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Multi Pixel Photon Counters (MPPC) and Scintillating Fibers (Sci-Fi) as a trigger system for the

Multi Pixel Photon Counters (MPPC) and Scintillating Fibers (Sci-Fi) as a trigger system for the AMADEUS experiment. Alessandro Scordo (L.N.F.) (in behalf of AMADEUS experiment) 23° Indian-Summer School of Physics & 6° HADES Summer School 2011. Contents .

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Multi Pixel Photon Counters (MPPC) and Scintillating Fibers (Sci-Fi) as a trigger system for the

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  1. Multi Pixel Photon Counters (MPPC) and Scintillating Fibers (Sci-Fi) as a trigger system for the AMADEUS experiment Alessandro Scordo (L.N.F.) (in behalf of AMADEUS experiment) 23° Indian-Summer School of Physics & 6° HADES Summer School 2011

  2. Contents The AMADEUS experiment: a brief introduction Trigger system requirements MPPC working principle and status of art 10 channels prototype and MPPC characterization Results of tests on DAFNE New electronics and 64 channels prototype Tests on hadronic beam Conclusions

  3. The AMADEUS experiment: a brief introduction KLOE - The main aim of AMADEUS is to confirm or deny the existance of Kaonic Clusters, - EXTENDED PROGRAM: Low-energy interactions, cross sections in light nuclei, decay of resonance states and exotic channels in nuclear medium will be studied DAΦNE

  4. The AMADEUS experiment: a brief introduction DeeplyBoundKaonicNuclearStates First suggestedbyS.Wycech (1986) Y.Akaishi and T. Yamazaki (Phys. Rev. C65 (2002) 044005) “Nuclearboundstates in light nuclei” NormalNuclearbindingenergyparameters: Ebind~ 20 MeV G ~ 100 MeV DBKNS bindingenergyparameters: Ebind~ 100 MeV G ~ 30 MeV New kindofmatterwith astrophysicalimplications (Neutronstars, prof. Heuser talk) K- + 4He reaction (3-barionic state)

  5. The AMADEUS experiment: a brief introduction

  6. The AMADEUS experiment: a brief introduction Target: A gaseous He target for a first phase of study First 4p fully dedicated setup!

  7. The AMADEUS experiment: a brief introduction

  8. Trigger system requirements Smalldimensions Working in magneticfield Working at room temperature Verygoodtimeresolution (s ~ 300 ps) High efficiency Multi Pixel Photon Counters (MPPC)

  9. MPPC : working principle P-N junction array working in Geiger mode (micropixel) Output signal is the sum of all the micropixels Each micropixel gives a high gain signal (105 – 106) indipendent of the number of incident photons and has a fixed amplitude (binary mode)

  10. First prototype and MPPC characterization Is cooling needed ? A scintillating fiber is activated by a beta Sr90 source Both ends are coupled to detectors; one is used as trigger

  11. First prototype and MPPC characterization Studying rates with and without the beta source, it turned out that starting from the 4th p.e. peak, dark count contribute is negligible This means that non cooling is needed in this case!!!!

  12. Montecarlo simulations: what are we expecting? Momentum distribution of kaons is taken from Kloe Monte Carlo BCF-10 1mm diameter Kaons are expected to leave almost a factor 7 more energy than MIP electrons GEANT3 simulation

  13. Results of tests on DAФNE 22-24 January 2009

  14. Results of tests on DAФNE

  15. Results of tests on DAФNE • KM scintillator at 6 cm from Interaction Point • Fibers 5 cm below the lowest scintillator • RF/2 and KM coincidence as DAQ trigger • Pure KM signal also collected MIPs coming from the I.P. are below the KM threshold

  16. Results of tests on DAФNE Kaon Monitor TDC (upper/lower coincidence) Single peak resolution Is ~ 100 ps MIP/K separation ~ 1 ns K- MIPs MPPC tdc spectra Single peak resolution Is ~ 300 ps Missing MIPs

  17. New electronics and 64 channels prototype 32 Sci-Fi read at both sides 2 indipendent double layers with adjustable angle Amplification of a factor 10 64 Constant Fraction Discr. Logic OR of all detectors

  18. Tests on hadronic beam p,m,e-,p beam (similarto DAFNE situation) pM-1 beam at Paul Scherrer Institute (PSI, Zurich) Single particle conditon (to be further checked) Double anular setup 1 3 2 4 DAQ trigger: Sc1&Sc2 Scintillator 1 Scintillator3&2

  19. Tests on hadronic beam Common cuts for the whole analysis Protons Cut fot T > 31.0 C MIPs

  20. Tests on hadronic beam Left Right Perfect correlation and coupling Sc1 is used as reference

  21. Tests on hadronicbeam: efficiency 73% Fiber 5: eff = 99 % 92% 90% 70% Fiber 6 : eff = 98,4 % Double layer efficiency Single layer efficiency

  22. Tests on hadronic beam Beamprofile Geometrical correlation

  23. Tests on hadronic beam: cross talk Fired fibers of layer 4 if fiber i of layer 4 is fired 4,6% 2% 2,4% 5,2% 6,5% 2% 1% 0,06%

  24. Conclusions… Small dimensions Working in magnetic field Working at room temperature Very good time resolution (s ~ 300 ps) High efficiency … …and future plans Temperature feedback circuitimplementation New efficiencymeasurementswithscintillators New tests in DAFNE New ideas and applicationsforthisnicesetup

  25. Spare slides

  26. MPPC : working principle Thermally generated electrons can activate the avalanche process in some pixel, with a high rate of 105-106 Hz (dark current) The main contribute is a peak corresponding to 1 pixel (photoeletron)‏ Luminescence of carriers can also be absorbed by another pixel giving a noise signal

  27. First prototype and MPPC characterization Pre-Amplifiers (X 100)‏ 5 Channles HV power supply (stability better than 10 mV)‏ Scintillating fibers Bicron BCF-10 (blue)‏ SiPM (HAMAMATSU U50) (400 pixels)‏ Operating voltage ~70V • Sr90 beta source (37 MBq)‏

  28. First prototype and MPPC characterization Threshold at 5 p.e. Peak with most counts: 5 p.e. (15%) Black spectra are the trigger-used MPPC Red spectra are the signal outputs of the NON trigger MPPC

  29. New electronics and 64 channels prototype s ~ 80 ps s ~ 40 ps MPPC + Sci-Fi Direct laser on MPPC

  30. New electronics and 64 channels prototype RF/n Laser MPPC HV HV Fiber Preamp RF Coincidence TDC RF=90 MHz (≈ RF/4) n ≈ 10000 s ~ 200 ps No jitter from photon generation (to be considered)

  31. Tests on hadronic beam: “relative” efficiency Fiber 5: eff = 27,3 % In the case of non parallel double layers the geometrical efficiency is drastically reduced Fiber 6: eff = 30,1 %

  32. Tests on hadronic beam: “relative” efficiency Fiber 5: eff = 27,3 % In the case of non parallel double layers the geometrical efficiency is drastically reduced Fiber 6: eff = 30,1 %

  33. Tests on hadronic beam: “relative” efficiency Proton events = 6580 Proton on fibers = 1772 Nhits on fibers > 5 = 29 (1,6%) Single particle configuration !

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