1. UK involvement in Neutrino Factory Detector R&D UK Neutrino Factory Meeting 3 May 2006 Paul Soler University of Glasgow

2. 2 UK Neutrino Factory Meeting RAL, 3 May 2006 Contents 1. Beam 2. Event rates 3. Large Volume Water Cherenkov 4. Magnetised Segmented Calorimeters 5. Liquid Argon TPC 7. Hybrid Emulsion Detectors 8. Near Detector 9. Conclusions

3. 3 UK Neutrino Factory Meeting RAL, 3 May 2006 1. Neutrino Factory Beams o Neutrino beams from decay of muons: Spectra at Production (e.g. for 50 GeV muons) Number CC interactions Polarisation dependence

4. 4 UK Neutrino Factory Meeting RAL, 3 May 2006 2. Event rates o Number of events and size of beam in a far detector (700-7000 km): Yearly  CC rate/kton Need very massive detectors!

5. 5 UK Neutrino Factory Meeting RAL, 3 May 2006 o Suitable for low energy neutrino detection (~ 1 GeV)  Excellent   e separation 3. Water Cherenkov Electron-likeMuon-like o Difficult (or impossible?) to put a magnetic field around it, so not suitable for neutrino factory. o Suitable for beta-beams or super-beams o UK has expertise (e.g. SNO) but unlikely to be built for a neutrino factory UNO/Hyperkamiokande: ~1 Mton

6. 6 UK Neutrino Factory Meeting RAL, 3 May 2006 4. Magnetised Segmented Calorimeters o Golden channel signature: “wrong-sign” muons in magnetised calorimeter o In my view, this is the front-running technology for a far detector at a neutrino factory o Some issues: electron ID, segmentation, readout technology (RPC or scintillator?) – need R&D to resolve these o There exists expertise in the UK, natural progression from MINOS 8xMINOS (5.4 KT) iron (4 cm) + scintillators (1cm) beam 20 m B=1 T 40KT

7. 7 UK Neutrino Factory Meeting RAL, 3 May 2006 4. Magnetised Segmented Calorimeters o Magnetic Iron Detector Optimised for small  13 Strong cut on muon momentum > 5 GeV/c Problems below muon momentum < 3 GeV/c (cannot see second maximum) Main background: production of charm

8. 8 UK Neutrino Factory Meeting RAL, 3 May 2006 4. Magnetised Segmented Calorimeters  Compromise between Large Magnetic Detector and No a concepts? o Iron free regions: improve momentum and charge determination Iron (4cm) + active (1cm) air + active (1cm) hadron shower muon 1m o Combining No a and iron-free regions ? Iron (2cm) + active (4cm) air + active (1cm) hadron shower muon Liquid scintillator iron

9. 9 UK Neutrino Factory Meeting RAL, 3 May 2006 4. Magnetised Segmented Calorimeters Simulation of a magnetised scintillating detector using No a and Miner a concepts with Geant4 3 cm 1.5 cm 15 m 100 m –3333 Modules (X and Y plane) –Each plane contains 1000 slabs –Total: 6.7M channels o Three lepton momenta: –“Low”: 100 MeV/c – 500 MeV/c initial momentum –“Medium”: 500 MeV/c – 2.5 GeV/c initial momentum –“High”: 2.5 GeV/c – 12.5 GeV/c initial momentum 0.15 T magnetic field 0.30 T magnetic field 0.45 T magnetic field o Three fields studied: Ellis, Bross

10. 10 UK Neutrino Factory Meeting RAL, 3 May 2006 4. Magnetised Segmented Calorimeters Position resolution ~ 4.5 mm Red Red: 0.15 T Magnetic Field Green Green: 0.30 T Magnetic Field Blue Blue: 0.45 T Magnetic Field Muon reconstructed efficiency

11. 11 UK Neutrino Factory Meeting RAL, 3 May 2006 4. Magnetised Segmented Calorimeters  turns 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) Coil: Aluminium (Alain: LN2 cooled). Problem: Periodic coil material every 15m: Increase length of solenoid along beam?  How thick? Possible magnet schemes for TASD Camilleri, Bross

12. 12 UK Neutrino Factory Meeting RAL, 3 May 2006 5. Liquid Argon TPC  Liquid argon detector is the ultimate detector for e and  appearance (“silver channel”). Simultaneous fit to all wrong and right sign distributions. o ICARUS has constructed 600 t modules and observed images o Main issues: inclusion of a magnetic field, scalability to ~20-100 kT. o There exists UK expertise in liquid Xe TPC for dark-matter. To contribute, we would need to bring in dark matter community

