Development of the LZ Dark Matter Experiment

广泛的天体物理学和宇宙学观测表明，宇宙中80%的物质是以一种新的形式存在的，这种形式既不发射也不吸收光，而且还没有在实验室中遇到过。 许多物理模型表明，暗物质可能由一个或多个以前未观察到的弱相互作用大质量粒子（WIMP）组成。通过地球粒子探测器中的相互作用对这种粒子进行天体物理探测，将对宇宙学和基本相互作用产生深远影响，同时也会产生一种新型的观测天体物理学。这项工作支持关键的研发和设计工作，以建设一个7吨重的液体氙暗物质探测器，被称为“LZ”，将安装在4850水平的桑福德地下研究设施铅，南达科他州。该探测器将使用已建立的液体氙时间投影室技术，读出用于粒子识别的初级和次级闪烁信号，以及三维位置重建，以利用液体氙的自屏蔽，去除表面伪影和校准位置相关的响应函数。该实验将利用LUX实验的现有基础设施和探测器组件，该实验目前正在部署到矿井中，以便在实验寿命结束时快速周转。更广泛的影响通过利用公众对暗物质的自然好奇心以及与重力的联系和熟悉，该项目将提供一个丰富的环境，在其中开发一系列活动，从图尔斯和展示到与当地学校和个人的合作伙伴关系，旨在培养对科学和科学职业的兴趣。通过LUX和LZ计划，合作将继续在桑福德的教育和公共宣传计划中发挥关键作用。暗物质科学还要求开发对辐射超敏感的新技术和实现超低放射性背景的新方法。这与广泛的核安全和医学成像领域所使用的方法直接重叠。将开发的工具还将在本科生、研究生和博士后层面提供直接的教育和培训福利，并将通过提供非博士学位的机会来促进基础科学研究。授予机构，特别是那些在地理上接近铅，可持续发展。

A broad range of astrophysical and cosmological observations indicates that 80% of the matter in the universe is in a new form which does not emit or absorb light, and has not yet been encountered in the laboratory. Many physics models suggest that the dark matter may be composed of one or more previously unobserved Weakly Interacting Massive Particles, or WIMPs. The astrophysical detection of such a particle through its interactions in a terrestrial particle detector would have a profound impact on cosmology and fundamental interactions, while also giving rise to a new type of observational astrophysics. This work supports key research and development and design efforts toward construction of a 7-ton liquid Xenon dark matter detector, known as 'LZ', to be installed at the 4850 level of the Sanford Underground Research Facility in Lead, South Dakota. This detector will use established liquid Xenon Time Projection Chamber technology with read out of primary and secondary scintillation signals for particle identification, together with 3-d position reconstruction to exploit the self-shielding of the liquid Xenon, removal of surface artifacts and calibration of position-dependent response functions. The experiment will take advantage of existing infrastructure and detector components from the LUX experiment, which is currently being deployed into the mine, allowing a rapid turn-around at the conclusion of that experiment's life. Broader Impacts By exploiting the natural curiosity of the public in dark matter as well as the connection and familiarity with gravity, this project will provide a rich environment in which to develop a range of activities from tours and displays to partnerships with local schools and individuals, aimed at fostering an interest in science and science careers. Through both LUX and LZ programs, the collaboration will continue to play a key role in the efforts at Sanford in education and public outreach programs. Dark matter science also demands the development of new technologies that are ultra-sensitive to radiation and new methods for achieving ultra-low radioactive backgrounds. There is direct overlap with the methods used in a wide range of nuclear security and medical imaging contexts. The instrument that will be developed will also provide direct educational and training benefits at the undergraduate, graduate and postdoctoral levels, and will promote basic science research by providing access to non-Ph.D. granting institutions, particularly those in geographical proximity to Lead, SD.