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Masaki M, Maesaka H, Soutome K, Takano S, Watanabe T, Kubota K, Fujita T, Dewa H, Fukui T, Sugimoto T, Takeuchi M, Tanaka H. Adaptive feedforward control of closed orbit distortion caused by fast helicity-switching undulators. J Synchrotron Radiat 2021; 28:1758-1768. [PMID: 34738929 PMCID: PMC8570204 DOI: 10.1107/s160057752101047x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 10/08/2021] [Indexed: 06/13/2023]
Abstract
A new correction algorithm for closed orbit distortion based on an adaptive feedforward control (AFC) has been developed. At SPring-8, two helicity-switching twin-helical undulators (THUs) had been implemented with conventional feedforward corrections. However, the validity of these corrections turned out to be expiring due to unforeseen variation in the error magnetic fields with time. The developed AFC system has been applied to the THUs dynamically updating the feedforward table without stopping the helicity switching amid user experiments. The error sources in the two THUs are successfully resolved and corrected even while the two THUs are switching simultaneously with the same repetition period. The actual operation of the new AFC system enables us to keep the orbit variations suppressed with an accuracy at the sub-micrometre level in a transparent way for light source users.
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Affiliation(s)
- Mitsuhiro Masaki
- Light Source Division, Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Hirokazu Maesaka
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Kouichi Soutome
- Light Source Division, Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Shiro Takano
- Light Source Division, Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Takahiro Watanabe
- Light Source Division, Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Kouji Kubota
- SPring-8 Service Co. Ltd, 1-20-5 Kouto, Shingu-cho, Tatsuno, Hyogo 679-5165, Japan
| | - Takahiro Fujita
- Light Source Division, Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Hideki Dewa
- Light Source Division, Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Toru Fukui
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Takashi Sugimoto
- Light Source Division, Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Masao Takeuchi
- Light Source Division, Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Hitoshi Tanaka
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
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