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Measurement and Modeling of Radiation Temperature Fluctuations in the HSX Stellarator
Measurement and Modeling of Radiation Temperature Fluctuations in the HSX Stellarator
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211152012
- ISBN
- 9798382826479
- DDC
- 530
- 저자명
- Singh, Luquant.
- 서명/저자
- Measurement and Modeling of Radiation Temperature Fluctuations in the HSX Stellarator
- 발행사항
- [Sl] : The University of Wisconsin - Madison, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 133 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 85-12, Section: B.
- 주기사항
- Advisor: Geiger, Benedikt.
- 학위논문주기
- Thesis (Ph.D.)--The University of Wisconsin - Madison, 2024.
- 초록/해제
- 요약The Helically Symmetric Experiment (HSX) stellarator has been optimized for low neoclassical transport. Anomalous transport attributed to drift-wave turbulence remains an important loss channel. High-resolution plasma diagnostics can be used to study fluctuations in equilibrium plasma parameters, such as plasma density and temperature, which are sensitive quantities of the underlying turbulence. In this work, core radiation temperature fluctuations were measured in the HSX stellarator using a correlation electron cyclotron emission radiometer. The experimental measurements have been compared with gyrokinetic simulations of plasma turbulence.The HSX correlation electron cyclotron emission diagnostic measures radiation temperature fluctuations from second harmonic X-mode wave emission in optically semi-transparent plasmas. Multiple pass raytracing calculations indicate reinforcement of single pass emission on the high-field side of the magnetic axis, permitting localized measurements. Interpretation of radiation temperature fluctuations as electron temperature fluctuations is within reasonable uncertainty, based on modeling of density fluctuation effects. It is found that long-wavelength radiation temperature fluctuations increase with the inverse scale length of electron temperature. This is consistent with linear gyrokinetic simulations of trapped electron mode turbulence, which show enhanced dominant linear growth rates at higher inverse scale length of electron temperature, and nonlinear gyrokinetic simulations, which when coupled with a synthetic diagnostic, reproduce the experimental trend in fluctuation amplitude. A synthetic frequency spectrum derived from a simulation of the trapped electron mode is similar in shape to the experimental frequency spectrum. The experimental observations and gyrokinetic predictions indicate that electron-temperature-gradient-driven trapped electron modes are destabilized in the core of HSX plasmas. These results improve the understanding of core turbulence in an optimized stellarator and inform optimization strategies for future devices.
- 일반주제명
- Plasma physics
- 일반주제명
- Electrical engineering
- 일반주제명
- Electromagnetics
- 일반주제명
- Nuclear physics
- 키워드
- Nuclear fusion
- 키워드
- Stellarator
- 기타저자
- The University of Wisconsin - Madison Electrical and Computer Engineering
- 기본자료저록
- Dissertations Abstracts International. 85-12B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
008250123s2024 us c eng d■001000017162437
■00520250211152012
■006m o d
■007cr#unu||||||||
■020 ▼a9798382826479
■035 ▼a(MiAaPQ)AAI31331300
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a530
■1001 ▼aSingh, Luquant.
■24510▼aMeasurement and Modeling of Radiation Temperature Fluctuations in the HSX Stellarator
■260 ▼a[Sl]▼bThe University of Wisconsin - Madison▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a133 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 85-12, Section: B.
■500 ▼aAdvisor: Geiger, Benedikt.
■5021 ▼aThesis (Ph.D.)--The University of Wisconsin - Madison, 2024.
■520 ▼aThe Helically Symmetric Experiment (HSX) stellarator has been optimized for low neoclassical transport. Anomalous transport attributed to drift-wave turbulence remains an important loss channel. High-resolution plasma diagnostics can be used to study fluctuations in equilibrium plasma parameters, such as plasma density and temperature, which are sensitive quantities of the underlying turbulence. In this work, core radiation temperature fluctuations were measured in the HSX stellarator using a correlation electron cyclotron emission radiometer. The experimental measurements have been compared with gyrokinetic simulations of plasma turbulence.The HSX correlation electron cyclotron emission diagnostic measures radiation temperature fluctuations from second harmonic X-mode wave emission in optically semi-transparent plasmas. Multiple pass raytracing calculations indicate reinforcement of single pass emission on the high-field side of the magnetic axis, permitting localized measurements. Interpretation of radiation temperature fluctuations as electron temperature fluctuations is within reasonable uncertainty, based on modeling of density fluctuation effects. It is found that long-wavelength radiation temperature fluctuations increase with the inverse scale length of electron temperature. This is consistent with linear gyrokinetic simulations of trapped electron mode turbulence, which show enhanced dominant linear growth rates at higher inverse scale length of electron temperature, and nonlinear gyrokinetic simulations, which when coupled with a synthetic diagnostic, reproduce the experimental trend in fluctuation amplitude. A synthetic frequency spectrum derived from a simulation of the trapped electron mode is similar in shape to the experimental frequency spectrum. The experimental observations and gyrokinetic predictions indicate that electron-temperature-gradient-driven trapped electron modes are destabilized in the core of HSX plasmas. These results improve the understanding of core turbulence in an optimized stellarator and inform optimization strategies for future devices.
■590 ▼aSchool code: 0262.
■650 4▼aPlasma physics
■650 4▼aElectrical engineering
■650 4▼aElectromagnetics
■650 4▼aNuclear physics
■653 ▼aMagnetic confinement
■653 ▼aMicrowave radiometry
■653 ▼aNuclear fusion
■653 ▼aPlasma diagnostics
■653 ▼aPlasma turbulence
■653 ▼aStellarator
■690 ▼a0759
■690 ▼a0544
■690 ▼a0607
■690 ▼a0756
■71020▼aThe University of Wisconsin - Madison▼bElectrical and Computer Engineering.
■7730 ▼tDissertations Abstracts International▼g85-12B.
■790 ▼a0262
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17162437▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
