Author: A. TakahashiPublisher:
ISBN:
Category : Magnetohydrodynamic instabilities
Languages : en
Pages : 29
Book Description
Observation of SOL Current Correlated with MHD Activity in NBI-heated DIII-D Tokamak Discharges
Author: A. TakahashiPublisher:
ISBN:
Category : Magnetohydrodynamic instabilities
Languages : en
Pages : 29
Book Description
Observation of SOL Current Correlated with MHD Activity in NBI-heated DIII-D Tokamak Discharges
Author: A. TakahashiPublisher:
ISBN:
Category : Magnetohydrodynamic instabilities
Languages : en
Pages : 29
Book Description
Advanced Tokamak Stability Theory
Author: Linjin ZhengPublisher: Morgan & Claypool Publishers
ISBN: 1627057072
Category : Science
Languages : en
Pages : 178
Book Description
This book describes the advanced stability theories for magnetically confined fusion plasmas, especially in tokamaks. As the fusion plasma sciences advance, the gap between the textbooks and cutting-edge researches gradually develops. This book fills in
Fusión Nuclear
Author: Observation of Abrupt- and Fast-rising SOL Current During Trigger Phase of ELMs in DIII-D Tokamak
Author: Hironori TakahashiPublisher:
ISBN:
Category : Tokamaks
Languages : en
Pages : 8
Book Description
Observation of Abrupt- and Fast-rising SOL Current During Trigger Phase of ELMs in DIII-D Tokamak
Author: Hironori TakahashiPublisher:
ISBN:
Category : Tokamaks
Languages : en
Pages : 8
Book Description
Energy Research Abstracts
Author: Simulation of Enhanced Tokamak Performance on DIII-D Using Fast Wave Current Drive
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 4
Book Description
The fast magnetosonic wave is now recognized to be a leading candidate for noninductive for the tokamak reactor due to the ability of the wave to penetrate to the hot dense core region. Fast wave current drive (FWCD) experiments on D3D have realized up to 120 kA of rf current drive, with up to 40% of the plasma current driven noninductively. The success of these experiments at 60 MHZ with a 2 MW transmitter source capability has led to a major upgrade of the FWCD system. Two additional transmitters, 30 to 120 NM, with a 2 MW source capability each, will be added together with two new four-strap antennas in early 1994. Another major thrust of the D3-D program is to develop advanced tokamak modes of operation, simultaneously demonstrating improvements in confinement and stability in quasi-steady-state operation. In some of the initial advanced tokamak experiments on D3-D with neutral beam heated (NBI) discharges it has been demonstrated that energy confinement nine can be improved by rapidly elongating the plasma to force the current density profile to be more centrally peaked. However, this high-l[sub i] phase of the discharge with the commensurate improvement in confinement is transient as the current density profile relaxes. By applying FWCD to the core of such a [kappa]-ramped discharge it may be possible to sustain the high internal inductance and elevated confinement. Using computational tools validated on the initial DM-D FWCD experiments we find that such a high-l[sub i] advanced tokamak discharge should be capable of sustainment at the 1 MA level with the upgraded capability of the FWCD system.
Progress Towards Sustainment of Internal Transport Barriers in DIII-D.
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Neutral beam heated discharges with internal transport barriers (ITB) have been observed in most of the world's major tokamaks including DIII-D, TFTR, JT-60U and JET. Improved core confinement has been observed over a range of q profiles, including negative central magnetic shear (NCS) and weak positive shear. In discharges with an L-mode edge, the duration of ITBs is generally limited to a few energy confinement times ([tau][sub e]) by low-n MHD activity driven by the steep core pressure gradient or by q[sub min] passing through low-order rational values. In order for ITBs to be useful in achieving a more compact advanced tokamak, the radius of the ITB must be expanded and the pressure gradient must be controlled in order to optimize[beta][sub N] and the bootstrap alignment. In this paper, the authors discuss the results of recent experiments on DIII-D to produce and sustain ITBs for longer pulse lengths. Three techniques are evaluated: (1) reduction of neutral beam power (P[sub NBI]) and plasma current to form a weaker ITB which can be sustained; (2) use of an ELMing H-mode edge to help broaden the pressure profile and improve MHD instability; (3) modification of the plasma shape (squareness) to achieve smaller ELMs with a lower density pedestal at the edge.
Author: