康卜吞成像光譜儀:資料分析與偏極化的測定

The Nuclear Compton Telescope: Data Analysis and Polarization Determination

梁昭賢(Jau-Shian Liang)

指導教授 ： 張祥光

國立清華大學/理學院/物理學系/博士(2010年)

https://doi.org/10.6843/NTHU.2010.00335

摘要

康卜吞成像光譜儀是一個以高空氣球運載之伽瑪射線望遠鏡。此康卜吞成像儀由十二個具有三維空間敏感度之鍺偵測器所組成。每一個偵測器為15公厘厚，54平方公分有效面積，兩側各覆蓋37個2公厘寬電極。此康卜吞成像儀被設計成以測量康卜吞散射方式觀測天文物理天體之原子核譜線與伽瑪射線偏極化。其極緊密設計與新偵測技術使得康卜吞成像儀得以藉由其優異的光譜解析力與背景抑制能力達到高偵測效率。
2009年，在新墨西哥州成功飛行了一次38小時的高空氣球實驗。此次實驗約收集了23小時的資料。我們並已建立了一系列用於氣球實驗資料分析之資料處理軟體，此軟體並可用處理來自蒙地卡羅模擬之數值資料。
本論文對2009年實驗資料進行了數項分析，包括時間分析、影像分析與偏極化分析。且測量並模型化飛行高度之背景輻射。蟹狀星雲之影像並成功在此資料被偵測到。為了偏極化分析並與真實資料比較，以蒙地卡羅法模擬飛行時的觀測資料。蟹狀星雲之偏極化未能在此次實驗被測量出來。實驗資料與模擬之結果大致互相吻合。
康卜吞成像儀計畫由美國與台灣數個組織共同合作執行。本論文著重呈現本人在計畫中參與的部分包括資料處理程序與蒙地卡羅法模擬並呈現2009年資料分析結果。

關鍵字

康卜吞成像儀 ； 伽瑪射線 ； 蟹狀星雲 ； 偏極 ； 偵測器

並列摘要

Abstract The Nuclear Compton Telescope (NCT) is a balloon-borne soft gamma-ray (0.2-10 MeV) telescope. The NCT consists of twelve 3D position sensitive germanium strip detector. Each detector is 15-mm thick, 54 cm^2 of active area, and covered by 37 2-mm pitch electrode strips on the opposite faces. The NCT is designed to observe astrophysical sources of nuclear line emission as well as gamma-ray polarization with higher sensitivity by using multiple Compton scattering technique. The ultra-compact design and new technologies allow NCT to achieve high efficiencies with excellent spectral resolution and background reduction.

Abstract A balloon flight was flew on a high altitude balloon from Fort Sumner, New Mexico on 2009 May 17 for a 38 hours fight. About 23 hours data has been collected during the flight. For data analysis of the NCT, the data processing pipeline for either flight data or Monte Carlo simulation has been established.

Abstract The data analysis, including timing analysis, image analysis and polarization analysis, was performed to the 2009 flight data. The background at float altitude was measured and modeled. The image of Crab nebula was detected. For the gamma-ray polarization analysis of Crab nebula and for comparison with flight data, detailed Monte Carlo simulations were performed. The polarization of Crab nebula was not detected in the flight data. Both the results of simulations and flight data are consistent with each other.

Abstract The NCT project involves the collaboration of several institutions in US and in Taiwan. The thesis presents an overview of the data processing pipeline, the Monte Carlo simulation and also the results from the data analysis of 2009 flight data in which the author heavily plays a major role.

並列關鍵字

Nuclear Compton Telescope ； NCT ； Gamma-ray ； polarization ； Crab nebula

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