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arXiv 1708.01059astro-ph.IMphysics.ins-det
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宽视场gamma-ray探测器阵列ALTO的模拟研究

Simulation study for the proposed wide field-of-view gamma-ray detector array ALTO

Satyendra Thoudam, Yvonne Becherini, Michael Punch

摘要:

ALTO是一个用于甚高能伽马射线天文学的宽视场空气簇射探测器阵列,拟安装在南半球海拔约5.1公里的高度。该阵列将使用水切伦科夫探测器,如HAWC天文台,但与闪烁探测器相结合,以探测大气中VHE伽马射线引起的空气簇射。它的设计是为了获得更低的能量阈值、更好的能量和角分辨率以及更高的灵敏度。该阵列将由分布在直径约160米的圆形区域内的约1250个小型(直径3.6米)探测器单元组成。每个探测器单元将由一个水切伦科夫探测器和一个液体闪烁探测器组成,液体闪烁探测器下面将优先识别μ子,促进背景(宇宙射线)抑制,从而提高灵敏度。由于探测器的紧密排列和体积小,可以对地面的空气簇射足迹进行精细采样,因此,背景抑制能力将进一步增强。在这方面的贡献,我们提出了蒙特卡罗模拟的实验进行CORSIKA和GEANT 4模拟包。阵列的重建精度的簇射核心和到达方向,以及初步估计的触发能量阈值后,初步选择削减一个点状伽马射线源的预期性能。

英文摘要:

ALTO is a wide field-of-view air shower detector array for very-high-energy (VHE) gamma-ray astronomy, proposed to be installed in the Southern Hemisphere at an altitude of about 5.1 km above sea level. The array will use water Cherenkov detectors, as in the HAWC observatory, but combined with scintillator detectors, to detect air showers induced by VHE gamma rays in the atmosphere. It is being designed to attain a lower energy threshold, better energy and angular resolution, and improved sensitivity. The array will consist of about 1250 small-sized (3.6 m diameter) detector units distributed over a circular area of about 160 m in diameter. Each detector unit will consist of a water Cherenkov detector and a liquid scintillation detector underneath which will preferentially identify muons, facilitating the background (cosmic ray) rejection, thereby improving the sensitivity. The background rejection will be further enhanced by the close-packed arrangement and the small size of the detectors which will allow a fine sampling of air-shower footprints at the ground. In this contribution, we present the Monte-Carlo simulation of the experiment performed using CORSIKA and GEANT4 simulation packages. The expected performance of the array in terms of reconstruction accuracies of the shower core and arrival direction, as well as preliminary estimate of the trigger energy threshold after preliminary selection cuts for a point-like gamma-ray source are presented.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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