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WIN’11, Cape Town, South Africa, 31 st Jan – 5 th Feb 2011. CERN Neutrinos to Gran Sasso: The CNGS Facility at CERN l Edda Gschwendtner, CERN. Lake Geneva. LHC. CNGS. SPS. CERN. PS. Outline. Introduction to CNGS at CERN Layout and Main Parameters Performance and Operational Experience

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CERN Neutrinos to Gran Sasso: The CNGS Facility at CERN l Edda Gschwendtner, CERN

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Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

WIN’11, Cape Town, South Africa, 31st Jan – 5th Feb 2011

CERN Neutrinos to Gran Sasso:The CNGS Facility at CERNlEdda Gschwendtner, CERN


Outline

Lake Geneva

LHC

CNGS

SPS

CERN

PS

Outline

  • Introduction to CNGS at CERN

  • Layout and Main Parameters

  • Performance and Operational Experience

  • Operating a High Intensity Facility

  • Summary

Edda Gschwendtner, CERN


Neutrino introduction

CERN

Gran Sasso

Neutrino Introduction

  • Dm232… governs thenm to nt oscillation

  • Up to now: only measured by disappearance of muon neutrinos:

    • Produce muon neutrino beam, measure muon neutrino flux at near detector

    • Extrapolate muon neutrino flux to a far detector

    • Measure muon neutrino flux at far detector

    • Difference is interpreted as oscillation from muon neutrinos to undetected tau neutrinos

       K2K, NuMI

  • CNGS (CERN Neutrinos to Gran Sasso):

    long base-line appearance experiment:

    • Produce muon neutrino beam at CERN

    • Measure tau neutrinos in Gran Sasso, Italy (732km)


Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

Introduction

Approved for 22.5·1019 protons on target

i.e. 5 years with 4.5·1019 pot/ year(200 days, intensity of 2.4·1013 pot/extraction )

Gran Sasso

CERN

  • Expect ~10 nt events in OPERA

measure

tau-neutrinos

732km

produce

muon-neutrinos

Physics started in 2008  today: 9.5·1019 pot

~2 nt/year (~1·1017nm/year)

~4·1019 p/year ~2·1019nm/year

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

Posc*stcc

(arbitrary units)

500m

Typical size of a

detector at Gran Sasso

nm-fluence

1000m

3000m

Introduction

  • Beam optimization:

    • Intensity: as high as possible

    • Neutrino energy: matched for nm-ntappearance experiments

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


How to detect a tau neutrino

e-, -, h-

-



3h-

-



How to Detect a Tau Neutrino?

  •  ntinteraction in the target produces a t lepton.

  • t lepton: very short lifetime

  • CNGS:

  • tau: lorenzboost of ~10:

  • Tau tracklength: ~1mm

  • Tau lifetime: 2.9·10-13s

  • c*lifetime: 87 mm

 Identification of tau by the characteristic ‘kink’ on the decay point.

  • Need high resolution detector to observe the kink

  • Large mass due to small interaction probability


Neutrino detectors in gran sasso

Neutrino Detectors in Gran Sasso

OPERA

1.2 kton emulsion target detector

~146000 lead emulsion bricks

ICARUS

600 ton Liquid Argon TPC


Cngs classical method to produce neutrino beam

CNGS: Classical method to produce neutrino beam

CNGS Facility – Layout and Main Parameters

 Produce high energy pions and kaons to make neutrinos

p + C (interactions) p+,K+ (decay in flight) m+ + nm

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

Lake Geneva

LHC

CNGS

SPS

CERN

PS

CERN Accelerator Complex

  • From SPS: 400 GeV/c

  • Cycle length: 6 s

  • 2 Extractions: separated by 50ms

  • Pulse length: 10.5ms

  • Beam intensity: 2x 2.4 · 1013 ppp

  • Beam power: up to 500kW

  • s ~0.5mm

9

Neu2012, 27-28 Sept. 2010, CERN

Edda Gschwendtner, CERN


Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

target

magnetic

horns

decay tunnel

hadron absorber

muon detector 1

muon detector 2

Edda Gschwendtner, CERN


Cngs challenges and design criteria

CNGS Challenges and Design Criteria

  • High Intensity, High Energy Proton Beam (500kW, 400GeV/c)

    • Induced radioactivity

      • In components, shielding, fluids, etc…

    • Intervention on equipment ‘impossible’

      • Remote handling by overhead crane

      • Replace broken equipment, no repair

      • Human intervention only after long ‘cooling time’

    • Design of equipment: compromise

      • E.g. horn inner conductor: for neutrino yield: thin tube, for reliability: thick tube

  • Intense Short Beam Pulses, Small Beam Spot

    (up to 3.5x1013 per 10.5 ms extraction, < 1 mm spot)

