Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People’s Republic of China
HUST, Wuhan, People’s Republic of China
A proton therapy facility based on an isochronous superconducting cyclotron is under development in HUST (Huazhong University of Science and Technol-ogy). A fast kicker magnet will be installed in the up-stream of the degrader to perform the beam switch function by kicking the proton beam to the down-stream beam stop. The rising and falling time of the kicker is about 100us, and the maximum repetition rate is 500Hz. This paper introduces simulation and opti-mization of the eddy current and dynamic magnetic field of the fast kicker, by using FEM code OPERA-3D. For kicker materials, laminated steel and soft ferrite are compared and the MnZn ferrite is chosen. Design-ing considerations includes the eddy current effect, field hysteresis, and mechanical structure of the kicker will also be introduced.
BNL, Upton, Long Island, New York, USA
Closed orbit calculations of the AGS synchrotron were performed and the beam parameters at the extraction point of the AGS [1] were calculated using the RAYTRACE computer code [2] which was modified to generate 3D fields from the experimentally measured field maps on the median plane of the AGS combined function magnets. The algorithm which generates 3D fields from field maps on a plane is described in reference [3] which discusses the details of the mathematical foundation of this approach. In this presentation we will discuss results from studies [1,4] that are based on the 3D fields generated from the known field components on a rectangular grid of a plane. A brief overview of the algorithm used will be given, and two methods of calculating the required field derivatives on the plane will be presented. The calculated 3D fields of a modified Halbach magnet [5] of inner radius of 4.4 cm will be calculated using the two different methods of calculating the field derivatives on the plane and the calculated fields will be compared against the ’ideal’ fields as calculated by the OPERA computer code [6]. [1] N. Tsoupas et. al. ’Closed orbit calculations at AGS and Extraction Beam Parameters at H13 AD/RHIC/RD-75 Oct. 1994 [2] S.B. Kowalski and H.A. Enge ’The Ion-Optical Program Raytrace’ NIM A258 (1987) 407 [3] K. Makino, M. Berz, C. Johnstone, Int. Journal of Modern Physics A 26 (2011) 1807-1821 [4] N. Tsoupas et. al. ’Effects of Dipole Magnet Inhomogeneity on the Beam Ellipsoid’ NIM A258 (1987) 421-425 [5] ’The CBETA project: arXiv.org > physics > arXiv:1706.04245’’ [6] Vector Fields Inc. https://operafea.com/