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Characterization and Monitoring of XENONnT Photosensors and Search for New Physics with the First XENONnT Science Data


Volta, Giovanni. Characterization and Monitoring of XENONnT Photosensors and Search for New Physics with the First XENONnT Science Data. 2023, University of Zurich, Faculty of Science.

Abstract

Contents
1 The quest for Dark Matter 1
1.1 Evidence of Dark Matter............................................................................................................... 1
1.1.1 Galactic and extragalactic scales................................................................................. 1
1.1.2 The cosmological scale............................................................. 3
1.1.3 Dark Matter in the Milky Way.......................................................................................... 4
1.2 The anthology of dark matter.................................................... 7
1.2.1 Dark matter properties....................................................... 8
1.2.2 Dark matter candidates................................................................................................... 8
1.3 Dark Matter detection experiments ........................................ 13
1.3.1 Direct detection of WIMP-nucleus scattering . . . .................................................... 14
1.3.2 State of the art in direct detection................................................................................. 17
2 Invisible nucleon decay 20
2.1 The baryon asymmetry of the Universe ..................................................................................20
2.2 State of the art of baryon number violation process................................................................... 22
2.2.1 Exclusive and inclusive searches .....................................................................................22
2.2.2 Xenon-based nucleon disappearance searches.......................................................... 23
3 The XENON project 26
3.1 Xenon as a detector medium......................................................................................................... 26
3.2 Dual-phase time projection chamber.......................................................................................... 31
3.3 The XENONnT experiment............................................................................................................ 34
3.3.1 The XENONnT TPC............................................................................................................ 35
3.3.2 The vetos and auxiliary systems of XENONnT.................................................................36
3.3.3 XENONnT challenges..................................................................................................... 37
3.3.4 Main physics goals of the XENONnT experiment .............. 41
4 XENONnT photosensors: from testing to assembly in the TPC 43
4.1 Design and operating principle of XENONnT PMT.......................................................................43
4.1.1 PMT operating principle ................................................................................................ 44
4.1.2 Design of R11410-21 PMT................................................................................................... 47
4.2 The XENONnT PMT testing campaign.............. 49
4.2.1 MarmotX facility................................................................................................................. 50
4.2.2 Testing campaign result .....................................................................................................50
4.2.3 Conclusion............................................................................................................................ 55
4.3 Installation of XENONnT PMTs........................................................................................................55
4.3.1 The XENONnT PMT cables.............................................................................................. 56
4.3.2 The XENONnT PMT connectors..................................................................................... 57
4.3.3 Cables and bases production, assembly and cleaning...................................................... 59
4.3.4 The PMT array assembly.....................................................................................................60
4.3.5 The XENONnT TPC installation ..................................................................................... 61
5 Characterization and performance optimization of XENONnT PMTs: from commissioning
TO SCIENCE DATA TAKING 66
5.1 The PMT calibration...................................................................................................................... 67
5.1.1 The PMT calibration system........................................................................................... 67
5.1.2 The PMT calibration processing..................................................................................... 68
5.1.3 The gain calculation..............................................................................................................70
5.1.4 The SPE acceptance calculation..................................................................................... 72
5.1.5 Important remarks .......................................................................................................... 73
5.2 PMT commissioning phase.......................................................................................................... 75
5.2.1 Outgassing and nitrogen phase..................................................................................... 75
5.2.2 Cooling and xenon filling phase..................................................................................... 76
5.2.3 Performances optimization for science run 0 ............................................................. 80
5.3 Performance of the PMTs during the first science run............................................................. 84
5.3.1 Time monitoring of PMT performances......................................................................... 84
5.3.2 SPE shape........................................................................................................................ 86
6 First science run of XENONnT 91
6.1 A brief summary of the first XENONnT science run ................................................................ 92
6.2 Data processing pipeline............................................................................................................ 93
6.2.1 Event building.................................................................................................................. 93
6.2.2 Event corrections................................................................................................................94
6.3 Data quality criteria.......................................................................................................................100
6.3.1 Cuts overview.................................................................................................................... 102
6.3.2 The S1 area fraction top cut .............................................................................................102
6.3.3 The S1 pattern likelihood cuts..........................................................................................106
6.3.4 Total selection efficiency...................................................................................................110
6.4 Energy calibration........................................................................................................................... 111
6.5 Optical Monte Carlo-data matching in XENONnT......................................................................... 113
6.5.1 XENONnT MC framework................................................................................................... 113
6.5.2 Optical simulation............................................................................................................... 114
6.5.3 Optical parameters............................................................................................................ 116
6.5.4 Data-MC matching procedure...........................................................................................117
6.6 Signal and background modeling...................................................................................................119
6.6.1 Low-energy ER and WIMP analysis techniques and the sought-after signals............120
6.6.2 Backgrounds sources........................................................................................................ 121
6.6.3 Review of radiogenic ER material background prediction..............................................122
6.7 Results.......................................................................................................................................... 124
6.7.1 Low-energy ER analysis results ......................................................................................125
6.7.2 WIMP search results ........................................................................................................125
6.8 Conclusions..................................................................................................................................128
7 Search for nucleon disappearance in 129Xe with the first XENONnT science data 131
7.1 Preliminary studies before the analysis...................................................................................... 131
7.1.1 Validation of full chain simulation...................................................................................132
7.1.2 The effective simulator: FastSimulator.......................................................................... 138
7.1.3 Updates on the radiogenic background from detector materials..................................142
7.2 Analysis of nucleon disappearance in XENONnT............... 143
7.2.1 Expected signals ............................................................................................................. 143
7.2.2 Data selection............................................................... 145
7.2.3 Total selection efficiency................................................................................................. 149
7.2.4 Background model .......................................................................................................... 153
7.2.5 Statistical framework....................................................................................................... 165
7.2.6 Results...............................................................................................................................167
l.in Conclusion . .. ............................................................ 177
8 Conclusion 179
Appendix A HI hypothesis fitting results 183