    • Thermo mechanical shocks by energy deposition (designing target rods, thin windows, etc…)

 Proton beam: needs tuning, interlocks!

secondary beam area: most challenging zone (target–magnetic horns)

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cngs primary beam line

CNGS Primary Beam Line

840 m total length, 100 m extraction together with LHC

Magnet System:

  • 73 MBG Dipoles

    • 1.7 T nominal field at 400 GeV/c

  • 20 Quadrupole Magnets

    • Nominal gradient 40 T/m

  • 12 Corrector Magnets

    Beam Instrumentation:

  • 23 Beam Position Monitors (Button Electrode BPMs)

    • recuperated from LEP

    • Last one is strip-line coupler pick-up operated in air

    • mechanically coupled to target

  • 8 Beam profile monitors

    • Optical transition radiation monitors: 75 mm carbon or 12 mm titanium screens

  • 2 Beam current transformers

  • 18 Beam Loss monitors

    • SPS type N2 filled ionization chambers

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Primary beam line

Primary Beam Line

Edda Gschwendtner, CERN


Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

CNGS Facility – Layout and Main Parameters

Downstream end of the proton beam:

last beam position and beam profile monitors

BN collimator, d=14mm

Be window, t=100mm


Cngs secondary beam line

TBID

2.7m

43.4m

100m

5m

1095m

18m

5m

67m

CNGS Secondary Beam Line

  • Air cooled graphite target

  • Multiplicity detector

    • TBID, ionization chambers

  • 2 magnetic horns (horn and reflector)

  • Decay tube

  • Hadron absorber:

    • Absorbs 100kW of protons and other hadrons

  • 2 muon monitor stations:

    • Muon fluxes and profiles

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cngs target

CNGS Target

CNGS Target: 13 graphite rods

each 10 cm long, Ø = 5 mm and/or 4 mm, 2.7 interaction length

Note:- target rods thin / interspaced to “let the pions out”

- target shall be robust to resist the beam-induced stresses

- target is air-cooled (particle energy deposition)

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cngs target1

CNGS Target

Target magazine: 1 unit used, 4 in-situ spares

17

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cngs horn and reflector

150kA/180kA, pulsed

7m long

inner conductor 1.8mm thick

Designed for 2·107 pulses

1 spare horn (no reflector yet)

Design features

Water cooling circuit to evacuate 26kW

In situ spare, easy switch

Remote water connection

Remote handling & electrical connections

Remote and quick polarity change

0.35 m

inner conductor

CNGS Horn and Reflector

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Decay tube

Decay Tube

  • 994m long

  • steel pipe

  • 1mbar

  • 2.45m diameter, t=18mm, surrounded by 50cm concrete

  • entrance window: 3mm Ti

  • exit window: 50mm carbon steel, water cooled


Muon monitors

270cm

60cm

11.25cm

Muon Monitors

  • 2 x 41 fixed monitors

  • (Ionization Chambers)

  • 2 x 1 movable monitor

  • LHC type Beam Loss Monitors

  • Stainless steel cylinder

  • Al electrodes, 0.5cm separation

  • N2 gas filling

  • Muon Intensity:

    • Up to 8 107 /cm2/10.5ms

CNGS

Edda Gschwendtner, CERN


Cngs timeline until today

CNGS Timeline until Today

Civil engineering works for the drains & water evacuation

OPERA detector

ready

Target inspection

Additional shielding

Reconfiguration of service electronics

Repairs & improvements in the horns

2000-2005

Civil

Engineering,

Installation

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

Achieved protons on target: 4.04E19Expected protons on target: 3.83E19

CNGS Run 2010

SPS CNGS efficiency: 81.15%


Cngs physics run comparison of yearly integrated intensity

Nominal (200days):

4.5E19 pot/yr

2010

(218days):

2009 (180 days) :

4.04E19 pot

3.52E19 pot

2008 (133days) :

1.78E19 pot

CNGS Physics Run: Comparison of Yearly Integrated Intensity

 Total today: 9.5E19 pot

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Sps efficiencies for cngs

SPS Efficiencies for CNGS

2008

2009

2010

Integrated efficiency:

60.94%

Integrated efficiency:

72.86%

Integrated efficiency:

81.15%

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cngs operation in 2009 2010

CNGS Operation in 2009/2010

  • 2009: 11% more protons on target than expected

  • 2010: 5% more pot than expected

  • 57% duty cycle for CNGS with LHC operation and Fixed Target program

1 beam cycle to

Fix Target Experiments

5 beam cycles to CNGS

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

  • Improvements in SPS control system

    • Allows fast switching between super cycles  gain in time

  • Improvements in CNGS facility and shutdown work

    • No additional stops for maintenance

Edda Gschwendtner, CERN


Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

CNGS Performance: Beam Intensity

Protons on target per extraction for 2010

Typical transmission of the CNGS beam through the SPS cycle ~ 94%.

