1. Detector Working Group: review of progress, issues to be addressed
4th Neutrino Factory International Design Study Meeting, Mumbai
Joint with EUROnu Meeting
12 October 2009
Paul Soler

2. 4th Neutrino Factory International Design Study Meeting
Contents
Detector requirements
Magnetised Iron Neutrino Detector (MIND)
Indian Neutrino Observatory
Totally Active Scintillator Detectors (TASD)
Water Cherenkov
Liquid Argon
Emulsion Cloud Chamber (ECC)
Near Detector
Detector R&D
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

3. Detector requirements
Detector requirements established by International Scoping Study (ISS) for a Neutrino Factory Detector Report:
(arxiv: v1 [physics.ins-det], JINST 4:T05001,2009)
Baseline detector requirements are:
Two detectors at 4000 km and 7500 km
Magnetised Iron Neutrino Detector (MIND)
of 50 kton fiducial (gold channel)
Possible addition of Magnetised Emulsion
Cloud Chamber (MECC) of 10 kton (silver)
Beyond the baseline improvements for
platinum channels (R&D needed):
Magnetised Liquid Argon: kton
Magnetised Totally Active Scintillating
Detector (TASD): kton
Near detectors: magnetised to measure flux and hadron background
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

4. Magnetised Iron Neutrino Detector (MIND)
M~ Kton m
15-20 m
1cm transverse resolution
n beam
From ISS report:
15-20 m
Old analysis II: Pμ>5 GeV, Qt> 0.7 GeV
Old analysis I: Pμ>7.5 GeV, Qt> 1 GeV
nmCC signal
Lμ> 75 cm
Lμ>150 cm
Lμ>200 cm
B=1 T
Advantages:
Easy to detect sign of muons
Easy to discriminate hadronic showers
Easy to magnetise
Based on known technology
Can be very massive kton
Cost is not prohibitive: $300M-$400M
Disadvantages:
Difficult (not impossible!) to detect electrons
Cannot detect taus
Energy threshold too high for 2nd maximum
iron (4 cm)
scintillators (1 cm)
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

5. Magnetised Iron Neutrino Detector (MIND)
Performance of IDS-NF baseline detectors (two MIND detectors, one at 4000 km and one at 7500 km) at 3s, from ISS Physics report (arXiv:  [hep-ph], Rept.Prog.Phys.72:106201,2009.)
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

6. Simulation and resolution (from ISS)
GEANT3 simulation
Detector effects not simulated
Perfect pattern recognition
Reconstruction based on parameterisation
Dipole field instead of toroidal
Fully contained muons by range
Scaping muons by curvature
Hadron shower:
Ehad Em
Including QE
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

7. 4th Neutrino Factory International Design Study Meeting
MIND analysis
Kinematic analysis to eliminate background
Variables used: En
Pm=|Pm|
Qt=Pmsin2 q q
Cuts in En-Pm and En-Qt planes
Main background: hadron decay (charm decay in CC and pion decay in NC)
not detected CC
Hadron decay NC
Pion decay
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

8. 4th Neutrino Factory International Design Study Meeting
MIND background
Backgrounds from charm, NC and charge misidentification
Charge mis-ID
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

9. Aims of full simulation/reconstruction
Need to verify results with full simulation/reconstruction
Demonstrate that for En < 10 GeV:
Backgrounds are below 10-3
The efficiency can be increased with respect to fast analysis
Compute:
Signal and backgrounds efficiency as a function of energy
Energy resolution as a function of energy
Identify crucial parameters to be optimised to maximise the sensitivity to the osc. parameters
Optimise segmentation and B field based on the above parameters and taking into account feasibility and cost
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

10. Detector optimisation: Longitudinal segmentation
Move from 4 cm Fe + 1 cm scintillator to 3 cm Fe + 2 cm scintillator
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

11. Detector optimisation: Transverse segmentation
Assuming perfect pattern recognition 1 cm transverse resolution is enough for charge and Qt measurements
Pattern recognition:
better segmentation should improve it
which resolution saturates the patter recognition performance ?
1 cm transverse segmentation looks appropriate
Lines: 1, 1.5 and 2 GeV/c muon momentum
BFe=1.25 Tesla
Fe thickness = 4 cm
BFe=1.25 Tesla
Fe thickness = 2.5 cm
BFe=2 Tesla
Fe thickness = 2.5 cm
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

