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Introduction to the Neutrino Factory. Simone Gilardoni DPNC - Université de Genève CERN - AB/ABP Division. Neutrino oscillation. Observation: n into another n of different flavour Results: NEUTRINOS HAVE MASS MASS STATES FLAVOUR STATES. Parameters: 3 masses
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Introduction to the Neutrino Factory Simone Gilardoni DPNC - Université de Genève CERN - AB/ABP Division Simone Gilardoni
Neutrino oscillation Observation:n into another nof different flavour Results: NEUTRINOS HAVE MASS MASS STATES FLAVOUR STATES Parameters: • 3 masses • Two Dm2 differences • Three mixing angles • One delta phase Simone Gilardoni
Neutrino Oscillations Mixing described by For 3-flavour eigenstates U is Maki-Nakagawa-Sakata (MNS): 6 parameters:3 mixing angles - θ23,θ12 and θ13 CP-violation angle - δ 2 mass differences - Δm223 and Δm212 Transition probability: Simone Gilardoni
Three family oscillation Atmospheric Neutrinos SolarNeutrinos Phase d CP • Super-K atm. • P(nm nm) • Maximalmixing • Dm2 3 10-3 eV2 • L/E = 1 GeV/500 km • SNO • P(ne nx) • Large Mixing (LMA) • Kamland • L/E MeV/1.5 1011m • Limit from CHOOZ • Goal of next generation of neutrino-beam • If q13 is zero, IMPOSSIBLE to observe CP violation Simone Gilardoni
Two friends for Nufact Kamland:nedisappearance from Nuclear Reactor LMA solution for solar neutrinos SNO: D2O detectorNon-ne flux in solar neutrinos Simone Gilardoni
THE last results The LMA solution for solar neutrinos is confirmed The L/E oscillation pattern is confirmed G.Fogli et al., PR D66, 010001-406,(2002) Simone Gilardoni
B.Kaiser Simone Gilardoni
Road Map • Experiments to look for 13 • Look for nmne in nm beam (ICARUS, MINOS) • Off-axis beam (JHF-SK, off axis NUMI) • Low energy SuperBeams • Experiments to look for CP/T violation or for 13 (if too small) • Beta-beams (combined with SuperBeam) • Neutrino Factory Simone Gilardoni
Sensitivity of Nufact 5o 0.1o 1o 2.5o 13o Simone Gilardoni
JHF ready in 2007 (0.77MW) JAERI@Tokai-mura (60km N.E. of KEK) Super Conducting magnet for n beam line Construction 2001~2006 (approved) Near n detectors @280m and @~2km 1021POT(130day)≡ “1 year” Simone Gilardoni
Far Detectors 1st Phase (2007~, ≥5yrs) Super-Kamiokande(22.5kt) 2nd Phase (201x~?) Hyper-Kamiokande(~1Mt) 48m × 50m ×500m, Total mass = 1 Mton Simone Gilardoni
Proposal for a CERN - Super Beam Simone Gilardoni
Nufact CERN layout Simone Gilardoni
Nufact FAQ • Why neutrinos from stored muons: • Pure nm, ne beam • Switching the helicity by switching the muon sign • Hope for a muon collider (may be… one day…) • Why high energy ? • High cross section neutrino interaction • Small E/L (50GeV/3500 km) • Why so many neutrinos? • Is there someone that can do better before? • See the roadmap Simone Gilardoni
Beam Composition Nufact Beam WANF Beam The scales are different ! Simone Gilardoni
Energy and flux specs NuFact near detector 1020 decay/year4.0 106n CC evt. 1.7 106 n CC evt. per kg-year Minos near detector 3.7 1020 pot/year2.5 106n CC evt. 0.6 106n CC evt. per ton-year Physics at far detector Simone Gilardoni
The Holy Grail: any leptonic CP violation? CP is observable IF: • sin2q12 and Dm212 are large (LMA) and sin2q13 small (but not too small…) • Appearance experiment: P(em) • P(ee) is T invariant CP is conserved(CP not observable from solar or reactor neutrinos) Simone Gilardoni
Physics at a Nufact • Measure q13 via P(nenm) with a precision of 10-3 or setting a limit to 10-6 • Determine via MSW the sign of Dm2 • Discover and measure the CP violation in the leptonic sector (phase d) P(nenm)P(nenm) Need of high energy ne: m+e++ ne+ nm Simone Gilardoni
1016p/s m+ e++ nm +ne Oscillation nmm+ 0.9 1021 m/yr nmm- 3 1020 ne/yr 3 1020 nm/yr Wrong Sign muons Simone Gilardoni
SPL @ 2.2 GeV Superconducting Proton Linac • High Power • LINAC @ 4 MW • Rep. Rate 50 Hz • 2.27 1014 p/pulse spaced by 22.7 nsec (44 MHz) • Accumulator ring to reduce the pulse length • CERN interested at least in the low energy part forthe LHC upgrade and the improvement of CNGS Simone Gilardoni