Injection losses ~ 6%.

2E13 pot/extr

  • Nominal beam intensity:

  • 2.4E13 p.o.t./extraction

  • Intensity limits:

    • Losses in the PS

    • SPS RF

Mean: 1.88E13 pot/extraction

26

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Beam position on target

shielding

BPM

horn

beam

target

collimator

shielding

Beam Position on Target

  • Excellent position stability; ~50 (80) mm horiz (vert) over entire run.

  • No active position feedback is necessary

    • 1-2 small steerings/week only

RMS =54mm

RMS =77mm

Vertical beam position [mm]

Horizontal beam position [mm]

Horizontal and vertical beam position on the last Beam Position Monitor in front of the target

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

target

magnetic

horns

decay tunnel

hadron absorber

muon detector pit 1

muon detector pit 2

Edda Gschwendtner, CERN


Muon monitors1

Muon Monitors

Muon Detector

Muon Profiles Pit 2

  • Offset of beam vs target at 0.05mm level

270cm

  • Offset of target vs horn at 0.1mm level

    • Target table motorized

    • Horn and reflector tables not

11.25cm

Muon Profiles Pit 1

Very sensitive to any beam changes! Online feedback on quality of neutrino beam

Centroid =∑(Qi * di) / ∑(Qi)

Qi is the number of charges/pot in the i-th detector,

di is the position of the i-th detector.

29

Edda Gschwendtner, CERN

WIN’11, Cape Town, 31st Jan – 5th Feb 2011


Beam stability seen on muon monitors

Beam Stability Seen on Muon Monitors

  • Beam position correlated to beam position on target.

    • Parallel displacement of primary beam on target

Centroid of horizontal profile pit2

~80mmparallel beam shift

 5cm shift of muon profile centroid

30

Edda Gschwendtner, CERN

WIN’11, Cape Town, 31st Jan – 5th Feb 2011


Cngs polarity puzzle

270cm

11.25cm

CNGS Polarity Puzzle

Muon Detector

  • Observation of asymmetry in horizontal direction between

    • Neutrino (focusing of mesons with positive charge)

    • Anti-neutrino (focusing of mesons with negative charge)

31

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cngs polarity puzzle1

Anti-neutrino

Focusing on

negative charge

Neutrino

Focusing on

positive charge

Lines: simulated m flux

Points: measurements

Normalized to max=1

FLUKA simulations, P. Sala et al 2008

CNGS Polarity Puzzle

Explanation: Earth magnetic field in 1km long decay tube!

  • calculate B components in CNGS reference system

  • Partially shielding of magnetic field due to decay tube steel

  • Results in shifts of the observed magnitude

  • Measurements and simulations agree very well

    (absolute comparison within 5% in first muon pit)

32

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Muon monitors measurements vs simulations

Horizontal Profile Pit 1

Horizontal Profile Pit 2

Measurements

Simulations

Vertical Profile Pit 2

Vertical Profile Pit 1

Muon Monitors: Measurements vs. Simulations

P. Sala et al, FLUKA simulations 2008

  • Data & simulation agree within 5% (~10%) in first (second) muon pit

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Operating a high intensity facility

Operating a High Intensity Facility

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

2005-07: Magnetic Horns Repair and Improvements

  • Water leak:

  • Failure in one ceramic connector in drainage of the 2nd magnetic horn

    • Repair work and design improvements in the cooling circuit on both magnetic horns

       detailled radiation dose planning, extra shielding.

  • Damage in one of the flexible strip-line connectors

35

Edda Gschwendtner, CERN

WIN’11, Cape Town, 31st Jan – 5th Feb 2011


Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

Ventilation units in the service gallery

High-energy (>20MeV) hadrons fluence (h/cm2) for 4.5E19 pots

A. Ferrari, L. Sarchiapone et al, FLUKA simulations 2008

2007-2008 CNGS Radiation Issues

CNGS: no surface building above CNGS target area

 large fraction of electronics in tunnel area

Failure in ventilation system installed in the CNGS Service gallery

 due to radiation effects in electronics

(SEU – Single Event Upsets- due to high energy hadron fluence)

36

Edda Gschwendtner, CERN

WIN’11, Cape Town, 31st Jan – 5th Feb 2011


2007 2008 cngs radiation issues

2006/07

2008++

106 h/cm2/yr

109 h/cm2/yr

2007-2008 CNGS Radiation Issues

Modifications during shutdown 2007/08:

