The document introduces a new compact superconducting synchrocyclotron (SSC) proton therapy accelerator designed by ACCEL Instruments GmbH. Some key points: 1) The SSC design aims to provide protons with energies from 70-250 MeV, fast intensity modulation, safety, reliability, low costs, and a small footprint compatible with beam scanning. 2) While synchrocyclotrons were used in the past, the SSC features a more compact high-field design using ACCEL's superconducting technology and sophisticated modeling. 3) The SSC could serve as the heart of a single room proton therapy facility with all components mounted on a rotating gantry for a compact and cost-

1. PTCOG 45
The ACCEL Single Room
Proton Therapy Facility
Jan Timmer – ACCEL Instruments GmbH
October 7 – 11, 2006
Houston, Texas

2. Introducing a compact new accelerator…
700
600
210
150
90
0
200
400
600
800
Machineweight(ton)
IBA C400 HIT
Gantry
IBA C230 Proton
Gantry
ACCEL
K250
ACCEL
???

3. Specifications for a proton therapy accelerator
Energy variable from 70 MeV to 250 MeV
Fast intensity modulation
Safety, reliability and high availability
Low investment and operational costs
Small floor space
Compatible with scanning
Turn key system

4. Synchrotron or cyclotron for proton therapy?
Cyclotron:
+ simple, reliable and cost effective + continuous beam
+ fast current modulation - fixed energy
Synchrotron:
+ variable energy - pulsed beam
+ intrinsic safety - complicated technology
The market seems to give a clear answer:
Total of PT projects this century 12
With a cyclotron 10
With a synchrotron 2

5. Commercially available cyclotrons
IBA C230
First commercially available cyclotron for PT
230 MeV protons
Dedicated to therapy
ACCEL K250
Compact superconducting cyclotron
Higher magnetic field halving the volume!
High extraction efficiency and reproducible beam
parameters

6. … the superconducting synchrocyclotron

7. … the superconducting synchrocyclotron
Design features:
Particles: Protons
Energy: 250 MeV
Diameter: 1.7 m
Magnetic field: 8.5 Tesla
Beam structure: Pulsed, 1 kHz
Extremely Compact Design
Superconducting coil
Very high magnetic field
Variable RF Frequency

8. …is it really a new accelerator?
No!
Henry Blosser twenty years ago:
“Synchrocyclotrons are often characterized as
the „DC3‟ of accelerators…”
Synchrocyclotrons were installed at several
institutes (E.g. CERN, ICPO and Uppsala)
Yes!
A more compact high-field design
using:
ACCEL‟s superconducting core
technology
Sophisticated modeling
techniques

9. Advantages of a superconducting coil
High magnetic fields
Low power consumption
Saturated iron
Absence of non-linear behavior
Excellent reproducibility and reliability
High extraction efficiency
Low activation
Turn key system
Machine Efficiency and
Internal Beam Loss
0
5
10
15
20
25
30
0 20 40 60 80 100
Extraction Efficiency (%)
Normalised
InternalBeamLoss
(a.u.)

10. A complex concept …
Strong magnetic field makes injection and
extraction much more challenging than in
isochronous cyclotrons
High quality modeling a necessity
ACCEL know-how from K250 successful
development
… with considerable advantages
Mechanically the synchrocyclotron is less
complicated
with fewer precision parts
more compact
less costly

11. A new compact accelerator…
700
600
210
150
90
15
0
200
400
600
800
Machineweight
(ton)
IBA C400 HIT
Gantry
IBA C230 Proton
Gantry
ACCEL
K250
ACCEL
SSC

12. Application of a compact synchrocyclotron

13. Gantry with integrated accelerator and ESS

14. Footprint of the single room facility
~ 23 m
~19m

15. Advantages of the compact therapy facility
Compact and cost effective proton therapy solution
All components mounted on the rotating gantry
Reduced length of the beam transport system
Benefiting from ACCEL‟s superconducting core
technology
Minimized floor space and building costs
Based on standard ACCEL gantry components
No interference between multiple gantries

16. Specifications for a proton therapy accelerator
Energy variable from 70 MeV to 250 MeV
Fast intensity modulation
Safety, reliability and high availability
Low investment and operational costs
Small floor space
Compatible with scanning
Turn key system

17. Test of Scanning System at HMI, Berlin
Nozzle 3D-View
Scanning Magnets
Dose and Position Monitors
Vacuum Chamber
Diagnostic Flat Panels
(Position Verification)
Patient Specific Devices
(Range Shifter, Ripple Filter, Collimator, etc.)
…compatible with scanning?
ACCEL scanning nozzle
• Scanning with continuous beam completely
commissioned and tested at RPTC
• Concepts for pulsed beam scanning are
available
• Adaptation for new single room system
in progress
• Scattering alternative

18. Thank you!