1. Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Bianca KeilhauerTokyo, February 26th, 2004 Summary and Issues of Workshop, Bad Liebenzell, Dec. 2003

2. 4 interesting days in December 2003 39 participants 25 presentations 10 projects ⇒ improvements in understanding the aspects of molecular physics and in experimental measurements http://www.auger.de/events/air-light-03/ Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Bianca KeilhauerTokyo, February 26th, 2004

3. Bianca KeilhauerTokyo, February 26th, 2004 Fluorescence Light - starting theory - A. N. Bunner: Cosmic Ray Detection by Atmospheric Fluorescence, PhD thesis 1967 Franck-Condon-Principle for absorption and fluorescence

4. Fluorescence from Nitrogen N２＋N２＋ Data from Bunner (1964) : weighted averages of three experiments with an accuracy of not better than ±30%. Kakimoto et al (1996) : 1.4MeV-1000MeV are mainly used in UHECR experiments. 1st Negative band 2nd Positive band N2N2 M. Nagano

5. Energy Spectrum M. Risse

6. Bianca KeilhauerTokyo, February 26th, 2004 conventional approach: R. Engel E. Marques Idea The „classic“ method of determination of N e (X) is subject to a purely geometrical correction due to the lateral spread of shower particles. Discussion on Fluorescence Yield of an EAS

7. ionization energy approach: R. Engel Bianca KeilhauerTokyo, February 26th, 2004 E. Marques Discussion on Fluorescence Yield of an EAS

8. Ionization energy deposit: problems Assumption - No clear experimental evidence - Precision of energy reconstruction will depend on fluorescence yield data Angular spread and definition of track length dX - Track length along shower axis - Actual track length of particles Energy loss in fluorescence yield experiments - Low energy ( E ≪ E c ): ionization loss - High energy: ionization and radiative losses (small cascades) - Detailed simulation of ionization energy deposit needed Calorimetric energy E cal not equal to total shower energy R. Engel

9. Air light 03 Dependencies Processdependenceparameters Deposed Energy By Ionisation Incident particle Air density E, nature P,T QuenchingQuencher density N 2 or N 2 + T, P O 2, P H 2 O,(λ) Process Decay Time dependenceparameters Fluorescence τFτF Band width λ Internal Quenching τ IQ Temperature T, (λ) Collision Quenching τCτC Molecular speed Air density P, T Measured dependencies today : only E, P and λ Macfly project : P O 2, P H 2 O, (T, nature) Excitation Desexcitation P. Colin

10. Excitation processes The C 3  u electronic state is a forbidden state; it cannot be directly excited by fast charged particles. E lim (C 3  u ) = 11.03 eV P.I. = 15.6 eV W ~ 36 eV M. Fraga H. Brunet, PhD thesis, UPS,Toulouse,1973 Brunet PhD: http://www.auger.de/events/air-light-03/#phd_brunet

11. Fluorescence Light  EAS excites N 2 molecules in air  18 transitions in 2P system between 300 and 400 nm  1 transition in 1N system between 300 and 400 nm  Calculation follows the principle way suggested by A. Bunner, 1967 ⇒ quantum efficiency of fluorescence = with and B. Keilhauer

12. Fluorescence Efficiency with p/p‘ ν for air (79% N 2 and 21% O 2 ): B. Keilhauer

13. sum in the region 300 – 400 nm 337,1 nm ≙ ① 357,7 nm ≙ ② 391,4 nm ≙ ③ fluorescence efficiency (photons/MeV) height (km) @ 0 km: ① + ② + ③ = 65,7% @ 20 km: ① + ② + ③ = 63,2% 31,8% 25,3% 8,6% 29,2% 23,3% 10,7% Fluorescence Efficiency Profiles B. Keilhauer

14. Electron impact cross sections for N 2 and O 2 Pitchford and Phelps, MagBoltz Qd rot vib ion exc-S exc-T el. att vib ion Dashed curves - excitations Magboltz -CERN M. Fraga

