Transcript Slides

37th Meeting of the LNF
Scientific Committee
OPERA Status Report
Lucia Votano
On behalf of the OPERA Collaboration
Lucia Votano
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Containers for the
emulsion-lead bricks
(« walls »)
General support structure
OPERA-LNF
F. Bersani Greggio, A. Cazes, V. Chiarella, C. Di Troia, B. Dulach, G. Felici, A.
Franceschi, F. Grianti, T. Napolitano, M. Paniccia, A. Paoloni, M. Spinetti, F.
Terranova, L. Votano
In collaboration with
LNF-SEA, LNF-SPAS, LNF-SSCR, LNF-DA_
Veto
Scintillators
Brick insertion machine
Automatic
scanning of
nuclear
emulsion
RPC
Drift tubes
Magnets
LNF projects
Projects with
partecipation of
LNF Lucia Votano
Non-LNF projects
Brick
production
machine
(“BAM”)
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t identification
Target is divided in about 151000 ECC’s
Neutrino
Long
event
40%
125mm
100mm
Short
event
60%
75.4mm
II
10 X0
lead plate
Nuclear Emulsion
(OPERA film)
Piled up
alternately
ECC
（Emulsion Cloud Chamber）
～ 8.3 kg
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Sensitivity of tau neutrino detection
Full mixing after 5 years run at 4.5x1019 pot / year
Signal
(Full mixing)
t- decay
Background
m2
m2
2.5 x 10-3 (eV2)
3.0 x 10-3 (eV2)
t-  µ-
2.9
4.2
0.17
t-  e-
3.5
5.0
0.17
t-  h-
3.1
4.4
0.24
t-  3h
0.9
1.3
0.17
ALL
10.4
15.0
0.76
channels
Background sources:
- Charm production and decays
- Hadron re-interactions in lead
- Large-angle muon scattering in lead
Occur if primary muon is not
detected and possible wrong
charge
measurement
of
secondary muon.
Muon ID is very crucial issue for
the experiment!
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• 2003 : start
building detector
Brick Target
Target mass 1.35 kt
~ 151000 Bricks
~ 8 millions of
nuclear Emulsion
January 2007: start
filling target
Brick filling (146621 bricks) completed in July 2008:
Lucia Votano
4500 bricks will be produced at the end of 2008
once additional lead will be delivered after J.L. Goslar fire accident
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2007 CNGS neutrino run
Sept-Oct 2007
8.24E17 pot
2008 CNGS neutrino run
18 June -3 Nov 2008
1.78E19 pot
2009 CNGS neutrino run
requested 4.5E19 pot ( nominal),
scheduled 3.5E19 pot
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(168 days 48s supercycle 80%
efficiency 2.4E13 pot/extraction)
2007 CNGS ( OPERA 80% SM1 filled = 0.5 kton)
 Sept-Oct 2007: 8.24x1017 integrated pot
12/10/07
Comissioning Physics
20/10/07
9/10/07
6.72 1017 pot
CNGS “Nominal”:
4.5 1019 pot /yr (1yr=200 days)
Problems in
ventilation control
units of the proton
target
59 : CNGS very stable
at 1.58 1017 pot/day
326 expected events in bricks
5/10/07
3.91 1017 pot
38 events registered:
29 CC
Time: in ns from 1/01/1970
9 NC
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CNGS 2008potintegrated intensity: 1.782E19 pot
3/11 8:00
1.782E19 pot
CNGS “Nominal” :
4.5 1019 pot /yr (1yr=200 days)
Horns filters
19-20/10
18KV cable accident
25/7
Beam loss, vacuum
accident 27/6-2/7
Wed 18/6 17:00
Start of
commissioning
at low intensity
June 26th- November 3rd
6-8/10 MD
CNGS quadrupole
14-17/9
10/7-18/7 Earth
fault on the PS
magnet
Horn + PS vacuum
Week 1/9
PS septum + Long MD
8-14/8
Long MD stop + MTE kicker problem
7/7 6:00 – 10/7 12:00
Unix Time
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2008 Statistics
•Duty cycle increased since September 24th (suppression of LHC pilot cycle)
•Further increase after October 6th (stop of north area)
•This allowed to partially recover the initial bad performance:
Final statistics delivered by CNGS: 1.782E19 pot collected,
(80% of the 2008 expectations)
about 10100 on time events
1700 neutrino interactions in the bricks
Important note:
This year we had two different running conditions
From June 26th June to September 24th : ~0.75x1019pot in 8 Unix Time Units
From September 25th to November 3rd : ~1.03x1019pot in 3.5 Unix Time Units
The event rate/day during the second period was ~25 (~170 events/week)
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OPERA 2008 run (Electronic Detectors)
Average rate
Reference sample:
long tracks
(>5 TT planes)
(x20)
CNGS on-time
events
(x100)
CNGS start: 18 june 2008
•
137 days of data taking
•
~10.5 million events acquired
•
~10100 events on time with CNGS
•
1700 neutrino interactions in the bricks
•
The electronic detectors and the DAQ ran smoothly (99.96% efficiency for the target tracker
Votano cuts in LNGS)
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during operation, loss of 2*1017 pot due toLucia
power
OPERA working chain
1. Trigger on event “on time” with CNGS and selection of the brick using electronic detectors information
(brick finding algorithm)
2. Brick removed by BMS (brick manipulating system)
3. The emulsion interfaces (CS) are separated from the brick, developed and a connection with respect to
the electronic predictions is searched for in one of the two Scanning Stations, located in Europe (LNGS)
and in Japan (Nagoya)
4. If any track is found in the CS, the brick is exposed to X-rays beam and to cosmic rays for sheets
alignment
5. The brick is disassembled and the emulsion films are developed and sent to one of the scanning labs
6. The selected scanning lab acquire the brick, looking for the particles previously found in the CS and
