Sudbury Neutrino Observatory - Queen's

萨德伯里中微子天文台（Sudbury Neutrino Observatory，SNO）是一个研究太阳和超新星中微子的大型国际项目。天文台已经通过证明中微子具有质量以及它们在不同类型的中微子之间振荡，为理解中微子做出了重大贡献。最常见的中微子被称为电子中微子，其性质与电子非常相似-除了中微子不带电荷且质量小得多。电子和电子中微子是轻子的一部分，其他轻子是μ子和τ子，以及μ子和τ中微子。当中微子穿过物质时，它们之间的相互作用非常少--只有一小部分在穿过整个太阳或地球时停止。太阳中产生大量的电子中微子-太阳产生的能量中约有2%以电子中微子的形式发射。由于它使用重水作为探测介质，SNO能够分别测量电子中微子的通量和所有中微子的总通量。该探测器基于1000吨重水，位于萨德伯里附近的克雷顿矿井地下2公里处。地下的位置是必要的，以过滤掉其他高能宇宙辐射。研究工作的很大一部分是尽量减少重水和其他组成和包围探测器的材料中自然发生的放射性，以便我们可以清楚地看到相对罕见的中微子事件（约10/天）。女王以多种方式参与其中。该项目的管理是女王的。我们负责校准检测器、光电倍增管、高纯水系统部件、电子设备、数据采集软件以及数据分析。我们在了解探测器性能、校准和数据分析方面发挥了重要作用。

The Sudbury Neutrino Observatory (SNO) is a large international project to study neutrinos from the sun and supernova. The observatory has already made a major contribution to the understanding of neutrinos by demonstrating that neutrinos have mass and that they oscillate between different neutrino types. The most common neutrino is called an electron neutrino, and has properties that are very similar to those of an electron- except that the neutrino has no charge and a much smaller mass. Electrons and electron neutrinos are part of a group of particles called leptons; the other leptons are muons and taus, and muon and tau neutrinos. When neutrinos travel through matter they interact only very rarely- only a tiny fraction stop in passing through the entire sun or earth. Electron neutrinos are produced in copious quantities in the sun- about 2% of the energy produced in the sun is emitted in the form of electron neutrinos. Because it uses heavy water as a detection medium, SNO is able to separately measure the flux of electron neutrinos and the total flux of all neutrinos. The detector is based on 1000 tonnes of heavy water, which is located 2 km underground in the Creighton mine near Sudbury. The underground location is necessary to filter out other high energy cosmic radiation. A large part of the research effort has been to minimize the amount of naturally occurring radioactivity in the heavy water and the other materials that make up and surround the detector, so that we can clearly see the relatively rare neutrino events (about 10/day). Queen's is participating in several ways. The administration of the project is Queen's. We are responsible for the calibration of the detector, for the photomultiplier tubes, and for parts of the high purity water system, electronics, data acquisition software, and for analysis of the data. We have taken a major role in understanding the detector performance, calibration and data analysis.