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標題: | 從極高能量的伽瑪射線到紅外單光子偵測: 在對撞能量十三兆電子伏特的質子對撞中,利用緊湊渺子螺線圈實驗尋找高質量光子對,以及超導奈米線單光子偵測器的發展 From ultra high energy to infrared photon detection: Search for beyond the Standard Model heavy diphoton resonances from proton-proton collisions at √s = 13TeV using the CMS detector with full Run-2 data & Development of Superconducting Nanowire Single Photon Detectors |
作者: | 吳新業 Hsin-Yeh Wu |
指導教授: | 裴思達 Stathes Paganis |
關鍵字: | 大型強子對撞機,緊湊渺子螺線圈,超導奈米線單光子偵測器,超導單光子偵測器,中遠紅外單光子偵測,量子資訊與通訊, LHC,CMS,SNSPD,Superconducting Single Photon Detectors,MIR Single Photon Detection,Quantum communication and information, |
出版年 : | 2023 |
學位: | 博士 |
摘要: | 單光子量測在許多領域的科學發現和應用中扮演著重要角色。由於光子與物質的相互作用機制,在不同光子能量尺度下並不相同,因此針對不同光子能量尺度,需選用不同的量測機制與手段。本論文著重於光子偵測分析和偵測器開發的兩個不同面向進行討論研究。
論文的第一部分介紹了使用2016年至2018年由CMS探測器在LHC上收集的數據,尋找高質量光子對共振態生成於質子-質子對撞過程。該數據集對應於138 fb-1的積分亮度。分析使用了'bump-hunt'技術,即對平滑下降的背景進行曲線擬合。研究重點放在自旋0和自旋2,質量範圍為0.6至7TeV以及質量寬度比為1.4*10-4、1.4*10-2和5.6*10-2 的共振態上。對通過膠子-膠子融合產生的純量共振態和Randall-Sundrum引力子設置了界限。以95%信心水準,根據關聯耦合參數值0.01、0.1和0.2,確定了Randall-Sundrum反曲空間模型中引力子的第一個Kaluza-Klein激發的下限質量為2.3、4.9和5.6TeV。此外,還為純量共振提供了碰撞截面的上限。該研究通過整合2016年至2018年的數據改進了以前CMS的結果,從而得到對新理論更嚴格的限制。這項分析中有多種策略已精進,包括使用可變直方圖區間、訊號形狀插值、訂定量測空間以去除純量模型雙光子質量譜的低質量尾部變形的影響以及背景研究的包絡線方法。 論文的第二部分集中在超導奈米線單光子偵測器(SNSPDs)的初步開發。由台大以及中研院合作開發的SNSPD原型採用7奈米厚的NbN超導體薄膜製成,置於MgO基板上。該元件由100奈米寬度和間距的奈米線圖案結構組成,覆蓋面積共12um*12um。使用中研院奈米光子學團隊的attoDRY800低溫系統進行實驗測試。奈米線的臨界電流(Ic),在4.6K測量時,約為176微安培,臨界溫度(Tc)約為8K。 SNSPD原型元件展示了兩種不同的工作模式:電阻模式和超導模式。在超導模式下,利用低於臨界電流的偏壓電流,使偵測器以類似Geiger模式的二元方式工作,當光子照射時,從超導狀態轉變為完全非超導狀態。在電阻模式下,偏壓電流超過臨界電流,導致連續的電阻變化,其變化量取決於吸收的光子的總能量。與超導模式中的離散電阻跳躍不同,電阻模式顯示出訊號振幅與光強度的直接相關性。訊號振幅光譜中具有可分辨的離散高斯峰,展示了光子數目解析的潛力。 基於第一個工作的SNSPD原型取得的結果,我們提出進一步優化和推進SNSPD,將其靈敏度擴展到更長的波長,具體目標是2微米至20微米甚至更長的範圍。實際所需優化包括製程技術,低溫系統重新設計和實現覆蓋此擴展波長範圍的雷射。該提議將為系外行星研究、深空通訊和暗物質研究等領域的突破開創新的可能性。 Single photon detection plays a pivotal role in numerous scientific discoveries and applications across various fields. The interaction of photons with matter differs significantly based on their energy, leading to diverse detection mechanisms. This thesis focuses on two distinct aspects of photon detection analysis and detector development. The first part of the thesis presents a comprehensive search for the resonant production of high-mass photon pairs, utilizing data collected from the CMS detector at the Large Hadron Collider (LHC) between 2016 and 2018. The dataset corresponds to an integrated luminosity of 138 fb-1. The analysis employs the bump-hunt technique, involving parametric fits to smoothly falling backgrounds. The signal interpretation focuses on spin-0 and spin-2 resonances with mass ranges spanning from 0.6 to 7 TeV and width-to-mass ratios of 1.4*10-4, 1.4*10-2, and 5.6*10-2. Limits are established for scalar resonances produced via gluon-gluon fusion, as well as for Randall-Sundrum gravitons. At a 95% confidence level, lower mass limits for the first Kaluza-Klein excitation of the graviton in the Randall-Sundrum warped extradimensional model are determined to be 2.3, 4.9, and 5.6 TeV, considering different values of the associated coupling parameter: 0.01, 0.1, and 0.2. Additionally, upper limits on the fiducial cross sections are provided for scalar resonances. This study improves upon previous CMS results by incorporating data from 2016 to 2018, leading to more stringent constraints to the signal model. Several analysis strategies are enhanced, including the utilization of variable binning, signal shape interpolation, generated mass fiducial region for the low mass tail in scalar model diphoton mass spectrum, and the envelope method for background studies. The second part of the thesis focuses on the preliminary development of superconducting nanowire single photon detectors (SNSPDs). The first working SNSPD prototype, developed through collaboration between NTU and AS, features a 7nm-thick NbN superconductor thin film on a MgO substrate. The device consists of a nano-wire meander pattern structure with 100nm width and pitch, covering a 12um*12um area. Experimental testing is conducted using the attoDRY800 cryogenics system at the AS nanophotonics group. The critical current (Ic) of the nano-wire, measured at 4.6 Kelvin, is approximately 176 uA, with a critical temperature (Tc) of around 8K. The SNSPD prototype exhibits two distinctive working modes: the resistive mode and the superconducting mode. In the superconducting mode, a bias current below the critical current is employed, allowing the detector to operate in a binary fashion similar to a Geiger-mode detector. It transitions from a superconducting to a fully non-superconducting state upon photon illumination. In the resistive mode, a bias current surpasses the critical current, resulting in continuous resistance changes dependent on the absorbed photons' total energy. Unlike the discrete resistance jump observed in the superconducting mode, the resistive mode demonstrates a direct correlation between signal amplitude and light intensity. The single photon peaks identified in the signal amplitude spectra reveal the single photon operation of the detector. Building upon the promising results obtained from the first working SNSPD prototype, we propose further optimization and advancement of SNSPD technology aiming to expand the sensitivity of SNSPDs towards longer wavelengths, specifically targeting the range of 2um to 20um or even beyond. The demanding optimizations include improvement in fabrication (such as new photon-coupling-enhancement design or SC materials other than NbN and WSi), cryogenics system redesign and the implementation of lasers covering the extended wavelength range. This proposal opens up new possibilities for breakthroughs in fields such as wideband optical communication to satellites (with the atmospheric window of wavelength region ~10um), exoplanet research, deep space communication and dark matter studies. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/89977 |
DOI: | 10.6342/NTU202303179 |
全文授權: | 同意授權(全球公開) |
顯示於系所單位: | 物理學系 |
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