Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 1 T. Waldenmaier, J. Blümer, E. Bollmann, H. Klages, M. Kleifges, S. Klepser Measurement of the Fluorescence Efficiency in Air with the AirLight-Experiment

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 2 Motivation Energy Reconstruction of EAS Longitudinal Profile of released Energy (CORSIKA) This work ! Observed photons at shower axis Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook Pierre Auger Project  Klages (Sunday, July 11)

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 3 Air Fluorescence Excitation Process Fluorescence emission in air between 300 and 400 nm comes almost entirely from transitions of exited N 2 and N 2 + molecules! 1N (1th negative) System: 2P (2th positive) System: Auger Transitions of the N 2 + 1N-System Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 4 De-excitation can occur through: - Optical transition (  fluorescence) - Collisional energy transfer to other electrons or molecules (  Quenching) Relaxation Rate of excited states:  Effective lifetime: Kinetic gas theory  Increasing of mean collission time with increasing temperature and pressure Air Fluorescence De-Excitation Process Intrinsic lifetime Mean collision time Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 5 Which parameters are important for the emission of fluorescence light through an EAS? Excitation: Cross sections depend on: - Particle Type (98 % electrons and positrons) - Particle Energy (100 keV to 1 GeV) De-Excitation: Quenching depends on: - Pressure(10 hPa to 1000 hPa) - Temperature(-60 °C to 20 °C) - Air Composition(N 2, O 2, Ar, water vapor) Air Fluorescence Parameter Space Releaseable energy per energy and depth in an EAS (M. Risse et al.) Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 6 Experimental Setup AirLight Chamber Design - 90 Sr-Source: 37 MBq, E max = 2.3 MeV - 1 PMT with M-UG6 filter [320,400] nm - 6 PMTs with narrow filters (FWHM ~ 10 CWL 317, 340, 360, 380, 394, 430 nm Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 7 Experimental Setup Timing Coincidence Unit Free RateCoincident Rate Electron Rate Data Sampling Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook Coincidence measurement between the scintillator triggers and any signal of the PMTs:

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 8 Experimental Setup Data Aquisition Time development of: - Free Rates - Coincident Rates - Electron Triggers - Temperatures - Pressure Data Sampling of: - Free Electron Energy Spectrum - Coincident Electron Energy Spectrum - Single Photo-Electron Spectra - Time Spectra Data Aquisition with LabView: Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook ADC, TDC Scalers

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 9 22 Na Compton Spectrum:  Fit with gauss-convoluted cross-sections for Compton Scattering  ADC to energy conversion:  Energy 1 MeV Experimental Setup Energy Calibration Compton Edge, 511 keV Gammas Compton Edge, 1.2 MeV Gammas excluded from fit Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 10 Experimental Setup Time Calibration Generation of discrete time spectrum:  TDC to Time conversion:  T = 80 ns Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 11 Preliminary Results Data Analysis Free Energy Spectrum Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 12 Preliminary Results Electron Energies  lineary decreasing Count Rate with pressure due to increasing Multiple Scattering effects.  Low energetic Electrons are affected more of the Multiple Scattering.  Fraction of low energetic electrons is increasing with decreasing pressure Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 13 Preliminary Results N 2 * Lifetimes 1/  0 Fit of the time spectra with gauss convoluted exponential function:  Signal over noise  Effective lifetime at different pressures  Intrinsic lifetime through extrapolation to zero pressure. Nitrogen 100 hPa Nitrogen 1000 hPa Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 14 Calculation of the Signal Rates for every cycle with the scaler informations: N C : # coincidences N B C : # coincident background N F : # free PMT events N E : # electron triggers T: Aquisition time  T: coincidence Intervall (120 ns) Preliminary Results Signal Rates NSNS NBCNBC NCNC NFNF Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 15 Preliminary Results Fluorescence Efficiency  Increasing Number of excited nitrogen molecules for higher pressure.  Increasing number of molecular collisions (Quenching) for higher pressure.  Increasing (but flattening) Fluorescence Efficiency for higher pressure. Fit with Bethe-Bloch-Formula  As expected the Fluorescence Efficiency seems to be proportional to ionization energy loss in the gas. Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook

Forschungszentrum Karlsruhe Erice, 7th July th International School for Cosmic Rays Astrophysics Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook 16 Outlook Achievements up to now:  Build-up of the experiment completed  DAQ is working  First relative measurements for nitrogen were performed  Analysis up to PMT-Cathode is working. Next steps:  Comparison between measurement and Geant4 simulations  Further analysis development and improvement  Relative measurements for different gases (air) at different pressures  Absolute calibration  Absolute analysis Motivation Energy Reconstruction Air Fluorescence Excitation Process De-Excitation Process Parameter Space Experimental Setup Chamber Design Timing Data Aquisition Energy Calibration Time Calibration Preliminary Results Data Analysis Electron Energies N 2 * Lifetimes Signal Rates Fluorescence Efficiency Outlook