王名儒臺灣大學：物理研究所洪桂苓Hung, Kuei-LingKuei-LingHung2007-11-262018-06-282007-11-262018-06-282006http://ntur.lib.ntu.edu.tw//handle/246246/54564Abstract NuTel is an experiment to observe the ultra-high energy cosmic tau neutrinos with the earth skimming technique. Mountains are used as targets to convert tau neutrinos to tau leptons and also as a filter to block cosmic ray backgrounds. The signature of a high energy tau is an air shower that originates from the mountains or the ground. NuTel is designed to observed the Cherenkov in such air showers. The optical and electronic systems of NuTel have been designed and are being built and tested. A simulation program to describe both the optics and the electronics is developed. Based on the simulated photo-image, the energy and inicident angle of the shower can be determined by a reconstruction program, which also handles background filtering and desaturation. It is found that the simple and rough filter produces the largest error due to loss of accuracy in position and amplitudes.Contents 1 Introduction 5 1.1 Ultra-High Energy Cosmic Neutrino . . . . . . . . . . . . . . . . . . . . . . . 5 1.2 Earth-Skimming Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3 Organization of the Thesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2 The NuTel Telescope Apparatus 9 2.1 The Optical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.2 Multi-Anode Photomultiplier Tube (MAPMT) . . . . . . . . . . . . . . . . . 10 2.3 Charge Sharing Board (CSB) . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.4 Preamplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.5 Data Collection Module (DCM) . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.6 Night Sky Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3 Simulation 17 3.1 CORSIKA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.2 The Optical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.2.1 Focusing Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.2.2 Light Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.3 Multi-Anode Photomultiplier Tubes (MAPMTs) . . . . . . . . . . . . . . . . 23 3.3.1 Transform Photon to Photoelectron . . . . . . . . . . . . . . . . . . . 24 3.3.2 Transform Photoelectrons to Charges . . . . . . . . . . . . . . . . . . 24 3.4 Charge Sharing Board (CSB) . . . . . . . . . . . . . . . . . . . . . . . . . . 24 3.5 Preamplifer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.6 Data Collection Module (DCM) . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.7 Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.8 Background Mixer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3 4 CONTENTS 3.9 Simulation Result . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 4 Reconstruction 31 4.1 Detector Reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 4.1.1 Desaturate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4.1.2 Filter Out Noise and Background . . . . . . . . . . . . . . . . . . . . 33 4.1.3 DCM Reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4.1.4 Direction Reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . 40 4.1.5 Result of Telescope Reconstruction . . . . . . . . . . . . . . . . . . . 41 4.2 Shower Reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 4.2.1 Shower Maximum Position . . . . . . . . . . . . . . . . . . . . . . . . 50 4.2.2 Shower Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 4.3 Total Reconstruction Result . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.4 Conclustion of Reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . 62 A Parameters in calib.db 63 B Classes 65 B.1 Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 B.2 Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 671123289 bytesapplication/pdfen-US微中子NuTelneutrinothesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/54564/1/ntu-95-R93222003-1.pdf