Next generation of ν beams Challenges Ahead I. Efthymiopoulos - CERN LAGUNA Workshp Aussois,...

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


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


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

4

Neutrino beams


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


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?

6

Target systems


Present facilities

CNGS : graphite rods 4(5)mm , air cooled∅ T2K: graphite, forced He cooling

NUMI: graphite, water cooling

7

Target systems – future facilities


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

8

The MERIT experiment


MMW target concept – proof-of-principle experiment

1234

Syringe PumpSecondaryContainment

Jet Chamber

ProtonBeam

Solenoid

9

The MERIT Experiment


Jet surface smoothens out with the increased magnetic field

Setup

Experimental setup @ CERN Hg-jet stabilization by magnetic field

0TJet velocity: 15m/s

10T

10



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

11



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


Neutrino Factory – MMW target station

P. Spampinato - ORNL

13



LBNE – super beam design

P.Hurh - FNAL

14


Designed for Mega-W proton beam power

Massive shielding to acceess the beam elements


15 T2K target station

Beam elements

Shielding (movable)

Target station - Remote handling


LBNE – target station hot cell

P.Hurh - FNAL

16

Target station - Remote handling


Remote handling operations for target exchange

T2K facility

C.Densham - RAL

17

Focusing elements


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

18

Decay pipe


Shielding & cooling(?) along the decay pipe

T2K: He container

19

T2K decay pipe

Hadron stop – Beam dump


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


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


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

Next generation of ν beams Challenges Ahead I. Efthymiopoulos - CERN LAGUNA Workshp Aussois,...

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