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Dosimetry of Electron-Irradiated Insulators at Conventional and Ultra-High Dose Rates
Dosimetry of Electron-Irradiated Insulators at Conventional and Ultra-High Dose Rates
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202105145
- ISBN
- 9798293807574
- DDC
- 610.69
- 서명/저자
- Dosimetry of Electron-Irradiated Insulators at Conventional and Ultra-High Dose Rates
- 발행사항
- [Sl] : The University of Wisconsin - Madison, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 171 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-03, Section: B.
- 주기사항
- Advisor: Culberson, Wesley.
- 학위논문주기
- Thesis (Ph.D.)--The University of Wisconsin - Madison, 2025.
- 초록/해제
- 요약In the field of medical physics, precise and reliable dosimetry is essential to ensure the safety and efficacy of radiation therapy. However, when insulating materials commonly used in dosimetric phantoms are exposed to high-energy electron beams, some electrons can become trapped within the material, leading to charge accumulation over time. This trapped charge generates internal electric fields that can distort the measured dose distribution, resulting in significant inaccuracies. This work presents a comprehensive investigation into this phenomenon under both conventional and ultra-high dose rate (UHDR) electron irradiations.Through a combination of experimental measurements and computational modeling, this work characterizes the influence of beam parameters (energy, dose rate, and field size), material properties, and detector configurations on charge accumulation and its dosimetric impact. Polymethyl methacrylate (PMMA) phantoms were shown to exhibit the highest charge retention, especially at high doses and large field sizes. Interestingly, UHDR conditions appeared to reduce the effects of charge buildup, offering potential benefits for improving dosimetric accuracy in emerging clinical applications. A physics-based computational model was developed and validated against experimental data to simulate charge deposition and resulting electric fields in three-dimensional phantoms. This model advances the work of Rawlinson et al. [1] by incorporating modern Monte Carlo techniques and accounting for spatial variations in charge and field distributions, departing from assumptions of uniform deposition in previous models. The model successfully predicted dose alterations due to charge buildup in conventional regimes and revealed the need for further refinement in UHDR conditions due to observed behavioral discrepancies.Mitigation strategies were also investigated, including phantom geometry modifications and photon-induced discharge. While annealing showed limited effectiveness, photon irradiation and optimized phantom designs, such as reduced size and strategic detector placement, significantly minimized the impact of trapped charge on dose measurements.This work contributes a validated simulation tool, new experimental insights, and practical design recommendations for managing charge buildup in high-energy electron dosimetry. The findings not only improve the reliability of current dosimetric practices but also lay a foundation for future research in charge mitigation, particularly in the evolving field of UHDR therapy.
- 일반주제명
- Medical personnel
- 일반주제명
- Materials science
- 일반주제명
- Health sciences
- 일반주제명
- Therapy
- 키워드
- Medical physics
- 키워드
- Phantom geometry
- 기타저자
- The University of Wisconsin - Madison Medical Physics
- 기본자료저록
- Dissertations Abstracts International. 87-03B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520260202105145
■006m o d
■007cr#unu||||||||
■020 ▼a9798293807574
■035 ▼a(MiAaPQ)AAI32241092
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a610.69
■1001 ▼aJackson, Jocelyn.
■24510▼aDosimetry of Electron-Irradiated Insulators at Conventional and Ultra-High Dose Rates
■260 ▼a[Sl]▼bThe University of Wisconsin - Madison▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a171 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-03, Section: B.
■500 ▼aAdvisor: Culberson, Wesley.
■5021 ▼aThesis (Ph.D.)--The University of Wisconsin - Madison, 2025.
■520 ▼aIn the field of medical physics, precise and reliable dosimetry is essential to ensure the safety and efficacy of radiation therapy. However, when insulating materials commonly used in dosimetric phantoms are exposed to high-energy electron beams, some electrons can become trapped within the material, leading to charge accumulation over time. This trapped charge generates internal electric fields that can distort the measured dose distribution, resulting in significant inaccuracies. This work presents a comprehensive investigation into this phenomenon under both conventional and ultra-high dose rate (UHDR) electron irradiations.Through a combination of experimental measurements and computational modeling, this work characterizes the influence of beam parameters (energy, dose rate, and field size), material properties, and detector configurations on charge accumulation and its dosimetric impact. Polymethyl methacrylate (PMMA) phantoms were shown to exhibit the highest charge retention, especially at high doses and large field sizes. Interestingly, UHDR conditions appeared to reduce the effects of charge buildup, offering potential benefits for improving dosimetric accuracy in emerging clinical applications. A physics-based computational model was developed and validated against experimental data to simulate charge deposition and resulting electric fields in three-dimensional phantoms. This model advances the work of Rawlinson et al. [1] by incorporating modern Monte Carlo techniques and accounting for spatial variations in charge and field distributions, departing from assumptions of uniform deposition in previous models. The model successfully predicted dose alterations due to charge buildup in conventional regimes and revealed the need for further refinement in UHDR conditions due to observed behavioral discrepancies.Mitigation strategies were also investigated, including phantom geometry modifications and photon-induced discharge. While annealing showed limited effectiveness, photon irradiation and optimized phantom designs, such as reduced size and strategic detector placement, significantly minimized the impact of trapped charge on dose measurements.This work contributes a validated simulation tool, new experimental insights, and practical design recommendations for managing charge buildup in high-energy electron dosimetry. The findings not only improve the reliability of current dosimetric practices but also lay a foundation for future research in charge mitigation, particularly in the evolving field of UHDR therapy.
■590 ▼aSchool code: 0262.
■650 4▼aMedical personnel
■650 4▼aMaterials science
■650 4▼aHealth sciences
■650 4▼aTherapy
■653 ▼aMedical physics
■653 ▼aUltra-high dose rate therapy
■653 ▼aMonte Carlo techniques
■653 ▼aPhantom geometry
■653 ▼aPolymethyl methacrylate
■690 ▼a0207
■690 ▼a0566
■690 ▼a0794
■690 ▼a0212
■71020▼aThe University of Wisconsin - Madison▼bMedical Physics.
■7730 ▼tDissertations Abstracts International▼g87-03B.
■790 ▼a0262
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17359606▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
