PAMELA Particle Accelerator for MEdicaL Applications
Suzie Sheehy, DPhil candidateJohn Adams Institute for Accelerator Science
Particle Physics, University of Oxford
Clinical RequirementsCharged Particle Therapy (CPT)
Protons and light ionsUsed to treat localised cancers
Less morbidity for healthy tissue
Less damage to vital organs
Particularly for childhood cancers
With X-raysWith Protons“When proton therapy facilities become available it will become malpractice not to use them for children
[with cancer].”Herman Suit, M.D., D.Phil., Chair, Radiation Medicine, Massachusetts General Hospital
27/5/2009
1
Charged Particle TherapyBragg Peak
27/5/2009
2
Less morbidity for healthy tissue
Less damage to vital organs
“Around 50% of all patients diagnosed with cancer worldwide would benefit from radiotherapy at some
stage of their illness”-World Cancer Report 2003, International Agency for Research on Cancer (IARC)
Accelerator Technology
Synchrotron Cyclotron FFAG
Intensity(>100nA)
Low(1-16nA)
Plenty Plenty>100nA
Maintenance Normal Hard Normal
Extraction eff. Good Poor Good
Operation Not Easy Easy Easy
Ions Yes Not yet Yes
Variable Energy Yes No Yes
Repetition Up to 50Hz Continuous ~1 kHz
27/5/2009
3
Treatment plan should be determined by clinical need, not limited by accelerator technology!
PAMELABASROC: British Accelerator Science and Radiation Oncology Consortium
CONFORM: COnstruction of a Non-scaling FFAG for Oncology, Research and Medicine
http://www.conform.ac.uk/
The project will1. build a 20 MeV electron accelerator, EMMA to test the principle
2. design a proton/ion accelerator for medical applications, PAMELA
3. investigate possible applications, from archaeology to zoology
27/5/2009
4
What on earth is an NS-FFAG!?“Non-Scaling, Fixed Field, Alternating Gradient”
‘AG’ – F/D magnets = strong focusing like a synchrotron
‘FF’ – don’t ramp up field = fixed field like a cyclotron
‘NS’ – orbit shape is allowed to vary and magnets are simpler than scaling FFAG
27/5/2009 [email protected]
5
What is an NS-FFAG?
Challenges
27/5/2009
6
EMMA Ring
Need to align magnets to ~10μm to avoid losing beam!
Present DesignProton ring (30 to 250 MeV)
Carbon ring (up to 400 MeV/u C6+)
Design Principle:Start with scaling FFAG
Relax scaling law Rectangular magnets
Aligned on straight line
Multipoles up to octupole
Results in FFAG with...Small orbit excursion (<172 mm)
Compact magnets
No/little tune shift
12 cells, FDF-tripletStraights: 1.7 m
Sufficient spaceInjection/extraction, RF
6.251m8.5m
27/5/2009
7
PAMELA Magnets (small ring)
Combined function magnet
Superconducting at 4K
One double-helix coil per multipole
DipoleQuadSext.Oct.
27/5/2009
8
Magnet design: H.Witte
Layout of facility
27/5/2009
9
Carbon ions Protons (30 MeV)
RFQ Linac, 7MeV/u
FFAG rings
Protons 70- 250MeV
Carbon 170- 400MeV/u Treatment
rooms
Fixed
Fixed
Gantry
Summary
Charged particle therapy – advantages:Less morbidity for healthy tissue
Less damage to vital organs
Current treatment limited by accelerator technologyNew NS-FFAG technology can overcome this
Design relies on new principle for NS-FFAG
PAMELA – design by late 2010Cheaper, easier to run, reliable accelerator for CPT
27/5/2009 [email protected]
10
Acknowledgements
Thanks to the PAMELA design team & wider collaboration:
27/5/2009 [email protected]
11
Ken Peach, John Cobb, Suzanne Sheehy, Holger Witte, Takeichiro Yokoi (JAI, Oxford)Richard Fenning, Akram Khan (Brunel University, UK) Rebecca Seviour (Cockcroft Institute, Lancaster, UK)Carol Johnstone (Fermilab, USA)Mark Hill, Bleddyn Jones, Borivoj Vojnovic (Gray Institute for Radiation Oncology and Biology, Oxford, UK) Morteza Aslaninejad, Matt Easton, Jaroslaw Pasternak (Imperial College, UK)Jürgen Pozimski (Imperial College and STFC/RAL, UK)Neil Bliss, Carl Beard, Peter McIntosh, Susan Smith, Stephan Tzenov (STFC/DL, UK) Rob Edgecock, David Kelliher, Shinji Machida, James Rochford (STFC/RAL, UK)Roger Barlow, Hywel Owen, Sam Tygier (University of Manchester, UK)