Accumulator and Compressor • Accumulator • Macrobunch with internal 23 ns structure (44 MHz) MUON BUNCHES KEEP THIS STRUCTURE • Macrobunch Rep. rate: 20 ms (50 Hz) • Compressor • Microbunch length reduction to from 3.5 ns to 1 ns • Time spread dueto Pion decay 1 ns Simone Gilardoni
PDAC time scheme 44 MHz structure 50 Hz Simone Gilardoni
Proposed site Old ISR tunnel, site of accumulator + bunch compressor Radius = 50 m Simone Gilardoni
Target Nufact • Target: • Mercury: Z = 80 short target Liquid easy to replace (v// 20 m/s) • Dimensions: L 30 cm, R 1 cm • 4 MW of proton into a pint of beer 4 MW= 40000 Simone Gilardoni
Target experiment Experiments @BNL and @CERN • Measurements of Hg explosion speed • Speed of protons >> Speed of sound • Maximum v 20 m/s • v// 3 m/s 1 cm Protons Simone Gilardoni
Jet test a BNL E-951 Event #1125th April 2001 Protons Picture timing [ms] 0.00 0.75 4.50 13.00 P-bunch: 2.71012 ppb 100 ns to = ~ 0.45 ms Hg- jet : diameter 1.2 cm jet-velocity 2.5 m/s perp. velocity ~ 5 m/s K. Mc Donald, H. Kirk, A. Fabich Simone Gilardoni
The Harp experiment Hadron production cross section measurement Simone Gilardoni
Protons 12 GeV Be target Front view Top view Side view Simone Gilardoni
Magnetic horn Current of 300 kA p To decay channel Protons B = 0 Hg Target B1/R Simone Gilardoni
First piece of Nufact Merci à l’ atelier du CERN Simone Gilardoni
Decay channel Solenoid B=1.8 T, L=30 m “Life Time” 18 m @ p=400 MeV/c Geometry • Huge Energy spread • Huge velocity spread • LEP sE/E 10-3 • NF sE/E 2 • Debunching • Beam type • b 0.8 • E-t correlation 30 m Energy(GeV) m p Time (arb.) Energy spread reduction needed Simone Gilardoni
Nufact CERN layout Simone Gilardoni
What is a “Phase Rotation”? • Aim:Reducing the energy spread of a non-relativistic beam • How: series of RF cavities that • - accelerates low-energy particles • - decelerates high-energy particles Simone Gilardoni
Phase rotation example 100 E 300 MeV E = 200 50 MeV MeV 300 200 100 time 30 RF cavities: 2 MV/m 44 MHz L = 1 m B = 1.8 T Simone Gilardoni
88 MHz cavity prototype Simone Gilardoni
Cooling: the problem(transverse phase space) Accelerato • Problem: m Beam pipe radius of storage ring P or x’ and x reduction needed:COOLING Accelerator acceptance R 10 cm, x’ 0.05 rad rescaled @ 200 MeV p and mafter focusing Simone Gilardoni
Ionization Cooling : the principle Liquid H2:dE/dx sol H2 rf Beam sol RF restoresonly P//: E constant Simone Gilardoni
Cooling : the channel 1) Cooling I: x’ reduction 3)Cooling II: x’ reduction ‘ Cooling works best with high x’ 2) Focusing: a) Needed whenx’ reduction comparablewith multiple scattering b) same rotation center for the spiral motion. (Rematching) Heating term H2 has X0= 8.9 m Simone Gilardoni
Cooling: the results IN OUT Results:phase space density increased by 16 (Cooling rate for MICE: 16%) Simone Gilardoni
Channel engineering design Simone Gilardoni
MICE: Muon Ionisation Cooling Experiment Proposal to be submitted to RAL before end of the year Simone Gilardoni
Accelerator and Particle physics together Example of cooling TPG Tracker SciFi Tracker Simone Gilardoni
Mice roadmap (at RAL?) m - STEP I: 2004 STEP II: summer 2005 STEP III: winter 2006 STEP IV: spring 2006 STEP V: fall 2006 STEP VI: 2007 Simone Gilardoni
Nufact CERN layout Simone Gilardoni
Storage ring • Two straight sections pointing to two detectors • Two possible shapes • triangle • bow tie • Lattice design for beam divergencex’=1/10bg n beam divergence dominated bym decay q=1/bg=mm/pm= 2mrad (@ 50 GeV) • 25% useful decays per direction Simone Gilardoni
Technical problems Could you imagine a screw driver falling down from here? 14 Simone Gilardoni
Nufact CERN layout Simone Gilardoni
Around Europe... • First possible location: Gran Sasso 732 km • Second location: 3500 km away bestCandidates: Svalbards (Norway) Gran Canaria (Spain) Simone Gilardoni
Where do you prefer to take shifts? Simone Gilardoni
Why two locations? • Fit of q13 and d a the same time • No sensitivity at 732 km • Better to combine with 2810 km From P. Hernandez Simone Gilardoni