ADS Developments in Britain Roger Barlow Manchester University and the Cockcroft Institute Workshop on Applications of High Intensity Proton Beams Fermilab: October 20th 2009

What it is An organisation “ThorEA is a research association to promote the use of thorium-fuelled energy amplifier systems as a safe, sustainable and publicly-acceptable of nuclear power. The goal of the organisation is the construction of a thorium-fuelled ADSR (accelerator-driven subcritical reactor) in the United Kingdom.” An organisation “ThorEA is a research association to promote the use of thorium-fuelled energy amplifier systems as a safe, sustainable and publicly-acceptable of nuclear power. The goal of the organisation is the construction of a thorium-fuelled ADSR (accelerator-driven subcritical reactor) in the United Kingdom.” Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain2 Members: 80 (loose) or 40 (public) Accelerator Scientists Particle Physicists Nuclear Physicists Nuclear Engineers Economists … Members: 80 (loose) or 40 (public) Accelerator Scientists Particle Physicists Nuclear Physicists Nuclear Engineers Economists … From: Cockcroft, JAI, RAL, DL Imperial, Glasgow, Cambridge, Brunel, Huddersfield Industry Non-UK From: Cockcroft, JAI, RAL, DL Imperial, Glasgow, Cambridge, Brunel, Huddersfield Industry Non-UK A website

Workshops Last one in Glasgow September 7-8 Next one Daresbury November 24 Talks accessible from the website Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain3 What it does(1)

Funding bids: Partnerships formed to respond to opportunities Some successes already: – Use of FFAG for ADSR – Economics of ADSR – Use of Thorium fuel rods in conventional reactors by pre-exposure more applications on the way Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain4 What it does(2)

Neutron production: MC validation Tuesday, October 20, 2009Roger Barlow: ADS developments in BritainSlide 5 Slides from work by Cristian Bungau Validate GEANT4 against MCNPX, FLUKA, and data

Modelling spallation Tuesday, October 20, 2009Roger Barlow: ADS developments in BritainSlide 6

Energy deposition from the beam Tuesday, October 20, 2009Roger Barlow: ADS developments in BritainSlide 7

Publicity/outreach Website, Articles and press releases, Talks to the public and politicians Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain8 What it does(3)

Drayson Report Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain9 Science Minister visited Daresbury: we told him about ADSRs and he asked for a report. Now ready (85 pages) and submitted. Makes the case for a 5 year £300M R and D program, leveraging £1-2Bn private investment. 3 stage acceleration system: 35 MeV, 400 MeV, 1 GeV

Design Choices Thorium fuelled fast reactor Emphasize energy production with transmutation as extra benefit 1 GW Thermal. Go for production reactor as 1 st system k=0.985 Accelerator (or multiple accelerators) deliver 10 mA of protons at 1 GeV Lead as target+coolant+moderator Recycle spent fuel rods after ~10 years FFAG accelerator Tuesday, October 20, 2009Roger Barlow: ADS developments in BritainSlide 10 Those are my principles, and if you don't like them... well, I have others. Groucho Marx

Acceleration System The FFAG is our preferred solution: EMMA, first nsFFAG, being built at Daresbury (starting soon) Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain11

FFAGs101 Magnetic field fixed in time but varies in space, so more energetic particles see stronger field Keeping constant betatron tune requires gentle B ~ r k field variation Relaxing this constraint permits simpler more compact magnets: the nonscaling FFAG Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain12

FFAG Pros and Cons Advantages (compared to a Synchrotron) DC magnets: cheap and reliable Fast acceleration. Not limited by magnet iron. Acceleration to 1 GeV in ~1000 turns envisaged (say 50 m radius ring: take ~ 1 ms) Disadvantages Complicated Magnet shape May require varying RF frequency Limited gain in energy (momentum change factor 2-5 depending on design) nsFFAG principle not yet proven Tuesday, October 20, 2009Roger Barlow: ADS developments in BritainSlide 13

Duty cycle Synchrotron-style Inject 1 pulse Accelerate Extract For 10 mA at 1 kHz, Q=10 μC = protons/bunch Compare space charge limits ~ protons/bunch Harmonic factor (bunches/turn) may help a bit Cyclotron-style CW injection Acceleration CW extraction Only particles/bunch. Easy But sweeping the RF frequency limits the duty cycle. Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain14

Reliability Requirement ~5 trips/year. (Where does this come from? Needs checking.) Thermal stresses in window and target Thermal stresses in the core and its components Economics: a 1 GW plant can’t just drop out of the Grid when it feels like it, and the financial system will ensure this Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain15

Reliability: the Next Accelerator Frontier How to achieve this: Needs redundancy and robustness – Ion Source: use several – Magnets: reliability possible with DC magnets – Multiple accelerators – RF: components will fail. Must not be fatal. Probably rules out SOC, RLA, Harmonic number jump and other clever schemes – Also vacuum, power, etc Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain16 ENERGY LUMINOSITY RELIABILITY

The possibilities Cyclotrons 1 GeV is really pushing the edge Synchrotrons 10 mA is really pushing the edge Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain17 FFAGs Linacs Ideal but nonexistant. As yet. Seriously Expensive

Conclusions The UK is waking up We have a wide range of specialists working together across discipline boundaries Check out the ThorEA website, and send me an to join We are very much aware that we have a lot to learn from others Small amounts of funding are coming through. Larger sums are possible Tuesday, October 20, 2009Roger Barlow: ADS developments in Britain18