nEXO: a Search for Neutrino-less Double Beta Decay with a Tonne-Scale Enriched Xenon Time Projection Chamber

nEXO：利用吨级浓缩氙时间投影室寻找无中微子双贝塔衰变

• 批准号: 2111213
• 负责人: Andrea Pocar
• 金额: $ 72.5万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2111213&HistoricalAwards=false
• 关键词: nEXO; Search; Neutrino; less; Double

A fundamental question in contemporary science is why the Universe contains more matter than anti-matter. This award supports investigations into one possible explanation for the origin of this imbalance through the study of whether the mass of the lightest fundamental massive particle in Nature, the neutrino, is matter or anti-matter, or perhaps is a combination of both at the same time. A neutrino could simultaneously be both, enabling a nuclear process known as neutrino-less double-beta decay in which a nucleus transforms into another by emitting two electrons and no neutrinos. If observed, this decay would indicate that neutrinos and anti-neutrinos are the same particle. The NSF/DOE Nuclear Science Advisory Committee (NSAC) has recommended a US-led, ton-scale neutrino-less double-beta decay experiment as the top priority for the field. The UMass group, along with scientists from universities and national laboratories in the US, Canada, China, France, Germany, Russia, South Africa, South Korea, and Switzerland have proposed the nEXO experiment to search for neutrino-less double-beta decay of xenon-136. Using five tons of isotopically enriched liquid xenon nEXO will achieve a 100-fold improved sensitivity with respect to today’s experiments. The work at UMass focuses on R&D for the design and optimization of nEXO and the extraction of science from the dataset previously recorded by EXO-200, the nEXO predecessor. The nEXO detector will be built around a Time Projection Chamber (TPC) that allows scientists to identify and suppress background signals which can mimic neutrino-less double-beta decay. The detector measures the position and energy of every ionizing event inside its volume. Combined with a detector design that minimizes the radioactivity in its constituents, the feeble neutrino-less double beta decay signal can emerge above environmental noise.The UMass group will work on the development of key elements for the nEXO detector. The PI is the Level-2 scientist for the nEXO TPC Support (TPCS) team and the UMass group will develop cryogenics, refrigeration infrastructure, Liquid Xenon storage capabilities, xenon handling, and purification systems. The PI will also study the long-term stability of VUV-sensitive Silicon PhotoMultipliers (SiPMs) for nEXO using a cryostat where xenon can be condensed into a test cell. The group will develop a calibration source for nEXO which can be injected into the xenon flow stream. And the group will also search for sub-dominant neutrino-less double beta decay of xenon-136 and xenon-134 in the previously recorded EXO-200 dataset. The activities covered by this award will train students in STEM fields, open doors for students from diverse backgrounds, and develop technologies that align with strategic sectors of our economy such as data science, artificial intelligence, nuclear medicine, and national security. The Amherst Center for Fundamental Interactions (ACFI) contributes to promoting the physics related to this proposal to the broader physics community.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

当代科学中的一个基本问题是，为什么宇宙包含的物质比反物质多。该奖项支持通过研究自然界中最轻的基本质量粒子-中微子的质量是物质还是反物质，或者可能同时是两者的组合-来调查这种不平衡的起源的一种可能的解释。一个中微子可以同时是两个，从而实现了一个被称为无中微子双β衰变的核过程，在这个过程中，一个原子核通过发射两个电子而不发射中微子来转变为另一个原子核。如果观察到，这种衰变将表明中微子和反中微子是同一粒子。美国国家科学基金会/美国能源部核科学咨询委员会(NSAC)建议将美国主导的、吨级规模的无中微子双β衰变实验作为该领域的首要任务。来自美国、加拿大、中国、法国、德国、俄罗斯、南非、韩国和瑞士的大学和国家实验室的科学家提出了Nexo实验，以寻找Xe-136的无中微子双β衰变。与今天的实验相比，使用5吨同位素浓缩的液体氙气，Nexo将实现100倍的灵敏度提高。马萨诸塞州大学的工作重点是Nexo的设计和优化的研发，以及从Nexo的前身EXO-200之前记录的数据集提取科学。Nexo探测器将围绕一个时间投影室(TPC)建造，使科学家能够识别和抑制可以模拟无中微子双β衰变的背景信号。探测器测量其体积内每个电离事件的位置和能量。结合探测器设计，最大限度地减少其成分中的放射性，微弱的无中微子双贝塔衰变信号可以出现在环境噪声之上。美国质量小组将致力于Nexo探测器的关键元件的开发。PI是Nexo TPC支持(TPCS)团队的二级科学家，UMASS团队将开发低温、制冷基础设施、液体氙气存储能力、氙气处理和净化系统。PI还将研究用于Nexo的真空紫外光敏硅光电倍增管(SiPM)的长期稳定性，使用低温恒温器，氙气可以浓缩到测试单元中。该小组将为Nexo开发一种可以注入氙流的校准源。该小组还将在之前记录的EXO-200数据集中寻找Xe-136和Xe-134的次主中微子少双贝塔衰变。该奖项涵盖的活动将培训STEM领域的学生，为来自不同背景的学生打开大门，并开发与我们经济的战略部门相一致的技术，如数据科学、人工智能、核医学和国家安全。阿默斯特基础相互作用中心(ACFI)致力于向更广泛的物理界推广与这项提议相关的物理学。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Kiloton-scale xenon detectors for neutrinoless double beta decay and other new physics searches

