Transcript Summary Detector Session

Summary Detector Session
3rd International Scoping Study Meeting
Rutherford Appleton Laboratory
27 April 2005
Paul Soler
University of Glasgow
Contents
1. Magnetic Scintillation Detectors
1.1 Segmented Magnetised Detectors
1.2 Totally Active Scintillation Detector
2. Finnish underground laboratory
3. Liquid Argon Detectors
4. Hybrid Emulsion Detectors
5. T2K design
6. MINOS experience
7. Neutrino Generators
8. Near Detector
9. Conclusions and Outlook
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1. Magnetic Detectors

Two main talks:
o
o

Anselmo Cervera: Segmented Magnetised Detectors
Malcolm Ellis: Totally Active Scintillator Detector (TASD)
The golden signature: wrong sign muons
o
o
Need to identify charge of muon
Backgrounds:
Muon misidentification (mainly pions)
Wrong sign muons from p, K decays
Wrong sign muons from D decays
Charge misidentification of right sign muons
All of them increase when going to low muon momentum!
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1.1 Segmented Magnetised Detectors

Large Magnetic Iron Detector
o
o
o
o
Cervera
40-100 kton
B field ~1 T
Transverse resolution ~1 cm
Readout: scintillator (liquid or solid) or RPC
Optimised for small q13
Strong cut on muon momentum > 5 GeV/c
Problems below muon momentum < 3 GeV/c (cannot see second maximum)
20 m
n beam
10 m
10 m
B=1 T
iron (4 cm)
scintillators (1cm)
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1cm transverse resolution
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1.1 Segmented Magnetised Detectors

Indian Neutrino Observatory (INO)
o
o
o
Optimised for atmospheric neutrinos
Planes horizontal
Maybe planes at 45o???
Monolith, similar concept

Totally Active Scintillator Detector (TASD): Magnetised Nona
o
o
o
Aim to go down to 1-2 GeV neutrino energies
Second maximum?
Charge ID, if we can put magnetic field
Two ATLAS type toroids as Helmholtz coils?
6 cm
4 cm
Liquid scintillator cell
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1.1 Segmented Magnetised Detectors

Compromise between Large Magnetic Detector and Nona concepts?
Iron free regions: improve momentum and charge determination
o
1m
air + active (1cm)
muon
hadron shower
o
Iron (4cm) + active
(1cm)
Combining Nona and iron-free regions: to be studied Geneva/Valencia groups
?
air + active (1cm)
Iron (2cm) + active
(4cm)
Liquid
scintillator
iron
muon
hadron shower
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1.2 Totally Active Scintillation Detector
Simulation of a magnetised scintillating detector using Nona and Minerna
Ellis, Bross
concepts with Geant4
15 m
1.5 cm
15 m
– 3333 Modules (X and Y plane)
– Each plane contains 1000 slabs
– Total: 6.7M channels
3 cm

Three lepton momenta:

– “Low”: 100 MeV/c – 500 MeV/c initial momentum
– “Medium”: 500 MeV/c – rd2.5 GeV/c initial momentum
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– “High”: 2.5 GeV/c – 12.5 GeV/c
initial
momentum
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Three fields studied:
• 0.15 T magnetic field
• 0.30 T magnetic field
7 field
• 0.45 T magnetic
1.2 Totally Active Scintillation Detector

