Next generation of ν beams Challenges Ahead
I. Efthymiopoulos - CERNLAGUNA WorkshpAussois, France, September 8,2010
what it takes to design and construct a MW class Super-beam or Neutrino Factory
First event from OPERA/CNGS
EDMS Id:
Neutrino beams
I.Efthymiopoulos-CERN, Sep 8,2010
Three “conventional” ν beams operational today Overview
CERN
FNAL
JPAR
C
2
Neutrino beams
I.Efthymiopoulos-CERN, Sep 8,2010
Conventional neutrino beam
Super-beam if proton beam power >1MW
Super beams
43.4m100m
1095m 18m 5m 5m67m
2.7m
TBID
p + C (interactions) π+, K+ (decay) μ+ + νμ
3
Neutrino beams
I.Efthymiopoulos-CERN, Sep 8,2010
IDS-NF baseline Neutrino factory
p + C (interactions) μ± (capture, accelerate, store, decay) ) νμ, νe
Typically a MMW system for the target and front-end
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Neutrino beams
I.Efthymiopoulos-CERN, Sep 8,2010
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
Challenges5
Neutrino beams - Targetry
Targets are key elements in the production of neutrino beams
I.Efthymiopoulos-CERN, Sep 8,2010
Overview
High-power primary beam (protons)
Target Secondaries•π (for Super ν beams)•μ (for Neutrino Factory or Muon Collider)
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
Material Choices Solid targets
Fixed Moving Particle beds
Liquid Hybrid
Particle beds in liquids Pneumatic driven particles
Where is the limit for solid
targets?
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Target systems
I.Efthymiopoulos-CERN, Sep 8,2010
Present facilities
CNGS : graphite rods 4(5)mm , air cooled∅ T2K: graphite, forced He cooling
NUMI: graphite, water cooling
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Target systems – future facilities
I.Efthymiopoulos-CERN, Sep 8,2010
Neutrino Factory – MMW target station
IronPlug
ProtonBeam
NozzleTube
SC-1SC-2 SC-3 SC-4
SC-5Window
MercuryDrains
MercuryPool
Water-cooledTungsten ShieldMercury
Jet
ResistiveMagnets
Neutrino Factory Study 2 Target Concept
ORNL/VGMar2009
SplashMitigator
V.Graves - ORNL
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The MERIT experiment
I.Efthymiopoulos-CERN, Sep 8,2010
MMW target concept – proof-of-principle experiment
1234
Syringe PumpSecondaryContainment
Jet Chamber
ProtonBeam
Solenoid
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The MERIT Experiment
I.Efthymiopoulos-CERN, Sep 8,2010
Jet surface smoothens out with the increased magnetic field
Setup
Experimental setup @ CERN Hg-jet stabilization by magnetic field
0TJet velocity: 15m/s
10T
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The MERIT Experiment
I.Efthymiopoulos-CERN, Sep 8,2010
Hg-jet disruption mitigated by magnetic field 20 m/s jet operation allows
up to 70Hz operation with beam
Key results
Hg-jet 4×1012 p, 10T fied
0 1 2 3 4 5 6 7 8 9
0.0
0.1
0.2
0.3
0.4
Dis
rup
tion
len
gth
(m
)
Total energy deposition (103 J)
B=0T, 24GeV B=5T, 24GeV B=10T, 24GeV B=15T, 24GeV B=5T, 14GeV B=5T, 14GeV B=5T, 14GeV
Disruption threshold: >4×1012 protons@14 GeV, 10T field
115kJ pulse containment demonstrated 8 MW capability demonstrated
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The MERIT Experiment
I.Efthymiopoulos-CERN, Sep 8,2010
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
Summary12
Target station – Future facilities
I.Efthymiopoulos-CERN, Sep 8,2010
Neutrino Factory – MMW target station
P. Spampinato - ORNL
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Target station – Future facilities
I.Efthymiopoulos-CERN, Sep 8,2010
LBNE – super beam design
P.Hurh - FNAL
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Target station – Future facilities
Designed for Mega-W proton beam power
Massive shielding to acceess the beam elements
I.Efthymiopoulos-CERN, Sep 8,2010
15 T2K target station
Beam elements
Shielding (movable)
Target station - Remote handling
I.Efthymiopoulos-CERN, Sep 8,2010
LBNE – target station hot cell
P.Hurh - FNAL
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Target station - Remote handling
I.Efthymiopoulos-CERN, Sep 8,2010
Remote handling operations for target exchange
T2K facility
C.Densham - RAL
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Focusing elements
I.Efthymiopoulos-CERN, Sep 8,2010
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
Design issues - horns
CNGS horn
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Decay pipe
I.Efthymiopoulos-CERN, Sep 8,2010
Shielding & cooling(?) along the decay pipe
T2K: He container
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T2K decay pipe
Hadron stop – Beam dump
I.Efthymiopoulos-CERN, Sep 8,2010
20
They both take substantial amount of the beam power non trivial to design !!! Cooling and RP issues the main
worries
T2K Hadron Stop
T. Ishida – JPARC
T. Davonne - RAL
Hg-Jet/Beam dump impact
Technical challenges
I.Efthymiopoulos-CERN, Sep 8,2010
21
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 !!!
To complete the picture
Summary
I.Efthymiopoulos-CERN, Sep 8,2010
22 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