1 status of the opera long-baseline neutrino experiment magali besnier pic 07- annecy june 27 th...
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Status of the OPERA Status of the OPERA long-baseline long-baseline
neutrino experimentneutrino experimentMagali Besnier
PIC 07- Annecy
June 27th 2007
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Search for tauneutrino appearance at Gran Sasso laboratory
in a pure muon neutrino beam produced at CERN (732 km)
First direct observation of First direct observation of oscillationoscillation
37 INSTITUTS, ~160 PHYSICISTS
OPERAOscillation Project with Emulsion tRacking Apparatus
International Collaboration (Europe + Japan)
IIHE (ULB-VUB), Brussels Sofia IHEP Beijing, Shandong IRB Zagreb LAPP Annecy, IPNL Lyon, IRES Strasbourg Berlin Humboldt, Hagen, Hamburg, Münster, Rostock Technion Haifa Bari, Bologna, LNF Frascati, L’Aquila, LNGS, Napoli, Padova, Roma La Sapienza, Salerno Aichi, Kobe, Nagoya, Toho, Utsunomiya INR Moscow, ITEP Moscow, JINR Dubna, Obninsk Bern, Neuchâtel, Zurich METU Ankara
Possibility of Possibility of eeoscillation search for oscillation search for 1313 measurement measurement
3Hadron stopHadron stop
HornHorn
Civil engineering completed (June ’03)
Hadron stopper and decay tube installed (June ’04)
Target section completed in 2006 (first CNGS beam in August 2006)
Decay tube Decay tube vacuum tests successfulvacuum tests successful
CNGS beam (CERN Neutrino to Gran Sasso)
vacuum 4.5 1019 p.o.t. /year
700 m 100 m 1000m 67 m
400GeV
Ø at GS=2km 3.2° angle
To Gran Sasso
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P(CC) m2
23 = 2.5 10-3
eV²
Flux at Gran Sasso (given by Fluka)
flux
CNGS beam (CERN Neutrino to Gran Sasso) 4.5 1019 p.o.t. /year
Number of expected events at Gran Sasso (0-100 GeV):
(before reconstruction and detection efficiencies)
N CCyr/kT
N eCCyr/kT
N CCyr/kT
.Detection of CC interaction and direct observation of decay topology
.High background rejection
(17.4%) e- (17.8%)
h- n (49.5%) n() (14.5%)
decay kink
~ 0.6
mm
appearance signature
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OPERA Performances for oscillationoscillation
channel Signal (m2 (eV2)) .BR Background
1.9 10-3 2.4 10-3 3.0 10-3 e 2.7 4.3 6.7 3.7% 0.23 2.2 3.6 5.6 3.1% 0.23 h 2.4 3.8 5.9 3.3% 0.32
3h 0.7 1.1 1.7 1.0% 0.22 total 8.0 12.8 19.9 11.1% 1.00
full mixing, 5 years run @ 4.5x1019 pot / year
Number of expected signal and background events
Most important background : charm particle production
Best value ofm223
= 2.5 10-3 eV²3 range : 1.9 - 3.2 10-3 eV²
T.Schwetz, hep-ph/0606060
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rock thickness 1400m (3800 m.w.e.)cosmic muon flux: 1/m2/h
OPERA (CNGS1)
ICARUS (CNGS2)
Hall C
Hall B
BOREXINO
OPERA detector at LNGS (Notional Laboratories of Gran Sasso, Italy, 120 kms from Rome)
spectrometer: Dipolar magnet + RPC chambers
Target Trackers
Pb/Em. target
Precision tracker: Drift tubesB=1.6 T
2 super modules
1 super module = 31 walls + 31 Target Tracker + 1 muon spectrometer (21 RPC planes + 6 drift tube planes)
206 336 bricks
Lead target : 1.8 kTon ~6000 CC/yr
52*64 bricks/wall
p/p < 20% for E<50GeV
brick(56 Pb/Em. “cells”)
8 cm (10X0)
scintillator strips
brick wall
module
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OPERA bricks : main target detector component
2mm
6mm
Emulsion Cloud Chamber (ECC) : 1 ECC brick = 56 sheets Pb + 57
photographic emulsions
Pb
Emulsion layers
1 mm 12 M emulsion films and12 M thin lead foils
byFuji Film (Japan)JLGoslar (Germany)
This technology allows a spatial micrometric resolution, and a 3D reconstruction of particle
tracks, necessary for detection
12.5 cm
8 cm
8.6 kg
10 cm 12.5cm10.2cm
2 emulsion layers (44 m thick) poured on a 200 m plastic base
The most precise trackerThe most precise tracker
Résolution (microtracks) spatial : 0.06 µm Angular : ~ 2 mrad
Vertex position resolution : ~1µm in transverse plane
- Measurement of hadrons momenta by MCS- dE/dx pion/muon separation at low energy- Electron identification and energy measurements for electrons and photons
Reconstructed electronic
shower
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BAM (Brick Assembling Machine)Automatic
lead/emulsion piling in a dark room (500-700
bricks/day)
Insertion and extraction of bricks following intelligent
procedures.
The BMS(Brick Manipulator System)
one robot on each side of the
detector
Target preparation
Daily
total
Begining 2007 now
25000
30000
20000
15000
10000
5000
Brick production and insertion
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Detector today : electronics fully instrumented and testedBrick filling on the way : 27000 Bricks already inserted
LNGS Hall C
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20-30 bricks extracted / day
selection of the interaction brick provided by time
correlation of electronic detectors
Emulsion Development
of candidate bricks at Gran Sasso (surface
facilities)
Example of a vertex in emulsion
Emulsion Scanning with automated microscopes :
15 laboratories in Europe and Japan
Emulsion shipment
OPERA event analysis procedure
0 max
p.h.
