BTF加速器物理设计

Concept Design of the BTF Accelerator

北京X射线自由电子激光试验装置(BTF)将“寄生”在BEPCⅡ直线注入器这一国内能量最高, 性能最好的电子直线加速器上．BTF将弃用现有直流枪予注入器,采用光注入器(photoinjector)经低能输运线斜注入到BEPCⅡ直线加速器主加速器,同时拆掉三节加速管以安装两级磁压缩器,并在A46 后拆掉二节加速管引出束流,经高能输运线后进入波荡器．模拟结果表明改造后的直线加速器BTF电子能量可达1．18GeV、能散0．15％、归一化发射度小于2．5mm·mrad．

Beijing X-ray free electron laser test facility (BTF) will reside in the BEPCⅡ Linac, which is the best electron linac in China. The BTF will not use the existing DC gun pre-injector, but use photoinjector to obliquely inject beam to the main linac of the BEPCⅡ. At the same time, three accelerator sections will be removed in order to install two magnetic compressors to compress the electron bunch. After the accelerator section A46, the beam is extracted and injected to the undulator through high energy transport line. The BTF will provide the electron beam with the energy of 1.18GeV, the energy spread of 0.15%, and the normalized emittance of less than 2.5mm·mrad.