kT 100 yrs;5 /yr;decays 1019

kT 100 yrs;8 /yr;decays 106.2 20

kT 100 yrs;5 /yr;decays 1019

kT 100 yrs;8 /yr;decays 106.2 20

Sensitivity

• Key parameters:―Degree of matter-antimatter

symmetry violation → ―Degree of mixing e- and -

neutrinos → 13

Neutrino Factory has highest sensitivity

Neutrino oscillations

• A neutrino created as one ‘type’ or ‘flavour’ changes into another type as it travels:

• Implications for particle physics:―Neutrinos are massive and mix: Standard

Model is incomplete―Neutrinos may violate matter-antimatter

symmetry• Impact on astrophysics and cosmology:

―Origin of matter-dominated universe―Contribution to dark matter known to

exist in universe• Require dedicated experimental programme

to:―Search for matter-antimatter symmetry

violation―Precisely measure parameters

created

Distance travelled

created

Distance travelled

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180MeV DTL (Drift Tube Linac)

Stripping Foil(H- to H+/protons)

Achromat for removing beam halo

Two Stacked Proton Synchrotrons (boosters)• 1.2GeV• 39m mean radius• Both operating at 50Hz

Two Stacked Proton Synchrotrons (full energy)• 6GeV• 78m mean radius• Each operating at 25Hz, alternating for 50Hz total

Proton bunches compressed to 1ns duration at extraction• Mean power 5MW

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Target Studies

Parameters of the NF Target

Proton Beam pulsed 10-50 Hz pulse length 1-2 ms energy 2-30 GeV average power ~4 MW

Target (not a stopping target)

mean power dissipation 1 MW energy dissipated/pulse 20 kJ (50 Hz) energy density 0.3 kJ/cm3

The target operates at very high mean power dissipation and extremely high energy density. This high power density creates severe problems in dissipating the heat and the short pulses produce thermal shocks due to the rapid expansion of the target material. These shocks can potentially exceed the mechanical strength of solid materials.

In addition the pions and muons created in the target must be collected in a 20 Tesla solenoidal field or a magnetic horn. This imposes strong restraints on the target and collector system which must ultimately be designed as a single entity.

2 cm

20 cm

beam

Several targets which potentially can withstand the huge power density are currently being considered worldwide:a. Mercury (or a liquid metal) jetsb. Contained flowing mercury (or a liquid metal)c. Solid target - tantalum rotating toroid, thermally radiating at ~2300 Kd. Granular solid target

rotating toroid

proton beam

solenoid magnet

toroid at 2300 K radiates heat to water-cooled surroundings

toroid magnetically levitated and driven by linear motors

The UK is currently investigating solid targets. The solid target is simple in concept, but may be susceptible to shock damage. There are many examples of solids bombarded by proton beams at similar power densities and even targets operating at an order of magnitude higher power density have been shown to survive many pulses. Shock studies are the main thrust of the UK activity.

A toroid or band, rotating in vacuum and thermally radiating its power to water-cooled vacuum chamber walls could provide a simple, clean and reliable high power target. It would not require beam windows between the incoming proton beam and the outgoing pion beam. It is proposed to consider electromagnetic levitation and guidance of the toroid and rotation by linear motors, so that there are no moving parts (except for the toroid) in the vacuum and no physical contact with the toroid.

Schematic diagram of the radiation cooled rotating toroidal target

Muo

n C

oolin

g R

ing

FFAG I(2-8GeV)

FFAG II(8-20GeV)FFAG III

(20-50GeV)

R109

Near Detector

Muon Decay Ring(muons decay to neutrinos)

To F

ar D

etec

tor 2

To Far Detector 1

Muon Linac to 2GeV(uses solenoids)

Schematic of the UK Neutrino Factory DesignThe UK is playing a significant role in the international design effort towards a neutrino factory.

Proton Driver Front-End Test Stand at RALAny accelerator complex muststart with a particle source (inthis case H− ions) and asequence of componentsthat are either tailored forlow-energy beam trans-port and acceleration(LEBT, RFQ), or performfunctions that are mosteffectively done at lowenergy (the chopper).The specification of aproton driver for a neutrinofactory demands that thesecomponents push the envelopeof high beam current with verylow uncontrolled losses. RAL hasan active ion source researchprogramme and a chopper development project running in parallel with CERN.

UK Targetry R&D ProgrammeThe target must survive an extreme degree of heating: dissipating 1MW of heat at temperatures reaching over 2000°C, while having to withstand physical shocks caused by 50 proton pulses per second. RAL is working with the RMCS at Cranfield University to investigate these phenomena.

