1. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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

2. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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)

3. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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

4. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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

5. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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

6. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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 nm) @ 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

7. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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:

8. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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

9. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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 resolution: @ 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

10. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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

11. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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

12. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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

13. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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

14. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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

15. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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

16. Forschungszentrum Karlsruhe Erice, 7th July 2004 14th 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