15. Bianca KeilhauerTokyo, February 26th, 2004 E kin (MeV)< 0.10.1 - 11 -1010 - 100100 -1000> 1000 Contr. (%)10122335173 source e - - gune - from 90 Srbeam from accelerator experiment Arqueros, Madrid, < 30 keV Ulrich, Munich, 12 keV Nagano, Fukui Univ. Waldenmaier, AirLight Gorodetzky, Paris Colin, MacFly 1. phase Fraga, LIP-Lisboa Kemp, Campinas 1. phase 2. phase: medical acc. 5-12 MeV Privitera, AIRFLY, e ± - beam at BTF, 50-750 MeV Colin, MacFly 2. ph., e ± / μ- beam at CERN 25-100 GeV Reil, Flash, e - - beam at SLAC 28 GeV Kemp, 2. ph., e - -beam at LNLS 1.37 GeV

16. Photon yields vs Bethe-Bloch Nagano et al. Astroparticle Phys. (2003) FY seems to be proportional to dE/dx for E > 0.8 MeV. FY seems to be proportional to dE/dx for E > 0.8 MeV. dE/dx grows fast at low energies. Does this relationship hold at very low energy? dE/dx grows fast at low energies. Does this relationship hold at very low energy? F. Arqueros

17. Preliminary set-up: the collision chamber Nd:YAG collision chamber gas inlet Faraday cup or scintillator PMT UV filter photodiode/trigger Digital Scope HV (0  – 30 kV ) vacuum pump  Differential pumping (up to 100 mtorr)  1 PMT ORIEL 77348 (single counting) + UV filter  Digital scope (1 ns) F. Blanco and M. Ortiz vacuum pump Electron beam features  Energy up to 30 KeV.  Pulse Rate = 1 – 20 Hz  Time width = 20 ns (limited by the laser / plasma).  Intensity up to 200 mA peak.  Beam diameter  2 mm. Some stability problems !! F. Arqueros

18. Bianca KeilhauerTokyo, February 26th, 2004 High-precision Measurements of Experts for „Particle beam induced light emission“ A. Ulrich Energy deposition in the gas (1 bar Ar) Modelled using the „Casino“ Program P. Drouin, A.R. Couture, R. Gauvin, P. Hovington, P. Horny, H. Demers, Univ. de Sherbrooke, Quebec, Canada (2002) Parameters for low energy electron beam excitation: Particle energy:typically 15 keV Foil:300 nm silicon nitride Gas:typically 0.1 to 2 bar Beam currentcw typ. 10 μA av. (0.15 W) or pulsed

19. Usage of the membranes: (principle)Diagnostics and gas system: Time resolved optical spectroscopy Grating monochromators (f=30cm, 0.03 nm resolution 1.order) Wavelength range ~30 nm to 700 nm Time resolution ~10ns beam pulses, ~1ns electronic res. Detectors VUV-PMT,VUV MCP and diode array Sensitivity measurements: two WI-17G Lamps (OSRAM) and D 2 arc-lamps (Cathodeon) Gas pressure 0 to ~ 2 bar (foil: 10 bar) Gas mixing system with hot-metal gas purifiers (rare gases) Capacitive manometers (MKS Baratron) A. Ulrich

20. III. Preliminary results from air Spectra: Overview, 1 bar, ~12 keV electron beam excitation Preliminary result. Needs to checked! Assignment: High resolution spectrum: A. Ulrich

21. Bianca KeilhauerTokyo, February 26th, 2004 E kin (MeV)< 0.10.1 - 11 -1010 - 100100 -1000> 1000 Contr. (%)10122335173 source e - - gune - from 90 Srbeam from accelerator experiment Arqueros, Madrid, < 30 keV Ulrich, Munich, 12 keV Nagano, Fukui Univ. Waldenmaier, AirLight Gorodetzky, Paris Colin, MacFly 1. phase Fraga, LIP-Lisboa Kemp, Campinas 1. phase 2. phase: medical acc. 5-12 MeV Privitera, AIRFLY, e ± - beam at BTF, 50-750 MeV Colin, MacFly 2. ph., e ± / μ- beam at CERN 25-100 GeV Reil, Flash, e - - beam at SLAC 28 GeV Kemp, 2. ph., e - -beam at LNLS 1.37 GeV

22. Electron beam Electron beam 90 Sr （ 28.8y ） β 90 Y （ 64.1h ） 90 Zr β 2.28MeV 3.3MBq average 0.85MeV 99.98% 0.02% 1.75MeV M. Nagano

23. A and B of various bands M. Nagano ⇒ For details: N. Sakaki --- right after this presentation

24. AirLight Experiment Goals precise measurement of the... → pressure dependence → temperature dependence → effect of water vapor → effect of oxygen and argon Filters [nm]: 317, 340, 360, 380, 394, 430, M-UG6 T. Waldenmaier

