CAREER Towards a GZK Neutrino Detector at the South Pole

该奖项是根据2009年《美国复苏和再投资法案》(Public Law 111-5)资助的。在发现宇宙射线近100年后，中微子望远镜正在成为探索宇宙射线起源的多重信使方法的组成部分。中微子是独特的天文信使，它可以为识别宇宙射线的来源和产生宇宙射线的物理过程提供关键信息。中微子通过磁场保持其方向信息，并指向其来源。它们可以在距离源头很远的地方传播，而不会有明显的衰减。观测到来自天体物理源的中微子将是强子加速的明确证据，因为宇宙质子加速器预计会产生类似光度的宇宙射线、伽马射线和中微子。最近来自HiRes和Auger的数据似乎支持“GZK截止”的存在，这是由于光产生效应引起的宇宙射线光谱的改变，因此人们预计带电的介子衰变会产生超高能中微子。由于极高能量下的低通量，必须使用新的技术来建立一个具有成本效益的阵列，足够大到足以在GZK能量下获得大量具有统计意义的事件。一种这样的技术使用阿斯基恩效应，在这种效应中，无线电频率(RF)中的切伦科夫辐射被用来测量中微子相互作用产生的簇射的能量和方向。该奖项提供资金，继续研究和开发一种探测器，以探测中微子在冰等射频透明介质中诱导的簇射的射频发射。在南极安装这种射频传感器将大大提高冰立方阵列的通量灵敏度。该项目的更广泛影响包括参与公共宣传，努力将美国马里兰州的QuarkNet计划扩大到更多的受众，以及访问当地高中，与学生和教师谈论研究和作为科学家的经验。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Nearly one hundred years after the discovery of cosmic rays, neutrino telescopes are becoming an integral part of a multi-messenger approach to discovering their still elusive origins. Neutrinos are unique astronomical messengers which may provide critical information in identifying sources of cosmic rays and the physics processes out of which they are born. Neutrinos retain their directional information through magnetic fields and point back to their source. They can travel long distances from their sources without significant attenuation. The observation of neutrinos from an astrophysical source would be unambiguous evidence for hadronic acceleration, since cosmic proton accelerators are expected to produce cosmic rays, gamma rays and neutrinos with similar luminosities. Recent data from HiRES and AUGER seem to support the existence of the "GZK cutoff", the modification of the cosmic ray spectrum due to the photoproduction effect and hence one expects a flux of ultra-high energy neutrinos from the charged pion decays.Because of the low flux at extremely high energies, novel techniques must be employed to build a cost effective array large enough to gain a statistically meaningful number of events at GZK energies. One such technique uses the Askaryan effect where the Cerenkov radiation in the radio frequencies (RF) is used to measure the energy and direction of the showers that result from the neutrino interactions. This award provides funds to continue research and development towards a detector to sense the RF emission from neutrino induced showers in RF transparent media such as ice. Such an RF sensor at the South Pole would significantly extend the flux sensitivity of the IceCube array. The Broader Impacts of this project include involvement in public outreach, working to expand U. Maryland's QuarkNet program to a larger audience and visiting local high schools to talk to students and teachers about research and experiences as a scientist.