자료유형  

 학위논문

Control Number  

0016933359

International Standard Book Number  

9798379793159

Dewey Decimal Classification Number  

530

Main Entry-Personal Name  

Saperstein, Alex R. .

Publication, Distribution, etc. (Imprint  

[S.l.] : Columbia University., 2023

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2023

Physical Description  

1 online resource(183 p.)

General Note  

Source: Dissertations Abstracts International, Volume: 85-01, Section: B.

General Note  

Advisor: Mauel, Michael.

Dissertation Note  

Thesis (Ph.D.)--Columbia University, 2023.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Summary, Etc.  

요약Halo currents (HCs) in post-disruption plasmas can be large enough to exert significant electromagnetic loads on structures surrounding the plasma. These currents have axisymmetric and non-axisymmetric components, both of which pose threats to the vacuum vessel and other components. However, the non-axisymmetric forces can rotate, amplifying the displacements they cause when the rotation is close to the structures' resonant frequencies. A new physically motivated scaling law has been developed that describes the rotation frequencies of these HCs and has been validated against measurements on HBT-EP, Alcator C-Mod, and other tokamaks [1, 2]. This scaling law can describe the time-evolution of the asymmetric HC rotation throughout disruptions on HBT-EP as well as the time-averaged rotation on C-Mod. The scaling law can also be modified to include the edge safety factor at the onset of rotation (qonset), which significantly improves its validity when applied to machines like C-Mod, where qonset changes frequently. The qonset dependence is explained by the relationship between the poloidal structure of the HC asymmetries and the MHD instabilities that drive them, which has been observed experimentally for the first time using a novel set of current sensing limiter tiles installed on HBT-EP. The 1/a2 and qonset-dependence of the rotation suggest that the HCs predominantly rotate poloidally. This remains consistent with the toroidal rotation observed on HBT-EP and other tokamaks through the "Barber Pole Illusion" and the direction of rotation's dependence on the direction of Ip. This scaling law is used to make projections for next generation tokamaks like ITER and SPARC, which predicts that rotation will be resonant on ITER. However, resonant effects can still be avoided if the duration of the disruption is kept short enough to prevent two rotations from being completed [3].

Subject Added Entry-Topical Term  

Plasma physics.

Subject Added Entry-Topical Term  

Electromagnetics.

Index Term-Uncontrolled  

Fusion

Index Term-Uncontrolled  

Halo currents

Index Term-Uncontrolled  

Tokamaks

Index Term-Uncontrolled  

Non-axisymmetric components

Index Term-Uncontrolled  

Vacuum vessel

Added Entry-Corporate Name  

Columbia University Applied Physics

Host Item Entry  

Dissertations Abstracts International. 85-01B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

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Control Number  

joongbu:640077