BASROC and CONFORM. Roger Barlow Instrumentation workshop 11 th April 2008. BASROC. British Accelerator Science Radiation and Oncology Consortium Universities + laboratories + hospitals + industry Goal is establishment of UK hadron therapy centres using FFAG technology
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11th April 2008
Irradiate with protons of energy 50-250 MeV such that they stop in the tumour.
No exposure behind the tumour.
Small exposure before tumour (Bragg peak maximum).
Small spot size (mm) – can ‘paint’ dose with 3D raster scan
Energy loss damages DNA more effectively than X rays
Evidence that Carbon nuclei may be even more effective!
They’re expensive… but effective
Fixed Field (like a cyclotron)
B varies with space but not in time
Particles experience greater field as energy increases (like a synchrotron)
Cyclotron currents at Synchrotron energies
B constant, R varies
R varies slightly
B varies with R but not t
R constant, B varies
As particle energy increases:
v increases T falls f increases
L increases T increases f falls
For cyclotrons these cancel exactly
For FFAGs these may cancel approximately. May get away with constant RF frequency
Or can scan using low Q Finemet cavities. Go from CW to pulsed operation – high frequency and high duty cycle
High duty cycle
High Rep rate
Variable energy extraction
Increase in p= increase in B x increase in R
How big an increase in B can we manage?
Realistic – factor 2: Optimistic – factor 5
How big an increase in R can we manage?
Realistic – factor 1: Optimistic – factor 2
Conventional (scaling) FFAGs:
Focussing scales with momentum
Focussing changes with momentum
resonances unavoidable but harmless(?)
More compact aperture
More compact ring (all magnets bending)
Never been built!
CONFORM - the COnstruction of a Non-scaling FFAG for Oncology, Research and Medicine
£5.6 M funded through the Basic Technology Programme
Electron Machine with Many Applications
World’s first non-scaling FFAG
Accelerates electrons from 10 to 20 MeV in 16 turns
Off-axis for bending
Major components ordered
Build starts summer 08
Commissioning Summer 09
Accelerator Driven Subcritical Reactor
Protons ~1 GeV
Neutron multiplication factor typically k=0.98
Workshop May 7th at Daresbury
Proton Energy ~ 1 GeV
For 1GW thermal power:
Current 5 mA. Power = 5 MW
High current rules out synchrotron
Compare: PSI proton cyclotron:
590 MeV, 72 MeV injection
3 stage FFAGs at 120Hz
0.1 – 2.5 MeV
2.5 – 20 MeV ( ½)
20 – 150 MeV (?)
Current ~1 nA
Aim: study neutron production
Protons up to 250 MeV, Carbon ions up to 400 MeV/nucleon
Designs being considered
Goal is design we can take to MRC/NHS/Charities for funding at ~£50M
Deliver doses at ~100 Hz
Scan in 2D position through gantry and beamline magnets, and in energy(=depth). Order not yet fixed
Need to reject pulses if patient alignment wrong or if dose already reached. (We have plenty of pulses, not a problem)
Need to know WHAT is being delivered and WHERE it is being delivered and WHERE you want it
Maybe 1+ GeV protons for tomography and 400 MeV/u Carbon for therapy?
… we need Instrumentation ideas