HALO-1kT at LNGS

LNGS 的 HALO-1kT

• 批准号: SAPPJ-2019-00055
• 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: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762649
• 关键词: HALO; 1kT; LNGS

A type II supernova is powered by the energy liberated in the gravitational collapse of the core of a massive star. Post core collapse, the initially very hot proto-neutron star cools primarily by the emission of neutrinos, of all flavours, roughly equally partitioned. In fact, about 99% of the initial gravitational potential energy is released in a short burst of ~10 MeV neutrinos over a few tens of seconds. The measurement of the time evolution of the neutrino luminosity, flavour partition, and average energy is a direct window into supernova dynamics though a gravitational wave is also anticipated. The nuclear physics of lead, as a target material for the supernova neutrinos, provides for a dominant sensitivity to charged current (CC) interactions of the electron neutrino flux; complete insensitivity to CC interactions of the electron antineutrino flux; and minor sensitivity to all neutrino flavours through neutral current excitation channels. A detailed understanding of supernova dynamics is at the forefront of large-scale computational physics efforts and, when combined with observational data, offers the possibility of extracting fundamental neutrino properties as well as advancing our understanding of the supernova mechanism, heavy element nucleosynthesis, and other astrophysical questions. HALO-1kT is a proposed lead-based supernova neutrino detector to be constructed at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. It is an evolution of the successful, but smaller, HALO detector at SNOLAB. HALO-1kT is expected to outperform HALO by a factor of 25 in sensitivity. The scientific collaboration is Canadian-led with major participation by Italian and American groups. This SAP Project grant application is for stable and adequate funding for the Canadian group through the finalization of the full Experimental Proposal; the application for capital funding through CFI; and studies and preparations for experiment deployment. HALO-1kT is timely and possible due to the experience gained in the construction and operation of HALO at SNOLAB; the availability of 1000 tonnes of lead from the OPERA experiment and the enthusiasm at LNGS to re-invigorate their supernova detection capabilities; and the end of the American moratorium on the distribution of He-3 and its availability once again through the DOE Isotope Program. Neither HALO nor HALO-1kT can be claimed to be fully understood and calibrated until the neutrino-lead cross sections are known at supernova-relevant energies. A component of the funds requested here will support a measurement of these cross sections at Oak Ridge National Laboratory's Spallation Neutron Source. However, the bulk of the support for the cross section measurement is coming from a combination of the McDonald Institute (MI), Laurentian University, INFN, University of Washington, LNGS, and SNOLAB and a CFI-JELF submission in preparation.

II型超新星是由大质量星星核心引力坍缩释放的能量提供动力的。在核心坍缩后，最初非常热的原中子星星主要通过发射中微子而冷却下来，中微子有各种味道，大致均匀分布。事实上，大约99%的初始引力势能是在几十秒内以~10 MeV中微子的短爆发释放的。测量中微子光度、味分配和平均能量的时间演化是研究超新星动力学的一个直接窗口，尽管引力波也是预期的。作为超新星中微子的靶材料，铅的核物理学对电子中微子通量的带电电流（CC）相互作用具有主导的敏感性;对电子反中微子通量的CC相互作用完全不敏感;对所有通过中性电流激发通道的中微子味具有轻微的敏感性。对超新星动力学的详细了解是大规模计算物理学工作的最前沿，当与观测数据相结合时，提供了提取基本中微子性质的可能性，以及推进我们对超新星机制，重元素核合成和其他天体物理问题的理解。HALO-1 kT是一个拟议中的铅基超新星中微子探测器，将在意大利的大萨索国立科学院（LNGS）建造。它是SNOLAB成功的、但较小的HALO探测器的改进。预计HALO-1 kT的灵敏度将超过HALO 25倍。科学合作由意大利领导，意大利和美国团体参与其中。该SAP项目赠款申请旨在通过最终确定完整的实验提案为加拿大集团提供稳定和充足的资金;通过CFI申请资本资金;以及实验部署的研究和准备。HALO-1 kT是及时和可能的，因为在SNOLAB的HALO建造和运行中获得了经验; OPERA实验提供了1000吨铅，LNGS对重振其超新星探测能力的热情;美国停止分发He-3并再次通过能源部同位素方案提供He-3。在超新星相关能量的中微子-铅截面已知之前，HALO和HALO-1 kT都不能被完全理解和校准。这里所要求的资金的一部分将用于支持在橡树岭国家实验室的斯普林中子源测量这些横截面。然而，横截面测量的大部分支持来自McDonald Institute（MI）、Laurentian University、INFN、华盛顿大学、LNGS和SNOLAB的联合，以及正在准备的CFI-JELF提交。