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					         HEP03

Advanced Neutrino Beams
       Rob Edgecock
           RAL
                       Candidates…….

                                                           Decay ring
• Conventional super beam                                  Brho = 1500 Tm
            SPL
                                                           B=5T
• Neutrino Factory                                         Lss = 2500 m


• Beta beam                                                    He3 Li e 
                                              
                                                           6      6
                                                           2

                                                   Decay   Average Ecms  1.937 MeV
 ISOL target                                       Ring
 & Ion source                SPS                           18
                                                           10   Ne18Fe e 
                                                                    9

                                                           Average Ecms  1.86 MeV
 Cyclotrons
 Storage ring
 and fast
 cycling          PS
 synchrotron




                                     , e                 e , e
                  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:   m me  207
• But…….luminosity!
• Fast cooling technique – ionisation cooling – invented 1981:
              Skrinsky and Parkhomchuk
• Another problem…….neutrino radiation!

               Enough neutrinos to be a problem
                 Must be enough to do physics

                           Neutrino Factory!
                       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

                      (0.77MW)
  J-PARC Facility
               JAERI@Tokai-mura
               (60km N.E. of KEK)     Super Conducting
                                      magnet for  beam line
Construction
2001~2006
(approved)




                                         Near  detectors
                                         @280m and
                                         @~2km
                         1021POT(130day)≡ “1 year”
                         JHF


        Plan to start in 2007
                                                Kobayashi

          Kamioka ~1GeV  beam
                                     JAERI
Super-K: 22.5 kt                  (Tokaimura)

Hyper-K: 1000 kt                   0.77MW 50 GeV PS
                                   4MW 50 GeV PS
                                  ( conventional  beam)

              Phase-I (0.77MW + Super-Kamiokande)
              Phase-II (4MW+Hyper-K) ~ Phase-I  200
                            JHF Superbeam
  “Conventional” neutrino beam                             Kobayashi
                                         Decay Pipe
                            Focusing
 Proton           Target
                            Devices              
 Beam
                                p,K                           
  “Off-axis”
                              Far Det.                Beam Dump
     Horns Decay Pipe
Target                  q
                         Target
   Many difficulties: enormous power density
                                 lifetime problems
                      pion capture

                                    Stationary target:
  Replace target between
         bunches:
Liquid mercury jet or rotating
        solid target


     Proposed rotating
     tantalum target
     ring

                                  CERN

   RAL
                    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




        0.0ms        0.5ms        1.2ms   1.4ms   2.0ms    3.0ms

                  Dispersal velocity ~10m/s, delay ~40s
                  Magnet Tests

Tests with a 20T magnet at Grenoble.

                                   Mercury jet (v=15 m/s)




                         B = 0T                             B = 18T




                   Jet deflection                       Smoothing
                   Reduction in velocity
                   Reduction in radius
      Pion Capture




20T                  1.25T
            Horn Capture



                  Current of 300 kA


            p
  Protons                       To decay channel

                                 B=0
Hg target       B1/R
Target Facility
            Pion Production Experiments

Data taking:
    2001-2002
Proton energy:
    2-15 GeV
Targets:
    H2-Pb
    2, 5, 100% Xo
X-section to few %
Optimise beam
energy and target
material for NF




                     The Hadron Production Experiment
          Pion Production Experiments


Data-taking:
        2003-200?
Proton energy:
        5-120 GeV
Targets:        NuMI
Be, C, H2, N2, Be, C,
         Cu, Pb
Re-use existing
detectors




                  Main Injector Particle Production Experiment
                Phase Rotation




Beam after drift plus        Beam after ~200MHz rf rotation;
adiabatic buncher –          Beam is formed into
Beam is formed into          string of equal-energy bunches;
string of ~ 200MHz bunches   matched to cooling rf acceptance
                Transverse Cooling
• Cooling  >10 increase in muon flux
• Existing techniques can’t be used  ionsation cooling
                                               beam in




• Cooling is delicate balance:

      d , N  N dE  x 13.6MeV/c 
                                    2

                 
        dz    E dz     2  3 Em LR
                                                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




S = solenoid, A = absorber, 36 cavities in blocks of 3
                          RAL Ring
• Main problem: kicker!
             RFOFO Ring
       Tetra Ring   Quadrupole Ring
                         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 area                   Stage 2 construction




    What it will look like when it is finished
                                      MICE

                   Muon Ionisation Cooling Experiment

     SC Solenoids;
                                                       Liquid H2 absorbers
     Spectrometer, focus pair, compensation coil
                                                       or LiH ?




                                      201 MHz RF cavities
T.O.F. I & II
Pion /muon ID    Tracking devices:
precise timing   He filled TPC-GEM (similar to TESLA R&D)           T.O.F. III
                 or sci-fi                                          Precise timing
                 Measurement of momentum angles and position

                                                            Electron ID
                                                            Eliminate muons that decay
                     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
                          MICE
                          FFAGs
• Fixed Field Alternating Gradient  magnets not ramped
• Cheaper/faster RLAs/RCSs
• Large momentum acceptance
• Large transverse acceptance
       less cooling required!




                                           B ~ rk
                           MICE
                           FFAGs

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

                        Staging
• High Power Proton Driver         Physics outcomes
   – Muon g-2
• Muon Factory (PRISM)               at each stage
   – 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
                       MICE
                       FFAGs

R&D:

       • Injection and extraction
       • Magnets – 10-20 GeV ring (120m radius): 6T SC
       • RF – low frequency (6.5MHz), 1MV/m
                                MICE
                                VRCS

• 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: 1.8GV @ 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
                          MICE
                       Conclusions

• 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

				
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posted:9/14/2012
language:English
pages:38