A Wideband Intelligent Trigger

宽带智能触发

• 批准号: 1242514
• 负责人: Henry Sobel
• 金额: $ 32.57万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-15 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1242514&HistoricalAwards=false
• 关键词: Wideband; Intelligent; Trigger

The ability to observe very low-energy electrons is crucial for the physics reach of the Super-Kamiokande (SK) experiment at the Kamioka mine in Japan. It influences the sensitivity to a wide range of physics topics from solar neutrinos to proton decay to particle identification. This work will develop new software and hardware for a new very low-energy trigger for the SK experiment. In late 2008, all of the electronics and data acquisition components in SK were replaced, leading to an entirely new data-taking approach using real-time software triggers; however, the initial computing and storage capabilities of this system only allow an energy threshold similar to that of the previous system. The Wideband Intelligent Trigger (WIT) system will provide sufficient connectivity, storage, and CPU power to completely process the data in the un-triggered, raw stream and extract electrons with high efficiency down to a total energy of 3 MeV, which is the limit of stable and reliable event reconstruction at SK. It operates by evaluating each data block independently in a massively parallel fashion and applying new software algorithms that culminate in a two-stage vertex reconstruction. This procedure reduces the background, the processing time and the final data size to a manageable level. The new low energy threshold will: (1) improve SK's sensitivity to spectral distortions of solar neutrinos due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect, bringing new sensitivity to to the as-yet-unobserved upturn in the solar neutrino spectrum expected from large mixing angle MSW oscillations; (2) provide new functionality by acting as a galactic supernova burst trigger; and (3) by adding Gadolinium to the water, enable SK to detect neutrons with high efficiency, significantly reducing the atmospheric neutrino background to both the observation of proton decay and relic supernova neutrinos. The research supported by this award is an example of how advances in computing can extend the capabilities of existing instruments for basic research, effectively extending the physics reach and leveraging existing investments. The Kamioka Laboratory in Japan has an extensive program for involving the public, undergraduate students and K-12 students in the excitement of physics research. The postdoc and graduate student working on WIT will be integrated into these activities and lectures on the physics that comes from looking at low-energy events in Super-Kamiokande. Undergraduate students from the U.S. will work with this group in Japan during the summer for one to two months to help implement WIT and to help analyze the first data. They will maintain a collaborative relationship with faculty at a local undergraduate institution. They will also participate in the effort by attending Super-Kamiokande collaboration meetings, taking shifts at the experiment and participating in the scientific research.

观察极低能量电子的能力对于日本神冈煤矿的超级神冈(SK)实验的物理覆盖范围至关重要。它影响到对从太阳中微子到质子衰变到粒子识别等广泛物理主题的敏感性。这项工作将为SK实验开发一种新的极低能量触发器的新软件和硬件。2008年底，SK的所有电子和数据采集组件都被更换，导致了一种使用实时软件触发器的全新数据获取方法；然而，该系统的初始计算和存储能力仅允许与前一系统类似的能量阈值。宽带智能触发(WIT)系统将提供足够的连接、存储和CPU能力，以完全处理未触发的原始数据流中的数据，并高效地提取电子，总能量低至3 MeV，这是SK稳定可靠的事件重建的极限。它的运作方式是以大规模并行的方式独立评估每个数据块，并应用新的软件算法，最终完成两个阶段的顶点重建。此过程将背景、处理时间和最终数据大小减少到可管理的水平。新的低能量阈值将：(1)提高SK对由于Mikheyev-Smirnov-Wolfenstein(MSW)效应引起的太阳中微子光谱扭曲的敏感度，为大混合角MSW振荡预期的太阳中微子光谱迄今尚未观察到的上升带来新的灵敏度；(2)通过作为星系超新星爆发的触发器提供新的功能；以及(3)通过在水中添加Gd，使SK能够高效地探测中微子，大大减少了观测质子衰变和残留超新星中微子的大气中微子背景。该奖项支持的研究是一个例子，说明计算方面的进步如何扩展现有基础研究仪器的能力，有效地扩大物理覆盖范围并利用现有投资。日本神冈实验室有一个广泛的项目，让公众、本科生和K-12年级的学生参与到物理研究的兴奋中来。从事WIT研究的博士后和研究生将被整合到这些活动和讲座中，这些活动和讲座来自于观察超级神冈德的低能量事件。来自美国的本科生将在暑假期间与这群人一起在日本工作一到两个月，帮助实施WIT并帮助分析第一批数据。他们将与当地本科院校的教职员工保持合作关系。他们还将通过参加超级神冈合作会议、在实验中轮班和参与科学研究来参与努力。