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Antonis Leisos. Physics Laboratory. School of Science and Technology. Hellenic Open University. KM3NeT Design Study. Calibration systems and methods for underwater neutrino telescope.
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Antonis Leisos Physics Laboratory School of Science and Technology Hellenic Open University KM3NeT Design Study Calibration systems and methods for underwater neutrino telescope G. Bourlis, E. P. Christopoulou, N. Fragoulis, N. Gizani, A. Leisos, S. E. Tzamarias, A. Tsirigotis, B. Verganelakis • the calibration principle using atmospheric showers • construction and performance of the prototype detector station • Monte Carlo Studies XXV Workshop on Recent Developments in High Energy Physics & Cosmology NTUA Greece 28 - 31 March 2007
spase-amanda 1 km 2 km SPASE air shower arrays calibration of AMANDA angular resolution and pointing ! resolution Amanda-B10 ~ 3.5°
The General Idea… • Angular offset • Efficiency • Resolution • Position Physics ? (ex. ICETOP) C.R. composition UHE ν - Horizontal Showers Veto atmospheric background – Study background
Isotropic on the top of the atmosphere BUT … ~4km ~20km
reweighting Blind fit Okada model Pierre Auger: M. Are et al. Ast.Part. 14: 109-120 2000 Haverah Park (www.ast.leeds.ac.uk/haverah/havpark.html): 12km2 effective area and 2π coverage in φ for 10 years operation less than 100 detected showers with NESTOR: muon flux @ 4000m
We propose a minimum of 3 stations with at least 16 m2 scintillator detectors each The Concept Floating stations
HELYCON Station Single Station Set-Up GPS Scintillator-PMT Scintillator-PMT 1 m2 Scintillator-PMT ~20 m Scintillator-PMT Triangulation Shower Direction DAQ 4·(1W/counter)+30W(PC+electronics)
The HELYCON Detector Module GPS timestamp Station Server Scintillator 2 Scintillator 3 Scintillator 3
Simulation Tools CORSIKA (Extensive Air Shower Simulation) GEANT4 (Scintillation, WLS & PMT response) Fast Simulation also available Energy: 105 GeV – 5 105 GeV Number of particles to the ground
Simulation Tools DAQSIM (DAQ Simulation) HOUANA (Analysis & Track Reconstruction) Height (mV) Time (ns) Zentih (degrees)
d L-dm (x,y,z) θc dγ Track Parameters θ : zenith angle φ: azimuth angle (Vx,Vy,Vz): pseudo-vertex coordinates dm (Vx,Vy,Vz) pseudo-vertex Simulation Tools GEANT4 Muon Propagation to KM3 HOU-KM3 Muon track (s) reconstruction
Monte Carlo Studies- Outlook1014 - 5·1015 eV E~ 1014 - 5·1015 eV: 2500 showers/m2/year Single station detection: 351m2 effective area (depends on geometry and selection cuts) Multi-Station: separation <100m, better resolution E> 1016 eV: 1 shower/m2/year TO BE STUDIED 35% of the detected showers include a muon which arrives at the Neutrino Telescope (depth 4000m) with an energy >300GeV General Remark: 3 stations operating for 10 days can identify an angular offset with an accuracy of 0.15o
Monte Carlo Studies Atmospheric shower simulation by CORSIKA - muon transportation to the detector DEPTH by GEANT4 - Sea-Top Detector detailed simulation GEANT4_HOU Angular Resolution in Single Shower Reconstruction • Depends on: • Detector separation • Selection criteria • Shower direction • Typical Values • No cut: σ= 4.5ο • Total Collected Charge > 10 mips: σ=2.22ο • Total Collected Charge > 25 mips: σ=1.33ο • Total Collected Charge > 30 mips: σ=1.2ο PRELIMINARY Θrec-Θtrue
zenith angle resolution [degrees] Minimum of total collected charge [mip equivalent] Monte Carlo Studies Three Stations Working Independently for 10 days Single Station: 4 detectors (1m2 plastic scintillator), 20 m distance between the detectors, three out of four selection trigger PRELIMINARY Reconstruction efficiency Resolution (degrees)
Proposed Detector 5m 1 m2 Scintillation Counter 19m dt=0 dt1 dt2 dt3 19m
curvature thickness Multi-Station Operation Monte Carlo Studies in Progress First coming particles Time Spread (ns) Total collected charge [pe]
Timing vs Pulse Hight Input A Input B Discriminator (1.5 MIP) Trigger Slewing Resolution
Consistent Estimations Minuit Minimization
Detection Efficiency Efficiency Events A hit is considered when there is more than 4 mips deposited charge
Muon Propagation Accepted if muon with E>2TeV goes through km3 Geant Simulation (propagation & Energy Loss) μ track Zenith angle < 13 deg Muon Track Reconstruction (A. Tsirigotis talk) km3
Primary Zenith Angle Resolution • Deposited Charge per counter > 4 mips • Number of Hits > 10
Charge parameterization AGASA parameterization (S. Yoshida et al., J Phys. G: Nucl. Part. Phys. 20,651 (1994) Parameters depend on (θ,Ε, primary) “Mean particle density registered by an active counter”
Effective Area ~ 30 showers per day reconstructed at the surface and in the deep sea
Conclusions The operation of 3 stations (16 counters) for 10 days will provide: • The determination of a possible offset with an accuracy ~ 0.05 deg • The determination of the absolute position with an accuracy ~ 0.6 m • Efficiency vs Energy and Zenith angle… • Resolution…