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Impurity Transport Study Using High-n Rydberg Spectroscopy at W7-X
Impurity Transport Study Using High-n Rydberg Spectroscopy at W7-X
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211152722
- ISBN
- 9798383595459
- DDC
- 530
- 저자명
- Swee, Colin K.
- 서명/저자
- Impurity Transport Study Using High-n Rydberg Spectroscopy at W7-X
- 발행사항
- [Sl] : The University of Wisconsin - Madison, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 162 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-02, Section: B.
- 주기사항
- Advisor: Geiger, Benedikt.
- 학위논문주기
- Thesis (Ph.D.)--The University of Wisconsin - Madison, 2024.
- 초록/해제
- 요약Impurities will play a significant role in the plasma environments found inside fusion reactors. For example, accumulation of light impurities such as helium ash from fusion reactions can dilute the fuel mixture and reduce overall fusion rates. In the case of highly ionized heavy impurities, inner shell electrons undergo strong line transitions which radiate away the thermal plasma energy. To avoid such scenarios, a detailed understanding of impurity transport in fusion plasma is necessary. This dissertation describes novel work done on the W7-X stellarator to both measure impurity radiation and model impurity transport.At W7-X, a new charge exchange recombination spectroscopy (CXRS) diagnostic is used to measure heavy impurities injected using the laser blow off (LBO) method. This system was designed with improved photon throughput and speed compared to the existing CXRS system at W7-X and installed for the most recent experimental campaign (OP 2.1). To analyze the CXRS measurements, a novel approach has been developed for the determination of impurity densities based on the observation of visible wavelength, high-n Rydberg-like transitions of highly ionized heavy impurities. These emissions provide several benefits including simple line identification and a lack of passive emission components.The diagnostic measurements are forward modeled using a python framework consisting of the pySTRAHL impurity transport code and the Monte Carlo neutral simulation code known as pyFIDASIM. By using Bayesian inference to match the modeled signals to experimental measurements, impurity diffusion and convection velocities can be determined. Additionally, an integrated data analysis framework has been developed to self consistently model multiple complementary impurity diagnostics. By evaluating the inference uncertainty for the impurity transport when considering different combinations of diagnostics, a better understanding of the importance of each measurement is developed. Finally, the inferred impurity transport is found to be in qualitative agreement with theoretical calculations of turbulent impurity transport indicating pinch contributions to the total flux. The presented techniques are now readily available and can be applied to upcoming experimental campaigns.
- 일반주제명
- Plasma physics
- 일반주제명
- Nuclear physics
- 일반주제명
- Nuclear engineering
- 키워드
- Fusion reactors
- 키워드
- Impurities
- 키워드
- Plasma
- 기타저자
- The University of Wisconsin - Madison Nuclear Engineering & Engineering Physics
- 기본자료저록
- Dissertations Abstracts International. 86-02B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
008250123s2024 us c eng d■001000017163541
■00520250211152722
■006m o d
■007cr#unu||||||||
■020 ▼a9798383595459
■035 ▼a(MiAaPQ)AAI31489752
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a530
■1001 ▼aSwee, Colin K.
■24510▼aImpurity Transport Study Using High-n Rydberg Spectroscopy at W7-X
■260 ▼a[Sl]▼bThe University of Wisconsin - Madison▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a162 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-02, Section: B.
■500 ▼aAdvisor: Geiger, Benedikt.
■5021 ▼aThesis (Ph.D.)--The University of Wisconsin - Madison, 2024.
■520 ▼aImpurities will play a significant role in the plasma environments found inside fusion reactors. For example, accumulation of light impurities such as helium ash from fusion reactions can dilute the fuel mixture and reduce overall fusion rates. In the case of highly ionized heavy impurities, inner shell electrons undergo strong line transitions which radiate away the thermal plasma energy. To avoid such scenarios, a detailed understanding of impurity transport in fusion plasma is necessary. This dissertation describes novel work done on the W7-X stellarator to both measure impurity radiation and model impurity transport.At W7-X, a new charge exchange recombination spectroscopy (CXRS) diagnostic is used to measure heavy impurities injected using the laser blow off (LBO) method. This system was designed with improved photon throughput and speed compared to the existing CXRS system at W7-X and installed for the most recent experimental campaign (OP 2.1). To analyze the CXRS measurements, a novel approach has been developed for the determination of impurity densities based on the observation of visible wavelength, high-n Rydberg-like transitions of highly ionized heavy impurities. These emissions provide several benefits including simple line identification and a lack of passive emission components.The diagnostic measurements are forward modeled using a python framework consisting of the pySTRAHL impurity transport code and the Monte Carlo neutral simulation code known as pyFIDASIM. By using Bayesian inference to match the modeled signals to experimental measurements, impurity diffusion and convection velocities can be determined. Additionally, an integrated data analysis framework has been developed to self consistently model multiple complementary impurity diagnostics. By evaluating the inference uncertainty for the impurity transport when considering different combinations of diagnostics, a better understanding of the importance of each measurement is developed. Finally, the inferred impurity transport is found to be in qualitative agreement with theoretical calculations of turbulent impurity transport indicating pinch contributions to the total flux. The presented techniques are now readily available and can be applied to upcoming experimental campaigns.
■590 ▼aSchool code: 0262.
■650 4▼aPlasma physics
■650 4▼aNuclear physics
■650 4▼aNuclear engineering
■653 ▼aBayesian inference
■653 ▼aCharge exchange recombination spectroscopy
■653 ▼aFusion reactors
■653 ▼aImpurities
■653 ▼aPlasma
■690 ▼a0759
■690 ▼a0552
■690 ▼a0756
■71020▼aThe University of Wisconsin - Madison▼bNuclear Engineering & Engineering Physics.
■7730 ▼tDissertations Abstracts International▼g86-02B.
■790 ▼a0262
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17163541▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.