Abstract

Contents
1 The quest for Dark Matter 1
1.1 Evidence of Dark Matter............................................................................................................... 1
1.1.1 Galactic and extragalactic scales................................................................................. 1
1.1.2 The cosmological scale............................................................. 3
1.1.3 Dark Matter in the Milky Way.......................................................................................... 4
1.2 The anthology of dark matter.................................................... 7
1.2.1 Dark matter properties....................................................... 8
1.2.2 Dark matter candidates................................................................................................... 8
1.3 Dark Matter detection experiments ........................................ 13
1.3.1 Direct detection of WIMP-nucleus scattering . . . .................................................... 14
1.3.2 State of the art in direct detection................................................................................. 17
2 Invisible nucleon decay 20
2.1 The baryon asymmetry of the Universe ..................................................................................20
2.2 State of the art of baryon number violation process................................................................... 22
2.2.1 Exclusive and inclusive searches .....................................................................................22
2.2.2 Xenon-based nucleon disappearance searches.......................................................... 23
3 The XENON project 26
3.1 Xenon as a detector medium......................................................................................................... 26
3.2 Dual-phase time projection chamber.......................................................................................... 31
3.3 The XENONnT experiment............................................................................................................ 34
3.3.1 The XENONnT TPC............................................................................................................ 35
3.3.2 The vetos and auxiliary systems of XENONnT.................................................................36
3.3.3 XENONnT challenges..................................................................................................... 37
3.3.4 Main physics goals of the XENONnT experiment .............. 41
4 XENONnT photosensors: from testing to assembly in the TPC 43
4.1 Design and operating principle of XENONnT PMT.......................................................................43
4.1.1 PMT operating principle ................................................................................................ 44
4.1.2 Design of R11410-21 PMT................................................................................................... 47
4.2 The XENONnT PMT testing campaign.............. 49
4.2.1 MarmotX facility................................................................................................................. 50
4.2.2 Testing campaign result .....................................................................................................50
4.2.3 Conclusion............................................................................................................................ 55
4.3 Installation of XENONnT PMTs........................................................................................................55
4.3.1 The XENONnT PMT cables.............................................................................................. 56
4.3.2 The XENONnT PMT connectors..................................................................................... 57
4.3.3 Cables and bases production, assembly and cleaning...................................................... 59
4.3.4 The PMT array assembly.....................................................................................................60
4.3.5 The XENONnT TPC installation ..................................................................................... 61
5 Characterization and performance optimization of XENONnT PMTs: from commissioning
TO SCIENCE DATA TAKING 66
5.1 The PMT calibration...................................................................................................................... 67
5.1.1 The PMT calibration system........................................................................................... 67
5.1.2 The PMT calibration processing..................................................................................... 68
5.1.3 The gain calculation..............................................................................................................70
5.1.4 The SPE acceptance calculation..................................................................................... 72
5.1.5 Important remarks .......................................................................................................... 73
5.2 PMT commissioning phase.......................................................................................................... 75
5.2.1 Outgassing and nitrogen phase..................................................................................... 75
5.2.2 Cooling and xenon filling phase..................................................................................... 76