Brick finding :
31 tracking scintillator planes (TT)/super modules
Trigger(>99%) + Brick finding (7080%)
Neutrino events in OPERA-like bricks (PEANUT test-beam)
Salerno scanning lab analysis
NUMI beam at low energy configuration
Scanning labs performance tests and improvements with :
-/e test-beams- test-beam-cosmic runs
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First OPERA results with CERN neutrino beam
cosmicsBeam events
Positive electronic tests during first beam run (August 06 : 0.084 1019
integrated pot)
Next CNGS run : Autumn 2007
interaction in magnet (Fe)
More than 300 registred events correlated in time with beam : interactions inside the rock and inside the detector (TT and spectrometers)
First events from the CNGS neutrino beam detected in the OPERA experiment R. Acquafredda et al 2006 New J. Phys. 8 303
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Muon track inside emulsions
First OPERA results with target bricks from cosmic run (May 07)
April 17th- May 15th :
~30 bricks extracted
18 scanned
8/18 muons already found in emulsions
Cosmic muons in OPERA detector (ray bandle)
< 1 event per day inside the acceptance ! ~20 ‘good’ bricks per month
first data confirm the good accuracy of the ED predictions
Prediction accuracy :• Δx = 5.5 mm (along the tray)• Δy = 0.4 mm (vertical direction)• Δθx = 16.6 mrad• Δθy = 24.8 mrad
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ConclusionConclusionOPERA is the first experiment for appearance in a beam
Hybrid detector with passive lead target and active electronic detectors
Electronic parts fully instrumented and tested
27000 Bricks yet inserted in the detector - full detector expected for summer 2008
First results
-Neutrino events have been observed in emulsions from PEANUT NUMI test-beam
-CNGS beam run in August 2006 : electronic detectors gave good results
-Cosmic run : brick candidate extraction ; scanning and analysis on the way to validate the full analysis chain
Future
Next CNGS beam run : Autumn 2007
with ~60000-70000 bricks and a beam intensity of 0.43 1019 integrated pot 180 expected events in bricks
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6.9m1.7 m
64 strips/module
Target Tracker
●●Trigger: > 99%● Brick finding : 7080%● Initiate muon tagging
Plastic scintillator strips (AMCRYS-H, 6.7m x 2.6cm x 1cm)readout by Kuraray WLS fibres +Hamamatsu PMT’s (64 channels)
LNGSLNGS
Tracker wall
2 x 256 strips
Reconstructed cosmic track
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Muon spectrometer
B=
1.5
5 T
base
slabs
coil
8.2 m
M ~ 950t
Drift tubes
12 Fe slabs(5cm thick)
RPC’s
2 cm gaps
identification: > 95% (TT)
p/p < 20% , p < 50 GeV/c
misidentified charge prob. 0.1 0.3%
21 bakelite RPC’s (2.9x1.1m2) / plane
Precision tracker: 6 planes of drift tubes
diameter 38mm, length 8m4 staggered layers / plane,
each layer consisting of 168 tubes
efficiency: 99%space resolution: 300µm
Inner Tracker: 11 planes of RPC’s
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Reconstruction of micro-tracks (45µm)
2D images 2D images processingprocessing 3D reconstruction of 3D reconstruction of
particle tracksparticle tracks
speed : 20cm²/hour/emulsion side
Résolution (grains) spatial : 0.06 µm Angular : ~ 2 mrad
1 emulsion sheet (2 sides) : 12h scanning - ~5Go
15 scanning laboratories in Europe and Japan
2 emulsion sides (45
m)
1 plastic base (200 m)
16 tomographi16 tomographic c images images = 45µ= 45µmm
300µ
m300
µm
300µm300µm
Field ofField of vue vue
Scanning : emulsion digitisation
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PEANUT : OPERA test-beam at FERMILAB
Detector placed in the front of the MINOS near detector:
-4 walls of 3*4 OPERA bricks exposed to NUMI beam ( ) in « low energy » configuration (<E>=10GeV, Epeak=3GeV )
-DONUT SFT (scintillators) between each wall
goal : to observe neutrino interactions in OPERA bricks
5 events/brick /day expected bricks exposed ~20days
Exposure time: October 18th 2005 -> Mars 1st 2006
total 160 Bricks made, exposed and developped
Brick piling in dark room
developper
Salerno scanning lab analysis
Neutrino reconstruction in emulsions
SFT-emulsions alignment~500µm spatial resolution
~5mrad angular resolution
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e oscillation search
mm232322 = 2.5 x 10-3 eV2 23 23 = 45°= 45°
nominal CNGS beam 5 years
90% C.L. limits on sin2(213) and 13 :
Combined fit of ECombined fit of Eee, E, Evisvis, (pt), (pt)missmiss
sinsin22(2(21313)<0.06 )<0.06 13 13 < 7.1º< 7.1º
2.5x10-3 eV2
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October 27th 2006 shutdown : leaking Drain Connection in the reflector cooling system
Outer conductor (Al)
Titanium joints
Ceramic insulator (500V)
(brazed to the Ti joints)Clamps for vapor tightness
Rupture point – leak!!
Bellows to give (some) flexibility
Reason for rupture :
Alignment errors and geometry too rigid
Vibration
Accident during assembly (?)
Improvements of new design drain connection :
Absorb better any misalignment errors
Water and vapour tightness maintained
Rigourous Quality during assembly
Reparing on the way for Autumn 2007