1 / 33

TITLE

TITLE. Precise measurement of air fluo yield. How? Control everything. b) Work with Gwenaelle. The bench. The cross. Electron beam. 90 Sr spectrum. Electron ADC (1 st threshold). Electron ADC (2 nd threshold). “Integral” PMT. The spectrometer. Entrance slit alignment.

overton
Download Presentation

TITLE

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. TITLE Precise measurement of air fluo yield How? Control everything b) Work with Gwenaelle 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  2. The bench 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  3. 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  4. The cross 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  5. Electron beam 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  6. 90Sr spectrum 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  7. Electron ADC (1st threshold) 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  8. Electron ADC (2nd threshold) 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  9. “Integral” PMT 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  10. The spectrometer 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  11. Entrance slit alignment 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  12. Why a spectrometer? Filter properties vary with incident angle Here, we respect the Numerical Aperture 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  13. PMT window ===> Silica 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  14. Gas ∆P/P ~ 0.1% Very clean No argon Flow = 1 l/h 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  15. Daq 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  16. Photon spectrum (single pe) 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  17. TDC spectrum Atmospheric pressure 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  18. Discriminators dead-time 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  19. dE/dx 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  20. Analysis Fluo yield ε = Nphotons / Lelectrons How many Photoelectrons ? How many Photons ? Electrons travel? 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  21. dE/dx 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  22. How many Photoelectrons ? a) Région C : N(S+B) b) NB on the same interval c) NS = N(S+B) - NB d) Ns / Nhisto = Npe / Ncoïnc 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  23. Discriminator cut PMT-2020 : + 3.76 % PMT-JY : + 3.85 % Pressure and temperature Measured inside and outside the chamber. Values sent to a slow 2048 channels ADC Around 760 mm Hg and 22°, channels # around 1000 Variations in a run: typically 1 channel 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  24. Analysis • P: number of counts in TDC peak • T: integral of TDC spectrum • C: number of coinc (scaler) • D: discri cut • Ne: :Electrons that reached the scintillator (scaler) • TM: dead time of scaler • Lmoy :travel of electrons = 46.11 ± 0.2 mm • ePMT :absolute efficiency of PMT = 0.178 ± 0.004 • Tquartz: transmission of silica window = 0.992 ± 0.003 • Egeo: geometrical efficiency (3.689 ± 0.02)10-4 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  25. Results With our temp and pressure: 3.86 ± 0.09 ph / m for Ee = 1.19 MeV P = 753.8 mm Hg, T = 295.95 K 3.87 ± 0.09 ph / m for Ee = 1.54 MeV P= 751.8 mm Hg, T = 296.05 K to normalize to 0.85 MeV, we use dE/dx 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  26. Theoretical normalization b) To normalize to US standard P and T 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  27. Bianca 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  28. Normalized results [300-430 nm] Our results, normalized to 0.85 MeV, and US standard conditions 3.945 ± 0.120 photons / meter 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  29. Nitrogen to air ratio 4.90 ± 0.01 OK with Nagano (thanks to his error bars) Excludes Davidson & O’Neil 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  30. Spectrometer resolution With a He-Ne laser 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  31. Spectrometer calibration Not better than 20% 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  32. The lines Ulrich Our work with 6 nm FWHM Intensity (arb. units) Intensity (arb. units) 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

  33. Conclusion (preliminary) If HiRes took Kakimoto 1.4 MeV ==> their showers are now~ 20% lower in energy than published It does not go along Bahcall and Waxman explanation J.N. Bahcall and E. Waxman (hep-ph/0206217 v5 27 Feb 2003) 4th air fluo workshop Prague, 17-20 / 05 2006 P. Gorodetzky APC - Collège de France Paris

More Related