Author: Ohjin J. KwonPublisher:
ISBN:
Category : Nuclear fusion
Languages : en
Pages : 13
Book Description
Stability Analysis of High Beta Plasmas in JET
Author: Ohjin J. KwonPublisher:
ISBN:
Category : Nuclear fusion
Languages : en
Pages : 13
Book Description
Stability Analysis for Resistive Interchange Instability of High Beta Plasma
Author: Benjamin M. MaMHD stability analysis of high-#beta# JET discharges
Author: G. T. A. HuysmansPublisher:
ISBN:
Category : Plasma (Ionized gases)
Languages : en
Pages : 3
Book Description
High-beta Stability Studies of Jet Discharges with the Numerical Program HBT
Author: G.T.A. HuysmansHigh Beta and Second Stability Region Transport and Stability Analysis. Final Report
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 90
Book Description
This report describes ideal and resistive studies of high-beta plasmas and of the second stability region. Emphasis is focused on s̀̀upershot ̀̀plasmas in TFIR where MHD instabilities are frequently observed and which spoil their confinement properties. Substantial results are described from the analysis of these high beta poloidal plasmas. During these studies, initial pressure and safety factor profiles were obtained from the TRANSP code, which is used extensively to analyze experimental data. Resistive MBD stability studies of supershot equilibria show that finite pressure stabilization of tearing modes is very strong in these high?p plasmas. This has prompted a detailed re-examination of linear tearing mode theory in which we participated in collaboration with Columbia University and General Atomics. This finite pressure effect is shown to be highly sensitive to small scale details of the pressure profile. Even when an ad hoc method of removing this stabilizing mechanism is implemented, however, it is shown that there is only superficial agreement between resistive MBD stability computation and the experimental data. While the mode structures observed experimentally can be found computationally, there is no convincing correlation with the experimental observations when the computed results are compared with a large set of supershot data. We also describe both the ideal and resistive stability properties of TFIR equilibria near the transition to the second region. It is shown that the highest? plasmas, although stable to infinite-n ideal ballooning modes, can be unstable to the so called ì̀nfernal ̀̀modes associated with small shear. The sensitivity of these results to the assumed pressure and current density profiles is discussed. Finally, we describe results from two collaborative studies with PPPL. The first involves exploratory studies of the role of the 1/1 mode in tokamaks and, secondly, a study of sawtooth stabilization using ICRF.
Shear-Ballooning Stability Analysis of Low-Beta Plasmas
Author: Shoichi YoshikawaHigh Beta and Second Stability Region Transport and Stability Analysis
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 90
Book Description
This report describes ideal and resistive studies of high-beta plasmas and of the second stability region. Emphasis is focused on supershot'' plasmas in TFIR where MHD instabilities are frequently observed and which spoil their confinement properties. Substantial results are described from the analysis of these high beta poloidal plasmas. During these studies, initial pressure and safety factor profiles were obtained from the TRANSP code, which is used extensively to analyze experimental data. Resistive MBD stability studies of supershot equilibria show that finite pressure stabilization of tearing modes is very strong in these high [beta]p plasmas. This has prompted a detailed re-examination of linear tearing mode theory in which we participated in collaboration with Columbia University and General Atomics. This finite pressure effect is shown to be highly sensitive to small scale details of the pressure profile. Even when an ad hoc method of removing this stabilizing mechanism is implemented, however, it is shown that there is only superficial agreement between resistive MBD stability computation and the experimental data. While the mode structures observed experimentally can be found computationally, there is no convincing correlation with the experimental observations when the computed results are compared with a large set of supershot data. We also describe both the ideal and resistive stability properties of TFIR equilibria near the transition to the second region. It is shown that the highest [beta] plasmas, although stable to infinite-n ideal ballooning modes, can be unstable to the so called infernal'' modes associated with small shear. The sensitivity of these results to the assumed pressure and current density profiles is discussed. Finally, we describe results from two collaborative studies with PPPL. The first involves exploratory studies of the role of the 1/1 mode in tokamaks and, secondly, a study of sawtooth stabilization using ICRF.
Scientific and Technical Aerospace Reports
Author: Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 380
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Determination of Plasma Stability Using Resonant Field Amplification in JET
Author: M. P. GryaznevichPublisher:
ISBN:
Category : Plasma stability
Languages : en
Pages : 9
Book Description
"The Resonant Field Amplification has been systematically measured on JET using active MHD spectroscopy to probe plasma stability at high and low beta and compared with theoretical predictions. At high beta, RFA has been used to identify the ideal no-wall beta limit in several advanced regimes: the hybrid regime, with low magnetic shear and q(0) close to 1, and high beta plasmas being developed for steady-state application, with low or reversed magnetic shear and 1.0
Author: