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Studies of Ionization Backgrounds in Noble Liquid Detectors for Dark Matter Searches
Studies of Ionization Backgrounds in Noble Liquid Detectors for Dark Matter Searches
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211151522
- ISBN
- 9798384425342
- DDC
- 593.7
- 저자명
- Mizrachi, Eli.
- 서명/저자
- Studies of Ionization Backgrounds in Noble Liquid Detectors for Dark Matter Searches
- 발행사항
- [Sl] : University of Maryland, College Park, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 469 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-03, Section: B.
- 주기사항
- Includes supplementary digital materials.
- 주기사항
- Advisor: Xu, Jingke;Hall, Carter.
- 학위논문주기
- Thesis (Ph.D.)--University of Maryland, College Park, 2024.
- 초록/해제
- 요약Dark matter is believed to make up almost 85% of the total mass of the universe, yet its identity remains unclear. Weakly Interacting Massive Particles (WIMPs) have historically been a favored dark matter candidate, and dual-phase noble liquid time projection chambers (TPCs) have set the strongest interaction limits to date on WIMPs with a mass greater than several GeV. However, because no definitive interactions have been observed, the parameter space for conventional WIMPs is highly constrained. This has sparked greater interest in new sub-GeV dark matter models. At this mass scale, dark matter interactions with xenon or argon target media may still produce detectable signals at or near the single electron limit. However, these signals are currently obscured by delayed ionization backgrounds ("electron trains") which persist for seconds after an ionization event occurs. Electron trains have been observed in many different experiments and exhibit similar characteristics, but their cause is only partially understood. This work examines the nature of electron trains in various contexts, as well as possible strategies to mitigate them. First, a characterization of electron trains in the LZ experiment is presented, including new evidence of a dependence on detector conditions. The characterization also informed the development of an electron-train veto for LZ's first WIMP search, which set world-leading limits on the spin-independent and spin-dependent WIMP-nucleon cross-sections for medium and high-mass WIMPs. Next, to complement the analysis of LZ data, hardware upgrades were performed in XeNeu, a small xenon TPC at Lawrence Livermore National Lab. These included replacing plastics with low-outgassing metal and machinable ceramic components, as well as a replacement of XeNeu's photomultiplier tube array with silicon photomultipliers. The resulting reduction in the intensity of electron-trains and better position resolution from the respective upgrades will improve future studies of low energy interactions and phenomena. Concurrent with this work, XeNeu was used to perform a nuclear recoil calibration and a search for the Migdal effect, the latter of which can substantially enhance an experiment's low-mass dark matter sensitivity. Finally, the development of CoHerent Ionization Limits in Liquid Argon and Xenon (CHILLAX), is reported. CHILLAX is a new xenon-doped, dual-phase argon test stand that has the potential to have a higher sensitivity to low-mass dark matter interactions and lower backgrounds than current liquid xenon TPCs. The system is designed to handle high (percent level) xenon concentrations in liquid argon that can enable a range of ionization signal production and collection benefits. CHILLAX demonstrated the feasibility of such concepts by achieving a world record xenon doping concentration with stable operation.
- 일반주제명
- Particle physics
- 일반주제명
- Astrophysics
- 일반주제명
- Theoretical physics
- 키워드
- Dark matter
- 키워드
- Gas sampling
- 키워드
- Noble liquid
- 키워드
- Xenon
- 키워드
- Argon
- 기타저자
- University of Maryland, College Park Physics
- 기본자료저록
- Dissertations Abstracts International. 86-03B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520250211151522
■006m o d
■007cr#unu||||||||
■020 ▼a9798384425342
■035 ▼a(MiAaPQ)AAI31301696
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a593.7
■1001 ▼aMizrachi, Eli.▼0(orcid)0000-0001-6047-3588
■24510▼aStudies of Ionization Backgrounds in Noble Liquid Detectors for Dark Matter Searches
■260 ▼a[Sl]▼bUniversity of Maryland, College Park▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a469 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-03, Section: B.
■500 ▼aIncludes supplementary digital materials.
■500 ▼aAdvisor: Xu, Jingke;Hall, Carter.
■5021 ▼aThesis (Ph.D.)--University of Maryland, College Park, 2024.
■520 ▼aDark matter is believed to make up almost 85% of the total mass of the universe, yet its identity remains unclear. Weakly Interacting Massive Particles (WIMPs) have historically been a favored dark matter candidate, and dual-phase noble liquid time projection chambers (TPCs) have set the strongest interaction limits to date on WIMPs with a mass greater than several GeV. However, because no definitive interactions have been observed, the parameter space for conventional WIMPs is highly constrained. This has sparked greater interest in new sub-GeV dark matter models. At this mass scale, dark matter interactions with xenon or argon target media may still produce detectable signals at or near the single electron limit. However, these signals are currently obscured by delayed ionization backgrounds ("electron trains") which persist for seconds after an ionization event occurs. Electron trains have been observed in many different experiments and exhibit similar characteristics, but their cause is only partially understood. This work examines the nature of electron trains in various contexts, as well as possible strategies to mitigate them. First, a characterization of electron trains in the LZ experiment is presented, including new evidence of a dependence on detector conditions. The characterization also informed the development of an electron-train veto for LZ's first WIMP search, which set world-leading limits on the spin-independent and spin-dependent WIMP-nucleon cross-sections for medium and high-mass WIMPs. Next, to complement the analysis of LZ data, hardware upgrades were performed in XeNeu, a small xenon TPC at Lawrence Livermore National Lab. These included replacing plastics with low-outgassing metal and machinable ceramic components, as well as a replacement of XeNeu's photomultiplier tube array with silicon photomultipliers. The resulting reduction in the intensity of electron-trains and better position resolution from the respective upgrades will improve future studies of low energy interactions and phenomena. Concurrent with this work, XeNeu was used to perform a nuclear recoil calibration and a search for the Migdal effect, the latter of which can substantially enhance an experiment's low-mass dark matter sensitivity. Finally, the development of CoHerent Ionization Limits in Liquid Argon and Xenon (CHILLAX), is reported. CHILLAX is a new xenon-doped, dual-phase argon test stand that has the potential to have a higher sensitivity to low-mass dark matter interactions and lower backgrounds than current liquid xenon TPCs. The system is designed to handle high (percent level) xenon concentrations in liquid argon that can enable a range of ionization signal production and collection benefits. CHILLAX demonstrated the feasibility of such concepts by achieving a world record xenon doping concentration with stable operation.
■590 ▼aSchool code: 0117.
■650 4▼aParticle physics
■650 4▼aAstrophysics
■650 4▼aTheoretical physics
■653 ▼aDark matter
■653 ▼aGas sampling
■653 ▼aIonization backgrounds
■653 ▼aNoble liquid
■653 ▼aTime projection chambers
■653 ▼aXenon
■653 ▼aArgon
■690 ▼a0798
■690 ▼a0753
■690 ▼a0596
■71020▼aUniversity of Maryland, College Park▼bPhysics.
■7730 ▼tDissertations Abstracts International▼g86-03B.
■790 ▼a0117
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17162088▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
