Author Affiliations
1National Synchrotron Radiation Labratory, University of Science and Technology of China, Hefei 230027, China2Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China3School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230027, Chinashow less
Fig. 1. Electromagnetic field diagram of monopole mode and dipole mode
Fig. 2. Block diagram of measurement system
Fig. 3. Schematic diagram of the overall structure of the double cavity (a) 3D view, (b) Sectional view, (c) Side view
Fig. 4. Cavity field shape and choosing probe insert position (a) Cavity 1, (b) Cavity 2
Fig. 5. Resonant frequency varies with the cavity radius (a) Cavity 1, (b) Cavity 2
Fig. 6. Output signals of cavity 1 (a) Time domain, (b) Frequency domain
Fig. 7. Output signals of cavity 2 (a) Time domain, (b) Frequency domain
Fig. 8. Calibration of linear relationship for bunch length
Fig. 9. Calibration of linear relationship for bunch charge
Fig. 10. Block diagram of RF front-end
| 参数 Parameter | 值Value |
|---|
| 束团能量 Bunch energy / GeV | 1.0~3.5 | | 单脉冲长度 Bunch length / ps | 3.3 | | 正电子束团电荷量 Positron bunch charge / nC | 1.5 | | 单脉冲重复频率 Bunch Reptition rate / Hz | 50 |
|
Table 1. Beam parameters of STCF
| 参数 Parameter | 值Value |
|---|
| / mm | 77.73 | | / mm | 66.53 | | / mm | 37.00 | | / mm | 29.42 | | / mm | 2.0 | | / mm | 2.0 | | / mm | 10.0 | | / mm | 10.0 | | / GHz | 1.5 | | / GHz | 6.5 |
|
Table 2. Parameters of resonant cavity
| 品质因数Q values | TM010 | TM030 |
|---|
| Q0 | 717.9 | 1 517.8 | | QL | 687.4 | 940.8 | | Qext | 16 168.8 | 2 474.8 |
|
Table 3. Results of Q values
| 束团长度Bunch length / ps | TM010频谱幅度VTM010 / 10-8 | TM030频谱幅度VTM030 / 10-8 | 频谱幅度比值VTM010 /VTM030 | 束团长度测量值Measured bunch length / ps | 相对误差Relative error / % |
|---|
| 1.0 | 2.387 5 | 4.764 6 | 0.501 1 | 1.032 | 3.203 | | 2.0 | 2.387 2 | 4.752 9 | 0.502 3 | 2.005 | 0.264 | | 3.0 | 2.386 6 | 4.733 2 | 0.504 2 | 2.997 | 0.105 | | 4.0 | 2.385 9 | 4.705 8 | 0.507 0 | 3.995 | 0.136 | | 5.0 | 2.384 9 | 4.670 8 | 0.510 6 | 4.995 | 0.105 | | 6.0 | 2.383 7 | 4.628 2 | 0.515 0 | 5.996 | 0.066 | | 7.0 | 2.382 3 | 4.578 3 | 0.520 3 | 6.998 | 0.031 | | 8.0 | 2.380 7 | 4.521 5 | 0.526 5 | 8.000 | 0.001 | | 9.0 | 2.378 9 | 4.457 9 | 0.533 6 | 9.002 | 0.021 | | 10.0 | 2.376 9 | 4.387 9 | 0.541 7 | 10.004 | 0.041 |
|
Table 4. Simulation error of bunch length
| 束团电荷量 | TM030频谱幅度 | 束团电荷量测量值 | 相对误差 |
|---|
| Bunch charge / nC | VTM030 / 10-8 | Measured bunch charge / nC | Relative error / % | | 1.0 | 3.15 | 0.999 9 | 0.013 4 | | 1.1 | 3.46 | 1.099 9 | 0.013 4 | | 1.2 | 3.78 | 1.199 8 | 0.013 3 | | 1.3 | 4.09 | 1.299 8 | 0.013 3 | | 1.4 | 4.40 | 1.399 8 | 0.013 3 | | 1.5 | 4.72 | 1.499 8 | 0.013 3 | | 1.6 | 5.03 | 1.599 8 | 0.013 2 | | 1.7 | 5.35 | 1.699 8 | 0.013 2 | | 1.8 | 5.66 | 1.799 8 | 0.013 2 | | 1.9 | 5.98 | 1.899 7 | 0.013 2 | | 2.0 | 6.29 | 1.999 7 | 0.013 1 |
|
Table 5. Simulation error of bunch charge
| 束团横向偏移Transverse excursion/ mm | TM010频谱幅度相对偏差ΔVTM010/VTM010 | TM030频谱幅度相对偏差ΔVTM030/VTM030 | 束团长度测量相对误差Measured σ relative error/ % | 束团电荷量测量相对误差Measured q relative error/ % |
|---|
| 1×10-3 | 3.375×10-7 | 8.475×10-8 | 0.322 | 0.013 2 | | 1×10-2 | 4.218×10-8 | 1.229×10-6 | 0.316 | 0.013 4 | | 1×10-1 | 5.948×10-6 | 1.413×10-5 | 0.206 | 0.014 7 | | 1×100 | 9.090×10-5 | 1.841×10-4 | 1.274 | 0.031 7 |
|
Table 6. Simulation measurement error of bunch length and charge brought by bunch transverse excursion
| 束团轨迹倾斜角度Bunch trajectory angle/ mrad | TM010频谱幅度相对偏差ΔVTM010/VTM010 | TM030频谱幅度相对偏差ΔVTM030/VTM030 | 束团长度测量相对误差Measured σ relative error/ % | 束团电荷量测量相对误差Measured q relative error/ % |
|---|
| 1×10-3 | 6.732×10-7 | 2.318×10-10 | 0.327 | 0.013 2 | | 1×10-2 | 7.995×10-7 | 7.524×10-9 | 0.319 | 0.013 2 | | 1×10-1 | 1.262×10-7 | 1.271×10-7 | 0.322 | 0.013 3 | | 1×100 | 2.987×10-6 | 9.323×10-7 | 0.311 | 0.013 1 |
|
Table 7. Simulation measurement error of bunch length and charge brought by oblique angle of the trajectory
