1.3 GHz连续波超导射频腔的数字低电平射频系统和腔模拟器设计及测试

Liu Kui; Wang Cheng; Huang Yuxuan; Zhu Kuntuo; Wang Tao

doi:10.11884/HPLPB202436.230325

1.3 GHz连续波超导射频腔的数字低电平射频系统和腔模拟器设计及测试

doi: 10.11884/HPLPB202436.230325

刘奎^{1, 2,},
王程³,
黄宇轩^{1, 2},
朱坤托^{1, 2},
王滔^{1, 2}

1.
上海航天智能计算技术重点实验室，上海 201109
2.
上海航天电子技术研究所，上海 201109
3.
中国科学院上海高等研究院，上海 201210

详细信息

中图分类号: TL506
计量
- 文章访问数: 181
- HTML全文浏览量: 106
- PDF下载量: 38
- 被引次数: 0
出版历程
- 收稿日期: 2023-09-19
- 修回日期: 2024-04-15
- 录用日期: 2024-04-15
- 网络出版日期: 2024-06-15
- 刊出日期: 2024-07-04

Digital low-level radio frequency system and cavity simulator for 1.3 GHz continuous-wave superconducting radio-frequency cavity

Liu Kui^{1, 2
,},
Wang Cheng³,
Huang Yuxuan^{1, 2},
Zhu Kuntuo^{1, 2},
Wang Tao^{1, 2}

1.
Key Laboratory of Intelligent Computing Technology, SAST, Shanghai 201109, China
2.
Shanghai Aerospace Electronic Technology Institute, Shanghai 201109, China
3.
Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China

More Information

Author Bio:
Liu Kui, liukui_804@163.com

摘要

摘要:
1.3 GHz连续波超导射频腔需要高精度低电平射频（LLRF）系统来稳定超导腔的电磁场。但由于1.3 GHz CW射频腔的高负载品质因数和宽电磁频段，射频腔在频域中的电磁带宽较小。射频功率源与射频腔体之间的微小电磁频率差异易造成发生器驱动谐振器控制系统的不稳定，最终导致腔体电磁场的变化。开发了一种自激环控制系统，以防止“有质”不稳定性的发生，并补偿微噪声的影响。此外，还开发了数字1.3 GHz射频腔体模拟器，用于验证LLRF系统的设计算法。测试表明，即使在射频腔失谐5 Hz时，自激励控制系统也能确保腔场的稳定性。经过对比，验证了1.3 GHz射频腔体模拟器是测试新算法的可靠平台。
- RF腔模拟器 /
- 自激励环路 /
- 发生器驱动 /
- RF低电平控制系统
Abstract:
A highly precise low-level radio-frequency (LLRF) system for a 1.3 GHz continuous-wave (CW) superconducting radio-frequency (RF) cavity is required to stabilize the electromagnetic field of cavities. However, because of the high loaded quality factor and wide electromagnetic frequency band of the 1.3 GHz CW RF cavity, the RF cavity has a small electromagnetic bandwidth in the frequency domain. The small electromagnetic frequency mismatch between the RF power source and RF cavity can easily cause ponderomotive instabilities in the generator driven resonator control system, eventually resulting in variations in the electromagnetic field of the cavity. In this study, a self-excited loop (SEL) control system was developed to prevent the occurrence of ponderomotive instabilities and compensate for the effects of microphonics noise. In addition, a digital 1.3 GHz RF cavity simulator, which can easily verify the designed algorithms of the LLRF system, was developed. The recorded measurements show that the SEL control system can ensure stability of the cavity field even when the RF cavity is detuned by 5 Hz. The comparison and validation have verified that the cavity simulator is a reliable platform to test the new algorithms.
- RF cavity simulator /
- self-excited loop /
- generator driven resonator /
- low-level RF system

HTML全文

Figure 1. Simplified diagram of the GDR and SEL system

下载: 全尺寸图片幻灯片

Figure 2. Schematic diagram of LLRF system framework

下载: 全尺寸图片幻灯片

Figure 3. Structures of the SEL and GDR control algorithm

下载: 全尺寸图片幻灯片

Figure 4. Layout of the 1.3 GHz cavity simulator

下载: 全尺寸图片幻灯片

Figure 5. Comparison of bode plots with different bit lengths of the 1.3 GHz continuous wave superconducting cavity digital model (blue line: continuous model; green line: 32 bit; red line: 48 bit)

下载: 全尺寸图片幻灯片

Figure 6. Hardware of the LLRF system and cavity simulator

下载: 全尺寸图片幻灯片

Figure 7. Diagram of address space and interfaces connection of MicroTCA.4 firmware^[23]

下载: 全尺寸图片幻灯片

Figure 8. Measured values and ideal values of the cavity field under the cavity simulator detuned at 50 Hz

下载: 全尺寸图片幻灯片

Figure 9. Amplitude and phase of the cavity field and the output of the LLRF controller in the locked SEL mode when the detuning frequency is 5 Hz

下载: 全尺寸图片幻灯片

参考文献(24)