12. Detector optimisation: magnetic field
Even if we are able to isolate a 1 GeV/c muon, the ratio curvature/MS is not sufficient. ~5% charge mis-ID
The magnetic field strength is the crucial parameter
Going from 1.25 to 1.7 Tesla average is feasible (J. Nelson, Golden07)
> 1 o.o.m improvement at 1 GeV/c level
MINOS
MIND
1 GeV/c
2 GeV/c
1.5 GeV/c
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

13. Prospects MIND Analysis work
Fast simulation/reconstruction was very useful
For more than a year we have been developing a full simulation to address:
What are the main backgrounds at low energies ?
What is the background level ?
Where is the efficiency plateau ?
What are the parameters to be optimised ?
Prototyping R&D program should go in parallel to validate assumptions
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

14. MIND software framework✔
1/2
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

15. Kalman filter (RecPack)
Pattern recognition and Kalman filter already implemented
Kalman filter algorithm takes into account multiple scattering and energy loss
c2/DOF ~ 1 shows model working well
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

16. 4th Neutrino Factory International Design Study Meeting
Kink rejection
Further rejection background due to charge mis-id:
Established kink finding algorithm
(cut on maximum c2 hit of track) to
get rid of non-Gaussian scatters ~70% bck
A. Laing to report at this meeting improve-
ments pattern recognition, analysis and comparison to previous simulations
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

17. Indian Neutrino Observatory
Indian Neutrino Observatory (INO):
Main purpose: atmospheric neutrinos
Can be used for beam neutrinos
Detector size: 48 m x 16 m x 16 m
Readout: RPCs
B=1.5 T
Far detector at magic baseline of neutrino factory for most facilities:
CERN to INO: distance = 7152 km
JPARC to INO: distance = 6556 km
RAL to INO: distance = 7653 km
G Majunder and N Mondal
to report on progress
INO at ideal position!
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

18. Totally Active Scintillating Detectors (TASD)
Possible improvement: Totally Active Scintillating Detector (TASD) using Nona and Minerna concepts
A Bross to report at this meeting
3333 Modules (X and Y plane)
Each plane contains 1000 slabs
Total: 6.7M channels
15 m
100 m
3 cm
1.5 cm
15 m
Momenta between 100 MeV/c to 15 GeV/c
Magnetic field considered: 0.5 T
Reconstructed position resolution ~ 4.5 mm
Reduction threshold: access second oscillation maximum and electron identification
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

19. Totally Active Scintillating Detectors (TASD)
Neutrino CC reconstructed efficiency
Muon charge mis-ID rate
A. Bross will show electron identification efficiency based on
“visual” scans
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

20. Totally Active Scintillating Detectors (TASD)
Main problem: magnetisation of huge volume (difficulty and cost)
However, possible magnetisation can be achieved using magnetic cavern concept (10 modules with 15m x 15 m diameter)
Bross
Use Superconducting Transmission
Line (STL): cable has its own cryostat!
0.58 T at 50 kA
Developed for VLHC
R&D needed to develop concept! A.Bross to update
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

21. Totally Active Scintillating Detectors (TASD)
Possible use of TASD opens up possibility of running at a low energy neutrino factory (4 GeV)
Bross, Ellis, Geer, Mena, Pascoli, Li
Important topic of discussion at this meeting
95% CL CP violation at 1480 km
95% CL mass hierarchy at 1480 km
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

22. 4th Neutrino Factory International Design Study Meeting
Water Cherenkov
65m
60m
MEMPHYS
Water Cherenkov detector better suited for low energy options but…
P.Huber and Th.Schwetz, ArXiv:0805:2019
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

23. 4th Neutrino Factory International Design Study Meeting
Water Cherenkov
Water Cherenkov simulations with MEMPHYS:
Lots of progress in getting Water Cherenkov simulations up and running
Tonnazo,
Vassilopolous p m- g
p0 2g
nm(2GeV)
Number PE/MeV
MEMPHYS:
Time residuals fitted vertex:
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

24. 4th Neutrino Factory International Design Study Meeting
Liquid Argon TPC
Different approaches for large ( kton) Liquid Argon TPCs
LANNDD 2001
Glacier 2003 (Europe)
Flare 2004 (Fermilab, USA)
Modular 2007 (Europe)
Update on progress at dedicated LAr session
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

25. A tentative detector layout
Liquid Argon TPC
A tentative detector layout
(GLACIER)
Single detector: charge imaging, scintillation, possibly Cerenkov light
Charge readout plane
(LEM plane)
GAr
E ≈ 3 kV/cm
LAr
Electronic
racks
Extraction grid
E-field
E≈ 1 kV/cm
Field shaping
electrodes
Cathode (- HV)
UV & Cerenkov light readout PMTs
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

