A novel design of a cyclotron based accelerator system for multi-ion-therapy

Transcription

1 A novel design of a cyclotron based accelerator system for multi-ion-therapy Marco Schippers, Andreas Adelmann, Werner Joho, Marco Negrazus (PSI) Heinrich Homeyer (Hahn Meitner Inst. ) Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

2 Demand for heavy ion therapy Present facilities: (Berkeley) Himac GSI Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

3 Currently: synchrotron facilities Heidelberg HIT facility CNAO, Pavia Coming up: HIT, Japan, Pavia, Kiel, Marburg Vendors are offering (often in collaboration with laboratories): synchrotron (Siemens, PIMS, NIRS) cyclotron 250, 300, 400 MeV/nucl (IBA, Catania, JINR) Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

4 PSI: Pencil beam scanning intensity Spot scanning: step&shoot Continuous scanning khz-intensity modulation 0 time (ms) 10 Requirements for accelerator: - stable beam position: => any accelerator is OK allows fast target repainting: scans / 2 min. Requirements for accelerator: - stable beam position - continuous and stable beam - fast adjustable beam intensity - fast adjustable beam energy => Cyclotron is optimal choice Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

5 Cyclotron facility Observations: IBA protons + α Carbon Protons are proven work tools (also covered by insurances) Carbon is interesting Carbon offers research possibilities One prefers to start with protons => Often two-phases desired 700 tons SC coils Ø 7 m Int. Conf. Cyclotron and appl, Tokyo 2004 Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

6 A novel idea: Two steps: injector and booster AND: injector also provides (limited) carbon beams Beams from injector cyclotron: 250 MeV/nucl. (4.86 Tm) From Booster (6. 83 Tm) Proton (H 2 + ions) Helium 2+ (α) Carbon 6+ Carbon MeV/n Range in water (cm) Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

7 First concept Injector cyclotron 250 MeV/nucl: 250 MeV protons (H 2+ ) 250 MeV/nucl α, C (Heinz Homeyer, HMI, at European cyclotron workshop in Nice) Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

8 First concept Injector cyclotron 250 MeV/nucl: 250 MeV protons (H2+) 250 MeV/nucl α, C Booster = Separated Sector Cyclotron super conducting magnets MeV/nucl C (Heinz Homeyer, HMI, at European cyclotron workshop in Nice) Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

9 A possible injection cyclotron: 320 tons Ø 4.9 m Cyclotron conference, Tokyo 2004 Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

10 Magnet yokes too large for original idea. current ideas for a novel 450 MeV/nucl sep. sector cyclotron Separate locations of injector and booster more advantageous. Magnets with super conducting coils. H-magnets possible single gap cavities e.s. injection e.s. extraction MHz. h Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

11 Advantages 2 phase approach possible (first protons) in first phase already α and (up to 12.5 cm) Carbon Booster should be simpler than single cyclotron Use of proven well established techniques: Injector: existing similar SC cyclotrons (ACCEL/PSI, Groningen, Catania, East Lansing) Booster: extremely reliable ring cyclotrons at PSI ( injector 2 + ring cyclotron for neutron source) High fields in magnets: stable and reproducible Low power of SC magnets Beam dynamics in Booster relaxed and robust: no problems with resonances still many degrees of freedom to design strong vertical focusing large orbit separation => high extraction efficiency Ø 15 m Option: when employing both Carbon-energies: 2 simple degraders, one at each cyclotron Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

12 parameters of sep. sector cyclotron Magnet types Magnetic field H-magnets, superconducting coils 4 Tesla SC coils gap: 4 T Iron: 2 T Iron: 2 T Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

13 parameters of sep. sector cyclotron RF frequency 92 MHz; 3 single gap cavities, 600 kv ΔE per turn ~ 0.8 MeV/nucl 1m Advantages of single gap : - high ΔE per turn: 600 kv - less space azimuthally - smallest vacuum volume Scaled 150 MHz test cavity : Height 1.0 m 1.5 m 150 MHz test cavity at PSI => high injection and extraction efficiencies are expected Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