follow them until the neutrino interaction is found
7. A volume scan around the neutrino interaction is performed and the neutrino vertex is confirmed
8. The scanning lab stores the information about the brick in a local database. Information are then copied
in one of the two synchronized central databases
9. The events are reconstructed and analyzed off-line
by accessing to the database
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Computing and DB
• Electronic detector data
– Online analysis performed in HallB;
– Data are extracted twice a day: input for the brick finding;
– Once a week data are copied into the central DB
• Emulsion data
– Each scanning lab has its own local database;
– If a vertex is confirmed: data transferred into the the central DBs
• Central DBs
– We have two central DB: OPITA (located at the LNGS) and
OPFRA (located at the CCIN2P3 in Lyon).
– The central DBs contain:
•
•
•
•
electronic detectors data (including slow control data);
brick production & handling (BAM, BMS, film development…);
scanning data;
event reconstruction
• Hardware and software: data storage and batch systems
setup at the CCIN2P3 of Lyon
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OPERA DB
Oracle-based OPERA DB system
Two Central DB servers
(OPITA & OPFRA) collect
data from specific DBs
Analysis
Follower
BMS
Web service providing
quick data access to
summaries and reports
Napo
li Rom
a Frasc
ati
Electronic
DAQ
OPFRA
OPITA
Emulsion
Develop.
Bern
Bari
Lyon
Nagoya
LNGS
Lucia Votano
Pado
va
In case of hardware problems on either Central DB, the
other can undertake the load of the failed machine
Saler
Bolo no
gna
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Robust, redundant system
Emulsion scanning in OPERA
The European Scanning System
State-of-art automated microscopes
fast bi-dimensional image analysis
real-time high precision 3D tracking
 Scanning speed: 50 cm2/h/side average
(72 cm²/h/side peak)
custom parallel processing (FPGAs)
 Purity: 10 fake tracks / cm2 (slope < 0.4)
 Efficiency: 95% using tracks
Z stage (Micos)
0.05 μm nominal
precision
CMOS camera
1280×1024 pixel
256 gray levels
376 frames/sec
(Mikrotron MC1310)
Custom CMOS camera
512×512 pixel
3000 frames/sec
Piezoelectric fine drive
for Z motion of lens
Emulsion Plate
X axis is driven
with continuous motion
XY stage (Micos)
0.1 μm nominal
precision
Illumination system, objective
(Oil 50× NA 0.85)
and optical tube (Nikon)
 Scanning speed: 20 cm2/h/side
(40 GB/day/microscope of raw data)
 Purity: 10 fake tracks / cm2 (slope < 0.5)
 Efficiency: up to 95% using tracks,
~100% using microtracks
 0.3÷0.7 μm precision for recons. tracks
Oil objective 35× NA 0.85
Mechanics based on Nikon
microscope stages
X/Y/Z nominal
precision = 0.1mm
The S-UTS (Japan)
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Some numbers on brick handling and analysis flow
as Nov. 16th
CS delivered to the Scanning
Stations
CS scanned
QuickTime™ and a
decompressor
are needed to see this picture.
CS with a positive results
Only Europe
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CSd measurement efficiency using muons
355 CSd analysed  352 events = 271 CC + 81 NC
213 developped bricks ~ 60%
167 CC
45 NC
124 with muon candidate
41 without muon candidate
74 ± 6% finding efficiency (80% expected)
Independent estimate based on all tracks: e 74±4%
 ebt 86% to find a track in a single emulsion film
Recently ¾ microtracks method implemented: ebt 89±3%
(this option not yet applied to the analysis shown in the following)
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Estimate brick finding efficiency
• Having measured the efficiency of the CSd in measuring
a single track: 74%
• Knowing that the #tracks/event is about 2
– 6.8% is the probability to miss the event in the CSd
• Knowing that 3.8% interactions are in dead material
• We can compute the brick finding efficiency:
67±5 (stat)% (MC predicts 72%)
• Next steps: Removal of the 2nd most probable brick (MC
exp. 80%)
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Vertex location breakdown by using a subsample of the measured events
NC CC
Vertex location efficiency:
Bricks assigned
45
174
Bricks received by the labs
34
129
90/(112-5-2) = 86±12%
Scanning started
28
112
In the proposal we quoted 93%
Charged-current:
(108-5-2)/(112-5-2) = 96±13%
Neutral-current:
CS to brick connected
25
108
20/(28-1) = 74±18%
(25-1)/(28-1) = 89±22%
Vertices located in the brick
20
90
Passing through
0
5
Vertices in the dead material 1
2
Under analysis
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7
In the proposal we quoted 81%
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Event gallery
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Found a 3 prong vertex in the
bottom layer of the emulsion:
20
20
~20 GeV shower reconstructed
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Backward going particle
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Brick to brick connection
Pasquale Migliozzi - XXX LNGS Committee OPERA Status Report
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Topological and kinematical analysis - first charm-like event
PRELIMINARY
kink=0.204 rad
Daughter momentum = 3.9 +1.7-0.9
kink = 0.204 rad
Flight length = 3247 µm
kink
e.m.shower
PT = 796 MeV
PTMIN = 606 MeV (90% C.L.)
