1. Current Status of The OPERA Experiment
(Oscillation Project with Emulsion tRacking Apparatus)
Kunihiro Morishima
Nagoya university
On behalf of OPERA collaboration
NNN08

3. The OPERA Experiment Motivation and Conceptual Design
・ OPERA (Oscillation Project with Emulsion tRacking Apparatus) is
a long baseline neutrino oscillation experiment
・ The goal of the experiment is to directly measure for the first time
neutrino oscillation in an appearance mode
・ Using an almost pure νμbeam, the νμ→ντ transition is detected
by observing the τ lepton decay, induced after a neutrino-lead
CC interaction
・ τ lepton decay is observed by means of Emulsion Cloud Chambers
・ The detector is located on the CNGS (CERN to Gran Sasso) beam
line at a distance from the neutrino source of 730 km

4. The CNGS beam 730km The beam is optimized for  t appearance
in the atmospheric oscillation region
Δm232 = (2.43±0.13)×10-3 eV2
sin22θ23 = 1.0
CERN SPS
conventional  beam
 ( m-2 / pot) x10-9
 CC / pot / kton x10-17
< E > ( GeV )
(e + e) /  %
 /  %
t prompt negligible
730km
INFN Gran Sasso Institute

5. Principle of detecting tau neutrinont
Topology
～ s
cτ = 87 micron nt
Kink
t-　→　e-
17.8 ％
t- 　→　μ-
17.4 ％
t- 　→　h-
49.5 ％
Trident
t- 　→　h- h- h+
15.2 ％ nt t-
m-, e-, h- h h
Micrometric and milliradian resolution → Emulsion
Large Mass → Lead Target
Trigger Neutrino Interaction → Target Tracker
Identify muons and charge to reduce charm backgound → Spectrometer
ECC
Electronic
Detector
Hybrid Detector (Emulsion - Electronic Detectors)

6. t identification Pb Neutrino 125mm 100mm Tau Decay 75.4mm II 10 X0 ECC
Target is divided in about ECC’s
1 mm
125mm
100mm
Tau Decay t n Pb
Emulsion layers
75.4mm II
10 X0
lead plate
ECC
（Emulsion Cloud Chamber）
Piled up
alternately
Nuclear Emulsion
(OPERA film)
～ 8.3 kg

7. The OPERA Film The OPERA film position resolution ～ 50nm
Sub micron crystal 3D tracking device
50 micron
Microscopic Image
Recorded as silver grain
along the line particle passed through
sensitivity : 36grains/100micron
emulsion
(44 μm)
plastic base
(205 μm)
position resolution ～ 50nm

8. Tau Neutrino Interaction In ECC by DONUT

9. Sensitivity of tau neutrino detection
Full mixing after 5 years run at 4.5x1019 pot / year
- decay
channels
Signal
(Full mixing)
Background
m2
2.5 x 10-3 (eV2)
3.0 x 10-3 (eV2)
-  µ-
2.9
4.2
0.17
-  e-
3.5
5.0
-  h-
3.1
4.4
0.24
-  3h
0.9
1.3
ALL
10.4
15.0
0.76
Background sources:
　- Charm production and decays
- Hadron re-interactions in lead
- Large-angle muon scattering in lead
Muon ID by
electronic detector

10. Design of The OPERA Detector
Super Module 1
Super Module 2
CNGS Beam
10m
20m
10m
Target
(ECC + Target Tracker)
Spectrometer
Located in Hall C - INFN Gran Sasso Institute

11. The OPERA Detector - overview -
Emulsion - Counter Hybrid Detector
・ ECC （Brick Target）
・ Target Tracker
・ Spectrometer
　　　　＋
・ Scanning System
（Read-out Emulsion）
SM 2
SM 1
Located in Hall C - INFN Gran Sasso Institute

12. Brick Target Target mass 1.35 kt ~ 150000 Bricks ~ 8 millions of
The OPERA detector
Brick Target
Target mass 1.35 kt
　~　 Bricks
　~　8 millions of
nuclear Emulsion
Brick filling is finished in July 2008:
5000 bricks more will be added at the end of 2008 once additional lead will be delivered

13. BAM （Brick Assembling Machine）
The OPERA detector
BAM （Brick Assembling Machine）
Production of ECC
Working in a dark room
Speed ~700 bricks/day

14. BMS （Brick Manipulating System）
The OPERA detector
BMS （Brick Manipulating System）
Loading and Extraction of ECC

15. The OPERA detector
Electronic Detector
Spectrometer
Target Tracker

16. L. Scotto Lavina (INFN Napoli)
The OPERA detector
Target tracker
The main goals of the target tracker are the trigger on the neutrino events and the identification of the brick to be extracted and then analysed
It is made of plastic scintillator strips, each with a wavelength shifting fibre
The fibres are connected in groups of 64 to multi-anode Hamamatsu PMTs at both ends
Spatial resolution
~0.8 cm (2.6 cm pitch)
L. Scotto Lavina (INFN Napoli)

17. L. Scotto Lavina (INFN Napoli)
The OPERA detector
Spectrometer
The goal of the spectrometer is the momentum measurement and charge discrimination
In particular it is used to measure and identify muons, in order to reduce charm background
It is made by inner tracker (RPC planes) and precision tracker (Drift Tubes) in a 1.5 T magnetic field B B
L. Scotto Lavina (INFN Napoli)

18. The automated microscopes
~30 bricks will be daily extracted from the target and analyzed
European scanning system
S-UTS (Japan)
Scanning speed: 20cm2/h
Scanning speed: 72cm2/h
High speed CMOS camera (3 kHz)
Piezo-controlled
objective lens
Customized commercial optics and mechanics
Hardware corded algorithm (FPGA)
asynchronous DAQ software
asynchronous DAQ software
Data Base
Central Data Base
Data Base

20. Today ! ～ 6.0E18 pot
～500 bricks already tagged
(expected : 2200 bricks)

21. 2008 Run : One Example of Neutrino Event

22. 2008 Run : One Example of Neutrino Event
extraction
The most probable brick is detected
by brick finding algorithm
Development → Scanning CS
ECC ν

23. CS analysis by the Scanning Station
The Scanning Station scans the whole surface of the two emulsion
interfaces (CS) and selecting particle tracks found in both plates
2 plates
Trkid TX TY PX PY 1
-0.137
0.1947 2
0.0179 3
0.0987
0.0407
CS result validates the brick,
which is then sent to the developing facility

24. Location of the neutrino interaction in ECC
Predictions from the CS are
followed back in the brick,
looking for the position where
the neutrino interaction occurred.
Neutrino
Beam
ECC brick CS

25. Vertex Reconstruction in ECCZ
Tracks found in ECC
Reconstructed track parameter
at vertex Ax Ay IP
0.1822
4.0
0.0194
2.1
0.0893
0.0367
1.8
10.0
VTX:( ) X Y
The vertex is confirmed and all data are stored into the DB

26. 2007 Run : a charm candidate !
Electromagnetic shower (15 GeV)

27. Summary and Future The OPERA detector is taking data now
OPERA proved the possibility of producing emulsion detector
at the kiloton scale
Stream of locating Neutrino Interactions is systematically
running continuously.
Now: run 2008 started since June 18th, 123 days of data taking
Expected 2.28x1019 p.o.t. and 1 nt interaction
So far, collected 6x1018 p.o.t.
The 2008 run will produce important results for OPERA : events
for efficiency and BG estimates (charm,…) and maybe ~1 nt ???