應用於微中子無線電波探測器的無人機載校正器與IceCube做為ARA外部觸發的可行性模擬

Development of drone-borne cal-pulser for radio observatory of neutrino and Simulation study of neutrino coincidence between ARA and IceCube

郭仲耘(Chung-Yun Kuo)

指導教授 ： 陳丕燊

國立臺灣大學/理學院/物理學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202104268

摘要

在IceCube與Fermi-LAT同時偵測到來自相同活躍星系核的微中子與伽馬射線訊號後，微中子逐漸被科學家認為是一個觀測宇宙的新媒介，而透過無線電波來觀測宇宙微中子的技術也在近年來快速地發展，本論文將著重討論上述領域的軟體模擬與硬體製作。

在本論文的第一部分，我們率先提出了於南極透過無人機攜帶天線來校正微中子觀測站的新方法，並開發出可以安裝於無人機的輕量化校正模組，論文中詳述了模組中各個子系統的運作方式與測試細節，並已成功將這個無人機校正器運用於臺灣東海岸山區與南極墨爾本山的三座天線站。

在本論文的第二部分，我們提出運用冰立方偵測器(IceCube)的微中子資訊來增加天壇陣列(ARA)的靈敏度，為了驗證這個想法的可行性，我們同時針對這兩個偵測器進行模擬，並計算微中子產生的訊號同時觸發兩個偵測器的機率。然而，結果表明以目前IceCube與ARA的位置幾何關係，這個想法並不可行。即便如此，我們展示了如何在這個模擬的基礎上，對正在計劃中的IceCube-Gen2偵測器進行最佳化，來將共同觸發的機率達到最大。

關鍵字

高能微中子 ； 高能宇宙射線 ； 共同觸發 ； 蒙地卡羅模擬 ； 無線電天線校正

並列摘要

Since observing concordance between the cosmic neutrinos and the gamma-rays from an active blazar, the cosmic neutrino has been regarded as a promising messenger to probe our universe. Radio detection of cosmic neutrino has advanced rapidly in recent years. In this thesis, we report on my hardware and simulation contribution to the radio detection method.

In the first part of this thesis, we present a portable calibration pulser system applied to radio antennas detecting ultra-high energy cosmic neutrinos. The system consists of a solid-state high-voltage impulse generator, a digital attenuator, a wideband (150-500 MHz) bi-cone antenna, and a differential GPS. Taking advantage of the light weight of each component(less than $1$ kg), we developed an airborne calibration system by attaching them to a commercial drone. We used this system for the TAROGE experiments in high mountains as well as in Antarctica.

In the second part of this thesis, we examine the possibility of having neutrino coincidence events between IceCube and ARA via several types of neutrino interaction channels by simulation. With the coincidence technique, we expect to reduce the energy threshold of ARA and further extend the detection volume of IceCube for the double-bang event. However, the result shows that it's not feasible to have coincidence among current configurations. We further investigate the optimal design of optical and radio detectors for the neutrino coincidence events with this simulation.

並列關鍵字

UHE neutrino ； UHE cosmic ray ； Coincidence technique ； Monte-Carlo simulation ； Radio calibration

參考文獻

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[3] A. Romero-Wolf et al. An interferometric analysis method for radio impulses from ultra-high energy particle showers. Astropart. Phys. 60, 72–85 (2015).

[4] S. Prohira et al. HiCal 2: An instrument designed for calibration of the ANITA experiment and for Antarctic surface reflectivity measurements. Nucl. Instrum. Meth. A, 918, 60–66 (2019).

[5] C. Chang et al. Beam Calibration of Radio Telescopes with Drones. Publ. Astron. Soc. Pac. 127, 1131–1143 (2015).