Target specification of the beam for carbon therapy
• Beam species C6+
• E = 80 – 400MeV/u
• <I> = 1 x 6 nA
• Repetition rate 120Hz(240Hz)
Schematic diagram of the system
ion source
boostermain ring
RFQ DTL
62MeV/u C6+
230MeV proton400MeV/u C6+
1.2GeV proton
proton therapycarbon therapy
proton driver?
0.75MeV/u C6+
1.75MeV/u C6+
7MeV proton
Plasma Target Chamber
RFQ
Slit 4mm
Insulator(MC nylon)
C Target(Rotateable)
Na Cl
Laser Beam
Properties of the laser plasmaEnergy of the ions : about 100 eV/uEmission angle : less than ±20 degrees
Lens
Focal Spot Size on Target Surface:
d = 1.22f l/D = 64.7 m
Power Density:P = W/(p(d/2)2)
3.35 1012 W/cm2
H. V.
Booster (radial sector)Energy
B
Ncell
k
Bmax
tune
Long straight
r
excursion
1.75 – 62MeV/u
0.38 – 2.32Tm
12
12
2.0T
(4.2,1.4)
0.75m
4.353 – 5.000m
0.647m
Booster (spiral sector)Ncell
k
fpack
Bmax
tune
Long straight
r
excursion
12
12
0.35
57 degree
1.66T
(4.4, 1.3)
1.36m
3.483 – 4.000m
0.517m
Radial or Spiral
• Machine parameters tell spiral sector ring preferable.
• For medical use, extraction energy from the main ring should be able to changed 70-400MeV/u.
• Booster should be able to change k value.
• Can we change k in spiral lattice?
Main ring(spiral)E
B
Cirumference
Ncell
k
fpack
Bmax
tune
Long straight
r
excursion
62 - 400MeV/u
2.32 – 6.35Tm
45m
16
12
0.45
64 degree
1.97T
(3.9, 1.3)
1.55m
6.62 – 7.16m
0.533m
Injection and extraction scheme
booster
main ring
Injector1 turn injection
fast extraction
1 turn injection
massless extraction
Frequency 0.84MHz~ 4.15MHzAcc. voltage 11.0kV ( φ= 60°)# of cavities 2Core thickness 30mm# of cores 3/cavity
410mm
Booster(spiral) ring rf cavity parameters
Main ring rf cavity parameters
Frequency 6.62MHz~ 7.15MHzAcc. voltage 16.0kV ( φ= 60°)# of cavities 2Core thickness 30mm# of cores 3/cavity
410mm
Power consumption
Preinjector 350kW
Booster magnet 280kW
cavity 50kW
Main ring magnet 800kW
cavity 200kW
total 1680kW
Summary• Preliminary parameters of the carbon therapy
system have been obtained.• Spiral sector lattice seems to be ok for the main
ring and the booster considering optics and geometrical configuration.
• The main ring is very compact comparing to existing carbon machines. C=45m
• The booster ring can be used as proton therapy machine.
• Stability of the spiral lattice.
• Optimization of operating point
• Precise beam tracking simulation using TOSCA’s data.
• Injection / extraction calculation.
•Synchronization between the booster and the main ring
• Hardware feasibility study
- Injection/extraction kicker magnets and their power supplies
- How to realize 2.0T B field in the main ring
- Pole-face winding method
- etc
Things to do