• DOI: 10.1103/physrevd.104.112007
• 发表时间: 2021-10
• 作者: A. Avasthi;T. Bowyer;C. Bray;T. Brunner;N. Catarineu;E. Church;R. Guenette;S. Haselschwardt;J. Hayes;M. Heffner;S. Hertel;P. Humble;A. Jamil;S. Kim;R. Lang;K. Leach;B. Lenardo;W. Lippincott;A. Marino;D. McKinsey;E. Miller;D. Moore;B. Mong;B. Monreal;M. Monzani;I. Olcina;J. Orrell;S. Pang;A. Pocar;P. Rowson;R. Saldanha;S. Sangiorgio;C. Stanford;A. Visser

Performance of novel VUV-sensitive Silicon Photo-Multipliers for nEXO

• DOI: 10.1140/epjc/s10052-022-11072-8
• 发表时间: 2022-09
• 期刊: The European Physical Journal C
• 作者: G. Gallina;Y. Guan;F. Retière;G. Cao;A. Bolotnikov;I. Kotov;S. Rescia;A. Soma;T. Tsang;L. Darroch;T. Brunner;J. Bolster;J. Cohen;T. P. Franco;W. Gillis;H. P. Smalley;S. Thibado;A. Pocar;A. Bhat;A. Jamil;D. Moore;G. Adhikari;S. A. Kharusi;E. Angelico;I. Arnquist;P. Arsenault;I. Badhrees;J. Bane;V. Belov;E. Bernard;T. Bhatta;P. Breur;J. Brodsky;E. Brown;E. Caden;L. Cao;C. Chambers;B. Chana;S. Charlebois;D. Chernyak;M. Chiu;B. Cleveland;R. Collister;M.Cvitan;J. Dalmasson;T. Daniels;K. Deslandes;R. DeVoe;M. Vacri;Y. Ding;M. Dolinski;A. Dragone;J. Echevers;B. Eckert;M. Elbeltagi;L. Fabris;W. Fairbank;J. Farine;Y. Fu;D. Gallacher;P. Gautam;G. Giacomini;C. Gingras;D. Goeldi;R. Gornea;G. Gratta;C. Hardy;S. Hedges;M. Heffner;E. Hein;J. Holt;E. Hoppe;J. H¨oßl;A. House;W. Hunt;A. Iverson;X. Jiang;A. Karelin;L. Kaufman;R. Kr¨ucken;A. Kuchenkov;K. S. Kumar;A. Larson;K. Leach;B. Lenardo;D. Leonard;G.Lessard;G. Li;S. Li;Z. Li;C. Licciardi;R. Lindsay;R. Maclellan;M. Mahtab;S. Majidi;C. Malbrunot;P. Margetak;P. Martel-Dion;L. Martin;J. Masbou;N. Massacret;K. McMichael;B. Mong;K. Murray;J. Nattress;C. Natzke;X. Ngwadla;J. Ondze;A. Odian;J. Orrell;G. S. Ortega;C. Overman;S. Parent;A. Perna;A. Piepke;N. Pletskova;J. Pratte;V. Radeka;E. Raguzin;G. J. Ramonnye;T.Rao;H. Rasiwala;K. Raymond;B. Rebeiro;G. Richardson;J. Ringuette;V. Riot;T. Rossignol;P. Rowson;L. Rudolph;R. Saldanha;S. Sangiorgio;X. Shang;F. Spadoni;V. Stekhanov;X. Sun;A. Tidball;T. Totev;S. Triambak;R. Tsang;O. A.Tyuka;F. Vachon;M. Vidal;S. Viel;G. Visser;M. Wagenpfeil;M. Walent;K. Wamba;Q. Wang;W. Wang;Y. Wang;M. Watts;W. Wei;L. Wen;U. Wichoski;S. Wilde;M. Worcester;W. Wu;X. Wu;L. Xie;W. Yan;H. Yang;L. Yang;O. Zeldovich;J. Zhao;T. Ziegler;Rohde Schwarz

