EXTRACTION OF 250 MeV PROTON BEAM BY INJECTION OF THE 30 MEV CYCLOTRON PROTON BEAM INTO THE CONCEPTUALLY DESIGNED MEDICAL PROTON SYNCHROTRON

The existing C-30 cyclotron at NRCAM is currently capable of emitting a proton beam with only Emax=30 MeV. To improve this Emax to higher energies of 250 MeV for proton therapy, this beam is injected into the conceptually designed Medical Proton Synchrotron accelerator. Prior to injection, the beam emittances in both x- and y-directions were measured to be x=1.7610 -5 m.rad and y = 5.6410 -5 m.rad. The obtained extracted Twiss parameters at the point of injection were; x =-1.28, x =12.7, x =0.21, y =-0.55, y =3.28, and y=0.10. The AGILE computer program code was utilized for the lattice design of the Medical Proton Synchrotron. This design is composed of two achromatic arcs. Each arc bends 180° and has a closed dispersion bump. The designed lattice is composed of eight cells each consisting of two Quadrupoles, one Sextupole and two Dipole magnets. The extraction components of sextupole resonance (SR), electrostatic septum (ES) and magnetic septum (MS) were also placed in the designed lattice. The beta functions, as the main parameters of the lattice, have been chosen to meet requirements of the slow extraction. The working point (Qx, Qy) for adjusting the slow extraction were 1.33 and 2.62, respectively. The Hardt condition was met by minimizing the angular dispersion of the separatists corresponding to a different energy spread. The slow extraction of the accelerated particles was also analyzed. The calculation of the slow extraction is performed using the AGILE program. The obtained lattice Twiss parameters of the focusing structure are also presented.