Non-Accelerator Physics with The Super-Kamiokande Detector

该奖项将支持该集团在日本神冈实验室使用Super-Kamiokande(Super-K)探测器的非加速器物理项目。自1996年以来，Super-K一直是天体物理探测器帮助理解中微子性质和寻找质子衰变的主要例子。随着目前的升级，它现在正在准备用大气中微子精确确定中微子振荡参数。大气中微子还提供了一个机会来了解各种中微子的相对质量，并且对所谓的电荷宇称(CP)破坏阶段很敏感，这可能有助于确定为什么宇宙中的物质比反物质多得多。该奖项还将支持观察其他类型的中微子相互作用的可能性，这些中微子相互作用将把对暗物质的间接搜索扩展到中/低暗物质质量。神冈实验室有一个广泛的计划，让公众、本科生和K-12学生参与到这项研究中来。致力于新系统的研究生将被整合到这些活动中，并讲授在Super-K中观察天体粒子物理所产生的物理学。每年夏天，该组织都会挑选UCI的本科生和高中生到UCI或日本工作。加利福尼亚州的COSMOS计划为高中生提供住宿学术体验，其使命是激发新一代未来科学家、工程师和数学家最具创造力的头脑。加州大学学院的教职员工创建了从天体物理到数学建模再到仅针对宇宙的海洋生态系统等主题的课程群。在这里，他们建议在实验粒子物理学中发起一个强调探测技术的集群。之前的一笔NSF拨款支持设计、建造和安装一个新的触发系统-宽带智能触发(WIT)系统，该系统完全处理未触发的原始数据流中的所有数据，并高效地提取电子，低于2.49 MeV，这是Super-K稳定和可靠的事件重建的极限。UCI集团将利用上一次奖项的投资，并在阳逻港数据分析方面发挥带头作用。Super-K目前正在进行升级，添加了Gd，以增强其中子探测能力。目前，中子是通过氢捕获发出的2.2 MeV光子在大约200微秒后观察到的。平均只有7个被探测到的光子，探测效率相当低。溶解0.2%Gd2(SO4)3后，90%的中子将被Gd俘获，这将产生8 MeV的伽马级联，大约35微秒后每次捕获产生约22个探测光子。高效率的中子探测将使超K-Gd的许多物理课题受益。这个项目推进了NSF宇宙大理想之窗的目标。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award will provide support for the group’s non-accelerator physics program at the Kamioka Laboratory in Japan with the Super-Kamiokande (Super-K) detector. Super-K has been a prime example of an astrophysics detector searching to help understand the properties of neutrinos and the search for proton decay since 1996. With the current upgrade, it is now preparing to precisely determine neutrino oscillation parameters with atmospheric neutrinos. Atmospheric neutrinos also provide an opportunity to understand the relative masses of the various neutrino flavors and are sensitive to the so-called Charge-Parity (CP)-violation phase, which could help identify why there is so much more matter than anti-matter in the Universe. This award will also support the possibility of observing other types of neutrino interactions that will extend the indirect search for dark matter to medium/low Dark Matter masses.The Kamioka Laboratory has an extensive program for involving the public, undergraduate students, and K-12 students in the excitement of this research. The graduate student working on the new system will be integrated into these activities and lecture on the physics that comes from looking at astroparticle physics in Super-K. Each summer, the group selects undergraduate students from UCI and high school students to work at UCI or in Japan. The State of California COSMOS program provides a residential academic experience for high school students with a mission to motivate the most creative minds of the new generation of prospective scientists, engineers, and mathematicians. UCI faculty create course “clusters” in topics from astrophysics to mathematical modeling to marine ecosystems just for COSMOS. Here, they propose to originate a cluster in experimental particle physics emphasizing detection techniques.A previous NSF grant supported the design, construction and installation of a new trigger system, the Wideband Intelligent Trigger (WIT) system, which completely processes all of the data in the un-triggered, raw stream and extracts electrons with high efficiency down 2.49 MeV, the limit of stable and reliable event reconstruction at Super-K. The UCI group will capitalize on the investment of the previous award and take the lead in WIT data analysis. Super-K is currently in the process of being upgraded with the addition of gadolinium in order to enhance its neutron detection capabilities. At present, neutrons are observed by the 2.2 MeV photon emitted from capture on Hydrogen after about 200 micro-sec. On average there are only seven detected photons and the detection efficiency is quite low. After dissolving 0.2% Gd2(SO4)3, 90% of the neutrons will capture on Gd which makes an 8 MeV gamma cascade and produces about 22 detected photons per capture after about 35 micro-sec. High efficiency neutron detection will benefit many physics topics in Super-K-Gd. This project advances the goals of the NSF Windows on the Universe Big Idea.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.