Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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Improvement of transmission-line-based fault locating for typical traveling-wave accelerator with constant-gradient structures

  • T.N. Hu (State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology) ;
  • Y.F. Zeng (State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology) ;
  • K. Peng (China Academy of Space Technology (Xi' an)) ;
  • H. Hu (State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology) ;
  • H.M. Wang (State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology) ;
  • K.F. Liu (State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology)
  • Received : 2023.07.26
  • Accepted : 2024.01.06
  • Published : 2024.06.25
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Abstract

Since RF breakdown is one of the primary limitations to improving the performances of RF accelerators, extensive efforts have been dedicated to locating the breakdowns. However, most existing methods rely on specialized techniques, resulting in high financial burdens. Although the method based on transient response of transmission line (TL) is suitable for facilities with sporadic recoverable breakdowns, practical operations are susceptible to notable errors. This study revisits the fundamental theories of lossless TL and investigates the wave process to understand the characteristics of the reversed pulse induced by the breakdowns. By utilizing steadystate response of the TL and employing phasor method, we derive analytical formulas to determine the exact location of breakdowns within the faulty cell for constant-gradient TW accelerator. Furthermore, the derived formulas demonstrate their independence from RF phase, thereby distinguishing them from traditional phasebased methods. Additionally, experimental validations are conducted at the HUST injector, and the results confirm the consistency of the analysis. Thus, the proposed method represents a promising improvement over the TL-based approaches and serves as a valuable complement to current techniques. Importantly, this method demonstrates particular advantages for constructed TW accelerators seeking to achieve a balance among high performance, low costs, and compact layouts.

Keywords

Acknowledgement

This work was supported by National Natural Science Foundation of China (NSFC) under Project Numbers 11905074, and the Interdisciplinary program of Wuhan National High Magnetic Field Center (Grant No. WHMFC202142).