26. Magnetised Emulsion Cloud Chamber
Tau detection far detector: Emulsion detector à la OPERA: “silver channel”
Is tau detection needed at far detector: can Non Standard Interactions (NSI) be determined with near detector instead?
Electronic det:
e/p/m separator
&
“Time stamp”
Rohacell® plate
emulsion film
stainless steel plate
spectrometer
Shower absorber
target
Emulsion
Cloud
Chamber
Muon charge misidentification
Muon momentum resolution
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

27. Beam Diagnostics and Near Detector aims
Beam diagnostics (needed for flux measurement)
Number of muon decays (Beam Current Transformer?)
Measurement of divergence (Beam Cherenkov?)
Measurement of muon polarization (tagged spectrometer?)
Near detector measurements needed for neutrino oscillation systematics:
Measurement of neutrino flux
Extrapolation near detector flux to far detector
Measurement of charm background
Cross-section measurements: DIS, QES, RES scattering
Other electroweak and QCD physics with near detector
Search for Non Standard Interactions (NSI) by measuring taus in near detectors
M Apollonio to update
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

28. Flux Measurement at Near Detector
Best possibility: Inverse Muon Decay: scattering off electrons in the near detector. Known cross-sections
R Tsenov to update
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

29. Near Detector flux used to extract Pnenm
Original idea: use matrix method with Near Detector data (even if spectrum not identical in near and far detector!) to extract oscillation probability:
Where: M1=matrix relating event rate and flux of ne at ND (x-section + det)
M2=matrix relating event rate and flux of nm at FD (x-section + det)
M=matrix relating measured ND ne rate and FD nm rate (measured!)
MnOsc=matrix relating expected ne flux from ND to FD (extrapolation)
Method works well
but two inversions
affects fit convergence
Two matrix inversions!
Probability of oscillation determined by matrix method under “simplistic” conditions. Need to give more realism to detector and matter effects.
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

30. Near Detector flux used to extract Pnenm
Now we calculate in stages: ND simulated data to predict ND flux
where: M1=matrix relating event rate and flux of ne at ND
Extrapolate ND flux to FD: MnOsc=matrix relating ne flux from ND to FD
Extract FD interaction rate:
M2=matrix relating event rate and flux of nm at FD,
= prob oscillation
sND/E ~35%/√E
No oscillations
sFD/E ~55%/√E
Flux from ND
Hardly any change in contours from ND
Assume “true” flux
There is only one matrix inversion and fit to Pnenm seems to be more robust.
Work on this topic stopped for 6 months due to manpower: hope to take it up again in January
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

31. 4th Neutrino Factory International Design Study Meeting
Near Detector Design
Measure charm cross-section using
Impact Parameter with Si vertex
detector (can also search for NSI taus)
Muon chambers
EM calorimeter
Hadronic
Calorimeter
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009
Near detector design needs to be developed further

32. 4th Neutrino Factory International Design Study Meeting
Cross section measurements
Measure of cross sections in DIS, QE and RES.
Coherent p
Different nuclear targets: H2, D2
Nuclear effects, nuclear shadowing, reinteractions
What is expected cross-
section errors from
MiniBoone, SciBoone,
T2K, Minerva, before
NUFACT?
At NUFACT, with modest
size targets can obtain very
large statistics, but is <1%
error achievable?
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

33. 4th Neutrino Factory International Design Study Meeting
MIND and TASD R&D effort
Test assumptions of simulation in test beams
Build prototype TASD inside magnetic field
Build prototype MIND ~2x2x4 m3 (ie. ~10-3 full MIND
Important to contain m < 2 GeV
Could put INO test stand in beam
Technology tests: scintillator
bar readout, photon detectors and
electronics
Dedicated parallel session on R&D
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009

34. 4th Neutrino Factory International Design Study Meeting
Conclusions
MIND is still baseline detector at medium (~4000 km) distance – mass to be reviewed (50 vs 100 kton)
INO could be magic baseline (7500 km) detector at NuFact in Europe (34o storage ring still an issue)
Full simulation and performance still advancing
TASD is particularly useful in a LENF
Liquid Argon and Water Cherenkov still being considered
R&D issues to be discussed at meeting
Importance of Near Detector is becoming better appreciated
Happy Diwali!
4th Neutrino Factory International Design Study Meeting
Mumbai, 12 October 2009