Particle Astrophysics with Neutrinos and Weakly Interacting Dark Matter: Borexino and DarkSide

该奖项为马萨诸塞大学阿默斯特分校的粒子天体物理计划提供了基础支持，以参与Borexino太阳中微子实验和在我们银河系中搜索弱相互作用粒子暗物质(WIMP)的Darkside计划。太阳中微子在中微子具有质量和振荡的实验确认中发挥了关键作用。自2007年开始数据采集以来，Borexino已经达到了设计目标，并以足够高的精度测量了单能7-Be太阳中微子的通量，以检验目前太阳模型的预测。在2011年的闪烁体净化运动之后，Borexino正处于太阳中微子物理的新阶段，目标是测量整个太阳中微子光谱。对太阳中微子的精确了解将使我们能够了解太阳和其他恒星是如何工作的，测试MSW-LMA中微子振荡模式，并寻找偏离它的情况。Borexino可能会解决一个关于太阳核心金属丰度的悬而未决的问题，这是研究宇宙中较大恒星演化的重要信息。Darkside-50是一个双相时间投影室，计划于2012年底上线，它将为WIMP提供无背景多吨探测器的原型设计解决方案，并将液态Ar作为主动目标。零观测将排除一些目前领先的暗物质候选者。一个积极的探测将开始为我们这个时代的一个重大科学未知数提供答案。Darkside-50将在放射性39-Ar同位素中耗尽50公斤Ar超过100倍的情况下运行。Darkside-50 Agon低温恒温器被一个紧凑的液体闪烁体中子探测器包围，并浸入Borexino计数测试设施(CTF)水箱中，该水箱作为切伦科夫Muon否决权进行测量和操作。Borexino和Darkside的合作在人员、技术和业务资源方面有很大重叠。更广泛的影响：Borexino和Darkside项目为研究生和本科生提供了在软件和硬件开发应用以及基础物理方面进行培训的绝佳机会。为Borexino和Darkside-50开发的技术可以更广泛地惠及与医学成像、核不扩散和地质学相关的技术。

This award provides base support for the particle astrophysics program at the University of Massachusetts, Amherst to participate in the Borexino solar neutrino experiment and the DarkSide project for the search of weakly interacting particle dark matter (WIMPs) in our galaxy. Solar neutrinos have played a crucial role in the experimental confirmation that neutrinos have mass and oscillate. Since data acquisition started in 2007, Borexino has reached its design goal and measured the flux of mono-energetic 7-Beryllium solar neutrinos with enough precision to test the predictions of current solar models. After a scintillator purification campaign in 2011, Borexino is in a new phase of solar neutrino physics with the goal of measuring the entire solar neutrino spectrum. A precise knowledge of solar neutrinos will allow us to understand how the sun and other stars work, test the MSW-LMA neutrino oscillation paradigm and search for deviations from it. Borexino will possibly resolve an open question on the metallicity of the Sun's core, an important piece of information with which to study the evolution of larger stars in the universe. DarkSide-50, a dual-phase time projection chamber scheduled to come online in late 2012, will prototype design solutions for background free multi-tonne detectors with liquid argon as active target for WIMPs. A null observation would exclude some of the current leading dark matter candidates. A positive detection would begin to give answers to one of the big scientific unknowns of our times. DarkSide-50 will run with 50 kg of argon depleted more than 100-fold in the radioactive 39-Argon isotope. The DarkSide-50 Argon cryostat is surrounded by a compact, liquid scintillator neutron detector and immersed in the Borexino Counting Test Facility (CTF) water tank instrumented and operated as a Cherenkov muon veto. The Borexino and DarkSide collaborations have a significant overlap in personnel and technical and operational resources. Broader Impacts: The Borexino and DarkSide projects provide excellent opportunities for the training of graduate and undergraduate students in applications of software and hardware development, and fundamental physics. The techniques developed for Borexino and Darkside-50 can more broadly benefit technology relevant for medical imaging, nuclear non-proliferation and geology.