14 3 options, depending on h (=f RF /f particles ) Harmonic nr (f RF /f particles ) Weight (tons) 30-Apr-2008 Size C T92h8 (m) 0 4 E/A = MeV/Nucl. Bmax = Tesla Orbit radius = m RF freq = MHz, h= 8 spiral = degr Iron mass 1 sector = 56 tons 4 06-May C T100h Apr-2008 C T92h8 0 4 pole area = 1.3 m2, w idth= 0.8 inner yoke area = 0.7 m2 outer yoke area = 1.7 m2 Cover height 0.5 m, crosssec=0.8 m2 pole height = 0.3 m pole gap = 60 mm coil space = design options E/A = MeV/Nucl. Bmax = Tesla Orbit radius = m RF freq = MHz, h= 12 spiral = degr Iron mass 1 sector = 86 tons May-2008 C T100h12 pole area = 1.6 m2, w idth= 1.0 inner yoke area = 1.0 m2 outer yoke area = 2.1 m2 Cover height 0.7 m, crosssec=1.1 m2 pole height = 0.3 m pole gap = 60 mm coil space = spreadsheet designs 92h8 92h10 92h12 Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

15 Possible 450 MeV/nucl sep.sect. cyclotron H-Magnets 4 T SC coils 600 kv cavity ( single gap ) Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

16 Preliminary beam dynamics Tune diagram resonances E 4 E 3 E 2 E 1 NUz nur=nuz ν r (E) and ν z (E) nur=2nuz nur+nuz=2 nur-nuz=1 nur= => focusing strength ( ~ν 2 ) NUr => avoid (or use!) resonances far away from dangerous resonances ν r =1.5 could be used for extraction Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

17 Possible system layout 450 MeV/nucl. C 6+ <<< degrader New Treatment Rooms degrader <<< 250 MeV/nucl. H 2 + α C 6+ Phase 1: protons + Carbon ions ( <12 cm) and α Phase 2: protons + Carbon ions ( all) and α Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

18 alternative system layout New Treatment Rooms Phase 1: protons + Carbon ions ( <12 cm) and α Phase 2: protons + Carbon ions ( all) and α Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

19 Next to do: (parameters of) Injector Cyclotron optimize field and sector shape magnet design; minimize iron; injection and extraction cost estimate partner (industry and/or lab) Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

20 summary A novel idea for a 2 step approach of multi-particle therapy: Start with protons AND α + (up to 12.5 cm:) Carbon Second step: also 450 MeV/nucl Carbon 450 MeV/nucl. C 6+ Use of well established techniques Design of Booster is relaxed and robust Many options: phasing, layout, degrader For next project phase: partner(s) wanted 250 MeV/nucl. H 2 + α C 6+ Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

21 The long road still to go.. The End Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

22 Reserve slides and images Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

23 Details of sector magnet May-2008 C T92h10 pole area = 1.5 m2, w idth= 1.0 inner yoke area = 0.9 m2 outer yoke area = 1.9 m2 coil space = 0.3 Iron mass 1 sector = 74 tons xe Calculation of closed orbit parameters => Basic magnet shape H-Magnets 0.5 xbo 0 xy i xi polex xbi xc xo xy o SC coils -0.5 xp gap: 4 T Iron: 2 T Iron: 2 T Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

24 Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

25 Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

26 Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

27 Ideas for the 450 MeV/n. ring cyclotron Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

28 Preliminary beam dynamics Tune diagram NUz nur=nuz nur=2nuz nur+nuz=2 nur-nuz=1 nur= NUr Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

29 A novel idea: Two steps: injector and booster BUT: injector also provides (limited) carbon beams Beams from injector cyclotron: 250 MeV/nucl From separated sector cyclotron Proton 250 MeV/n (H 2 + ions) Helium 2+ (α) 250 MeV/n Carbon MeV/n Carbon MeV/n Magnetic rigidity (Tm) Range in water (cm) Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

30 parameters of sep. sector cyclotron Magnet types Magnetic field RF frequency ΔE per turn Harmonic nr (f RF /f particles ) Weight (tons) Size (m) Orbit separ. inj (mm) Orbit separ. extr (mm) Good field width (m) H-magnets, superconducting coils 4 Tesla 92 MHz; 3 single gap cavities 600 kv ~ 0.8 MeV/nucl design options Marco Schippers, PTCOG 47, Jacksonville, May 22-24,

31 Details of RF cavity 3m 92 MHz (= f Catania ) Single gap cavity Advantages of single gap : - high ΔE per turn: 600 kv - less space azimuthally - smaller vacuum volume PSI-ring cavity: 50 MHz, 1MV, 500 kw 1m 1.5 m Scaled 150 MHz test cavity 150 MHz test cavity at PSI Marco Schippers, PTCOG 47, Jacksonville, May 22-24, MHz, L=2.5 m 31