  • Move most of the electronics out of CNGS tunnel area

  • Create radiation safe area for electronics which needs to stay in CNGS

  • Add shielding 53m3 concrete  up to 6m3 thick shielding walls

p-beam

target chamber

p-beam

target chamber

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN

37


2009 2010 sump and ventilation system modification and improvements

2009-2010 Sump and Ventilation System Modification and Improvements

Modification of

  • Sump system in the CNGS area

     avoid contamination of the drain water by tritium produced in the target chamber

    • Try to remove drain water before reaches the target areas and gets in contact with the air

    • Construction of two new sumps and piping work

  • Ventilation system configuration and operation

    • Keep target chamber TCC4 under pressure wrt the other areas

    • Do not propagate the tritiated air into other areas and being in contact with the drain water

2 new small sumps (1m3), pump out water immediately

WIN’11, Cape Town, 31st Jan – 5th Feb 2011


Cngs 2011

CNGS 2011

2011 Injector Schedule

Physics run starts on 18th March 2011

End of physics: 21st November 2011

If all goes well, as in 2010, we expect

more than 4.5E19 protons on target

in 2011!

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Summary

Summary

  • All issues at CNGS so far come from ‘peripheral equipment’ and general services

    • start-up issues of CNGS have been overcome

  • BUT: Operating and maintaining a high-intensity facility is very challenging

    • Tritium issue, fatigue, corrosion,…

  • Beam performance since start of physics run in 2008 CNGS is very good

    • Expect to have 14 E19 pot by end of 2011

    • CERN will continue with physics running in 2012.

    • 1 year stop in 2013

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cern neutrinos to gran sasso the cngs facility at cern l edda gschwendtner cern

Additional slides

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cngs primary beam

CNGS Primary Beam

  • Extraction interlock modified to accommodate the simultaneous operation of LHC and CNGS

    • Good performance, no incidents

  • No extraction and transfer line losses

  • Trajectory tolerance: 4mm, last monitors to +/-2mm and +/- 0.5mm (last 2 monitors)

    • Largest excursion just exceed 2mm

Primary proton beam trajectory

Horizontal plane

2mm

target

Extracted

SPS beam

840m

2mm

Vertical plane

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Beam stability seen on muon monitors1

Beam Stability Seen on Muon Monitors

RMS =3.02cm

RMS =2.6cm

Horizontal centroid [mm]

Vertical centroid [mm]

  • Position stability of muon beam in pit 2 is ~2-3cm rms

43

Edda Gschwendtner, CERN

WIN’11, Cape Town, 31st Jan – 5th Feb 2011


Continuous surveillance

Continuous Surveillance

The CNGS facility is well monitored.

 Redundancy is important!

22E13

60°

11°

20°

Protons on Target/Extraction

Temp downstream Horn

Horn water conductivity

Horn cooling water temperature

13°

45°

44

Edda Gschwendtner, CERN

WIN’11, Cape Town, 31st Jan – 5th Feb 2011


Intensity limitations from the cngs facility

Working hypothesis for RP calculations

CNGS working hypothesis

Design limit for target, horn, kicker, instrumentation

Design limit for horn, shielding, decay tube, hadron stop

Intensity Limitations from the CNGS Facility

 Horn designed for 2E7 pulses, today we have 1.4E7 pulses  spare horn

 Intensity upgrade from the injectors are being now evaluated

WIN’11, Cape Town, 31st Jan – 5th Feb 2011


Multi turn extraction

Five beamlets separated by 1 PS turn

Multi-Turn-Extraction

Courtesy MTE project - M. Giovannozzi et. al.

  • Novel extraction scheme from PS to SPS:

    • Beam is separated in the transverse phase space using

      • Nonlinear magnetic elements (sextupoles and octupoles) to create stable islands.

      • Slow (adiabatic) tune-variation to cross an appropriate resonance.

    • Beneficial effects:

      • No mechanical device to slice the beam losses are reduced

      • The phase space matching is improved

      • The beamlets have the same emittance and optical parameters.

MTE extracted beam in 2009 during Machine Development periods

2010: Started with MTE, then classical extraction

Result of the first extraction test in the PS extraction line (TT2) with one bunch.

Evolution of the horizontal beam distribution during the splitting.

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cngs performance reminder

Examples:effect onντcc events

horn off axis by 6mm< 3%

reflector off axis by 30mm < 3%

proton beam on target < 3%

off axis by 1mm

CNGS facility misaligned< 3%

by 0.5mrad (beam 360m off)

CNGS Performance - Reminder

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


Cngs proton beam parameters

CNGS Proton Beam Parameters

Dedicated mode:

500kW

beam power

48

WIN’11, Cape Town, 31st Jan – 5th Feb 2011

Edda Gschwendtner, CERN


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