1. Accelerator layout
> 1000 components (almost 300 magnets and power converters, 153 beam diagnostic devices, about 400m of vacuum pipes, a not neglectable number of special magnets, ion sources, RF devices, etc,.. ), which need to be controlled!
From 220 suppliers from 23 different countries
Accelerator Layout
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2. Everything starts with a source… 3 (4) Ion Sources
Capable to deliver protons and carbon ions (He, O,… as future options)
As installed in our injector
ECR Ion source – Pantechnik
As installed in our injector
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3. In order to keep the beam on track and well focussed, we need magnets (dipoles and quadrupoles).
Bending force due to a dipole field
(De)focusing due to a quadrupole
Arrangements of quadrupoles (beam optics)
Synchrotron dipole test stand at CERN – Budker Institute
Synchrotron test stand at CERN - Sigmaphi
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4. Magnets without power can not fulfil their job, thus we need power converters.
5 different families (and many more types)
Up to 3.3 kA max output current
EEI power converters at MA
„Special Magnets“, specific components with their power converters (electrostatic and magnetic septa, kicker magnets, etc…) for specialized tasks.
Example of electrostatic extraction septum
Magnetic septum at test stand at CERN
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5. The beam needs to be accelerated.
Accelerating structures and their (RF) power sources.
Components placed in the injector and the synchrotron.
Radio frequency Quadrupole (RFQ)
Example of a synchrotron RF cavity
IH mode drift tube Linac
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6. Nothing would work without vacuum.
489 chambers
64 tanks
133 pumps
Down to 5 x 10-9 mbar (Synchrotron)
Vacuum chamber and valves
Chamber installed in Synchrotron dipole
The beam needs to be diagnosed.
153 monitors
16 different types
Slit, wire scanner and faraday cup in LEBT
Synch pick up at test stand at CERN
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7. Everything needs control.
Hundreds of devices need to be controlled and monitored.
Devices need to be synchronized.
User interface for operators/commissioners.
Accelerator Control Room
Safety systems ensure safety for personnel and HW (PCS, BIS).
Thermo switches at magnet
BIS Input and output modules
BIS/PCS panel in ACR
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8. All parts need to be installed, integrated and commissioned,
design work is required, cables need to be pulled (> 100 km, about 30 km of DC power cables), etc…
… in order to get an accelerator assembled.
Installation in injector hall
Accelerator requires a working infrastructure (power, cooling, ventilation, pressuarized air, IT,…)
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9. Main task: Accelerate a beam to 7 MeV
The Injector
Main task: Accelerate a beam to 7 MeV
El. Deflector
0.008 MeV/u
0.4 MeV/u
7 MeV/u
Stripper foil (H3+ to p, C4+ to C6+)
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10. Main task: Accelerate a 7 MeV/u beam to the desired extraction energy
The Synchrotron
Main task: Accelerate a 7 MeV/u beam to the desired extraction energy
From Injector (7 MeV/u)
Synchrotron – key parameters:
Active energy selection, 255 energy steps/ion species
Energy: MeV/u (C6+),
60 – 800 MeV (p)
Ramp speed: 0.5s (to highest carbon extraction energy)
Extraction time: s
approx. 25m
To Patient
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11. Typical Synchrotron Cycle
Typical cycle for a synchrotron for medical use with slow extraction.
Magnetic field
Bmax B1 B2
Injection
Extraction
energy 1
Injection
Extraction
energy 2
Time
2 s
4 s
Acceleration
Acceleration
Intensity
Time
Energy 1
Intensity 1
Energy 2
Intensity 2
Beam structure: pulsed, energy and intensity variable
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12. Multi Turn Injection and Slow extraction
MTI:
2μs (or 75m) ……
2μs (or 75m)
Beam pulse from the injector (length 30 μs)
Time for 1 turn in injection level: about 2 μs
Beam pulse from injector of about 30 μs (remember the electrostatic deflector)
Injection over 15 turns (multi-turn)
Special, synchronized equipment needed for this operation
(injection kickers)
Extraction:
Terms as “resonance tune”, “triangular phase space”, “Steinbach diagram”, etc…
…are related to resonance or slow extraction.
Imagine an onion which you peel off layer by layer.
Beam: Particles at the border are separated from the core of the beam (duration 1 – 10 s)
Devices needed: Sextupoles, betatron core, electrostatic and magnetic septa (special magnets).
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13. Beam Distribution and Scanning
Transverse “scanning” with small beams
Beam sizes variable from 4 to 10 mm (in steps, FWHM in vacuum).
Fast magnetic deflection (20 m/s).
One slice is about one pulse (spill), 1-10 s.
horizontal
deflection
vertical
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14. Rotator adapts the beam for different Gantry angles.
Gantry and Rotator
Rotator adapts the beam for different Gantry angles.
Gantry structure
Preliminary design of rotator structure
Rotator
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15. A million of beam combinations…
Accelerator is able to generate:
Number of ion species: 2
Number of different energies: 255
Number of beam sizes: 5
Number of intensities: 4
Number of extraction times: 8
Beam combinations per beam line:
Gantry: different angles needs to be considered
None clinical research: extended energy range
Requires a huge amount of commissioning work.
Most of the combinations obtained by interpolation.
Stepwise release for medical use.
Example for table to select a beam combination
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16. Let’s make our machine safe for the patient -> The Medical Front-End
Main task: Serves as a mitigation measure for hazards caused by the accelerator in order not to harm the patient.
Realized by online monitoring of beam properties during the entire patient treatment. (mainly done by Dose Delivery System (CNAO)).
Monitored beam characteristics by the DDS:
Intensity
Beam position
Beam size
In case of deviations:
Trigger an interlock
Switch off beam within very short time (few hundred μs).
Schematics of monitoring system. Does not represent our design.
Additionally control of scanner magnet PCOs
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17. Accelerator + Medical Front-End = Therapy Accelerator
The Medical Front-End II
Architecture of Medical Front-End:
Integrated into the overall system architecture.
Interfaces to other Medical Devices, Accelerator and Infrastructure
TCP: Start and stop irradiation
Energy verification
Independent beam termination system
etc…
Accelerator + Medical Front-End = Therapy Accelerator
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18. The MedAustron Particle Therapy Accelerator - MAPTA
Ion Sources
Linear Accelerator
Synchrotron
Beam Distribution System
Beam outlet for non clinical research
Accelerator Control System
Power Supplies
Dose Delivery System (part of medical front-end - MF)
Clinical beam outlet IR2 horizontal (A) uand vertical (B)
Clinical beam outlet IR3 horizontal (C)
Clinical beam outlet Gantry (D) MAPTA Treatment Control Panel (part of MF)
A/B C D
A/B C D
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19. Injector Commissioning
Beam emittance (profile + angle information)
in front of RFQ.
Beam profiles in S1
Horizontal
plane
Vertical
plane
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20. Injector Commissioning II
RFQ characterization (TB2):
Beam transmission:
dependence on RF power
Beam energy:
dependence on RF power
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21. Synchrotron Installation
MEBT installation is progressing as planned.
Synchrotron dipole installation has started.
Forecast: By the end of the year, all Synchrotron components will be installed.
MEBT installation
Dipoles in Synchrotron
Synchrotron hall – 2. Sept 2013
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