• Pulsed power 16TW

FFAG Electron Model at DaresburyAn unconventional kind of accelerator called a non-scaling FFAG is being devised to accelerate the muons rapidly enough before they decay. To verify this technology, a scaled model using electrons instead of muons is being designed for operation at Daresbury Laboratory, where synergies with existing electron machines can make it particularly cost-effective.

CCLRC - Imperial - Warwick Front End Test Stand

What? An experimental facility to test the all-important early stages of high power proton accelerators (HPPAs).High power proton accelerators are the bases of spallation neutron sources, transmutation machines, and neutrino factories.

Why? Because high power proton accelerators must produce high quality megawatt beams with beam losses of less than 0.0001% per

metre, and such high quality beams have yet to be demonstrated.

Where? At Rutherford Appleton Laboratory in Oxfordshire.

When? Design already under way. Construction starts 2005.

The test stand will consist of an H– ion source producing 60 mA, 2 ms pulses at 50 pps, a LEBT running at 75 keV to match the beam from the ion source into the RFQ, an RFQ accelerator driven by a 1–2 MW, 234 MHz RF driver to increase the beam energy to 2.5 MeV, a beam chopper switching between beam bunches in 2 ns, and a comprehensive suite of diagnostics to measure beam currents, emittances, energy distributions and bunch structures.The design of the test stand involves much sophisticated physics design, and the construction involves challenging electrical, electronic, mechanical, RF and vacuum engineering, together with the procurement of much high-tech apparatus.

RFQ Beam chopper DiagnosticsLEBTIon source

Magnetic spectrometer

20 metres

So far, four key areas have been identified in which R&D is particularly important: these are highlighted on this diagram and detailed elsewhere in

the presentation. Most of the technology demonstrations will be constructed within the next five years.

More about the front-end test stand, which will be an integrated demonstration of all these low-energy technologies, can be found below.

Muon Ionisation Cooling Experiment (MICE)The muon beam must be ‘cooled’, or reduced in size, to fit inside the accelerators downstream. MICE uses a muon beam from an intermediate target of the ISIS accelerator at RAL to prove the practicality of a technique called ionisation cooling, which is unique to muons. The international MICE collaboration are showing two posters here.

The UKNeutrino Factory

Project

UK Neutrino Factory collaboration

UK Neutrino Factory collaborationD. Rodger, H.C. Lai, F. Robinson

Applied Electromagnetics Research Group, Electronic and Electrical Engineering Department, University of Bath, Claverton Down, Bath, Avon BA2 7AY, UK

N.K. Bourne, A. MilneCranfield University, Royal Military College of Science, Shrivenham. Swindon, SN6 8LA, UK

M.W. PooleAccelerator Science and Technology Centre, Daresbury Laboratory, Daresbury, Warrington,

Cheshire, WA4 4AD, UKD. Wilcox

High Power RF Faraday Partnership, c/o Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX, UK

A.T. Doyle, F. J. P. SolerDepartment of Physics and Astronomy, Kelvin Building, The University of Glasgow, Glasgow,

G12 8QQ, UKP. Cooke, J. B. Dainton, J. R. Fry, R. Gamet, Ch. Touramanis

Department of Physics, University of Liverpool, Oxford St, Liverpool L69 7ZE, UKG. Barber, P. Dornan, M. Ellis, K. Long†, D.R. Price, J. Sedgbeer, A. Tapper

Imperial College London, Prince Consort Road, London SW7 2BW, UKG.D. Barr, J.H. Cobb, S. Cooper, G. Wilkinson,

Subdepartment of Particle Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK

H. JonesSubdepartment of Condensed Matter Physics, University of Oxford, Department of Physics,

Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UKG. Bellodi, J.R.J. Bennett, S. Brooks, M.A. Clarke-Gayther, C. Densham, P.V. Drumm,

R. Edgecock, D.J.S. Findlay, F. Gerigk, A.P. Letchford, P.R. Norton, C.R. Prior‡, G. Rees, J.W.G. Thomason, J.V. Trotman

CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX, UKP.F. Harrison

Department of Physics, Queen Mary University of London, Mile End Road, London, E1 4NSC. N. Booth, E. Daw, P. Hodgson

Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, UK and Fluid Gravity Engineering, 83 Market St., St. Andrews, Fife

and e2v technologies, 106 Waterhouse Lane, Chelmsford, Essex CM1 2QU, UK

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