JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
@inproceedings{zhang:cyclotrons2022-frbo04,
author = {L.G. Zhang and R.A. Baartman and Y. Bylinskii and T. Planche and Y.-N. Rao},
title = {{Error Magnetic Field due to the Median Plane Asymmetry and Its Applications in the Cyclotron}},
% booktitle = {Proc. CYCLOTRONS'22},
booktitle = {Proc. 23rd Int. Conf. Cyclotrons Appl. (CYCLOTRONS'22)},
pages = {381--384},
paper = {FRBO04},
language = {english},
keywords = {survey, cyclotron, resonance, coupling, site},
venue = {Beijing, China},
series = {International Conference on Cyclotrons and their Applications},
number = {23},
publisher = {JACoW Publishing, Geneva, Switzerland},
month = {10},
year = {2023},
issn = {2673-5482},
isbn = {978-3-95450-212-7},
doi = {10.18429/JACoW-CYCLOTRONS2022-FRBO04},
url = {https://jacow.org/cyclotrons2022/papers/frbo04.pdf},
abstract = {{Cyclotrons have a median plane symmetric structure. But the pole’s geometric error and the unevenly magnetized soft iron give rise to non-zero asymmetrical fields in the geometric median plane. The asymmetric field can shift the vertical position of the beam. Moreover, The error of the tilted median plane can be the driving force when the tunes pass through coupling resonances. In this paper, we take the TRIUMF 500 MeV cyclotron as an example to study the asymmetric field resulting from imperfect median plane symmetry. An approach due to M. Gordon, and a highly accurate compact finite differentiation method are used to investigate the historical field survey data, which reveals redundancy in the survey data. The redundancy was used in this study to correct the error in the measurement data. Further, the median plane asymmetry field could be manipulated using trim coils or harmonic coils with top and bottom coil currents in opposite directions (’Br-mode’). Using the created asymmetric field, we improved the vertical tune measurement method to investigate the linear coupling resonance in TRIUMF 500 MeV cyclotron. Eventually, the coupling resonance is corrected and avoided using the available harmonic coils and trim coils.}},
}