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Coupled Tearing-Kink Modes and Their Interactions With the Sawtooth Crash in HBT-EP
Coupled Tearing-Kink Modes and Their Interactions With the Sawtooth Crash in HBT-EP
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211153029
- ISBN
- 9798346764830
- DDC
- 530
- 서명/저자
- Coupled Tearing-Kink Modes and Their Interactions With the Sawtooth Crash in HBT-EP
- 발행사항
- [Sl] : Columbia University, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 171 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-06, Section: B.
- 주기사항
- Advisor: Mauel, Michael.
- 학위논문주기
- Thesis (Ph.D.)--Columbia University, 2024.
- 초록/해제
- 요약This thesis reports observations of kink and tearing modes in the High Beta Tokamak - Extended Pulse (HBT-EP) experiment. When unstable, these modes could limit the operation of tokamaks used for fusion power by terminating the plasma discharge and causing rapid loss of plasma energy. The aim of this work is to characterize the sudden transition after a sawtooth crash of coupled 2/1-3/1 tearing-kink modes into a sustained and disruptive 2/1 tearing mode. The following diagnostic techniques are used. Kink and tearing modes in HBT-EP distort the plasma edge, measured by a large array of Mirnov sensors, and perturb the interior of the plasma, observed routinely with Extreme Ultraviolet (EUV) detector arrays. Two arrays, with different transmission filters, are located with tangential views to estimate the time evolution of the plasma temperature profile. Four EUV arrays, with 16 detectors each, are positioned with different poloidal views for poloidal Extreme Ultraviolet (pEUV) emission tomography. The 2D emissive structures producing the pEUV signals are reconstructed with tomographic inversion using a pixel basis and fixed weighting smoothness regularization. Spatial and temporal correlations across these independent diagnostics are used to measure the evolution and structure of coupled modes using a technique called multi diagnostic Singular Value Decomposition (mdSVD). In mdSVD, orthogonal modes are identified within any fixed time window with their unique spatial and temporal characteristics. The technique uncovers: coherent behavior of coupled (\uD835\uDC5A/\uD835\uDC5B) = (2/1) and (3/1) tearing-kink modes and rapid changes in plasma structure associated with sawtooth crashes which trigger disruptive and nondisruptive tearing modes. HBT-EP's unique radially movable wall is found to significantly influence sawtooth triggering of disruptive tearing modes. The onset of sawtooth-triggered modes depends both on the plasma-wall separation, or wall coupling, and on the value of edge safety factor qa. We confirm that the condition for sawtooth triggering of disruptive (\uD835\uDC5A/\uD835\uDC5B) = (2/1) tearing modes does not correspond to the mode's single-helicity stability condition Δ'2/1. We identify a dependency of the sawtooth period \uD835\uDF0F\uD835\uDC60\uD835\uDC61 on the wall position and qa as a candidate to explain the onset of the saturated tearing mode. This thesis motivates future efforts to model the influence of a nearby resistive wall on sawtooth triggering of tearing modes.
- 일반주제명
- Plasma physics
- 일반주제명
- Electromagnetics
- 일반주제명
- Physics
- 키워드
- Disruption
- 키워드
- Fusion
- 키워드
- Kink mode
- 키워드
- Sawtooth crash
- 키워드
- Tearing mode
- 키워드
- Tokamak
- 기타저자
- Columbia University Applied Physics
- 기본자료저록
- Dissertations Abstracts International. 86-06B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520250211153029
■006m o d
■007cr#unu||||||||
■020 ▼a9798346764830
■035 ▼a(MiAaPQ)AAI31635020
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a530
■1001 ▼aChandra, Rian Naveen Blewett.
■24510▼aCoupled Tearing-Kink Modes and Their Interactions With the Sawtooth Crash in HBT-EP
■260 ▼a[Sl]▼bColumbia University▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a171 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-06, Section: B.
■500 ▼aAdvisor: Mauel, Michael.
■5021 ▼aThesis (Ph.D.)--Columbia University, 2024.
■520 ▼aThis thesis reports observations of kink and tearing modes in the High Beta Tokamak - Extended Pulse (HBT-EP) experiment. When unstable, these modes could limit the operation of tokamaks used for fusion power by terminating the plasma discharge and causing rapid loss of plasma energy. The aim of this work is to characterize the sudden transition after a sawtooth crash of coupled 2/1-3/1 tearing-kink modes into a sustained and disruptive 2/1 tearing mode. The following diagnostic techniques are used. Kink and tearing modes in HBT-EP distort the plasma edge, measured by a large array of Mirnov sensors, and perturb the interior of the plasma, observed routinely with Extreme Ultraviolet (EUV) detector arrays. Two arrays, with different transmission filters, are located with tangential views to estimate the time evolution of the plasma temperature profile. Four EUV arrays, with 16 detectors each, are positioned with different poloidal views for poloidal Extreme Ultraviolet (pEUV) emission tomography. The 2D emissive structures producing the pEUV signals are reconstructed with tomographic inversion using a pixel basis and fixed weighting smoothness regularization. Spatial and temporal correlations across these independent diagnostics are used to measure the evolution and structure of coupled modes using a technique called multi diagnostic Singular Value Decomposition (mdSVD). In mdSVD, orthogonal modes are identified within any fixed time window with their unique spatial and temporal characteristics. The technique uncovers: coherent behavior of coupled (\uD835\uDC5A/\uD835\uDC5B) = (2/1) and (3/1) tearing-kink modes and rapid changes in plasma structure associated with sawtooth crashes which trigger disruptive and nondisruptive tearing modes. HBT-EP's unique radially movable wall is found to significantly influence sawtooth triggering of disruptive tearing modes. The onset of sawtooth-triggered modes depends both on the plasma-wall separation, or wall coupling, and on the value of edge safety factor qa. We confirm that the condition for sawtooth triggering of disruptive (\uD835\uDC5A/\uD835\uDC5B) = (2/1) tearing modes does not correspond to the mode's single-helicity stability condition Δ'2/1. We identify a dependency of the sawtooth period \uD835\uDF0F\uD835\uDC60\uD835\uDC61 on the wall position and qa as a candidate to explain the onset of the saturated tearing mode. This thesis motivates future efforts to model the influence of a nearby resistive wall on sawtooth triggering of tearing modes.
■590 ▼aSchool code: 0054.
■650 4▼aPlasma physics
■650 4▼aElectromagnetics
■650 4▼aPhysics
■653 ▼aDisruption
■653 ▼aFusion
■653 ▼aKink mode
■653 ▼aSawtooth crash
■653 ▼aTearing mode
■653 ▼aTokamak
■690 ▼a0759
■690 ▼a0607
■690 ▼a0605
■71020▼aColumbia University▼bApplied Physics.
■7730 ▼tDissertations Abstracts International▼g86-06B.
■790 ▼a0054
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17164668▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
