Construction of the COUPP-500kg Bubble Chamber for Dark Matter Detection

芝加哥地下粒子物理观测站（COUPP）使用室温气泡室来寻找暗物质候选粒子。2011年，在加拿大萨德伯里的SNOLAB地下深处连续运行了一个含有4公斤三氟甲基碘化物（CF_3I）的腔室，COUPP目前对任何暗物质搜索中依赖自旋的WIMP（弱相互作用大质量粒子）-核耦合提供了最好的灵敏度。最近，在对α粒子的声学辨别和背景消除方面取得了巨大进展。有了这些新的发展，在SNOLAB已经安装了一个60公斤的腔室之后，COUPP也应该在对自旋独立耦合的灵敏度方面处于领先地位。这项技术达到的成熟水平促使这次合作启动了500公斤模块的概念设计。详细的蒙特卡罗模拟表明，该室将有能力对巨大的超对称WIMP参数空间进行详尽的探索。该设计将基于已经为60公斤的舱室开发和测试的系统的适度外推。该合同为完成COUPP-500的设计和开发提供支持。更广泛的影响：所描述的工作将在教育和指导领域产生实质性的更广泛的影响。COUPP一直致力于通过UC， IUSB和FNAL项目为本科生提供实验室研究机会，并指导和提升研究生和博士后。

COUPP (The Chicagoland Observatory for Underground Particle Physics) employs room temperature bubble chambers to search for dark matter particle candidates. Following continuous 2011 operation of a chamber containing 4 kg of trifluoromethyl iodide (CF_3I) at the underground depth of SNOLAB at Sudbury, Canada, COUPP presently offers the best sensitivity to spin-dependent WIMP (Weakly Interacting Massive Particles)-nucleus couplings from any dark matter search. Dramatic progress in acoustic discrimination against alpha particles and the abatement of backgrounds has recently been made. With these new developments, COUPP should also lead the field in sensitivity to spin-independent couplings, following the installation of an already-commissioned 60 kg chamber at SNOLAB.The level of maturity reached by this technique has prompted this collaboration to initiate the conceptual design of a 500 kg module. Detailed Monte Carlo simulations indicate that this chamber will have the ability to perform an exhaustive exploration of the vast supersymmetric WIMP parameter space. The design is to be based on a modest extrapolation of the systems already developed and tested for the 60 kg chamber. This award provides support to complete the design and development of COUPP-500. Broader Impacts: The effort described will generate substantial broader impacts in the areas of education and mentoring. COUPP has a long history of commitment to providing undergraduates with laboratory research opportunities, through UC, IUSB and FNAL programs, and to the mentoring and promotion of graduate students and postdocs.