HEP03 Advanced Neutrino Beams Rob Edgecock RAL

Candidates……. Conventional super beam Conventional super beam Neutrino Factory Neutrino Factory Beta beam Beta beam PS SPS ISOL target & Ion source SPL Cyclotrons Storage ring and fast cycling synchrotron Decay Ring Decay ring Brho = 1500 Tm B = 5 T L ss = 2500 m

Outline Introduction Proton driver Target and capture Muon frontend Acceleration Storage ring Conclusions Emphasis on problems and R&D to be done Discussion of options being considered

Introduction Idea for a Neutrino Factory: muon collider Concept of a muon collider: Tinlot (1960), Tikhonin (1968), Budker (1969), Skrinsky (1971) Neuffer (1979) Many advantages over electron collider: But…….luminosity! Fast cooling technique – ionisation cooling – invented 1981: Skrinsky and Parkhomchuk Another problem…….neutrino radiation! Neutrino Factory! Enough neutrinos to be a problem Must be enough to do physics

Muon Collider Three stage scenario: Neutrino Factory Higgs Factory Muon Collider Recently, much interest in Neutrino Factory alone. 5 different layouts: BNL CERN FNAL J-PARC RAL

RAL Layout RAL Neutrino Factory layout

Proton Driver Main requirements: 4 MW beam power* 1 ns bunch length  50Hz Two types: Linac RCS Range of energies: 2.2 to 50 GeV R&D: HIPPI * = F1 GP

Proton Driver 30 GeV Rapid Cycling Synchrotron in the ISR tunnel

Proton Driver CERN Super-conducting Proton Linac

Most advanced……J-PARC J-PARC Facility Construction 2001 ～ 2006 (approved) (60km N.E. of KEK) (0.77MW) Super Conducting magnet for beam line Near POT(130day)≡ “1 year”

JHF ~1GeV beam Kamioka JAERI (Tokaimura) 0.77MW 50 GeV PS ( conventional beam) Super-K: 22.5 kt 4MW 50 GeV PS Hyper-K: 1000 kt Phase-I (0.77MW + Super-Kamiokande) Phase-II (4MW+Hyper-K) ~ Phase-I  200 Plan to start in 2007 Kobayashi

JHF Superbeam Kobayashi Proton Beam Target Focusing Devices Decay Pipe Beam Dump  ,K,K  “Conventional” neutrino beam  Target Horns Decay Pipe Far Det. “Off-axis”

Target Proposed rotating tantalum target ring Many difficulties: enormous power density  lifetime problems pion capture Replace target between bunches: Liquid mercury jet or rotating solid target Stationary target: RAL CERN

Liquid Mercury Tests Tests with a proton beam at BNL. Proton power 16kW in 100ns Spot size 3.2 x 1.6 mm Hg jet - 1cm diameter; 3m/s 0.0ms0.5ms1.2ms1.4ms2.0ms3.0ms Dispersal velocity ~10m/s, delay ~40  s

Magnet Tests Tests with a 20T magnet at Grenoble. B = 0T 1cm Mercury jet (v=15 m/s) B = 18T Jet deflection Reduction in velocity Reduction in radius Smoothing

Pion Capture 20T1.25T

Horn Capture Protons Current of 300 kA To decay channel  Hg target B  1/R B = 0

Target Facility

Pion Production Experiments The Hadron Production Experiment Data taking: Proton energy: 2-15 GeV Targets: H 2 -Pb 2, 5, 100% X o X-section to few % Optimise beam energy and target material for NF

Pion Production Experiments Main Injector Particle Production Experiment Data-taking: ? Proton energy: GeV Targets:NuMI Be, C,H 2, N 2, Be, C, Cu, Pb Re-use existing detectors

Phase Rotation Beam after drift plus adiabatic buncher – Beam is formed into string of ~ 200MHz bunches Beam after ~200MHz rf rotation; Beam is formed into string of equal-energy bunches; matched to cooling rf acceptance

Transverse Cooling Cooling  >10 increase in muon flux Existing techniques can’t be used  ionsation cooling Cooling is delicate balance: beam in beam out

Transverse Cooling Cooling cells are complex R&D essential: MuCool, MuScat and MICE

Transverse Cooling Recent development: ring coolers Main advantages: shorter longitudinal cooling Tetra Ring Quadrupole Ring RFOFO Ring S = solenoid, A = absorber, 36 cavities in blocks of 3 RAL Ring Main problem: kicker!

MuScat Measurement of muon multiple scattering: only relevant data – e - scattering, Russia, 1942 Input for cooling simulations and MICE First (technical) run at TRIUMF summer 2000, M11 beam Run2: April 2003

MuCool Design, prototype, test all cooling cell components High beam-power test of a cooling cell Preparations for MICE  NCRF cavities with sufficient gradient in multi-T fields  Be windows  Up to kW power deposition in absorbers  Safety considerations  Low non-absorber thickness in beam: - Absorber windows - Safety windows - RF windows  Cost effective design and construction

MuCool Absorber window development 200MHz cavity development MuCool Test Area

MuCool Original areaStage 2 construction What it will look like when it is finished

MICEMICE T.O.F. III Precise timing Electron ID Eliminate muons that decay Tracking devices: He filled TPC-GEM (similar to TESLA R&D) or sci-fi Measurement of momentum angles and position T.O.F. I & II Pion /muon ID precise timing 201 MHz RF cavities Liquid H2 absorbers or LiH ? SC Solenoids; Spectrometer, focus pair, compensation coil Muon Ionisation Cooling Experiment

MICE Muon Acceleration Needs to be fast – muon lifetime Needs to be a reasonable cost – not linacs all the way Baseline: Recirculating Linear Accelerators Other possibilities……FFAGs & VRCS

MICEFFAGs Fixed Field Alternating Gradient  magnets not ramped Cheaper/faster RLAs/RCSs Large momentum acceptance Large transverse acceptance  less cooling required!

MICEFFAGs Proof Of Principle machine built and tested in Japan. 50keV to 500keV in 1ms. 150MeV FFAG under construction at KEK.

MICEFFAGs

Staging in Japan Staging High Power Proton Driver –Muon g-2 Muon Factory (PRISM) –Muon LFV Muon Factory-II (PRISM-II) –Muon EDM Neutrino Factory –Based on 1 MW proton beam Neutrino Factory-II –Based on 4.4 MW proton beam Muon Collider Physics outcomes at each stage

MICEFFAGs R&D: Injection and extraction Magnets – GeV ring (120m radius): 6T SC RF – low frequency (6.5MHz), 1MV/m

MICEVRCS Fastest existing RCS: ISIS at 50Hz  20ms Proposal: accelerate in 37  s  4.6kHz Do it 30 times a second 920m circumference for 4 to 20 GeV Combined function magnets 100micron laminations of grain oriented silicon steel 18 magnets,  20T/m Eddy currents iron: 100MW  350kW Eddy currents cu : 170kW RF: 201MHz; 15MV/m Muons: 12 orbits, 83% survival

MICE Storage Ring Main requirement: underground lab(s) at large distances Longyearbyen~ 3520km Pyhasalmi~ 2290km Tenerife~ 2750km   15 degrees for straight sections

MICEConclusions Neutrino oscillations: one of most important physics results Many new experiments conceived New beam neutrino facilities required: - Superbeams - Neutrino Factory - Beta beams All require extensive R&D For Neutrino Factory: - proton driver - target - frontend (MuCool, MICE) - acceleration World Design Study (WDS1) planned