Search for MeV electron recoils from dark matter in EXO-200

在 EXO-200 中搜索来自暗物质的 MeV 电子反冲

• DOI: 10.1103/physrevd.107.012007
• 发表时间: 2023
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Al Kharusi, S.;Anton, G.;Badhrees, I.;Barbeau, P. S.;Beck, D.;Belov, V.;Bhatta, T.;Breidenbach, M.;Brunner, T.;Cao, G. F.
• 通讯作者: Cao, G. F.

The EXO-200 detector, part II: auxiliary systems

EXO-200 探测器，第二部分：辅助系统

• DOI: 10.1088/1748-0221/17/02/p02015
• 发表时间: 2022
• 期刊: Journal of Instrumentation
• 影响因子: 1.3
• 作者: Ackerman, N.;Albert, J.;Auger, M.;Auty, D.J.;Badhrees, I.;Barbeau, P.S.;Bartoszek, L.;Baussan, E.;Belov, V.;Benitez-Medina, C.
• 通讯作者: Benitez-Medina, C.

An integrated online radioassay data storage and analytics tool for nEXO

• DOI: 10.1016/j.nima.2023.168477
• 发表时间: 2023-04
• 期刊: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
• 作者: R. Tsang;A. Piepke;S. Al Kharusi;E. Angelico;I. Arnquist;A. Atencio;I. Badhrees;J. Bane;V. Belov;E. Bernard;A. Bhat;T. Bhatta;A. Bolotnikov;P. Breur;J. Brodsky;E. Brown;T. Brunner;E. Caden;G. Cao;L. Cao;D. Cesmecioglu;C. Chambers;E. Chambers;B. Chana;S. Charlebois;D. Chernyak;M. Chiu;B. Cleveland;J. Cohen;R. Collister;M. Cvitan;J. Dalmasson;L. Darroch;K. Deslandes;R. DeVoe;M. L. di Vacri;Y.Y. Ding;M. Dolinski;J. Echevers;B. Eckert;M. Elbeltagi;R. Elmansali;L. Fabris;W. Fairbank;J. Farine;Y.S. Fu;D. Gallacher;G. Gallina;P. Gautam;G. Giacomini;W. Gillis;C. Gingras;D. Goeldi;R. Gornea;G. Gratta;Y. Guan;C. Hardy;S. Hedges;M. Heffner;E. Hein;J. Holt;E. Hoppe;A. House;W. Hunt;A. Iverson;A. Jamil;X.S. Jiang;A. Karelin;L. Kaufman;I. Kotov;R. Krücken;A. Kuchenkov;K. S. Kumar;A. Larson;K. Leach;B. Lenardo;D. Leonard;G. Li;S. Li;Z. Li;C. Licciardi;R. Lindsay;R. Maclellan;M. Mahtab;S. Majidi;C. Malbrunot;P. Martel-Dion;J. Masbou;N. Massacret;K. McMichael;B. Mong;D. Moore;K. Murray;J. Nattress;C. Natzke;X. Ngwadla;K. Ni;A. Nolan;S. Nowicki;J. Nzobadila Ondze;J. Orrell;G. S. Ortega;C. Overman;H. Peltz-Smalley;A. Perna;T. Pinto Franco;A. Pocar;J. Pratte;V. Radeka;E. Raguzin;H. Rasiwala;D. Ray;B. Rebeiro;S. Rescia;F. Retière;G. Richardson;J. Ringuette;V. Riot;P. Rowson;N. Roy;L. Rudolph;R. Saldanha;S. Sangiorgio;S. Schwartz;J. Søderstrøm;A. Soma;F. Spadoni;V. Stekhanov;X.L. Sun;E. Teimoori Barakoohi;S. Thibado;A. Tidball;T. Totev;S. Triambak;T. Tsang;O. A. Tyuka;R. Underwood;E. V. van Bruggen;V. Veeraraghavan;M. Vidal;S. Viel;M. Walent;K. Wamba;Q.D. Wang;W. Wang;Y. Wang;M. Watts;W. Wei;L. Wen;U. Wichoski;S. Wilde;M. Worcester;S. Wu;X.M. Wu;H. Yang;L. Yang;M. Yvaine;O. Zeldovich;J. Zhao;T. Ziegler