1.Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
2.School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing 100049, China
Scan for full text
Measurement of the cavity-loaded quality factor in superconducting radio-frequency systems with mismatched source impedance[J]. 核技术（英文版）, 2023,34(8):123
Jin-Ying Ma, Cheng-Ye Xu, An-Dong Wu, et al. Measurement of the cavity-loaded quality factor in superconducting radio-frequency systems with mismatched source impedance[J]. Nuclear Science and Techniques, 2023,34(8):123
Measurement of the cavity-loaded quality factor in superconducting radio-frequency systems with mismatched source impedance[J]. 核技术（英文版）, 2023,34(8):123 DOI： 10.1007/s41365-023-01281-5.
Jin-Ying Ma, Cheng-Ye Xu, An-Dong Wu, et al. Measurement of the cavity-loaded quality factor in superconducting radio-frequency systems with mismatched source impedance[J]. Nuclear Science and Techniques, 2023,34(8):123 DOI： 10.1007/s41365-023-01281-5.
The accurate measurement of parameters such as the cavity-loaded quality factor (,Q,L,) and half bandwidth (,f,0.5,) is essential for monitoring the performance of superconducting radio-frequency (SRF) cavities. However, the conventional "field decay method" employed to calibrate these values requires the cavity to satisfy a "zero-input" condition. This can be challenging when the source impedance is mismatched and produce nonzero forward signals (,V,f,) that significantly affect the measurement accuracy. To address this limitation, we developed a modified version of the "field decay method" based on the cavity differential equation. The proposed approach enables the precise calibration of ,f,0.5, even under mismatch conditions. We tested the proposed approach on the SRF cavities of the Chinese Accelerator Driven System Front-End Demo Superconducting Linac and compared the results with those obtained from a network analyzer. The two sets of results were consistent, indicating the usefulness of the proposed approach.
Loaded quality factorField decay methodSuperconducting cavityMismatchCalibrationCavity differential equationMeasurementAccelerator driven system
W.L. Zhan, Accelerator driven sustainable fission energy, in Proceedings of the 7th International Particle Accelerator Conference, IPAC2016, Busan, Korea, 2016. doi: 10.18429/JACoW-IPAC2016-FRYAA03http://doi.org/10.18429/JACoW-IPAC2016-FRYAA03.
Y.S. Qin, P. Zhang, H.J. Cai et al., Transfer line including vacuum differential system for a high-power windowless target, Phys. Rev. Accel. Beams 23, 113002 (2020). doi: 10.1103/PhysRevAccelBeams.23.113002http://doi.org/10.1103/PhysRevAccelBeams.23.113002.
S.H. Liu, Z.J. Wang, H. Jia et al., Physics design of the CIADS 25 MeV demo facility, Nucl. Instrum. Meth. A. 843, 11-27 (2017). doi: 10.1016/j.nima.2016.10.055http://doi.org/10.1016/j.nima.2016.10.055.
Y. He, T. Tan, A.D. Wu, et al., Operation experience at CAFe, in Oral Presenta-tion of the 2021 International Conference on RF Superconductivity, SRF’21, in: virtual conference, JACoW, virtual conference, 2021. Available at https://indico.frib.msu.edu/event/38/attachments/160/1298/MOOFAV03_yuan_he.pdfhttps://indico.frib.msu.edu/event/38/attachments/160/1298/MOOFAV03_yuan_he.pdf
Q. Chen, Z. Gao, Z.L. Zhu et al., Multi-frequency point supported LLRF front-end for CiADS wide-bandwidth application, Nucl. Sci. Tech. 31, 29 (2020). doi: 10.1007/s41365-020-0733-9http://doi.org/10.1007/s41365-020-0733-9
W.M. Yue, S. X. Zhang, C. L. Li, et al., Design, fabrication and test of a taper-type half-wave superconducting cavity with the optimal beta of 0.15 at IMP. Nucl. Eng. Technol. 52, 1777-1783 (2020). doi: 10.1016/j.net.2020.01.014http://doi.org/10.1016/j.net.2020.01.014.
W.M. Yue, S.X. Zhang, C.L. Li, et al., Development of a low beta half-wave superconducting cavity and its improvement from mechanical point of view. Nucl. Instrum. Meth. A. 953, 163259 (2020). doi: 10.1016/j.nima.2019.163259http://doi.org/10.1016/j.nima.2019.163259.
P. Sha, W.M. Pan, S. Jin et al., Ultrahigh accelerating gradient and quality factor of CEPC 650 MHz superconducting radio-frequency cavity. Nucl. Sci. Tech. 33, 125 (2022).doi: 10.1007/s41365-022-01109-8http://doi.org/10.1007/s41365-022-01109-8
Z.Y. Ma, S.J. Zhao, X.M. Liu, et al. High RF power tests of the first 1.3 GHz fundamental power coupler prototypes for the SHINE project. Nucl. Sci. Tech. 33, 10 (2022). doi: 10.1007/s41365-022-00984-5http://doi.org/10.1007/s41365-022-00984-5
J.P. Holzbauer, C. Contreras, Y. Pischalnikov, et al., Improved RF measurements of SRF cavity quality factors. Nucl. Instrum. Meth. A. 913, 7-14 (2019). doi: 10.1016/j.nima.2018.09.155http://doi.org/10.1016/j.nima.2018.09.155
F. Marhauser, Method for in situ and in operando cavity loaded Q extraction in superconducting rf accelerators. Phys. Rev. Accel. Beams 24, 032001 (2021), doi: 10.1103/PhysRevAccelBeams.24.032001http://doi.org/10.1103/PhysRevAccelBeams.24.032001.
