Setup of a Drift Tube Muon Tracker and Calibration of Muon ...

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N [a.u]Residuals20001800h0Entries 34970Mean 0.00539RMS 0.270216001400120010008006004002000-2 -1.5 -1 -0.5 0 0.5 1 1.5 2δ [mm]Figure 3.18: Distribution of residuals δ. The RMS gives a measure of the spatialresolution.N [a.u.]∆ α (x)600500400300σ α = 0.006977h_alpha_shift1Entries 1847Mean 0.0007823RMS 0.01144const 10.97 ±0.26σ 0.005765 ±0.000240lg 0.002523 ±0.000336∆ α0.0006121±0.00016702001000-0.3 -0.2 -0.1 0 0.1 0.2 0.3∆αFigure 3.19: Determination of the angular resolution of the CMT. The plot shows thedistribution of differences of the Hesse parameter α from a separate reconstruction oftwo parallel modules. A clear peak around 0 can be seen. The width of the distributiongives a measure of the angular resolution and has been determined by a fit to a Voigtian.50
Chapter 4The Borexino ExperimentThe Borexino Experiment was designed for the real time spectroscopic detection ofsolar neutrinos. Its main goal is the measurement of 7 Be neutrino flux, but also8 B, pep and CNO solar neutrinos belong to the scientific program. Apart fromsolar neutrinos, also geo-neutrinos have been observed recently. The detector islocated underneath approximately 1400 m of rock overburden (≈ 3800 m.w.e. 1 ) inthe LNGS underground laboratory in Italy. The detection of neutrinos is done usingliquid scintillator and the experiment is surrounded by ultra pure water acting as aČerenkov muon veto. Detecting low energetic neutrinos at low rates requires a highradio purity of all materials involved—especially the scintillator—which has beenachieved for Borexino. This chapter gives an overview of the detection methods ofneutrinos in liquid scintillators, especially in Borexino. A description of the detectordesign is then given. It is followed by a discussion of background sources. Specialcare is given to the cosmogenic background in the scintillator and how it can beaccounted for. In the last section of this chapter the results so far obtained byBorexino are presented.4.1 Neutrino Detection in BorexinoBorexino uses liquid scintillator for the detection of low energetic neutrinos. Thescintillator acts as both target and detection material. Neutrinos react with thescintillator through different processes. Neutrinos—electron type neutrinos ν e inparticular—can be detected through elastic scattering whereas anti-electron-neutrinoscan be detected via the inverse β decay. During both processes, energy is depositedin the scintillator which can be detected by the scintillation light. Both processesare described in detail below.4.1.1 Elastic Scattering in Liquid ScintillatorThe elastic scattering of neutrinos on electrons in the scintillator is the dominantprocess for the detection of solar neutrinos. The scattering process1 m.w.e. meter water equivalentν e + e − → ν e + e − (4.1)51
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Setup of a Drift Tube Muon Trackera
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AbstractIn this work the setup and
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3.5.5 Pattern Recognition . . . . .
Page 8 and 9: viii
Page 10 and 11: essential for vetoing these events.
Page 13 and 14: Chapter 2NeutrinosThe standard mode
Page 15 and 16: However, it did not yet deliver an
Page 17 and 18: Table 2.1: Neutrino oscillation par
Page 19 and 20: this assumption, the Standard Solar
Page 21 and 22: Figure 2.1: Neutrino flux at Earth
Page 23 and 24: asymmetry between neutrino and anti
Page 25 and 26: Figure 2.3: Expected ¯ν e energy
Page 27: Nb neutrino/fission-11010-2Neutrino
Page 30 and 31: 108−dE/dx (MeV g −1 cm 2 )65432
Page 32 and 33: Figure 3.3: Setup of the muon track
Page 34 and 35: zyxModule b.0Module a.0Module b.1Mo
Page 36 and 37: Figure 3.6: Display of the slow con
Page 38 and 39: plastic scintillators. To avoid all
Page 40 and 41: N hitsHitmap Plane 06000h_hitmap0En
Page 42 and 43: Table 3.4: Data structure for calib
Page 44 and 45: TDC SpectrumN/[2 Channels]1000800H_
Page 46 and 47: Table 3.5: List of variables calcul
Page 48 and 49: with ∆⃗q = ⃗q n − ⃗q n−
Page 50 and 51: N [a.u.]∆ α (x)2200020000da0Entr
Page 52 and 53: d[mm]Reco Drift Distances201816H_RE
Page 54 and 55: N [a.u.]Real DataReal data0.06MCh1E
Page 56 and 57: χ 2N [a.u.]Probability103×10hc2p0
Page 60 and 61: Counts/(10 keV × day × 100 tons)1
Page 62 and 63: 4.1.3 Čerenkov LightČerenkov dete
Page 64 and 65: 4.2 The Borexino DetectorThe Borexi
Page 66 and 67: muons, is reduced by going deep und
Page 68 and 69: (typically below 50 cm), the locati
Page 70 and 71: 510Counts/(10 keV x day x 100 tons)
Page 72 and 73: counts/days*4 hitsDay (Red) and Nig
Page 74 and 75: eeSurvival probability for ν e, P0
Page 76 and 77: the CMT to the Borexino tracking, t
Page 78 and 79: P C P DSCINT C SCINT DySCINT BSCINT
Page 80 and 81: Figure 5.2: The CMT setup on top of
Page 82 and 83: Angular AcceptanceAngular Acceptanc
Page 84 and 85: Comparison nhits=3 vs nhits=4N [a.u
Page 86 and 87: Table 5.3: Overview of all muon run
Page 88 and 89: N/dayAll Triggers vs Time12000h_tim
Page 90 and 91: Reco Hits in Scintillatory [mm]1000
Page 92 and 93: PMTPMTScintillatorPMTPMTFigure 5.16
Page 94 and 95: the CMT data file and the Borexino
Page 96 and 97: Zenith Angle CMT and BX-GL Tracks h
Page 98 and 99: Lateral x Resolution CMT - IDhlatx_
Page 100 and 101: Distance d between CMT and BX-GL Tr
Page 102 and 103: Angular difference αN [arbitrary u
Page 104 and 105: [m]z bxTrack Position in BX x=0 Pla
Page 106 and 107: N [arbitrary units]∆y all data200
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To determine the Borexino tracking
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Table A.1: Variables that can be se
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espectively. The channel numbers ar
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xyϕϕ ′βx ′µFigure C.2: Rela
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the z-coordinate z op,0 of the firs
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xyEvent: 470, Entry: 470, Time Tue
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[14] Ch. Kraus et al. Final Results
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[49] T. Araki et al. Experimental i
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Jan Lenkeit und Björn Wonsak sowie
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