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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=691332
• 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恒星核心的引力坍缩释放的能量提供能量的。在核心坍缩后，最初非常热的原中子星主要是通过发射各种类型的中微子来冷却的，这些中微子大致上是均匀分布的。事实上，大约99%的初始引力势能是在几十秒内释放的~10 MeV中微子的短爆发中释放的。中微子的光度、风味分配和平均能量的时间演化的测量是一个直接的窗口到超新星动力学，虽然引力波也预期。铅的核物理特性，作为超新星中微子的靶材料，提供了对电子中微子通量的带电电流（CC）相互作用的主要敏感性；对电子反中微子通量的CC相互作用完全不敏感；通过中性电流激发通道对所有中微子口味都有轻微的敏感性。对超新星动力学的详细了解是大规模计算物理工作的前沿，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，并推进了我们对超新星机制，重元素核合成和其他天体物理问题的理解。******HALO-1kT是一种基于铅的超新星中微子探测器，将在意大利的国家实验室建造。它是SNOLAB成功的小型HALO探测器的改进版。HALO- 1kt的灵敏度预计比HALO高25倍。这项科学合作是由加拿大领导的，意大利和美国的团体主要参与。本SAP项目拨款申请旨在通过完成完整的实验提案，为加拿大小组提供稳定和充足的资金；通过原讼法庭申请资金；以及实验部署的研究和准备。HALO- 1kt是及时和可能的，因为在SNOLAB的HALO建设和运营中获得了经验；OPERA实验中1000吨铅的可用性以及LNGS重新激活其超新星探测能力的热情；美国终止了对氦-3的分发，并再次通过美国能源部的同位素计划获得它。在超新星相关能量的中微子-铅截面已知之前，HALO和HALO- 1kt都不能被完全理解和校准。这里申请的资金的一部分将支持在橡树岭国家实验室的散裂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麦当劳研究所（MI）、劳伦森大学、INFN、华盛顿大学、LNGS和SNOLAB的联合，以及一份正在准备中的CFI-JELF提交。＊＊＊＊＊