抄録
Offer Organization: Japan Society for the Promotion of Science, System Name: Grants-in-Aid for Scientific Research, Category: Grant-in-Aid for Scientific Research (S), Fund Type: -, Overall Grant Amount: - (direct: 60800000, indirect: 18240000)
We have studied the self-organization mechanism in flowing plasmas to explore the diversity of structures created in space and astronomical systems, and also examined the applicability of the high-beta equilibrium for advanced-fusion concept.
1.Results of Theoretical Studies
We have developed some innovative methods for the analysis of equilibria and stability of flowing plasmas. Unlike the conventional theories of stationary (non-flowing) plasmas, the analysis of flowing plasmas may not invoke the well-known methods of spectral decomposition or energy principle. Analyzing the topological singularities of the non-canonical Hamiltonian formalisms, we have succeeded to characterize the basic vertical structures of flow-field coupling in terms of Casimir invariants (helicities). The corresponding variational principle yields a Lyapunov function, whose coercivity warrants the stability of the "Beltrami fields", the minimizer of the variational principle. The theory has been applied to explain the structural instabilities in solar corona, high-beta equilibria in Jupiter's magnetosphere, as well as new-type of flowing equilibria in Proto-RT and RT-1 devices.
2.Results of Experimental Studies
We have demonstrated stable formation of super-sonic (Mach number > 5) rotating plasma in the Proto-RT Device. The Proto-RT device can confine a non-neutral (pure electron) plasma in a "magnetosphere-like" configuration. A non-neutral plasma produces a flowing (spinning) equilibrium by its self-electric field. By applying an internal electric field in a quasi-neutral plasma, we can achieve a similar flowing plasma. We have established a unified understanding of non-neutral and flowing plasmas : (1)We have demonstrated stable confinement of non-neutral plasma in a magnetic-surface configuration,; (2)By applying a radial electric field, we have demonstrated the self-organization of stable super-sonic flowing plasma ; (3)We have demonstrated the production of a new branch of equilibrium by the effect of fast flow ; (4)We have developed new technologies to construct magnetosphere-like plasma confinement device.