Transcript Slide 1
Calibration and Optimization of a Very Large Volume Deep-Sea Neutrino Telescope using Extensive Air Showers Antonios Leisos International Workshop On Very large Volume Neutrino Telescopes 13-15 October 2009, Athens, Greece Outline Air Shower detection for Deep Sea ν-Telescope Calibration (updated analysis) • • Calibration using single muons or extensive (air) showers? • New Crude Analysis for Optimum angular offset determination (motivated from IceTop Analysis) A Calibration Study At least one muon with E>2TeV passing through the neutrino telescope μ track dt=0 dt1 dt2 Detailed Simulation dt3 (propagation & Energy Loss) L P(ti ; d ( , )) km3 d: distance from the shower axis A Calibration Study 3 stations for 10 days 5m Resolution in Estimating a Possible Angular Offset [deg] 19m Minimum number of Active counters Comparison of Estimations Detector: SeaWiet Depth: 2500 m Quality cuts: • mean deposited charge in active counters >1.7 • number of PMT hits > 10. φ array Θ array φ telescope σ=6.70 θTelescope-θarray σ=420 φTelescope-φarray Θ telescope σ=47m ΧTelescope-Χarray Monte carlo Results SeaWiet Depth 3X16 counters 10 days of operation νOne Offset Sensitivity θ φ 2500 0.040±0.005 0.26±0.03 3500 0.045±0.01 0.34±0.07 Depth Offset Sensitivity θ φ 2500 0.040±0.006 0.20±0.02 3500 0.09±0.02 0.46±0.05 1000m νOne SeaWiet Depth Offset Sensitivity θ φ 2500 0.05±0.005 0.24±0.04 3500 0.1±0.02 0.28±0.08 Depth Offset Sensitivity θ φ 2500 0.06±0.007 0.23±0.02 3500 0.15±0.07 0.42±0.07 Can we make it better? Shower vs Single muon Total number of muons through S for 10 days operation S Depth (m) S (m2) 3800 3115 2115 4538 14495 108095 2.5 103 (30% eff) * 1134 3624 27024 9 102 (30% eff) * 409 1304 9728 50 (30% eff) * 23 72 540 50 (10% eff- FR**) - 3500 15000 104 dN I 0 cos ddtds D *Numbers calculated assuming R0=1km, 30% reconstruction efficiency of ν-Telescope ** Results of MC simulation with full reconstruction (10 % efficiency) R0 dN D I 0 rdrd 2 2 2 2 dt r D r D (30% eff)* a Offset resolution in 10 days (3X16 m2) θ φ 0.005 0.02 Detector Module GPS timestamp DAQ S/W based on LabView Scintillation Tiles WLS fibers On-Line analysis - distributions Module Calibration Response to a MIP Single p.e Detector Uniformity Charge (pCb) @ “nominal” H.V. gain: ~ 4 105 <charge>/p.e. ~ 0.07pCb <pulse height>/p.e. ~ 1.05mV Typical Mean Numb. of p.e. per m.i.p. : 21 ± 10% variation Monte Carlo & Data Comparison Detailed Monte Carlo description A1 B2 A3Input C Trigger B1 A2 B3 At the Detector Center Data Data ___ M.C. Prediction - Monte Carlo Prediction Charge (in units of mean p.e. charge) μ=-0.1±0.3 σ=7.6 ± 0.2 θΑ-θΒ Use IceTop’s Analysis Thomas Geisser (Performance of IceTop Array-ICRC’07 Eμ>2 ΤeV (X0,Y0.Z0) Χμ-Χshower Crude & Accurate Estimation t anˆ d X N YN 60m X 0 Y0 10m (XN,YN) t anˆ ˆ cos 2 ˆ cos2 t anˆ 10 Θ0 d X N X 0 2 YN Y0 2 (X0,Y0) θ0-θshower Angular Offset Resolution ΔΤ~14 hours 16 m2 array 0.050 ΔΤ~1 day 3X16 m2 array 0.020 Detector: SeaWiet Depth: 2500 m Quality cuts: • number of PMT hits > 10. θest-θ0 ΔΤ~10 days 3X16 m2 array <0.010 Low & Higher multiplicity triggers Only 2 counters Detector: SeaWiet Depth: 2500 m est Quality cuts: •number of PMT hits > 10. θ -θ0 2 or more counters θest-θ0 Crude vs Weighted Mean (XN,YN) θest-θ0 Θw d (Xw,Yw ) Detector: SeaWiet Depth: 2500 m Quality cuts: •number of PMT hits > 10 θest-θw Azimuth Offset Resolution φ0-φshower Detector: SeaWiet Depth: 2500 m Quality cuts: •number of PMT hits > 10. φest-φo Position Correlation Xdet+10m θest-θ0 Xdet+50m Xdet+50m θest-θ0 φest-φo Detector: SeaWiet Depth: 2500 m Quality cuts: number of PMT hits > 10. Summary Of Results SeaWiet Depth (m) νOne Offset Sensitivity (deg) θ φ 2500 0.005 0.02 3500 0.014 0.05 Depth (m) Offset Sensitivity (deg) θ φ 2500 0.01 0.02 3500 0.02 0.06 Consistent Estimations when the array Is shifted in X or Y axis Estimation of the angular resolution of the KM3NeT – (Inter-Calibration) KM3NeT’s resolution measurement Impossible using EAS array KM3NeT resolution ~ 0.1 deg EAS Detector resolution ~ 2 deg (Inter-Calibration) 1. Divide the detector in 2 identical sub detectors 2. Reconstruct the muon separately for each sub detector 3. Compare the 2 reconstructed track directions Working Example IceCube Geometry 9600 OMs looking up & down in a hexagonal grid. 80 Strings, 60 storeys each. 17m between storeys MultiPMT Optical Module 125m Resolution Estimation (1 TeV Muons, isotropic flux, IceCube Geometry, 9600 OMs) •Simulated events with at least 14 active OMs, after filtering out the background hits. Mean 12 hits •The selected sample consisted, in average, of 24 active OMs per event, whilst the remaining contamination from K40 background hits was less than 0.5 OM per event. Number of active OMs in one subdetector •Each muon track was reconstructed using the information from the whole set of the active OMs as well as using the data from the two sub-groups, each containing the half of the selected OMs. Mean 24 hits Number of active OMs in whole detector Resolution Estimation (1 TeV Muons, isotropic flux, IceCube Geometry, 9600 OMs) •Simulated events with at least 14 active OMs, after filtering out the background hits. Mean 12 hits •The selected sample consisted, in average, of 24 active OMs per event, whilst the remaining contamination from K40 background hits was less than 0.5 OM per event. Number of active OMs in one subdetector •Each muon track was reconstructed using the information from the whole set of the active OMs as well as using the data from the two sub-groups, each containing the half of the selected OMs. Mean 24 hits Number of active OMs in whole detector Resolution Estimation (1 TeV Muons, isotropic flux, IceCube Geometry, 9600 OMs) σ=0.095o ±0.005o Zenith angle resolution of subdetectors (degrees) σ=0.07o±0.003o Zenith angle resolution of whole detector (degrees) Resolution Estimation (1 TeV Muons, isotropic flux, IceCube Geometry, 9600 OMs) σ=0.14o±0.01o Zenith angle difference between the 2 reconstructed directions (degrees) Space angle difference between the 2 reconstructed directions (degrees) ≈ 0.095o ±0.005o SeaWiet νOne