1. The UK ADSR programme Roger Barlow FFAG08 Manchester, 4 th September 2008

2. Roger BarlowUK ADSR ProgrammeSlide 2 History BASROC/CONFORM “Basic Technology” project for nsFFAGs Funded on the basis that nsFFAGs were an exploitable technology: we can build better+cheaper accelerators and open up lots of new applications 1.Build EMMA as proof of principle 2.Design PAMELA as a flagship application 3.Look for other applications ‘from Archaeology to Zoology’

3. Roger BarlowUK ADSR ProgrammeSlide 3 Application #2 ADSRs Accelerator Driven Subcritical Reactors “Manifestly Safe” Used for power and for waste transmutation Can use Thorium as fuel Accelerator Spallation Target Core

4. Roger BarlowUK ADSR ProgrammeSlide 4 Thorium Fertile, not fissile 232 Th +n  233 U Much smaller waste problems (no long- lived actinides) Proliferation resistant –No 235 U equivalent –Fissile 233 U contaminated by ‘too hot to handle’ 232 U Abundant Thoria – ThO 2 – has high melting point

5. Roger BarlowUK ADSR ProgrammeSlide 5 Energy Amplifier (Rubbia) Idea has been around for years Nobody’s built one yet! Feeling is that the accelerator is the weak point. Also MYRRHA, KURRI and others

6. Roger BarlowUK ADSR ProgrammeSlide 6 UK interest Past/Present Safer? But our reactors are safe… Waste problem? But we’ve solved it… Present/Future Increased awareness of power problem Global warming Fuel prices Global politics Hostility to conventional Nuclear Power continues Interest from Research Councils and individuals

7. Roger BarlowUK ADSR ProgrammeSlide 7 What energy do we need? Variation with proton energy of: (i) the neutron multiplicity np (ii) neutron yield per unit energy of incident proton (np/E p ) (Calculated using using MCNPX) The energy gain of an ADSR is directly proportional to np/E p. Clearly there is little need for proton energies greater than 1GeV Taken from Bob Cywinski

8. Roger BarlowUK ADSR ProgrammeSlide 8 Accelerator requirements Proton Energy ~ 1 GeV For 1GW thermal power: Need 3 10 19 fissions/sec (200 MeV/fission) 6 10 17 spallation neutrons/sec (k=0.98 gives 50 fissions/neutron) 3 10 16 protons/sec (20 spallation neutrons each) Current 5 mA. Power = 5 MW Compare: PSI proton cyclotron: 590 MeV, 72 MeV injection 2mA, 1MW

9. Roger BarlowUK ADSR ProgrammeSlide 9 Specification Cyclotron Energy too high for classical cyclotron. On the edge for other types FFAG Looks like the answer Similar to proton therapy except higher current and no need for variable energy extraction Very similar to neutrino factor proton driver Linac Can do the job. But VERY expensive Synchrotron Current far too high. Complicated (ramping magnets)

10. Roger BarlowUK ADSR ProgrammeSlide 10 Achieving high current Frequency must sweep (factor ~2) Need high duty cycle: Will not achieve cyclotron-like 100% but have to get within an order of magnitude Need to accelerate several pulses at slightly different energies with the same sweeping frequency Need several RF frequency systems (in same cavity or separate cavities)

11. Roger BarlowUK ADSR ProgrammeSlide 11 Reliability No long shutdowns – lose money No unplanned shutdowns – lose money and customers Spallation target runs hot. If beam stops, target cools and stresses and cracks: no more than 3 trips per year Cars and planes achieve this…

12. Roger BarlowUK ADSR ProgrammeSlide 12 Achieving reliability Component Underrating Redundancy (e.g. Ion source) Fault Tolerance Scheduled inspection and replacement programme Has to be integrated into the design

13. Roger BarlowUK ADSR ProgrammeSlide 13 Reliability and RF RF in a linac: Many cavities. Failure of one does not kill beam. Just gets slightly less energy RF in an FFAG: many cavities Failure of one should not kill beam Just gets slightly less energy, or takes slightly longer to accelerate Unless HNJ scheme is used. Probably ruled out

14. Roger BarlowUK ADSR ProgrammeSlide 14 The ultimate redundancy Could have several (3) accelerators for one reactor core If FFAGs are really as cheap as we’re promising

15. Roger BarlowUK ADSR ProgrammeSlide 15 UK Activities Grouping of interested people (accelerator scientists, reactor engineers, economists..) Held 2 1-day workshops this year Couple of small projects (EPSRC funded) to look at possibilities Increasing funding opportunities anticipated Upcoming 3 day workshop here, next week

16. Roger BarlowUK ADSR ProgrammeSlide 16 Formation of the Thorium Energy Amplifier Association: Universities and labs and industry A research consortium aimed at Networking (website, workshops) Sharing knowledge, within and outside UK Collaborative response to funding opportunities Design of a Thorium ADSR, aimed at power generation with transmutation as bonus. FFAG is baseline accelerator Forthcoming…

17. Roger BarlowUK ADSR ProgrammeSlide 17 Conclusions Things are moving fast. Two years ago my worry was that no-one wanted to know. Today my worry is that we’re going to get trampled in the rush.