [27,28], which were studied numerically by the aid of choosing suitable spatial vari-ations for plasma particle velocities and electromagnetic fields without application of the method of successive approximations. It was found in [27] that disturbances of azimuthal gaseous plasma flows didn't affect other components of the flow.…”