A. Bellandi, Ł. Butkowski, B. Dursun et al., Online detuning computation and quench detection for superconducting resonators. IEEE T. Nucl. Sci. 68, 385-393 (2021). doi: 10.1109/TNS.2021.3067598http://doi.org/10.1109/TNS.2021.3067598.
J. Branlard, V. Ayvazyan, O. Hensler, et al., Superconducting cavity quench detection and prevention for the European XFEL. in Proceedings of ICALEPCS2013, San Francisco, CA, USA. Available at https://accelconf.web.cern.ch/ICALEPCS2013/papers/thhppc072.pdfhttps://accelconf.web.cern.ch/ICALEPCS2013/papers/thhppc072.pdf
F. Qiu, S. Michizono, T. Miura et al., Application of disturbance observer-based control in low-level radio-frequency system in a compact energy recovery linac at KEK. Phys. Rev. ST Accel. Beams. 18, 092801 (2015), doi: 10.1103/PhysRevSTAB.18.092801http://doi.org/10.1103/PhysRevSTAB.18.092801
F. Qiu, S. Michizono, T. Matsumoto et al., Combined disturbance-observer-based control and iterative learning control design for pulsed superconducting radio frequency cavities. Nucl. Sci. Tech. 32, 56 (2021). doi: 10.1007/s41365-021-00894-yhttp://doi.org/10.1007/s41365-021-00894-y
Y. Cong, S.F. Xu, W.X. Zhou et al., Low-level radio-frequency system upgrade for the IMP Heavy Ion Reach Facility in Lanzhou (HIRFL). Nucl. Instrum. Meth. A. 925, 76-86 (2019). doi: 10.1016/j.nima.2019.01.086http://doi.org/10.1016/j.nima.2019.01.086.
M. Omet, Digital low level RF control techniques and procedures towards the international linear collider (Ph.D. thesis). School of High Energy Accelerator Science, 2014.
F. Qiu, T. Miura, D. Arakawa et al., RF commissioning of the compact energy recovery linac superconducting cavities in pulse mode. Nucl. Instrum. Meth. A. 985, 164660 (2021). doi: 10.1016/j.nima.2020.164660http://doi.org/10.1016/j.nima.2020.164660.
T. Schilcher, Ph.D. thesis, Universitt Hamburg, 1998.
J.Y. Ma, G.R. Huang, Z. Gao et al., The resonant frequency measurement method for superconducting cavity with Lorentz force detuning. Nucl. Instrum. Methods A 993, 165085 (2021). doi: 10.1016/j.nima.2021.165085http://doi.org/10.1016/j.nima.2021.165085
Z.C. Mu, Overview of the CSNS linac LLRF and operational experiences during beam commissioning. in Proceedings of the 57th ICFA Advanced Beam Dynamics Workshop on High-Intensity, High Brightness and High Power Hadron Beams, Malmö, Sweden, 2016, pp. 3-8.
A. Brandt, Development of a finite state machine for the automated operation of the LLRF control at FLASH(Ph.D. thesis). University Hamburg, 2007.
M. Grecki, V. Ayvazyan, J. Branlard et al., On-line RF amplitude and phase calibration for vector sum control. in Oral Presentation of the 9th Low-Level RF Workshop, LLRF2019, Chicago, USA September 29 – October 3, 2019.
F. Qiu, J.Y. Ma, G.D. Jiang et al., Approach to calibrate actual cavity forward and reflected signals for continuous wave-operated cavities. Nucl. Instrum. Methods A 1034, 166769 (2022). doi: 10.1016/j.nima.2022.166769http://doi.org/10.1016/j.nima.2022.166769.
David, M. Pozar., Microwave Engineering, 4th Edition, Wiley.
T. Czarski, K.T. Pozniak, R.S. Romaniuk et al., TESLA cavity modeling and digital implementation in FPGA technology for control system development. Nucl. Instrum. Methods Phys. Res., Sect. A 548, 283 (2005). doi: 10.1016/j.nima.2005.10.122http://doi.org/10.1016/j.nima.2005.10.122
F. Qiu, S. Michizono, T. Miura et al., Real-time cavity simulator based low-level radio frequency test bench and applications for accelerators. Phys. Rev. Accel. Beams 21, 032003 (2018). doi: 10.1103/PhysRevSTAB.18.0928014http://doi.org/10.1103/PhysRevSTAB.18.0928014