射頻偏轉腔自1960初被提出後，在加速器領域持續的被廣泛使用。對於束長量測，射頻偏轉腔可取得電子束完整縱向外觀、具高解析度、可實現單脈衝量測等特性使其在各大研究中心SLAC、CERN、DESY等不斷被改進及應用於其他實驗，如六維相空間診斷、自由電子雷射X光量測、粒子分離器、產生超短電子脈衝等，現在已成了加速器裝置束流診斷的重要工具。和加速器不同，大部分射頻偏轉腔的工作模態為〖TM〗_11，此模態在近軸處存在橫向磁力，對處於不同微波相位的帶電粒子作用不同的勞倫茲力，藉此使粒子偏離中心軸，達到束長量測的目的。
本研究中，我們以SPARC、SLAC、THU等的駐波結構射頻偏轉腔設計做為參考，依國家同步輻射研究中心所提出VUV/THz FEL 自由電子雷射設施構想的需求，設計一可對光陰極注射器進行束流診斷的2998 MHz、駐波形式、運作在π模的三腔偏轉腔，希望在電子能量為數個MeV下可達到sub-ps的解析長度。
我們從研究偏轉腔的結構和微波特性開始，計算出束流診斷所需的腔體形式、腔體數量和解析度，接著使用CST Microwave Studio作為模擬三維偏轉腔微波特性的工具，利用Eigenmode solver 和 Frequency solver調整腔體及耦合孔尺寸，使每個腔體有相同大小的磁場和工作於正確的頻率。另外使用CST Particle Studio 模擬電子束經偏轉腔的變化。最後製作原型，將其量測結果與理論及模擬比較。模擬的結果顯示，以同步輻射光陰極注射器的電子參數為例，設計出的腔體在輸入功率為1 MW下可以達到約500 fs的解析長度。

摘要 i
Abstract ii
致謝 iii
目錄 iv
表目錄 vii
圖目錄 viii

第一章 簡介 1
1.1 背景 1
1.2 研究動機 2
1.3 研究目的 4
第二章 文獻回顧 5
2.1 粒子分離器[11、12] 5
2.2 電子束六維空間量測設計[18~20] 7
2.3 FEL產生之X光脈衝時序上之量測[23~25] 9
2.4 駐波結構與行波結構偏轉腔之比較[14] 10
第三章 基本原理 11
3.1 微波共振腔原理 11
3.1.1 圓柱腔體之模態及電磁場分布[8] 11
3.1.2 偏轉腔工作模態[8] 13
3.2 偏轉腔相關之物理量 15
3.2.1 品質因子 15
3.2.2 偏轉電壓[8] 16
3.2.3 分流阻抗及R/Q[8、29] 18
3.3 電子束長測量理論 19
3.3.1偏轉腔傳輸矩陣[8] 19
3.3.2 離軸現象[16] 21
3.3.3 電子束長量測原理[5~8、13~15] 23
3.3.4 電子束長量測之解析度[5~8、13~15] 24
第四章 模擬及分析 25
4.1 模擬工具介紹 25
4.1.1 PAMELA[29] 25
4.1.2 CST&HFSS[30、31] 25
4.2 光陰極系統電子束模擬 26
4.3 設計方向 29
4.4 偏轉腔模擬 30
4.4.1 Eigenmode Solver 模擬結果 31
4.4.2 Frequency Solver 耦合孔模擬結果 34
4.4.3 Frequency Solver 完整結構模擬結果 36
4.5 粒子束行經偏轉腔之模擬 45
4.5.1 模擬方法 45
4.5.2 模擬結果 46
第五章 偏轉腔微波特性量測 52
5.1量測原理[32] 52
5.1.1 品質因子量測原理及方法[32] 52
5.1.2 電磁場分布量測原理及方法[18] 55
5.1.3 校正腔製作及測量 56
5.2偏轉腔原型量測結果 60
第六章 結論與討論 66
參考文獻 67
附錄A 模擬設置 70
A.1 射頻偏轉腔之CST模擬設置 70
A.2 粒子束經射頻偏轉腔之CST模擬設置 72
附錄B 工程圖 74
B.1 射頻偏轉腔工程圖 74
B.2 校正腔工程圖 77

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