Development of Technique to Use Lattice Defects in CCDs to Search for Dark Matter

List of Figures viii List of Tables xvi List of Abbreviations xviii 1 Introduction 1 1.1 The Universe and Dark Matter.................................................................. 1 1.1.1 Evidence of dark matter........................................................................ 2 1.1.1.1 Not enough visible matter........................................................ 4 1.1.1.2 Gravitational lensing ............................................................... 5 1.2 Direct detection of DM................................................................................. 6 1.2.1 Direct detection signals........................................................................ 9 2 Solid state devices 11 2.1 Solid state physics........................................................................................... 11 2.1.1 Quantum potential well........................................................................ 13 2.1.2 Semiconductor........................................................................................ 16 2.1.3 The P-N junction ................................................................................. 17 2.1.4 Diodes....................................................................................................... 19 2.1.5 Transistor................................................................................................. 20 2.2 CCDs.................................................................................................................... 21 2.2.1 Capacitative-coupled section: Gates and pixel.................................... 22 2.2.2 Transporting channel ............................................................................ 25 2.2.3 Readout component............................................................................... 26 3 Radiation damage 29 3.1 Damage mechanism incrystals.................................................................... 30 3.1.1 After collision with an lattice atom...................................................... 32 3.1.2 Defect production.................................................................................. 34 3.2 Effects of damage........................................................................................... 36 3.3 Defect identification andmitigation............................................................ 38 3.3.1 Thermal Stimulation Current (TSC) Analysis................................... 38 3.3.2 Deep Level Transient Spectroscopy (DLTS)...................................... 39 3.3.3 Defect recovery........................................................................................ 42 4 Dark Matter In CCDs 44 4.1 DAMIC CCDs................................................................................................. 46 4.2 DAMIC CCD Operations........................................................................... 50 4.2.1 Unbinned lxl images ........................................................................... 53 4.2.2 Binned 1x100 images............................................................................... 55 4.3 Image processing.............................................................................................. 57 4.3.1 Noise control and calibration............................................................... 57 4.3.2 Particle tracks separation and categorization ................................... 59 4.4 Dark Matter Searches usingionization.................................................... 63 4.4.1 DAMIC-SNOLAB, pre2019.................................................................... 63 4.4.2 DAMIC-M LBC..................................................................................... 65 4.4.3 DAMIC at SNOLAB, post 2021 ............................................................ 66 5 Device simulations 68 5.1 Device setup..................................................................................................... 68 5.1.1 Substructures of the DAMIC CCDs ................................................... 68 5.2 CCD operation simulation............................................................................ 74 5.3 Simulation support for CCDs..................................................................... 77 6 Radiation Damage in CCDs 84 6.1 Defects in DAMIC-S2019.......................................................................... 86 6.1.1 Development of edge finder algorithm ............................................... 86 6.1.2 Defect identification............................................................................... 89 6.1.3 Search for defect origin ........................................................................ 90 6.2 Daily modulation of defect production due to DM in Si................ 93 6.3 Defects in SENSEI CCDs........................................................................... 95 6.4 DAMIC Diodes and mini CCDs at CERN............................................ 97 7 Neutron irradiation campaign 105 7.1 Experimental setup....................................................................................... 106 7.1.1 General Procedure................................................................................. 109 7.1.2 Defect search.......................................................................................... 110 7.1.3 55Fe calibration....................................................................................... Ill 7.1.4 Proof of concept.................................................................................... Ill 7.1.5 AmBe irradiation 1.................................................................................. 112 7.1.6 AmBe irradiation 2.................................................................................. 112 7.2 Data analysis........................................................................................................114 7.2.1 Defect identification.............................................................................. 115 7.2.2 Background.............................................................................................. 115 7.2.3 Calibration.............................................................................................. 115 7.2.4 Defect analysis....................................................................................... 118 7.2.5 Neutrons and defects.............................................................................. 132 7.3 Further irradiation ............................................................................................135 8 Conclusions 136 Appendix A DAMIC diodes and packaging details 146 A.l Probing ................................................................................................................. 146 A.2 Dicing .....................................................................................................................146 A.3 Packaging.............................................................................................................. 148 Appendix B DAMIC-M calibration system 150 Appendix C DAMIC-M cold testing jig 151 C.l Target environment............................................................................................151 C. 2 Probing or bonding........................................................................................ 151 Appendix D Irradiation Campaign Parameters 154 D. l lxl readout used for both 10 and 1 minute exposures configuration file.............................................................................................................................. 154 D.2 Clear image configuration file...................................................................... 158 D.3 6k X 4, 1000 skip calibration image configuration file...................... 163 D.4 Fe-55 calibration table for UW6418......................................................... 167 Appendix E Defect efficiency of 100 keV neutrons 16

