Operation of the Utah High Energy Cosmic Ray Observatory (FEI, FEII)

这笔拨款将支持犹他大学“苍蝇之眼”（FE I和FE II）探测器的持续运行。这项研究关注的是围绕从太空进入地球大气层的最高能量宇宙射线的基本问题。这些射线的性质、来源和能量由位于犹他州杜格韦市（距离盐湖城约90英里）的FE I和FE II通过测量宇宙射线碎片通过时空气中氮发出的微量光来检测。在宇宙射线阵雨中产生的氮荧光被两组镜子（分别是FE I和FE II）聚焦到光电倍增管上。数据以电子方式记录，并通过离线计算机分析从位置和时间信息重建淋浴轨迹方向。星雨的形状、方向和大小被用来确定主要宇宙辐射的性质、来源和能量。

This grant will support continued operation of the Fly's Eye (FE I and FE II) detectors by the University of Utah. The research addressed concerns the fundamental questions surrounding the very highest energy cosmic rays which enter Earth's atmosphere from space. The nature, source and energy of these rays are examined by FE I and FE II situated at Dugway, Utah approximately 90 miles from Salt Lake City, by measuring the minute amounts of light emitted by nitrogen in the air as cosmic ray fragments pass through. Nitrogen fluorescence produced in cosmic ray showers is focussed by two arrays of mirrors (FE I and FE II, respectively) onto photomultiplier tubes. Data are recorded electronically, and shower track directions are reconstructed from position and timing information by off line computer analysis. Shower shape, direction and size are used to determine the nature, origin and energy of the primary cosmic radiation.