High momentum muon
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1.2 Totally Active Scintillation Detector
Preliminary performance plots
Reconstructed 10 GeV/c muon
Reconstructed 10 GeV/c positron
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1.2 Totally Active Scintillation Detector
Position resolution
Preliminary
Position resolution ~ 4.5 3mm
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1.2 Totally Active Scintillation Detector
Muon reconstructed efficiency
Charge misidentification
Preliminary
Red: 0.15 T Magnetic Field
Needs further
rd
Green: 0.30 T Magnetic3Field
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Blue: 0.45 T Magnetic Field
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1.2 Totally Active Scintillation Detector
Muon momentum resolution
Muon momentum from range
12%
Red: 0.15 T Magnetic Field
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Green: 0.30 T Magnetic3Field
Study Meeting
Blue: 0.45 T Magnetic FieldRutherford Appleton Laboratory
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1.2 Totally Active Scintillation Detector
Electron identification
Red: Positrons (0.3T)
Blue: Muons (0.3T)
Electron reconstruction
Red: 0.15 T Magnetic Field
Green: 0.30 T Magnetic Field
Preliminary
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Blue: 0.45 T Magnetic Field13
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1.2 Totally Active Scintillation Detector
Camilleri, Bross
10 solenoids next to each other. Horizontal field perpendicular to beam
Each: 750 turns, 4500 amps, 0.2 Tesla. 42 MJoules . 5Meuros.
Total: 420 MJoules (CMS: 2700 MJoules)
750 turns
Coil: Aluminium (Alain: LN2 cooled).
Possible magnet schemes for TASD
n
B
Problem: Periodic coil material every 15m:
Increase length of solenoid
along beam?
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How thick?
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2. Finnish underground lab
Peltoniemi
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2. Finnish underground lab
Peltoniemi
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2. Finnish underground lab
Peltoniemi
Cost: 12.7 MEuro
~200 Euro/m3
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3. Liquid Argon Detectors


Two talks: Scott Menary, Andres Badertscher
FLARE (North American effort) is progressing well
– Staged R&D effort
– Use of commercial liquified
natural gas (LNG) tanks
– Three stages: 150 ton, 1 kton,
15 (50) kton
130 ton
1 kton
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3. Liquid Argon Detectors

Use MINOS off-axis beam for evaluation and physics programme
– R&D effort:
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3. Liquid Argon Detectors

Argon purity monitor: 9 ms drift time achieved
Regeneration
Valving
Relief
Stack
LN2
trap
filter
Molecular
Sieve -->
Fermilab Purity Monitor
Insulating
Vacuum
Pump
Purge
Line
LArgon
Cryostat
PrM
drifttime = 9ms
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3. Liquid Argon Detectors

Long wire R&D: 18 m wires
sense
planes (4)
far end
18 m
near end

Mechanical Design Study:
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3. Liquid Argon Detectors

Integrated system test:
Long drift to 3
readout planes
system test...
Drift distance > 5 meters,
clear region 30 cms diameter
Test of purging a volume from atmosphere
Oxygen Content vs Time
25
200
Lower O2 Monitor
Upper O2 Monitor
PPM Monitor
5000 ppm
output
15
120
10
6 hrs to 100 ppm O2
160
80
100 ppm
output
5
Oxygen PPM
20
Oxygen Content (%)

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Time
0
3:17
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3. Liquid Argon Detectors

European effort: led by R&D effort for ICARUS (2x300 ton modules)
Cryostat (half-module)
View of the inner detector
4m
20 m
4m
Readout electronics
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3. Liquid Argon Detectors

Giant Liquid Argon Charge Imaging Experiment (GLACIER)
A 100 kton liquid Argon TPC detector
Electronic crates
f≈70 m
h =20 m
Max drift length
Passive perlite insulation
hep-ph/0402110
Venice, 2003
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3. Liquid Argon Detectors
Process system & equipment
- Filling speed (100 kton): 150 ton/day  2 years to fill
Electricity
(Argon is 1%!)
- Boiling-off volume at regime: ≈45 ton/day (≈10
years to evaporate entire Air
volume)
Hot GAr
W
Underground
complex
GAr
LAr
Joule-Thompson
expansion valve
Q
Heat
exchanger
External complex
Argon
purification
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LN2, LOX, …
3. Liquid Argon Detectors
A tentative detector layout
Single detector: charge
imaging, scintillation, possibly
Cerenkov light
Charge readout plane
GAr
E ≈ 3 kV/cm
Extraction grid
E-field
Electronic
racks
LAr
E≈ 1 kV/cm
Cathode (- HV)
Field shaping
electrodes
UV & Cerenkov light readout PMTs
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3. Liquid Argon Detectors
5m “Argontube”
• Full scale measurement of long
drift (5 m), signal attenuation and
multiplication
Install ARGONTUBE at the U. of Berne
(~ Sept. 2006)
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3. Liquid Argon Detectors