[1]	Rolles D. Time-resolved experiments on gas-phase atoms and molecules with XUV and X-ray free-electron lasers[J]. Advances in Physics: X, 2023, 8: 2132182.
[2]	McNeil B W J, Thompson N R. X-ray free-electron lasers[J]. Nature Photonics, 2010, 4(12): 814-821. doi: 10.1038/nphoton.2010.239
[3]	Liu Tao, Huang Nanshun, Yang Hanxiang, et al. Status and future of the soft X-ray free-electron laser beamline at the SHINE[J]. Frontiers in Physics, 2023, 11: 1172368. doi: 10.3389/fphy.2023.1172368
[4]	Liu Kui, Li Lin, Wang Cheng, et al. Multi-port cavity model and low-level RF systems design for VHF gun[J]. Nuclear Science and Techniques, 2020, 31: 8. doi: 10.1007/s41365-019-0711-2
[5]	Neumann A. Compensating microphonics in SRF cavities to ensure beam stability for future free electron lasers[D]. Hamburg: University of Hamburg, 2008.
[6]	Neumann A, Anders W, Kugeler O, et al. Analysis and active compensation of microphonics in continuous wave narrow-bandwidth superconducting cavities[J]. Physical Review Special Topics-Accelerators and Beams, 2010, 13: 082001. doi: 10.1103/PhysRevSTAB.13.082001
[7]	Luo Lei, Sun Jinwei, Huang Boyan. A novel feedback active noise control for broadband chaotic noise and random noise[J]. Applied Acoustics, 2017, 116: 229-237. doi: 10.1016/j.apacoust.2016.09.029
[8]	Badillo I, Jugo J, Portilla J, et al. Pxie-based LLRF architecture and versatile test bench for heavy ion linear acceleration[J]. IEEE Transactions on Nuclear Science, 2015, 62(3): 963-971. doi: 10.1109/TNS.2015.2418536
[9]	Reece C. Overview of SRF-related activities at Jefferson Lab[C]//Proceedings of the 10th Workshop on RF Superconductivity. 2001.
[10]	Schulze D. Ponderomotive stability of R. F. resonators and resonator control systems[R]. ANL-TRANS-944, 1972.
[11]	Delayen J R. Phase and amplitude stabilization of superconducting resonators[D]. California: California Institute of Technology, 1978.
[12]	Pławski T. Digital RF control system for superconducting cavity with large Lorentz force detuning coefficient[D]. Warsaw: Warsaw University of Technology, 2014.
[13]	Konrad M. Development and commissioning of a digital rf control system for the S-DALINAC and migration of the accelerator control system to an EPICS-based system[D]. Darmstadt: Technische Universität Darmstadt, 2013.
[14]	Powers T. Practical aspects of SRF cavity testing and operations[C]//SRF Workshop. 2011: 60-63.
[15]	Geßler P. Synchronization and sequencing of data acquisition and control electronics at the European X-ray free electron laser[D]. Hamburg: Technische Universität Hamburg, 2015.
[16]	Doolittle L, Ma Hengjie, Champion M S. Digital low-level RF control using non-IQ sampling[C]//Proceedings of LINAC2006. 2006: 568-570.
[17]	Geng Zheqiao, Kalt R. Advanced topics on RF amplitude and phase detection for low-level RF systems[J]. Nuclear Science and Techniques, 2019, 30: 146. doi: 10.1007/s41365-019-0670-7
[18]	Li Xiao, Sun Hong, Long Wei, et al. Design and performance of the LLRF system for CSNS/RCS[J]. Chinese Physics C, 2015, 39: 027002. doi: 10.1088/1674-1137/39/2/027002
[19]	Du Botao, Lin Hongxiang, Liu Wei, et al. DSP Frame and Algorithm of LLRF of IR-FEL[C]//Proceedings of IPAC2017. 2017: 4017-4019.
[20]	Andraka R. A survey of CORDIC algorithms for FPGA based computers[C]//Proceedings of the 1998 ACM/SIGDA Sixth International Symposium on Field Programmable Gate Arrays. 1998: 191-200.
[21]	Mittal S, Gupta S, Dasgupta S. System generator: the state-of-art FPGA design tool for DSP applications[C]//Third International Innovative Conference on Embedded Systems, Mobile Communication and Computing (ICEMC2 2008). 2008: 187-190.
[22]	Schilcher T. Vector sum control of pulsed accelerating fields in Lorentz forces detuned superconducting cavities[D]. Hamburg: University of Hamburg, 1998.
[23]	Qiu Feng, Michizono S, Miura T, et al. Application of disturbance observer-based control in low level radio-frequency system in a compact energy recovery linac at KEK[J]. Physical Review Special Topics-Accelerators and Beams, 2015, 18: 092801. doi: 10.1103/PhysRevSTAB.18.092801
[24]	Butkowski L, Kozak T, Yang Bin, et al. FPGA firmware framework for MTCA. 4 AMC modules[C]//Proceedings of the 15th International Conference on Accelerator and Large Experimental Physics Control Systems. 2015.