The main background source is the hadron
reinteraction
The probability that a hadron reinteraction has
a Pt larger than 600 MeV is 4x10-4
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Topological and kinematical analysis - second charm-like event
From a topological point of view the main
sources of background are:
• Kaon decays: probability 10-4
• Hadron reinteractions: probability 1x10-5
Further reduction from kinematical analysis.
A first result is shown here below
Only 4-5 plates available for momentum
measurement. Brick to brick is in progress
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First OPERA Brick measured
@ LNF Emulsion Scanning lab
Electronic-detectors muon track
Vertex reconstruction in ECC
µ
µ
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Momentum distribution of reconstructed muon track
Data = 4999 MC = 5123.
OpRec reconstructs the momentum of
the track at the vertex, for internal events,
or at the entrance of OPERA detector for
external events.
The events are selected requiring:
• on-time with CNGS
• minimum activity in the detector
• at least one OpRec track reconstructed
• muID
Fit: 3.4 ± 0.05 degree
Pasquale Migliozzi - XXX LNGS Committee OPERA Status Report
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OPERA EXECUTIVE SCHEME
Spokesperson:
A. Ereditato
Deputy Spokesperson:
K. Niwa
Spokesperson Office:
Composition:
Two Vice-Spokespersons + 1 member (all appointed by the SP)
Task:
assist the SP in the executive management of the Collaboration.
Members of the EB.
Composition:
P. Migliozzi (Vice-SP), F. Terranova (Vice-SP), M. Nakamura
(NOTE: there is the proposal to appoint Deputy Spokespersons the two Vice-Spokesperson)
Executive Committee:
Technical Coordinator + Deputy:
M. Spinetti + M. Nakamura
Physics Coordinator +Deputy:
D. Autiero + S. Dusini
Scanning Coordinator + Deputy:
G. De Lellis + O. Sato
Resource Coordinator:
L. Votano
Detector Operation & Maintenance Coordinator:
A. Paoloni
Data Acquisition Coordinator:
J. Marteau
Brick Manipulation Coordinator:
D. Duchesneau
Emulsion Development Coordinator:
C. Sirignano
CNGS Neutrino Beam Coordinator:
D. Autiero (pro tempore)
Data Base Coordinator:
C. Bozza
Observer from the Collaboration Board:
Y. Gornushkin
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Conclusions
• The OPERA detector and its infrastructures
successfully operated during 2008 CNGS run
• Partial recovery of the beam after a rather problematic
start: 1.782x1019 instead of 2.2x1019pot (80% of the
expectations)
• About 1700 events in the bricks: < 1 t but extremely
valuable sample to fine tune OPERA analysis and to
estimate efficiencies and background
• 2009 CNGS run aim is to at least double the integrated
intensity and collect the first t candidate
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Brick handling chain
UNDERGROUND
?
Brick Extraction
Brick
Finding
CP
CS
Scan
Decision
CP
C
E
N
T
R
A
L
D
A
T
A
B
A
S
E
B
M
M
Pick CS Decision
Back to
Detector
CS Xray Exposure
CS Dismounting
Brick Storage
CS
Development
Pick Up
Brick XRay
CP
Cosmic Ray
Exposure
CP
Development
Black CS
Brick
Dismounting
(underground)
Shipping
Brick
Lab Reception
CP = Control Point
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OPERA DB
DB-based Analysis Follower: Quasi on-line reporting on brick/event lifetime
Brick/event history
Event location feedback
This WEB interface allows a direct and simple Lucia
access
Votano to
database contents to everybody
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Emulsion development
•
•
•
•
CS and brick development smoothly running since July
Extended single shift mode: 11 h/d Mon-Frid.
8 people shift team (2 OPERA shifters, 6 operators).
Average load: 30 CS doublets and 20 bricks per day
The development activity was able to follow the
increase of the CSd scanning rate
Still room for improvement
Pasquale Migliozzi - XXX LNGS Committee OPERA Status Report
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