Readout: Large Electron Multiplyers (LEM)
High gain operation of LEM
in pure argon at high pressure
LEM thickness 1.6mm
GAIN 2.3bar
GAIN 2.9bar
GAIN 2.5bar
GAIN 2.7bar
GAIN 3.21bar
GAIN 3.41bar
GAIN 3.54bar
1200
1000
1000
Two-stage LEM
Etransf = 3 kV/cm
GAIN
Gain
800
600
400
200
0
3500
4000
4500
5000
5500
6000
Voltage (V)
GAr
LAr
Edrift = 5 kV/cm
A14
stable gain of 104 has been measured
0
350
0
14
Voltage (V)
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12.5
600
0
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12.9
3. Liquid Argon Detectors

Results of HV tests in cold

The largest system successfully operated
consisted of 80 stages and reached stable
operation up to 120 kV.

Test to 240 kV (≈4kV/cm) in preparation.
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3. Liquid Argon Detectors
Momentum measurement:
x=track length
Required field for 3s charge discrimination:
l=pitch angle
e–
2.5 GeV
Simulated electron shower in magnetic field B=1T

Operation of 10 lt LAR TPC in B field
Correlation energy vs
magnetic measurement
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3. Liquid Argon Detectors
Tentative coil parameters for solenodial superconducting coil
10 kton LAr
Magnetic induction (T)
0.1
0.4
100 kton LAr
1.0
0.1
0.4
1.0
ATLAS
solenoid
CMS
2.0
4.0
Solenoid diameter (m)
30
70
2.4
6
Solenoid length (m)
10
20
5.3
12.5
7700
77000
21
400
Magnetic volume (m3)
Stored magnetic energy
(GJ)
0.03
0.5
3
0.3
5
30
0.04
2.7
Magnetomotive force
(MAt)
0.8
3.2
8
1.6
6.4
16
9.3
42
4
64
400
4
64
400
1600
6500
8
20
5.6
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Radial magnetic pressure
(kPa)
Coil current (kA)
Total length conductor
(km)
Conductor type
30 (I/Ic=50%)
2.5
10
25
12
57
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NbTi/Cu
normal
superconductor, T=4.4K
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3. Liquid Argon Detectors
Small test solenoid built with High
Temperature Superconducting (HTS) wire
Iron ring
Iron
yoke
Cu spacer
Pancacke
Iron
yoke
LN2
LAr
Temperature
Max. applied current
On-axis B-field
LN2 (77K)
LAr (87K)
145 A
80 A
T
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Coil resistance at 4A

6 
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4. Emulsion Detectors
Magnetised Emulsion Cloud Chamber (MECC) detector for nt
appearance, a la OPERA
Esposito
10 X0
1 brick:
Target
Trackers
Pb/Em.
target
10.2x12.7x7.5 cm
57 Em. Plates + 2CS
56 Pb (1 mm)
8.3kg
Pb/Em. brick
Basic “cell”
8m

Extract selected
brick
8 cm
Pb Emulsion
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1 mm
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4. Emulsion Detectors

High precision tracking (dx<1m, dq<1mrad)
– Kink decay topology
– Electron and g/p0 identification

Energy measurement
– Multiple Coulomb Scattering
– Track counting (calorimetric measurement)

Ionization (dE/dx measurement)
–
p/ separation
– e/p0 separation
target
spectrometer
shower absorber
Electronic det:
e/p/ separator
&
“Time stamp”
stainless steel plate
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emulsion film
Rohacell® plate
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4. Emulsion Detectors
Optimization: 3 cm gap, 0.5 T
Muon momentum resolution
Muon charge misidentification
Electron momentum resolution
Electron charge misidentification
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4. Emulsion Detectors
Emulsion test beam
5s charge misidentification
0.5-2 GeV/c p
The relative error is roughly
ds/s = 0.20  0.029 p [GeV/c]
 ds/s should be about 0.35 in the
case of p = 10 GeV/c
 Assuming a Gaussian distribution,
probability of the charge
mis-identification for a 10 GeV
rd
lepton
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Meetingbe around 0.2%
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
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4. Emulsion Detectors
Possible design hybrid emulsion-scintillator far detector









