Design of a capacitive main power coupler for RF superconducting accelerators

• 作 者: 贺斐思 郝建奎 张保澄 赵夔
• 机 构: State Key Laboratory of Nuclear Physics and Technology,Peking University,Beijing 100871,China,State
• 出 处: 中国物理C
• 发表日期: 2008年07期
• 关键词: coupler capacitive accelerator ceramic Electron bandwidth antenna purity Peking

An updated main coupler has been designed for the superconducting accelerator of Free Electron Laser(FEL)project under construction in Peking University.A capacitive structure is chosen for the main coupler.Numerical investigation using CST Microwave Studio demonstrates the cold window part.The other nonstandard structures such as holding rods and antenna are also optimized.The coupler uses a 95% purity Al_2O_3 ceramic cold window.The VSWR(Vottage Standing Wave Ratio)is 1.02 at 1.3 GHz and the frequency bandwidth is 45 MHz with VSWR<1.1.The electric field intensity is 8.5×10~(-2)kV/mm around the window with 20 kW Continuous Wave(CW)transmitted power.The Q_(ext)is designed variable from 5×10~6 to 1×10~7.

An updated main coupler has been designed for the superconducting accelerator of Free Electron Laser (FEL) project under construction in Peking University. A capacitive structure is chosen for the main coupler. Numerical investigation using CST Microwave Studio demonstrates the cold window part. The other nonstandard structures such as holding rods and antenna are also optimized. The coupler uses a 95% purity Al_2O_3 ceramic cold window. The VSWR (Vottage Standing Wave Ratio) is 1.02 at 1.3 GHz and the frequency bandwidth is 45 MHz with VSWR <1.1.The electric The Q ext is designed variable from 5 × 10 ~ 6 to 1 × 10 ~ 7.