5.2.3 Performances optimization for science run 0 ............................................................. 80
5.3 Performance of the PMTs during the first science run............................................................. 84
5.3.1 Time monitoring of PMT performances......................................................................... 84
5.3.2 SPE shape........................................................................................................................ 86
6 First science run of XENONnT 91
6.1 A brief summary of the first XENONnT science run ................................................................ 92
6.2 Data processing pipeline............................................................................................................ 93
6.2.1 Event building.................................................................................................................. 93
6.2.2 Event corrections................................................................................................................94
6.3 Data quality criteria.......................................................................................................................100
6.3.1 Cuts overview.................................................................................................................... 102
6.3.2 The S1 area fraction top cut .............................................................................................102
6.3.3 The S1 pattern likelihood cuts..........................................................................................106
6.3.4 Total selection efficiency...................................................................................................110
6.4 Energy calibration........................................................................................................................... 111
6.5 Optical Monte Carlo-data matching in XENONnT......................................................................... 113
6.5.1 XENONnT MC framework................................................................................................... 113
6.5.2 Optical simulation............................................................................................................... 114
6.5.3 Optical parameters............................................................................................................ 116
6.5.4 Data-MC matching procedure...........................................................................................117
6.6 Signal and background modeling...................................................................................................119
6.6.1 Low-energy ER and WIMP analysis techniques and the sought-after signals............120
6.6.2 Backgrounds sources........................................................................................................ 121
6.6.3 Review of radiogenic ER material background prediction..............................................122
6.7 Results.......................................................................................................................................... 124
6.7.1 Low-energy ER analysis results ......................................................................................125
6.7.2 WIMP search results ........................................................................................................125
6.8 Conclusions..................................................................................................................................128
7 Search for nucleon disappearance in 129Xe with the first XENONnT science data 131
7.1 Preliminary studies before the analysis...................................................................................... 131
7.1.1 Validation of full chain simulation...................................................................................132
7.1.2 The effective simulator: FastSimulator.......................................................................... 138
7.1.3 Updates on the radiogenic background from detector materials..................................142
7.2 Analysis of nucleon disappearance in XENONnT............... 143
7.2.1 Expected signals ............................................................................................................. 143
7.2.2 Data selection............................................................... 145
7.2.3 Total selection efficiency................................................................................................. 149
7.2.4 Background model .......................................................................................................... 153
7.2.5 Statistical framework....................................................................................................... 165
7.2.6 Results...............................................................................................................................167
l.in Conclusion . .. ............................................................ 177
8 Conclusion 179
Appendix A HI hypothesis fitting results 183

Statistics

Additional indexing

Item Type:Dissertation (monographical)
Referees:Baudis L, Serra N, Galloway Michelle
Communities & Collections:07 Faculty of Science > Physics Institute
UZH Dissertations
Dewey Decimal Classification:530 Physics
Language:English
Date:2023
Deposited On:19 Jan 2024 14:06
Last Modified:19 Jan 2024 14:06
Number of Pages:209
OA Status:Closed
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