Injector Cyclotron for a Medical FFAG concept Design Results Injector Cyclotron for a Medical FFAG H- compact AIMA cyclotron M. Conjat, J. Mandrillon, P. Mandrillon, J. Pasternak

concept Tentative Layout (according to J.Pasternak) Design Results Preliminary geometry of injection line into RACCAM FFAG AIMA cyclotron (1.75 m diameter) Septum 0.7 T 6 quads in straights

concept Concepts….Design Choices Design Results Variable energy-extraction from 7 to 15 MeV Suitable: 1 energy step corresponds to a 1cm depth step in tissues. Fast acceleration Particles reach 15 MeV in 60 turns, well separated. Simple design H- acceleration Multi strippers extraction system with fast switches. High energy gain per turn Power is pulsed in order to get a 50 kV peak to peak acceleration voltage, with 6 gaps/turn. A single cavity 3 dees galvanically connected, working on the 3rd Harmonic External High Brightness H- MultiCusp Ion Source 10 mA/cm², 5mA dc (to accelerate 350mA)

Design Main Characteristics Results concept high brightness multicusp ion source TYPE OF CYCLOTRON: Negative ion Size 1.75 diameter Weight 13 tons Ion source: H- MultiCusp, external Extracted Current density (dc) 10 mA/cm² MAGNET: Closed geometry, 3 sectors Average field 1.55 tesla Pole radius 38 cm Amp turns 52580 RF SYSTEM: 1 single cavity Number of dees 3 RF voltage 50 kV RF frequency 70.6 MHz RF power ~2 kW, pulsed (dc: 2%) AIMA cyclotron for FDG Production

Design Extracted beam intensity requirements Results concept Maximum Dose Rate 5 Gray/min FFAG (100 Hz rep. rate) 2.5 108 proton/cycle, 3 109 proton/cycle needed at injection With multiturns injection (10t): 3 108 proton/ turn needed at injection 10 turns to fill the FFAG 3 ms (injection F: 3 MHz, 10 revolution time) With the Cyclotron at 70.6 /3rd Harm: ~200 cyclotron bunches Cyclotron: ~1.5 107 proton/bunch Cyclotron DC Current equivalent 170 mA Requirement at FFAG injection: Energy Dispersion < 50 keV Cyclotron DC Current goal:350 mA

Design About the magnet design nr nz Results concept 3D calculation CST, Compared with measures nr & nz versus Radius with ‘EUQUIL’ B-field Isochronisms versus Radius with ‘EUQUIL’ nr nz

Design About the Dynamic design Results concept Median plane acceleration Trajectories & Centers of Curvature 3D electrostatic calculation & Central region optimization with ‘AGORA’ Energy Gain in gap 6: 90 % Energy gain in gaps optimization to accelerate fast. R (cm)

Multiple strippers to find a Cyclotron Energy Focus concept concept Design Results Variable energy extraction Energy Focus Multiple strippers to find a Cyclotron Energy Focus Variable Energy ~7 to ~15 MeV Strippers

Extraction Energy - 14 Mev concept concept Design Results Tracking at Extraction Envelop at Focus Normalized Transversal Emittances: 0.5 p mm mrad vertical (worst case) 0.3 p mm mrad horizontal + multiple scattering due to stripper traversal Bunch length in 1st gap: 15° Extraction Energy - 14 Mev Horizontal Envelop (1 s) 0.3 p mm mrad Vertical Envelop (1 s) 5.3 p mm mrad Energy spread 75% < 50 KeV 1 mrad 4 mm 20 mrad 15 mm

Extraction Energy - 11 Mev concept concept Design Results Tracking at Extraction Envelop at Focus Normalized Transversal Emittances: 0.5 p mm mrad vertical (worst case) 0.3 p mm mrad horizontal + multiple scattering due to stripper traversal Bunch length in 1st gap: 15° Extraction Energy - 11 Mev Horizontal Envelop (1 s) 0.5 p mm mrad Vertical Envelop (1 s) 7.9 p mm mrad Energy spread 81% < 50 KeV 0.6 mrad 4 mm 30 mrad 20 mm

Extraction Energy - 8 Mev concept concept Design Results Tracking at Extraction Envelop at Focus Normalized Transversal Emittances: 0.5 p mm mrad vertical (worst case) 0.3 p mm mrad horizontal + multiple scattering due to stripper traversal Bunch length in 1st gap: 15° Extraction Energy - 8 Mev Horizontal Envelop (1 s) 0.50 p mm mrad Vertical Envelop (1 s) 10 p mm mrad Energy spread 91% < 50 KeV 0.4 mrad 4 mm 40 mrad 30 mm

Thank you for your attention concept Design Results Thank you for your attention