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On Electron Acceleration at Planetary Foreshocks
On Electron Acceleration at Planetary Foreshocks
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211152653
- ISBN
- 9798383671160
- DDC
- 530
- 저자명
- Shi, Xiaofei.
- 서명/저자
- On Electron Acceleration at Planetary Foreshocks
- 발행사항
- [Sl] : University of California, Los Angeles, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 169 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-02, Section: B.
- 주기사항
- Advisor: Angelopoulos, Vassilis.
- 학위논문주기
- Thesis (Ph.D.)--University of California, Los Angeles, 2024.
- 초록/해제
- 요약Shock waves, where supersonic and subsonic plasma flows meet, are primary sites for charged particle acceleration in various space plasma environments, including astrophysical and planetary bow shocks. Earth's bow shock is the most accessible site for experimental investigations of this acceleration process with in-situ measurements. Relativistic electrons, which are often observed near planetary bow shocks, show energy levels significantly higher than those of solar wind electrons, by at least four orders of magnitude. However, present electron acceleration mechanisms, viewed individually, fail to explain the full energization that electrons undergo in such settings. This thesis presents a compound scenario for such acceleration. Specifically, it investigates the combined role of electromagnetic whistler-mode waves and other plasma wave modes in electron acceleration and scattering in the foreshock region, studied in conjunction with Fermi and betatron acceleration, and applied in a realistic setting, as informed by multi-satellite observations. Whistler-mode waves are known for their role in electron scattering and acceleration in the inner magnetosphere, facilitating our studies of their role under the plasma conditions found in the foreshock. Statistical studies using in-situ observations from the THEMIS and MMS missions are utilized to reveal the properties of whistler-mode waves and their resonant interactions with electrons near Earth's bow shock and foreshock. Theoretical approaches are then developed to describe the effects of these waves on electron dynamics. Finally, a comprehensive acceleration model is constructed, which successfully replicates the observed near-relativistic electron energy spectra. The model assumes that acceleration to energies up to several hundred keV involves a complex, compound process, including shock acceleration, adiabatic heating, and resonant scattering by multiple plasma wave modes - a phenomenon previously underexplored. The model not only reproduces the observed power-law electron spectrum of ~ E -4 but also addresses the longstanding challenge of generating energetic and relativistic electrons at planetary shocks. This extends the theoretical framework of electron-wave interactions from the inner magnetosphere to the foreshock and opens new avenues for numerical simulations of electron acceleration in astrophysical shocks, potentially revolutionizing our understanding of particle acceleration in space plasmas.
- 일반주제명
- Plasma physics
- 일반주제명
- Geophysics
- 일반주제명
- Astrophysics
- 일반주제명
- Planetology
- 키워드
- Shock waves
- 키워드
- Space plasma
- 키워드
- Wave modes
- 기타저자
- University of California, Los Angeles Geophysics & Space Physics 0406
- 기본자료저록
- Dissertations Abstracts International. 86-02B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520250211152653
■006m o d
■007cr#unu||||||||
■020 ▼a9798383671160
■035 ▼a(MiAaPQ)AAI31487219
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a530
■1001 ▼aShi, Xiaofei.
■24510▼aOn Electron Acceleration at Planetary Foreshocks
■260 ▼a[Sl]▼bUniversity of California, Los Angeles▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a169 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-02, Section: B.
■500 ▼aAdvisor: Angelopoulos, Vassilis.
■5021 ▼aThesis (Ph.D.)--University of California, Los Angeles, 2024.
■520 ▼aShock waves, where supersonic and subsonic plasma flows meet, are primary sites for charged particle acceleration in various space plasma environments, including astrophysical and planetary bow shocks. Earth's bow shock is the most accessible site for experimental investigations of this acceleration process with in-situ measurements. Relativistic electrons, which are often observed near planetary bow shocks, show energy levels significantly higher than those of solar wind electrons, by at least four orders of magnitude. However, present electron acceleration mechanisms, viewed individually, fail to explain the full energization that electrons undergo in such settings. This thesis presents a compound scenario for such acceleration. Specifically, it investigates the combined role of electromagnetic whistler-mode waves and other plasma wave modes in electron acceleration and scattering in the foreshock region, studied in conjunction with Fermi and betatron acceleration, and applied in a realistic setting, as informed by multi-satellite observations. Whistler-mode waves are known for their role in electron scattering and acceleration in the inner magnetosphere, facilitating our studies of their role under the plasma conditions found in the foreshock. Statistical studies using in-situ observations from the THEMIS and MMS missions are utilized to reveal the properties of whistler-mode waves and their resonant interactions with electrons near Earth's bow shock and foreshock. Theoretical approaches are then developed to describe the effects of these waves on electron dynamics. Finally, a comprehensive acceleration model is constructed, which successfully replicates the observed near-relativistic electron energy spectra. The model assumes that acceleration to energies up to several hundred keV involves a complex, compound process, including shock acceleration, adiabatic heating, and resonant scattering by multiple plasma wave modes - a phenomenon previously underexplored. The model not only reproduces the observed power-law electron spectrum of ~ E -4 but also addresses the longstanding challenge of generating energetic and relativistic electrons at planetary shocks. This extends the theoretical framework of electron-wave interactions from the inner magnetosphere to the foreshock and opens new avenues for numerical simulations of electron acceleration in astrophysical shocks, potentially revolutionizing our understanding of particle acceleration in space plasmas.
■590 ▼aSchool code: 0031.
■650 4▼aPlasma physics
■650 4▼aGeophysics
■650 4▼aAstrophysics
■650 4▼aPlanetology
■653 ▼aPlanetary foreshocks
■653 ▼aShock waves
■653 ▼aSpace plasma
■653 ▼aElectron acceleration
■653 ▼aWave modes
■690 ▼a0759
■690 ▼a0596
■690 ▼a0590
■690 ▼a0373
■71020▼aUniversity of California, Los Angeles▼bGeophysics & Space Physics 0406.
■7730 ▼tDissertations Abstracts International▼g86-02B.
■790 ▼a0031
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17163327▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