Let us assume transverse dimension of a plane equal to
15.7x15.7 m2 (as in the case of Nova)
A brick contains 35 stainless steel plates 1 mm thick: it corresponds to
about 2 X0
A brick weigh 3.5 kg
The spectrometer part consists of 3 gaps (3 cm each) and 4 emulsion
films
A wall contains 19720 bricks  weight 68 tons
If I consider 60 walls  1183200 bricks  4.1 kton
In terms of emulsion films the target is: 47,328,000 pieces (in OPERA we
have 12,000,000)
If I consider as electronic detector 35 Nova planes (corresponding to 5.3
X0 ) after each MECC wall  2100 planes
The total length of the detector is: about 150 m
Synergy emulsion-magnetic scintillation detector
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5. T2K Design Considerations
Two talks:
̶ Clark McGrew: Goals of near Detector Complex at T2K
̶ Yoshi Uchida: Charged Current Measurement and Beam Characterization
Measuring ν μ Disappearance with
Measuring ν e appearance with
SuperKamiokande
SuperKamiokande


1-ring mu-like events in SK
Backgrounds
–
–
–
CC single pion (red)
NC single pion (yellow)
CC+NC multi pion (other)

1-ring electron-like events
Backgrounds
intrinsic ν e (60%)
– NC
single π° (40%)
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– other (negligible)
–
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5. T2K Design Considerations

Ratio far to near in T2K:
SK/ND280 varies by “large factors”
SK/ND2k remains almost constant.
However, cannot use ratio of event rates because
oscillations distorts the shape of the neutrino spectra.
Must use neutrino flux vs neutrino energy.
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5. T2K Design Considerations
Predicting Event Rates at SK

Measure ν-flux at ND280 off-axis
–

Measure charge current cross-sections at ND280
–

Quasielastic events (assume shape of QE cross-section!)
CC quasi-elastic, CC single π +, &c (relative to QE)
Understand pion kinematics in decay tunnel
–
HARP, ND280 on-axis, CCQE at ND280 off-axis, &c
– Use to extrapolate flux to SK

Use ND280 cross sections to predict events at SK

Measure νμN -> π°νμN vs. π° momentum

Determine Pπ°/Pν vs Pν
Predicting SK p0 background
Measure νμN -> π+μ-N
– Measure νμn -> π°μ-p
–


no Pauli
blocking
Measure φ280(Eν)
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-Q2
5. T2K Design Considerations
νμN -> π+μ-N
Measurement vs
“Cross Section” MC
 dN 
 
dpπ 0280
νμN -> π°νμN
νμN ->
need ~8%
to get 14%
μ-N
 dN 


dp
0
 π SK
νμN -> π°νμN
φ280(Eν)
need ~8%
φSK/φ280(Eν)
need ~8%
νμn -> π°μ-p
Measurement vs
“Beam” MC
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φSK(Eν)
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5. T2K Design Considerations
ND280 Detector Complex
Off-Axis Detector
Determine off-axis
flux and shape
Measure CC and NC
Main tool to
determine
expectation at SK
On-Axis Detector
Determine Beam
Profile
Monitor Beam
Direction
Constrain π
momentum
distribution
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5. T2K Design Considerations
PØD
Off-axis p0 Detector (PØD)
Forward part of Off-Axis
NC interactions
CC π° production
νe flux
Fiducial Volume
440 MeV/c π˚



Active Scintillator Neutrino Target
– Two modules (scintillator and water + scintillator)
NC π° reconstruction efficiency ~30%
– Expected to be higher for CC
E&M resolution ~15%/sqrt(GeV)
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Goals:Study
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and CC
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Systematics ~ 10%
π° production43
5. T2K Design Considerations
Off-axis Tracker
Downstream portion of PØD
Determine charged
particle momentum
ν μ flux with QE
CC single π production
νe flux with QE


