HALO at SNOLAB

SNOLAB 的光环

• 批准号: 355451-2012
• 负责人: Virtue, Clarence
• 金额: $ 4.74万
• 依托单位: Laurentian University of Sudbury
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=515183
• 关键词: HALO; SNOLAB

The Helium and Lead Observatory (HALO) is a supernova neutrino detector currently under construction at SNOLAB. HALO is a long term, low cost, high livetime, and low maintenance, dedicated supernova detector. A core-collapse supernova is powered by the energy liberated in the gravitational collapse of the core of a massive star. The core is transformed to a hot proto-neutron star that rapidly cools by the emission of neutrinos of all flavours. In fact, about 99% of the total energy is released in the form of ~ 10 MeV neutrinos, in some tens of seconds. The direct measurement of the time evolution of the luminosity, flavour partition, and average neutrino energies are our best experimental window into the challenging field of supernova dynamics which is expected to lead to an improved understanding of supernovae and of fundamental neutrino properties. Lead is particularly interesting, as a medium for supernova detection, due to its low cost, high neutrino cross-section and low neutron absorption cross-section. Neutrino interactions in lead expel neutrons from the lead nuclei making a burst of detected neutrons the signature for the detection of a supernova. Conceptually HALO is a volume of lead instrumented with neutron detectors and shielded from environmental neutrons by water. While other supernova detectors are primarily sensitive to electron antineutrinos the nuclear physics of lead makes HALO dominantly sensitive to electron neutrinos through the charged current interaction and to all flavours of neutrinos through the neutral current interaction. These complementary sensitivities ensure that supernova data from HALO will be vital to unravelling the supernova neutrino signal and extracting physics from the next galactic supernova. The public investment required for the construction of HALO was kept modest by having access to 79 tonnes of lead, from the decommissioned Deep River Cosmic Ray Station, and more than 600 meters of He-3 neutron detectors from the final phase of the SNO experiment. These assets, valued at approximately seven million dollars, have been employed in the construction of HALO in SNOLAB.

氦和铅天文台（Halo）是Snolab目前正在建设的超新星中微子检测器。 Halo是长期，低成本，高生计和低维护，专用的超新星探测器。核心溢出的超新星由在巨大恒星核心的重力崩溃中释放的能量提供动力。核心被转化为热原始恒星，该恒星通过所有口味的中微子发射而迅速冷却。实际上，总能量的约99％以〜10 meV中微子的形式释放，几十秒钟。亮度，风味分区和平均中微子能量的时间演变的直接测量是我们进入超新星动力学挑战性领域的最佳实验窗口，这将导致对超新星和基本中微子特性的了解得到改善。由于其低成本，高中微子横截面和低中子吸收横截面，铅作为超新星检测的介质特别有趣。从铅核中中微子相互作用的中微子相互作用使铅核中的中子导致了一系列检测到的中子，以检测超新星的签名。从概念上讲，光环是一大堆带有中子探测器的铅仪器，并通过水遮挡了环境中子。虽然其他超新星探测器主要对电子抗神经替代物敏感，但铅的核物理学通过带电的电流相互作用以及通过中性电流相互作用来对电子中微子的敏感性敏感。这些互补的敏感性确保Halo的超新星数据对于揭开超新星中微子信号并从下一个银河系超新星中提取物理学至关重要。从SNO实验的最后阶段，从退役的Deep River Cosmic射线站和超过600米的HE-3中子探测器中获得了79吨铅，从而使Halo建造所需的公共投资保持了谦虚。这些资产的价值约为700万美元，用于在Snolab的Halo建造中。