Determination of Magnet Specification of 13 MeV Proton Cyclotron Based on Opera 3D

Abstract

The magnet is one of the main components of a cyclotron, used to form a circular particle beam trajectories and to provide focusing of the beam. To support the mastery of 13-MeV proton cyclotron technologies, cyclotron magnet design must be done to satisfy cyclotron magnet requirements. This research was conducted by studying important parameters in designing the cyclotron magnet which is then used to determine the design requirements. The magnet design was based on the results of a 3D simulation using Opera 3D software. Opera 3D is a software developed by Cobham plc to solve physical problems in 3D such as magnetostatic using finite element methods. The simulation started by drawing a 3D model of the magnet using a modeler, followed by magnetic field calculations by Tosca module in the Opera 3D software. Simulation results were analyzed with the Genspeo software to determine whether the parameters of the cyclotron magnet have met design requirements. The results indicate that the magnet design satisfied the cyclotron magnet design requirement, that B in the median plane of the magnetic pole approached the isochronous curve, providing axial and radial focusing beam, crossing the resonance line at v r = 1 when the particle energy is low and the particle energy is more than 13 MeV, and lead to small enough phase shift of about 13°. The dimension of the cyclotron magnet is 1.96 m × 1.30 m × 1.21 m; its weight is 17.3 ton; its coil current is 88,024 ampere-turn; its center magnetic field is 1.27479 T; its maximum magnetic field is 1.942116 T; its minimum magnetic field is 0.7689 T; its valley gap is 120 mm; its hill gaps are 40 to 50.78 mm; and its hill angles are 35° to 44°.

Simulations of Beam Quality in a 13 MeV PET Cyclotron

“…The program requires the data of the magnetic field which is loaded using the loadB program. Because of symmetry, it was sufficient to have the data of only 1/8 of the overall field volume of 480 mm × 480 mm × 30 mm; the data was obtained from computation using Opera-3d software and TOSCA module [2]. The size of the binary data was about 38 MB for each of the B x , B y , and B z components.…”

“…Hence it should reach the puller within the duration of less than or equal to T/2, where T is the period of the RF electric field. If the initial velocity of the beam coming out from the IS ≈ 0, the maximum distance between IS to the puller is approximately s = ½at 2 …”

“…The beam initial velocity was approximated by the increase of the beam energy upon travelling 0.1 mm from the initial posisition. The motion, energy, and position were calculated by using equations (1), (2), and (3). The trajectory is plotted in the XY plane, while the energy and vertical position are plotted as the function of turn-number.…”

“…The proton beam's trajectory is determined by the distribution of the RF (radiofrequency) electric field which accelerates the beam, the distribution of the magnetic field which bends and focuses the beam, and the initial position and phase of the beam. The distributions of the electric and magnetic fields in three dimensions can be calculated by using the Opera-3d software and the TOSCA module (for static electric and magnetic fields [2]), the Soprano module (for RF electric  Corresponding author. E-mail address: pramudita@batan.go.id DOI: http://dx.doi.org/10.17146/aij.2015.411 fields), and the RELAX3D software (for static electric fields).…”

Optimation of Decy-13 Cyclotron Magnet Mapping System

“…The isochronous field was easy to obtained by changing the dimensions of the magnetic poles of the simulation magnet model. The DECY-13 magnet design has finished in 2013 and fulfilled the isochronous field requirement with integrated phase shift < ±15º [3]. The beam trajectory simulation also showed that the magnetic field data from the design caould accelerate the ion beam up to 13 MeV [4].…”