Next generation of ν beams Challenges A head

1. what it takes to design and construct a MW class Super-beam or Neutrino Factory Next generation of ν beams Challenges Ahead First nt event from OPERA/CNGS LAGUNA Workshp Aussois, France, September 8,2010 I. Efthymiopoulos - CERN EDMS Id:

2. Neutrino beams Overview CERN FNAL JPARC Three “conventional” ν beams operational today

3. TBID 2.7m 43.4m 100m 1095m 18m 5m 67m 5m Neutrino beams Super beams p + C (interactions) π+, K+ (decay) μ++νμ Conventional neutrino beam Super-beam if proton beam power >1MW

4. Neutrino beams Neutrino factory p + C(interactions) μ±(capture, accelerate, store, decay))νμ, νe • Typically a MMW system for the target and front-end IDS-NF baseline

5. Neutrino beams Challenges • Experience shows that DESIGNING and OPERATING a high-power neutrino beam facility is rather challenging • Key issues where present R&D effort is concentrated: • Target and Target chamber designs • SB: Secondary beam elements – NF: Front-end system • SB: horns – NF: cooling channel, RF & absorbers • SB: Hadron stop – NF: Beam dump • SB: Decay tunnel – NF: Storage ring • Neutrino beam monitoring & Near detector

6. Neutrino beams - Targetry Overview • Targets are key elements in the production of neutrino beams • High-power targetry challenges • Thermal management : • target melting (solid targets) – Target vaporization (liquid) • Radiation • Radiation protection - induced radiation - remote handling • Thermal shock • Beam induced pressure waves • Choice of materials Target High-power primary beam (protons) • Secondaries • π (for Super ν beams) • μ(for Neutrino Factory or Muon Collider) • Material Choices • Solid targets • Fixed • Moving • Particle beds • Liquid • Hybrid • Particle beds in liquids • Pneumatic driven particles Where is the limit for solid targets?

7. Target systems Present facilities CNGS : graphite rods 4(5)mm ∅, air cooled T2K: graphite, forced He cooling NUMI: graphite, water cooling

8. Neutrino Factory Study 2 Target Concept SC-5 SC-2 SC-3 SC-4 Window SC-1 Nozzle Tube Mercury Drains Mercury Pool Proton Beam Water-cooled Tungsten Shield Mercury Jet Iron Plug Splash Mitigator Resistive Magnets ORNL/VG Mar2009 Target systems – future facilities Neutrino Factory – MMW target station V.Graves - ORNL

9. Solenoid Jet Chamber Syringe Pump Secondary Containment Proton Beam 1 2 3 4 The MERIT experiment MMW target concept – proof-of-principle experiment

10. The MERIT Experiment Setup Hg-jet stabilization by magnetic field Experimental setup @ CERN 0T Jet velocity: 15m/s 10T Jet surface smoothens out with the increased magnetic field

11. The MERIT Experiment Key results Hg-jet 4×1012p, 10T fied • Disruption threshold: >4×1012 protons@14 GeV, 10T field • 115kJ pulse containment demonstrated • 8 MW capability demonstrated • Hg-jet disruption mitigated by magnetic field • 20 m/s jet operation allows up to 70Hz operation with beam

12. The MERIT Experiment Summary • The MERIT experiment successfully demonstrated the target concept of a liquid target (Hg-jet) for a Neutrino Factory/Muon Collider setup However…. • Going from the proof-of-principle to a real implementation of a target station for a 4MW beam operation requires additional R&D and engineering design • Key issues: • Radiation : to materials, shielding, access conditions, environment • Remote handling : maintenance and early repair operations • Ventilation, access • Dismantling

13. Target station – Future facilities Neutrino Factory – MMW target station P. Spampinato - ORNL

14. Target station – Future facilities LBNE – super beam design P.Hurh - FNAL

15. Target station – Future facilities T2K target station • Designed for Mega-W proton beam power • Massive shielding to acceess the beam elements Shielding (movable) Beam elements

16. Target station - Remote handling LBNE – target station hot cell P.Hurh - FNAL

17. Target station - Remote handling T2K facility C.Densham - RAL Remote handling operations for target exchange

18. Focusing elements Design issues - horns CNGS horn • Material • Few materials to avoid galvanic corrosion • Al typically he best choice • Radiation • Electrical issues • Cooling (water) • Mechanical stresses – pulsing • Alignment precision • Exchange and maintenance procedures

19. Decay pipe T2K decay pipe Shielding & cooling(?) along the decay pipe T2K: He container

20. Hadron stop – Beam dump T2K Hadron Stop Hg-Jet/Beam dump impact T. Davonne - RAL T. Ishida – JPARC • They both take substantial amount of the beam power  non trivial to design !!! • Cooling and RP issues the main worries

21. Technical challenges To complete the picture • Civil engineering – big slopes, depth for near detector • Installation/maintenance of equipment • Beam instrumentation • Beam collimators (around target area) • Alignment (installation & beam-based methods) • Ventilation • Air activation, tritium • Access • Cranes – remote handling • Decommissioning • … and think of early repairs !!!

22. Summary The design of neutrino beams from Mega-Watt proton beam sources is very challenging pushing materials and components to the limits Experience exists from the design and operation of conventional neutrino beams over the last years at CERN (CNGS), NUMI(FNAL), JPARC(T2K) which could easily operate at 0.75MW of proton beam power The T2K facility designed to accept up to 4-MW of primary beam power will hopefully grow up in intensity reaching the Mega-W region in few years, thus would provide useful information for the design of other neutrino superbeams presently under consideration