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

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

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)

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

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

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

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

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

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.

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.

Electron ID 50GeV electrons + muons Test Exp. @ CERN

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

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)

Structure for MC study DONUT/OPERA type target + Emulsion spectrometer B 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.)

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

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

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

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

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.

Emulsion Film Read-out

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

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　

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

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

SUTS + Old stage

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)

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)

Events in Neutrino Factory How many events? Scanning Power 1 m2/day/system~ 100events/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)

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.

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

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. 2005. Plan: Test of “ ECC in Magnet” with Permanent magnet (2006).

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

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

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

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

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