1 / 16

Physics Laboratory

Physics Laboratory. School of Science and Technology. Hellenic Open University. Report of the HOU contribution to KM3NeT TDR (WP2). A. G. Tsirigotis. WP2 Meeting - Marseilles , 29June-3 July 200 9. In the framework of the KM3NeT Design Study. GEANT4 Simulation – Detector Description.

scottconner
Download Presentation

Physics Laboratory

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Physics Laboratory School of Science and Technology Hellenic Open University Report of the HOU contribution to KM3NeT TDR (WP2) A. G. Tsirigotis WP2 Meeting - Marseilles, 29June-3July 2009 In the framework of the KM3NeT Design Study

  2. GEANT4 Simulation– Detector Description • Any detector geometry can be described in a very effective way Use of Geomery Description Markup Language (GDML-XML) software package • All the relevant physics processes are included in the simulation • (OPTICAL PHOTON SCATTERING ALSO) Fast Simulation EM Shower Parameterization • Number of Cherenkov Photons Emitted (~shower energy) • Angular and Longitudal profile of emitted photons Detector components Particle Tracks and Hits Visualization

  3. Charge Likelihood – Used in muon energy estimation Hit charge in PEs Probability depends on muon energy, distance from track and PMT orientation Not a poisson distribution, due to discrete radiation processes E=1TeV D=37m θ=0deg Ln(F(n)) Ln(n) Log(E/GeV)

  4. 67 meters maximum abs. length no optical photon scattering Detectors Benchmark Detector, and: NuOne: 91 Towers in a hexagonal grid, seperated by 130m. 20 floors each Tower. 30m between floors. Bar length 8m SieWiet: 91 Strings in a hexagonal grid, seperated by 130m, 20 MultiPMTs per floor, 30m between floors. Tower Geometry Floor Geometry 30m 45o 45o

  5. Optical Modules Single PMT Optical Module Multi PMTOptical Module • 10 inch PMT housed in a 17inch benthos sphere • 35%Maximum Quantum Efficiency • Genova ANTARES Parametrization for OM angular acceptance • 31- 3inch multi PMT OM housed in a 17inch benthos sphere • 35%Maximum Quantum Efficiency • NIKHEF Parametrization for PMT angular acceptance (0.1+0.9cos(θ)) 75KHz of K40 optical noise 7KHz of K40 optical noise

  6. Results Atmospheric Muon background (CORSIKA files – 1 hour lifetime) + Atmospheric Neutrino Background (bartol flux) Sensitivity signal

  7. Results : E-2 source flux (100GeV – 1000PeV) – 1 year of observation Point Source Sensitivity (x10-9E2(dN/dE)(cm-2s-1GeV) (VERY PRELIMINARY) NuOne Benchmark Effective area (m2) Neutrino Energy (log(E/GeV))

  8. Angular resolution at sensitivity limit Benchmark detector NuOne Detector Neutrino Neutrino Angular resolution (median degrees) Muon Muon Energy (log(E/GeV))

  9. Energy resolution at sensitivity limit (NuOne detector) RMS(Log(E/GeV)) Log(Etrue/GeV)

  10. Comparison between benchmark and SeaWiet Same cuts applied Muon angular resolution • Seawiet with OM-directionality • Seawiet without OM-directionality • Benchmark detector degrees Effective area (m2) Muon Energy (log(E/GeV)) Neutrino angular resolution degrees Neutrino Energy (log(E/GeV)) Neutrino Energy (log(E/GeV))

  11. Muon reconstruction statistical properties Chi-square probability

  12. Coming very soon • Estimation of sensitivity errors • Calculation of point source sensitivity of SeaWiet • Calculation of diffuse flux sensitivities for all detectors and depths

  13. The HOU software chain • Underwater Neutrino Detector • Generation of atmospheric muons and neutrino events (F77) • Detailed detector simulation (GEANT4-GDML) (C++) • Optical noise and PMT response simulation (F77) • Filtering Algorithms (F77 –C++) • Muon reconstruction (C++) • Effective areas, resolution and more (scripts) • Extensive Air Shower Calibration Detector (Sea Top) • Atmospheric Shower Simulation (CORSIKA) – Unthinning Algorithm (F77) • Detailed Scintillation Counter Simulation (GEANT4) (C++) – Fast Scintillation Counter Simulation (F77) • Reconstruction of the shower direction (F77) • Muon Transportation to the Underwater Detector (C++) • Estimation of: resolution, offset (F77)

  14. Event Generation – Flux Parameterization μ ν ν • Atmospheric Muon Generation • (CORSIKA Files, Parametrized fluxes ) • Neutrino Interaction Events • Atmospheric Neutrinos • (Bartol Flux) • Cosmic Neutrinos • (AGN – GRB – GZK and more) Earth Shadowing of neutrinos by Earth Survival probability

  15. Prefit, filtering and muon reconstruction algorithms 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 • Local (storey) Coincidence (Applicable only when there are more than one PMT looking towards the same hemisphere) • Global clustering (causality) filter • Local clustering (causality) filter • Prefit and Filtering based on clustering of candidate track segments (Direct Walk technique) • Combination of Χ2fit and Kalman Filter (novel application in this area) using the arrival time information of the hits • Charge – Direction Likelihood using the charge (number of photons) of the hits

  16. Kalman Filter application to track reconstruction State vector Initial estimation Update Equations timing uncertainty Kalman Gain Matrix Updated residual and chi-square contribution (rejection criterion for hit) Many (40-200) candidate tracks are estimated starting from different initial conditions The best candidate is chosen using the chi-square value and the number of hits each track has accumulated.

More Related