Initial Tests of Large Format Sensors for the ATLAS ITk Strip Tracker

For the production of the Inner Tracker (ITk) as part of the phase-II upgrade programme to prepare the ATLAS experiment for the High-Luminosity (HL) LHC, batches of Long Strip (LS) and Short Strip (SS) n-in-p type micro-strip sensors have been produced by Hamamatsu Photonics. The full size sensors measure approximately 98 x 98"mm^{2}" and are designed and engineered for tolerance against the 9.7 x "10^{14}", including a safety factor of 1.5, 1 MeV "n_{eq}/cm^{2}" fluence expected at the HL-LHC. Each sensor has 2 or 4 columns of 1280 individual channels arranged at 75.5μm horizontal pitch. To ensure the sensors comply with their specifications, a Quality Control (QC) procedure has been designed, comprising measurements on every individual sensor as well as on a sample basis. Every sensor is subjected to an initial visual inspection, after which the full surface of the sensor is captured with very high resolution by an automated camera setup. Non-contact metrology is performed to obtain the sensor surface profile. Electrical measurements establishing the reverse bias leakage current and depletion voltage are conducted automatically, with the recorded results uploaded to a production database following data quality checks. Sample sensors from every batch are subjected to 40 hour leakage stability checks in controlled atmosphere, and tests on every channel measuring leakage current, coupling capacitance and bias resistance are conducted. In this paper, QC test validation data and the compiled results for the first batches of production grade sensors, consisting of approximately 30 LS and SS sensors each are presented. Data from multiple test sites are compared with the data provided by Hamamatsu Photonics where possible. The QC protocol was validated, and the results of the first production sensors were confirmed to be within specification

Testbeam evaluation of silicon strip modules for ATLAS Phase - II Strip Tracker Upgrade

The planned HL-LHC (High Luminosity LHC) is being designed to maximise the physics potential of the LHC with 10 years of operation at instantaneous luminosities of \mbox{$7.5\times10^{34}\;\mathrm{cm}^{-2}\mathrm{s}^{-1}$}. A consequence of this increased luminosity is the expected radiation damage requiring the tracking detectors to withstand hadron equivalences to over $1x10^{15}$ 1 MeV neutron equivalent per $cm^{2}$ in the ATLAS Strips system. The silicon strip tracker exploits the concept of modularity. Fast readout electronics, deploying 130nm CMOS front-end electronics are glued on top of a silicon sensor to make a module. The radiation hard n-in-p micro-strip sensors used have been developed by the ATLAS ITk Strip Sensor collaboration and produced by Hamamatsu Photonics. A series of tests were performed at the DESY-II test beam facility to investigate the detailed performance of a strip module with both 2.5cm and 5cm length strips before irradiation. The DURANTA telescope was used to obtain a pointing resolution of 2$\mu$m, with an additional pixel layer installed to improve timing resolution to $\sim$25ns. Results will show that prior to irradiation a wide range of thresholds (0.5-2.0 fC) meet the requirements of a noise occupancy less than $1x10^{-3}$ and a hit efficiency greater than 99\%