1. NAKAMURA M. (NAGOYA Univ.)
Emulsion Detector for Future Neutrino Research Possibility of the Technology
NAKAMURA M.
(NAGOYA Univ.)

2. Emulsion in Magnetic field
CONTENTS
Emulsion Detector Overview
New Study. Emulsion Spectrometer
Emulsion in Magnetic field
Expected scanning power in near future

3. Intrinsic position resolution
Cross sectional view of an emulsion layer
Ag grain after development
Compton Electron
Fog
M.I.P. Track
100mm dx
M.I.P. Track
s = 0.06mm
30grains/100mm
grain diameter ~ 0.6mm
One Emulsion Layer = vector chamber with 60nm position resolution
& ~1mrad Angular resolution (100micron layer)

4. Achievement in OPERA R&D
Nuclear Emulsion Films
Suited for Mass production ~ 100,000m2
Uniform quality
Refresh function
　　 R&D by
Nagoya Univ. & Fujifilm
Fast Scanning systems
in Japan & Europe
125mm
100mm

5. Refresh We can reset the accumulated images by Refreshing.
Cosmic-rays
Before Refresh
After Refresh
Compton electrons by γ rays of natural radio activity
Emulsion film accumulates all signals during its live time
:No dead time.
We can reset the accumulated images by Refreshing.
Before use or re-use

6. OPERA ECC Brick 8cm １０ｃｍ １２．５ｃｍ
8kg：　Portable Unit for 2~10kton detectors

7. Decay search Tau detection : -> OPERA τ DONUT Topological decay
Kinematical analysis:
Momentum measurement by Multiple Coulomb Scatterings
(or Emulsion Spectrometer)
Electron ID by shower detection
Particle ID by dE/dX measurement τ
film Fe

8. dE/dX measurement @KEK/PS P=1.2GeV/c Hadron+ Pb dE/dX = b measurement
Film Pb
dE/dX = b measurement p P
dE/dX
~number of grains

9. dE/dX measurement : TEST exp at KEK
0.4 GeV/c
0.5 GeV/c
0.6 GeV/c
Entry 996 tracks
Entry 1310 tracks
Entry 1278 tracks π π π P P P D
VPH
0.74 GeV/c
0.87 GeV/c
1.14 GeV/c
2.0 GeV/c
Entry 1610 tracks
Entry 1345 tracks
Entry 1175 tracks
Entry 1206 tracks π π π P
P&π P P D D D D
Using only 5 ~ 6 films.
VPH, measured by the system, is ~propotional to dE/dX.

10. Particle ID by dE/dx Measurement
KEK Beam Test Preliminary
dE/dx
(MeV・cm2/g) P
VPH K π e
P andπ
Momentum(GeV/c)
Using 5 ~ 6 films.
VPH, measured by the system, is ~propotional to dE/dX.
Error bar is 1σof the distribution.
At 2 GeV/c , proton and pion are not separated in 5 or 6 OPERA films.
VPH of proton below 0.6GeV/c is saturated.

11. Electron ID
50GeV electrons + muons
Test CERN

12. Electron energy measurement
Test CERN MC
Data
Energy determination
by calorimetric method
( in study)
@ a few GeV

13. Emulsion in Magnetic Field
Charge Sign determination
+ increase sensitivity
+ increase BG-rejection power
o scanning load (mention later)
o cost??
We have experience
in CHORUS/ET(Emulsion Tracker)

14. Structure for MC study DONUT/OPERA type target + Emulsion spectrometerB
Air Gap
Stainless steel or Lead
Film
~ 3Xo ~10Xo
Assumption: accuracy of film by film alignment =10 micron
(conservative).
(Ex. 20mm gap structure gives 0.5mrad angular resolution.)

15. Charge determination (0.5T) MC
>=30mm Gap
20mm Gap
10mm Gap

16. Momentum resolution(0.5T) MC
10mm Gap
20mm Gap
30mm Gap
40mm Gap
50mm Gap

17. Charge determination (1.0T) MC
>=20mm Gap
10mm Gap

18. Momentum resolution(1.0T) MC
10mm Gap
20mm Gap
30mm Gap
40mm Gap
50mm Gap

19. Summary of the MC study
Emulsion Spectrometer ( B≧0.5T,Gap > 20mm, Total Length~10cm) has power to determine sign & momentum efficiently.
Further MC study:
Investigate the Possibility to open the sensitivity for hadronic and electric decay mode.
Sensitivity >~ x 3 (like OPERA)
Technological R&D : Unique track connection
How to keep air gap
Test exp.

