COUPP-250 kg. A Large-Mass Bubble Chamber Search for Weakly Interacting Massive Particles

COUPP-250 公斤。

• 批准号: 0707298
• 负责人: Juan Collar
• 金额: --
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0707298&HistoricalAwards=false
• 关键词: COUPP; 250; kg.; Large; Mass

The possibility of using room-temperature moderately superheated liquids in the bulk (i.e., bubble chambers) for rare event searches has been demonstrated within the COUPP project (Chicagoland Observatory for Underground Particle Physics). The prototype chambers developed display a stable behavior and by careful selection of operating temperature and pressure, the target liquid can be made sensitive to low-energy nuclear recoils like those expected from Weakly Interacting Massive Particles (WIMPs), while remaining insensitive to minimum ionizing particles: an unparalleled gamma rejection factor has been demonstrated for COUPP chambers. In this proposal, the PI requests funds for support towards a 250 kg total mass in the form of five small 50 kg chambers, to be deployed in one of the underground laboratories during the period covered by this proposal. The target liquid employed, CF3I, a safe industrial refrigerant commonly used as a fire extinguisher, is simultaneously maximally sensitive to both spin-dependent and -independent Lightest Supersymmetric Partner couplings. The proposed detector ensemble features a spin-independent potential sensitivity equivalent to ~550 kg of Germanium, and can simultaneously improve the present sensitivity to spin-dependent couplings to the point that supersymmetric models will be probed along both fronts. COUPP aims not at a mere improvement of present-day WIMP sensitivity, but also at implementing a variety of targets and methods able to provide convincing evidence that an eventual signal arises from WIMPs and not some irreducible background. This research will continue to provide multiple opportunities for undergraduate involvement. The use of stable, structurally simple mini-bubble chambers as background-insensitive, high-efficiency fast neutron monitors for portal monitoring of cargo containers is also being developed.

批量使用室温适度过热液体的可能性（即，气泡室）用于稀有事件搜索已经在COUPP项目（芝加哥地下粒子物理观测站）中得到证实。开发的原型室显示出稳定的行为，通过仔细选择工作温度和压力，目标液体可以对低能核反冲敏感，如弱相互作用大质量粒子（WIMP）所预期的那样，同时对最小电离粒子保持不敏感：COUPP室已经证明了无与伦比的伽马抑制因子。在本提案中，PI要求提供资金，以支持总质量为250 kg的5个50 kg小型室的形式，在本提案涵盖的时间段内部署在其中一个地下实验室中。采用的目标液体，CF 3 I，一种安全的工业制冷剂，通常用作灭火器，同时最大限度地敏感的自旋相关和独立的LiNbO 3超对称合作伙伴耦合。建议的探测器合奏功能的自旋无关的潜在灵敏度相当于~550公斤的锗，并可以同时提高目前的灵敏度自旋相关的耦合点，超对称模型将探测沿着两个方面。COUPP的目标不仅仅是提高当今WIMP的灵敏度，而且还在于实现各种目标和方法，这些目标和方法能够提供令人信服的证据，证明最终的信号来自WIMP，而不是一些不可约的背景。这项研究将继续为本科生参与提供多种机会。还在开发使用稳定、结构简单的微型气泡室作为对背景不敏感的高效快中子监测器，用于货物集装箱的入口监测。