MHD stability and disruptions in the SPARC tokamak
Artikel i vetenskaplig tidskrift, 2020

SPARC is being designed to operate with a normalized beta of beta(N) = 1.0, a normalized density of n(G) = 0.37 and a safety factor of q(95) approximate to 3.4, providing a comfortable margin to their respective disruption limits. Further, a low beta poloidal beta(p) = 0.19 at the safety factor q = 2 surface reduces the drive for neoclassical tearing modes, which together with a frozen-in classically stable current profile might allow access to a robustly tearing-free operating space. Although the inherent stability is expected to reduce the frequency of disruptions, the disruption loading is comparable to and in some cases higher than that of ITER. The machine is being designed to withstand the predicted unmitigated axisymmetric halo current forces up to 50 MN and similarly large loads from eddy currents forced to flow poloidally in the vacuum vessel. Runaway electron (RE) simulations using GO+CODE show high flattop-to-RE current conversions in the absence of seed losses, although NIMROD modelling predicts losses of similar to 80 %; self-consistent modelling is ongoing. A passive RE mitigation coil designed to drive stochastic RE losses is being considered and COMSOL modelling predicts peak normalized fields at the plasma of order 10(-2) that rises linearly with a change in the plasma current. Massive material injection is planned to reduce the disruption loading. A data-driven approach to predict an oncoming disruption and trigger mitigation is discussed.

fusion plasma

plasma instabilities

runaway electrons

Författare

R. Sweeney

Massachusetts Institute of Technology (MIT)

A. J. Creely

Commonwealth Fusion Systems

J. Doody

Massachusetts Institute of Technology (MIT)

Tünde Fülöp

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

D. T. Garnier

Massachusetts Institute of Technology (MIT)

R. Granetz

Massachusetts Institute of Technology (MIT)

M. Greenwald

Massachusetts Institute of Technology (MIT)

Linnea Hesslow

Chalmers, Fysik, Subatomär fysik och plasmafysik

J. Irby

Massachusetts Institute of Technology (MIT)

V. A. Izzo

Fiat Lux

R. J. La Haye

General Atomics

N. C. Logan

Princeton University

K. Montes

Massachusetts Institute of Technology (MIT)

C. Paz-Soldan

General Atomics

C. Rea

Massachusetts Institute of Technology (MIT)

R. A. Tinguely

Massachusetts Institute of Technology (MIT)

Oskar Vallhagen

Chalmers, Fysik, Subatomär fysik och plasmafysik

J. Zhu

Massachusetts Institute of Technology (MIT)

Journal of Plasma Physics

0022-3778 (ISSN) 1469-7807 (eISSN)

Vol. 86 5 865860507

Ämneskategorier

Rymd- och flygteknik

Farkostteknik

Fusion, plasma och rymdfysik

DOI

10.1017/S0022377820001129

Mer information

Senast uppdaterat

2020-11-05