The detection of atmospheric fluorescence light from extensive air showers has become a powerful tool for accurate measurements of the energy and mass of ultra-high energy cosmic ray particles. Employing large area imaging telescopes with mirror areas of 10m2 or more, showers out to distances of 30km and more can be observed. Matrices of low-noise photomultipliers are used to detect the faint light of the air showers against the ambient night-sky background noise. The signal-to-noise ratio of such a system is found to be proportional to the square root of the mirror area times the quantum efficiency of the phototube. Thus, higher quantum efficiencies could potentially improve the quality of the measurement and/or lead to the construction of more compact telescopes. In this paper, we shall discuss such improvements to be expected from high quantum efficiency phototubes that became available on the market only very recently. A series of simulations has been performed with data of different types of commercially available high quantum efficiency phototubes. The results suggest a higher aperture and thus increased statistics for such telescopes. Additionally, the quality of the reconstruction can be improved.
Atmospheric multiple scattering of fluorescence light from extensive air showers and effect of the aerosol size on the reconstruction of energy and depth of maximum
Neutrino Telescope Array Letter of Intent: A Large Array of High Resolution Imaging Atmospheric Cherenkov and Fluorescence Detectors for Survey of Air-showers from Cosmic Tau Neutrinos in the PeV-EeV Energy Range
本意向书（LoI）描述了中微子望远镜阵列（NTA）项目的大纲和计划。高能中微子为强子加速提供了独特而无可争辩的证据。最近，冰立方已经报道了超过预期的来自大气秒的天文中微子候选者，但受到水切伦科夫探测方法的限制。下一代高能中微子望远镜应该能够为宇宙高能中微子建立无可争辩的证据。它不仅应该有数量级的更大的灵敏度，而且还应该有足够的指向精度来探测已知或未知的天文物体，而不会受到大气层的影响。拟议的装置是一个大型阵列的成像大气切伦科夫和荧光探测器的复眼站，具有宽视场和精细的观测能力，从PeV-EeV能量范围的宇宙τ中微子的空气簇射。这套先进的光学复杂系统主要是在全天空巡天高分辨率空气簇射探测器（Ashra）的基础上发展起来的，并采用τ簇射掠地方法对PeV-EeV τ中微子进行巡天。在标准GRB中微子注量的条件下，它可以对PeV-EeV τ中微子进行宽（30 ° x 360 °）和深（~400 Mpc）的巡天观测，而且在基本无背景的条件下，它的指向精度优于0.2 °。通过在宽视场中对掠地τ阵雨进行先进成像，我们的目标是明确发现和识别天文τ中微子源，为天体物理强子模型提供不可逃避的证据，以加速和/或在精确确定的方向上传播极高能量的质子。