13. 13 UK Neutrino Factory Meeting RAL, 3 May 2006 5. Liquid Argon TPC LAr Cathode (- HV) E-field Extraction grid Charge readout plane UV & Cerenkov light readout PMTs E≈ 1 kV/cm E ≈ 3 kV/cm Electronic racks Field shaping electrodes GAr A tentative detector layout Very ambitious!! Single detector: charge imaging, scintillation, possibly Cerenkov light Magnetic field problem not solved Max field 0.4 T

14. 14 UK Neutrino Factory Meeting RAL, 3 May 2006 6. Hybrid Emulsion Detectors Plastic base Pb Emulsion layers  1 mm  Emulsion detector for  appearance, a la OPERA  Issues: high rate, selected by choosing only “wrong sign”  →  events o Assume a factor of two bigger than OPERA (~4 kt) o No UK expertise in this technology

15. 15 UK Neutrino Factory Meeting RAL, 3 May 2006 6. Hybrid Emulsion Detectors Electronic det: e/  separator & “Time stamp” Rohacell® plate emulsion film stainless steel plate spectrometertargetshower absorber Muon momentum resolution Muon charge misidentification

16. 16 UK Neutrino Factory Meeting RAL, 3 May 2006 6. Hybrid Emulsion Detectors o Let us assume transverse dimension of a plane equal to 15.7x15.7 m 2 (as in the case of Nova) o A brick contains 35 stainless steel plates 1 mm thick: it corresponds to about 2 X 0 o A brick weigh 3.5 kg o The spectrometer part consists of 3 gaps (3 cm each) and 4 emulsion films o A wall contains 19720 bricks  weight 68 tons o If I consider 60 walls  1183200 bricks  4.1 kton o In terms of emulsion films the target is: 47,328,000 pieces (in OPERA we have 12,000,000) o If I consider as electronic detector 35 Nova planes (corresponding to 5.3 X 0 ) after each MECC wall  2100 planes o The total length of the detector is: about 150 m Possible design hybrid emulsion-scintillator far detector Synergy emulsion-magnetic scintillation detector Detector of Everything (DoE)?

17. 17 UK Neutrino Factory Meeting RAL, 3 May 2006 o Near detectors should be able to measure flux and energy of and o Calibration and flux control: o High event rate: 8. Near detector(s) o Measure charm in near detector to control systematics of far detector (main background in oscillation search is wrong sign muon from charm) E.g. at 25 GeV, number neutrino interactions per year is: 20 x 10 6 in 100 g per cm 2 area. o Other physics: neutrino cross-sections, PDF, electroweak measurements,... o Possible technology: fully instrumented silicon target in a magnetic detector.

18. 18 UK Neutrino Factory Meeting RAL, 3 May 2006 8. Near detector(s) o Possible technology: fully instrumented silicon target in a magnetic detector. storage ring shielding the leptonic detector the charm and DIS detector Polarimeter Cherenkov d

19. 19 UK Neutrino Factory Meeting RAL, 3 May 2006 8. Near detector(s) A) Diagnostic devices along beamline: o BCT to 10 -3 o Beam Cherenkov for divergence measurement o Polarimeter devices B) Near Detector R&D programme: o Vertex detector options: hybrid pixels, monolithic pixels (ie. CCD, Monolithic Active Pixels MAPS or DEPFET) or strips. Synergy with other fields such as Linear Collider Flavour Identification (LCFI) collaboration. o Tracking: gas TPC (is it fast enough?), scintillation tracker (same composition as far detector), drift chambers?, cathode strips?, liquid argon (if far detector is LAr), … o Particle identification: dE/dx, Cherenkov devices such as Babar DIRC?, Transition Radiation Tracker? o Calorimetry: lead glass, crystals?, sampling calorimeter o Magnet: UA1/NOMAD/T2K magnet?, dipole or other geometry? C) Physics: Collaboration with theorists to enhance physics case of near detector and to determine cross-sections, etc.

20. 20 UK Neutrino Factory Meeting RAL, 3 May 2006 Conclusions  There are many interesting neutrino detector technologies to be considered  Many of these will be studied for the Scoping Study  In my view, the most promising include development of the magnetised calorimeter as a far detector (for the “wrong-sign muon” golden channel) and the development of the near detector and its physics programme (especially if neutrino factory based in UK!!!).  Both of these are at the centre of the physics from a neutrino factory (the numerator and the denominator!)  Other far detector technologies are either not mature enough, not relevant at a neutrino factory or there is no UK expertise in them.  A focused approach based on UK strengths