Development of theory of reversed-shear alfven eigenmodes in tokamaks

Konovalov, S. V.; Mikhailovskii, A.*; Kovalishen, E.*; Ozeki, Takahisa; Takizuka, Tomonori; Shirokov, M. S.*

Proceedings of 20th IAEA Fusion Energy Conference (FEC 2004) (CD-ROM), 8 Pages, 2004/00

http://www-naweb.iaea.org/napc/physics/fec/fec2004/datasets/TH_P5-10.html

Alfven eigenmodes in tokamaks with reversed magnetic shear are studied theoretically by incorporating into the mode description the effects known theories of Global, Kinetic and Toroidal Alfven Eigenmodes. In particular mode forming effect due to thermal plasma density gradient is examined. Criteria of the fast ion density and its gradient on the existence of a localized solution of the eigenmode equation is softened by this effect. Effects of finite Larmor radius, continuum damping and fast ion density gradient are also studied.

Stability of toroidal Alfven eigenmode in JT-60 super upgrade

Ozeki, Takahisa; C.Z.Cheng*; Nagashima, Keisuke

JAERI-Research 95-065, 22 Pages, 1995/10

JAERI-Research-95-065.pdf:0.75MB

no abstracts in English

Detail measurement on non-Kitaev term spin dynamics in -RuCl

Nakajima, Kenji; Kojima, Yuki*; Kurita, Nubuyuki*; Tanaka, Hidekazu*

no journal, , 

Kitaev model is an exactly solvable model which has a quantum spin liquid state as the ground state. In Kitaev model, S=1/2 spins arranged on a honeycomb lattice are connected via three non-equivalent bonds with Ising-type interactions. -RuCl has been considered to be an excellent candidate of a Kitaev material. On the other hand, as a real material, the system has deviations from the ideal Kitaev model. The interaction between spins has non-Kitaev (Heisenberg) term as well as Kitaev one, which makes the exact ground state of -RuCl rather difficult to understand. We have studied spin dynamics in -RuCl by means of neutron scattering technique especially in low temperature and relatively lower energy range to obtained the detail picture of the ground state spin dynamics in this system, in which the non-Kitaev term highly contributes. Detail of our results and analysis will be shown in our presentation.