References

  1. M.S. Sullivan, R.M. Jones, L.S. Cowie, et al., Phys. Rev. Accel. Beams 24 (2021) 082001.
  2. D. Angal-Kalinin, A. Bainbridge, A.D. Brynes, et al., Design,specifications, and first beam measurements of the compact linear accelerator for research and applications front end, Phys. Rev. Accel. Beams. 23 (2020) 044801.
  3. T.N. Hu, Y.J. Pei, G.Y. Feng, Electron beamline of a Linac-based injector applied to a compact free electron laser-terahertz radiation source, Jpn. J. Appl. Phys. 57 (10) (2018) 100310.
  4. V. Paramonov, S. Philipp, I. Rybakov, et al., Design of an L-band normally conducting RF gun cavity for high peak and average RF power, Nucl. Instrum. Methods Phys. Res. A. 854 (2017) 111-126.
  5. X.C. Lin, H. Zha, J.R. Shi, et al., Fabrication, tuning, and high-gradient testing of an X-band traveling-wave accelerating structure for VIGAS, Nucl. Sci. Tech. 33 (2022) 102.
  6. A. Grudiev, S. Calatroni, W. Wuensch, New local field quantity describing the high gradient limit of accelerating structures, Phys. Rev. ST Accel. Beams. 12 (2009) 102001.
  7. N. Catal'an Lasheras, T. Argyropoulos, D. Esperante Pereira, et al., Commissioning of XBox-3: a very high capacity X-band test stand, in: 28th Linear Accelerator Conf. (LINAC'16), September, , MI, USA, 2016, pp. 25-30. Paper 568, East Lansing.
  8. A. Hassanein, Z. Insepov, J. Norem, et al., Effects of surface damage on rf cavity operation, Phys. Rev. ST Accel. Beams. 9 (2006) 062001.
  9. F. Wang, C. Adolphsen, C. Nantista, Study of radio frequency breakdown in pressurized L-band waveguide for the International Linear Collider, Appl. Phys. Lett. (2013) 104106.
  10. X.W. Wu, J.R. Shi, H.B. Chen, et al., High-gradient breakdown studies of an X-band Compact Linear Collider prototype structure, Phys. Rev. Accel. Beams. 20 (2017) 052001.
  11. T. Abe, T. Kageyama, H. Sakai, et al., Breakdown study based on direct in situ observation of inner surfaces of an rf accelerating cavity during a high-gradient test, Phys. Rev. Accel. Beams. 19 (2016) 102001.
  12. M.D. Forno, V. Dolgashev, G. Bowden, et al., Experimental measurements of rf breakdowns and deflecting gradients in mm-wave metallic accelerating structures, Phys. Rev. Accel. Beams. 19 (2016) 051302.
  13. M. Jacewicz, V. Ziemann, T. Ekelof, et al., Spectrometers for RF breakdown studies for CLIC, Nucl. Instrum. Methods Phys. Res. Sect. A Accel. Spectrom. Detect. Assoc. Equip. 828 (2016) 63-71. https://doi.org/10.1016/j.nima.2016.05.031
  14. A. Degiovanni, S. Doebert, W. Farabolini, et al., Diagnostics and analysis techniques for high power X-band accelerating structures, in: 27th Linear Accelerator Conference, 2014. Geneva, Switzerland, Aug 31- Sep. 5.
  15. C. Obermair, T. Cartier-Michaud, A. Apollonio, et al., Explainable machine learning for breakdown prediction in high gradient RF cavities, Phys. Rev. Accel. Beams. 25 (2022) 104601.
  16. A. Palaia, V. Dolgashev, J. Lewandowski, et al., Diagnostics of RF breakdowns in high-gradient accelerating structures, in: 10th European Workshop on Beam Diagnostics and Instrumentation for Particle Accelerators, 2011. Hamburg, Germany.
  17. J.G. Navarro, Breakdown studies for high gradient RF warm Technology, in: CLIC and Hadron Therapy Linacs (Ph.D. Thesis), Valencia University, Valencia, Spain, 2016.
  18. B. Woolley, High Power X-Band RF Test Stand Development and High Power Testing of the CLIC Crab Cavity, Ph.D. thesis), Lancaster University, Lancaster, UK, 2015.
  19. T.G. Lucas, High Field Phenomenology in Linear Accelerators for the Compact Linear Collider (Ph.D. Thesis), School of Physics, University of Melbourne, Melbourne, Australia, 2018.
  20. C. Tennant, A. Carpenter, T. Powers, et al., Superconducting radio-frequency cavity fault classification using machine learning at Jefferson Laboratory, Phys. Rev. Accel. Beams. 23 (2020) 114601.
  21. E. Fol, R. Tom'as, J.C. De Portugal, et al., Detection of faulty beam position monitors using unsupervised learning, Phys. Rev. Accel. Beams. 23 (2020) 102805.
  22. O. Convery, L. Smith, Y. Gal, et al., Uncertainty quantification for virtual diagnostic of particle accelerators, Phys. Rev. Accel. Beams. 24 (2021) 074602.
  23. H.K. Liu, T. Jia, L. Mou, et al., Improved traveling wave based fault location scheme for transmission lines, in: 5th International Conference on Electric Utility Deregulation and Restructuring and Power Technologies (DRPT), 2015, pp. 26-29. Changsha, China, November.
  24. C.Q. Cui, Y.H. Cheng, B. Liu, et al., Fault location approach for teed transmission line independent of wave speed, IOP Conf. Ser. Earth Environ. Sci. 634 (2021) 012049. https://doi.org/10.1088/1755-1315/634/1/012049
  25. T.N. Hu, H.M. Wang, Y.F. Zeng, et al., Fault locating for traveling-wave accelerator based on transmission line theory, Nucl. Sci. Tech. 34 (2023) 116.
  26. T.N. Hu, J.Y. Li, Y.J. Pei, et al., Indirect estimations of energy and energy spread for a compact free electron laser-terahertz pre-injector using RF measuring parameters, Nucl. Instrum. Methods Phys. Res., Sect. A 1016 (2021) 165775.
  27. T.N. Hu, Y.J. Pei, G.Y. Feng, Bunch length evaluation for typical beam injectors based on RF-phasing techniques, Nucl. Instrum. Methods Phys. Res., Sect. A 916 (2019) 87-93. https://doi.org/10.1016/j.nima.2018.10.200
  28. Q.R. Yan, Circuit Theory[M], Chinese High Education Press, Beijing, 2018, pp. 287-290 (In Chinese).