25. S. Klepser Interference Filters Theory → CWL of filters should be 1-2 nm above the observed wavelength. Effective Transmission Curves → „Effective Transmission Curve“ for every Filter can be averaged. Rel. Error using 0°-Transmission > 20 % Rel. Error using eff. Transmission < 7 %

26. Probes (T, P) Gaz injection “integral” PMT (PMT #2) Plastic scintillator Focusing lensSpectrometer Source : 90 Sr Fluorescence zone Scintillator PMT (PMT #1) Spectrometer PMT (PMT #3) Source holder Bench Diagram PMT #1 below measures the 90Sr spectrum generates gates PMT #2 integral EUSO configuration [300- 400 nm] wavelength PMT #3 in spectrometer 1nm bandwidth G. Lefeuvre

27. Air light 03 Macfly specificities Key point: Real electromagnetic shower study Shower = Σ component electrons ?? Study of new dependencies : Composition and contaminant (Macfly 1) Mainly : O 2 Percentage and Humidity Shower Age (Macfly 2) Event by event measurement: Low electron density like in air shower. P. Colin

28. Results : primary scintillation of N 2 P = 10 5 Pa; T = 296 K;  = 9 nm 2 nd pos. system H. Brunet, PhD thesis, UPS, Toulouse, 1973;  (2.8 MeV) M. Fraga

29. Quenching by water vapor: 0-0 band intensity decreases with increasing concentration of water vapor. Atmospheric pressure was assumed. M. Fraga Plans for the future Measurement of band intensities of the 2nd positive system as a function of pressure and temperature; Study of the role of water vapor on the light yields and on the emission spectra. Participation in the tests at CERN in the SPS beam facility - proposal submitted by the Annecy group (Ref:MacFly-MEMO-01 of 11/24/2003)

30. Chamber Configurations Radioactive Source Particle Beam e-e- E. Kemp

31. Relative Efficiency Gas Filling: Dry Air → N 2 Y i = N E / N P N E : coincidence excesses N P : particle detector counting i : gas type Y air Y N2 Y N2 / Y air = 5.1± 0.3 Kakimoto et al., NIM 372A, 527 (1996) ~ 5.6 E. Kemp

32. Bianca KeilhauerTokyo, February 26th, 2004 E kin (MeV)< 0.10.1 - 11 -1010 - 100100 -1000> 1000 Contr. (%)10122335173 source e - - gune - from 90 Srbeam from accelerator experiment Arqueros, Madrid, < 30 keV Ulrich, Munich, 12 keV Nagano, Fukui Univ. Waldenmaier, AirLight Gorodetzky, Paris Colin, MacFly 1. phase Fraga, LIP-Lisboa Kemp, Campinas 1. phase 2. phase: medical acc. 5-12 MeV Privitera, AIRFLY, e ± - beam at BTF, 50-750 MeV Colin, MacFly 2. ph., e ± / μ- beam at CERN 25-100 GeV Reil, Flash, e - - beam at SLAC 28 GeV Kemp, 2. ph., e - -beam at LNLS 1.37 GeV

33. Beam monitoring with the calorimeter Calorimeter counts single electrons 1 e- 2 e- 3 e- 4 e- pedest. The calorimeter is used for absolute and relative beam intensity measurement (<1000 e-/bunch) ADC counts Time*24 (s) P. Privitera

34. Energy dependence of fluorescence yield Limited by multiple scattering on 1.5 mm thick exit Al window. The scan went down to 50 MeV. Preliminary N p.e. (fluor.) ADC cal x E/442 UG6 filter The scan was performed several times with consistent results. Positrons (493 MeV) gave same yield within 3% P. Privitera

35. Air light 03 CERN Beam simulation CERN-SPS-X5 : 50 GeV electron beam Macfly1 Macfly2 100 e - of 50 GeV Only 1 e - of 50 GeV Electrons Positrons P. Colin

36. ⇒ For details: J.N. Matthews --- right after the coffee break K. Reil

37. Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft Bianca KeilhauerTokyo, February 26th, 2004 Exchange of already existing theoretical knowledge Exchange of practical solutions for experiment „everyday life“ Fruitful discussion, even during night in the cellar Setup of an exchange platform on internet currently under construction http://www.auger.de/events/air-light-03/