20. Emulsion Film Read-out

21. Emulsion Readout History
E531, E653, etc . (~1994)
Semi-automatic scanning
CHORUS phase I
Track selector, New TS (1994~)
DONUT, CHORUS phase II
UTS (1998~)  Net scan (angle: |q|<0.4).
OPERA
Automatic Scanning

22. Automatic Scanning System (present system)
CCD
Imager
Microscope
Z-axis
CCD
Imager
Straight track recognition in the Tomographic image
Multi-layer image
16 Slices
Emulsion layer 　　40~550 mm
50-100mm
Film base
　70~800mm
Nuclear Emulsion Film
Emulsion layer
40~550 mm　

23. Bottle necks in the Read-out System
Speed of Image Data taking
Movement of Z Stage
Field of View :
Objective Lens
Movement of X-Y stage

24. Overcome the Bottle necks
Ultra High Speed Imager
120 fps -> 3000 fps
Image taking by follow shot
X-Y stage : Non-stop
Objective lens: Driven by piezo electric devices （fres>2kHz ）.
Enlarging size of Field of View
Effective FOV:
100mm×100mm-> 140mm×140mm
Ultra High Speed Imager with Real Time processing
Synchronized motion to cancel relative velo.
Stage moves at constant velocity
1cm2/h -> 60cm2/h

25. SUTS + Old stage

26. Evolution of the Scanning Power
0.008
0.25 3 60
0.001
0.01
0.1 1 10
100
TS(TTL)
NTS(CPLD)
UTS(FPGA)
S-UTS
Scanning System History
views/sec (
1view=120×90 m 2 )
CHORUS
DONUT
OPERA
Our code name (device technology)

27. Expected evolution of the Scanning Power in near future
Enlarge a Field of View × (1.25)2
reduce objective mag. × 50 -> × 40
Speed up Image data taking ×4
Ultra High Speed Camera 3kfps->12kfps.
400cm2/hours/system.
(~1m2/day/system)

28. Events in Neutrino Factory
How many events?
Scanning Power
1 m2/day/system~ events/day/system
( OPERA like ECC 1event/brick ~100cm2/event)
~25,000events/year/system
Normally one lab has ~10 system
~250,000 events/year/lab.
Events in Neutrino Factory
160,000 events/kton
(L=3000km,1021mu+ decays)

29. Event selection for 10kton
10kton Total event: 1,600,000
= 1,600,000/250,000
~ 6 Lab・year
　　Loose-selection is Acceptable.
During the RUN : Extract and Analyze wrong sign muon events.
End of the RUN : Extract all bricks which have tagged neutrino interactions in it.

30. Or Modified ATLAS TROID
OPERA 1SM 850t
L3 Magnet　0.5T

31. Related Works OPERA Exposure will start at the middle of 2006.
Scanning in many Labs
(Japan, Italy, France, Swiss….)
PEANUT
Test exp. at NUMI near detector site.
Start neutrino exposure at Aug
Plan: Test of “ ECC in Magnet”
with Permanent magnet (2006).

32. 現在のＧＳの状況
スケール
2nd Super Module
OPERA 1st Super Module

33. MINOS Near detector as mu ID
PEANUT Detector :DONUT SFT+ Mini Brick Wall

34. Location of Neutrino interactions in ECC brick
1. Pick up tracks in the most downstream plate
Neutrino
2. Follow tracks to the interaction veretex

35. Pb measurement using Multiple Scattering
Kinematical Analysis
Momentum measurement
Pb measurement using Multiple Scattering
For example: 10 GeV/c has rms deflection of 0.3mm

36. Pb measurement using Multiple Scattering
Momentum measurement
Pb measurement using Multiple Scattering
Expected Value for pion
Low dE/dX
Consistent with Pion
Resolution s pb ~16%
Expected Value for proton
Consistent with Proton
Higher dE/dX