Active Scintillator Neutrino Target
– Two modules (scintillator & scintillator + water)
– Measure activity near the neutrino vertex
TPC to measure momentum and provide PID
– σP/P < 10% for P < 1 GeV
– 3 σ e/μ separation between
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– Measure particle charge
(μ-/π+ Appleton
separation)
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5. T2K Design Considerations
Side Muon Range Detector (SMRD)
Embedded in UA1 Magnet
Measure momentum of
side-going muons
T2K Systematic Error Goals
– 10% ne appearance (background)
– 5% on n far/near events vs energy
 We need flux, cross-section and
efficiency independently
– BUT, measure the product
– Depend on external inputs to break
the loop

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5. T2K Design Considerations
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5. T2K Design Considerations
CC QE Muon
CC
CC 1p+ Muon
True n Energy [MeV]
1p+ Pion
True n Energy [MeV]
CC QE Electron
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True n Energy [MeV]
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True n Energy [MeV]
5. T2K Design Considerations
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5. T2K Design Considerations
Spectrum Variation Across Off-Axis Detector
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5. T2K Design Considerations
K2K, T2K and SciBooNE Beam Spectra + HARP inputs for
control of beam systematics
T2K off-axis
SciBooNE
on-axis
K2K
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6. MINOS Near to Far Ratio
Prediction far detector spectrum from near detector
Look for a deficit of νμ events at Far Detector

P νμ  νμ

Weber
 Δm2 L 
 1 sin θ sin 

E


νμ spectrum
Monte Carlo
2
2
Spectrum ratio
Monte Carlo
Unoscillated
Oscillated
The
Million $Scoping
Question:
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How to predict
the Far
Detector
spectrum?
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6. MINOS Near to Far Ratio
Three beams in MINOS

Problems
–
1
1 
Flux  2 

L  1 γ 2θ 2 

Hadron production uncertainties
2
– Cross-section uncertainties
Near and Far Detector energy spectra are not identical
– Both detectors cover different solid angles
– Near Detector sees extended line source
target
p(soft)
to Far
Detector
p(stiff)
Decay Pipe
1
1 
Flux  2 

L  1 γ 2θ 2 
qf
qn
2
ND
International
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
Appleton Laboratory
2 2
3rd
1 γ θ
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6. MINOS Near to Far Ratio

Four possible methods for beam flux extrapolation
– NDFit method
– 2D Grid method
– Near to far ratio
– Beam matrix method

NDFit: Reweighting hadronic distributions
LE-10/185kA
pME/200kA
LE-10/
Horns off
Not used in the fit
LE-10
events
pHE/200kA
Weights applied as
a function of
hadronic xF and pT.
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6. MINOS Near to Far Ratio

2D Grid method
– Bin data in reconstructed Eν & y
– Fit weight as a function of true Eν & y

Near to far ratio
– Look at differences between data and MC in Near
Detector as a function of reconstructed Energy
– Apply correction factor to each bin of re-constructed
energy to Far Detector MC: c = ndata / nMC

Beam matrix
– It uses the measure Near Detector distribution and
extrapolates it using a BEAM Matrix to the Far Detector.
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6. MINOS Near to Far Ratio


Predictions for far detector do not
give perfect agreement but well
controlled.
Predicted FD true spectrum
from the Matrix Method
Four methods agree very well
– Different systematics
0.931020 POT
Predicted spectrum
Nominal MC
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7. GENIE Neutrino Interaction Generator



Andreopoulos
Neutrino interaction tools need to improve.
A lot of theoretical work and (now) starting to have experimental data to
measure neutrino interactions
A generally accepted neutrino generator to take all available knowledge
into account is needed by the community
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7. GENIE Neutrino Interaction Generator
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7. GENIE Neutrino Interaction Generator
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8. Near Detectors

Alain Blondel gave talk on flux determination at a neutrino factory
 polarization controls ne flux:
+ -X> ne
in forward direction
Main parameters to MONITOR
1. Total number of muons circulating in the ring: BCT,
near detector for purely leptonic processes
2. muon beam polarisation, polarimeter
3. muon beam energy and energy spread,
race-track or triangle. NO BOW-TIE!
+polarimeter
We believe that the neutrino
4. muon beam angle and angular divergence.
flux can be monitored to 10-3
straight section design
IF
+beam divergence monitors e.g. Cerenkov?
+ design of accelerator
foresees sufficient diagnostics. 5. Theory of  decay, including radiative effects
OK
+ quite a lot of work to do to
design and simulate these
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diagnostics.
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8. Near Detector Beam Flux



Soler
Near detector(s) are some distance (d~30-1000 m)
from the end of straight section of the muon storage ring.
Muons decay at different points of straight section: near detector is
sampling a different distribution of neutrinos to what is being seen by the
far detector
If decay straight is L=100m and
Different far detector baselines:
̶
̶
̶
730 km, 20 m detector: q~30 rad
2500 km, 20 m detector: q~8 rad
7500 km: 20 m detector: q~3 rad
Cherenkov
shielding
Polarimeter
storage ring
d
d =30 m, at 8 rad, lateral
displacement of neutrinos is
0.25-1.0mm to subtend same angle.
the charm and DIS detector
the
leptonic detector
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8. Near Detector Beam Flux
d=30 m, r=0.5 m
Flux
Antin
d=130 m, r=0.5 m
d=1km, r=0.5 m
Neutrino point source (muon decays not taken into account)
34.1 GeV
17.8 GeV
21.6 GeV
ne
18.5GeV
29.2 GeV
15.3 GeV
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8. Near Detector Event Rates
d=30 m, r=0.5 m
Event rates Antin

25.5 GeV
d=130 m, r=0.5 m
26.6 GeV
d=1km, r=0.5 m
37.1 GeV
ne
32.5 GeV
22.3 GeV
23.2 GeV
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8. Near Detector Event Rates
Compared to far detector: d=2500 km, r=20 m
Flux
35.8 GeV
38.1 GeV
Antin
ND at 1 km has
similar spectra to FD
Event rates
ne
30.0 GeV
33.3 GeV
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9. Conclusions and Outlook
 There are many interesting neutrino detector technologies to be
considered for a neutrino factory (maybe too many?)
 There has been progress in the simulation of the performance of an
improved version of a fully active scintillation detector, but full pattern
recognition and performances need to be understood.
 One of the outstanding issues is the magnetisation of large detector
volumes. Clearly this is an area where we need to dedicate more effort.
 There is an impressive R&D effort on liquid Ar both in Europe and
America, with longer drift times, feasibility studies, etc. Again, the issue
of magnetisation of a huge LAr tank remains as outstanding.
 There was also impressive performance of the emulsion cloud chamber
technology in test beams. This suggests that one could think of a
Detector of Everything (DoE) in which one mixes emulsion walls with
scintillator in a magnetic field and do all channels: golden, silver and
platinum simultaneously. The main issue remaining is the time needed
for scanning. Do we have to wait 5 years before starting to scan?
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9. Conclusions and Outlook
 There is important synergy between existing (or planned) experiments
such as MINOS and T2K and the technology for future near detectors.
Cross-sections and fluxes remain an issue. Learning the techniques that
these experiments are adopting helps to formalise the problem that we
will face at a neutrino factory.
 A near detector at a neutrino factory needs to measure flux and crosssections with unprecedented accuracy. It is worth noting that the beams
measured by a near detector if it is close to straight sections (<100m)
are quite different from far detector. However, at 1 km, beams start to
look very similar.
 We need to develop the tools to carry out cross-section measurements:
GENIE is becoming a de-facto standard, and we should use this tool.
 Where have we failed? We still do not have realistic detector
characteristics needed for the physics groups. Lack of manpower and
time that it takes to perform realistic simulations has been the problem.
However, we feel that we might be able to achieve this by the June
detector and physics workshops.
 R&D plans are still in their infancy. We need to formulate this ASAP.
Tomorrow at the BENE3rdmeeting
we will have the first chance to discuss
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the R&D plans for detectors.
Rutherford Appleton Laboratory