Deep Underground Neutrino Experiment (DUNE) 1 Technical Proposal 2 - PDF document

Deep Underground Neutrino Experiment (DUNE) 1 Technical Proposal 2 Volume n: Sample for Overleaf Editing 3 March 13, 2018 4

1

Contents 1 Contents i 2 List of Figures iii 3 List of Tables iv 4 1 Photon Detection System 1 5 1.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6 1.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 7 1.1.2 Physics and the Role of Photodetection . . . . . . . . . . . . . . . . . . . . . . 2 8 1.1.3 Technical Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 9 1.1.4 Detector Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 10 1.1.5 Operation Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 11 1.2 Photosensor System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 12 1.2.1 Photodetector Selection and Procurement . . . . . . . . . . . . . . . . . . . . 5 13 1.2.2 Photodetector Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . 6 14 1.2.3 High Voltage System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 15 1.2.4 Wavelength Shifters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 16 1.2.5 Light Collectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 17 1.3 Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 18 1.3.1 Mechanical Structure of the Photosensor . . . . . . . . . . . . . . . . . . . . . 9 19 1.3.2 Photosensor Fixation to the Membrane Floor . . . . . . . . . . . . . . . . . . . 10 20 1.4 Readout Electronics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 21 1.4.1 PMT High Voltage Dividers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 22 1.4.2 High Voltage/Signal Splitters . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 23 1.4.3 Signal Readout Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 24 1.5 Photon Calibration System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 25 1.5.1 System Design and Procurement . . . . . . . . . . . . . . . . . . . . . . . . . 14 26 1.5.2 Validation Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 27 1.6 Photon Detector Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 28 1.6.1 Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 29 1.6.2 Use of light data in DP prototypes . . . . . . . . . . . . . . . . . . . . . . . . 23 30 1.7 Photon Detector Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 31 1.7.1 Trigger Strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 32 1.7.2 Data Quality Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 33 1.8 Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 34 i

1.9 Installation, Integration and Commissioning . . . . . . . . . . . . . . . . . . . . . . . . 26 1 1.9.1 Transport/Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2 1.9.2 Integration and Testing Facility Operations . . . . . . . . . . . . . . . . . . . . 27 3 1.9.3 Underground Installation and Integration . . . . . . . . . . . . . . . . . . . . . 27 4 1.9.4 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 5 1.10 Quality Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 6 1.10.1 Production and Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 7 1.10.2 Post-Factory Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 8 1.11 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 9 1.12 Management and Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 10 1.12.1 Consortium Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 11 1.12.2 Planning Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 12 1.12.3 WBS and Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 13 1.12.4 High-Level Cost and Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 14 15 ii

List of Figures 1 1.1 The DUNE DP detector (partially open) with cathode, PMTs, field cage and anode 2 plane with chimneys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 1.2 Picture of the Hamamatsu R5912-MOD2 PMT. . . . . . . . . . . . . . . . . . . . . . 6 4 1.3 Picture of the PMTs being installed in the testing vessel used for the ProtoDUNE-DP 5 PMTs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6 1.4 Sketch of the setup for PMT characterization tests. . . . . . . . . . . . . . . . . . . . 7 7 1.5 Cryogenic Hamamatsu R5912-MOD2 photomultiplier fixed on the membrane floor. . . . 10 8 1.6 Positive power supply and cathode grounding scheme. . . . . . . . . . . . . . . . . . . 11 9 1.7 Generic splitter circuit diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 10 SPE waveforms and amplitudes from 3 × 1 × 1 m 3 detector at different voltages. . . . . 1.8 13 11 Event rates for different trigger thresholds observed on the WA105 3 × 1 × 1 m 3 detector. 14 1.9 12 1.10 Diagram of the photon calibration system to be implemented in ProtoDUNE-DP. . . . . 15 13 1.11 A sketch depicting the mechanism of light production in argon. . . . . . . . . . . . . . 17 14 1.12 Landau fits (red line) of the travel time distributions (black histogram) for a source close 15 (left) and far (right) to the PMT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 16 1.13 Evolution of the visibility seen by a central PMT (pointed by the arrow) as a function 17 of different source positions in x and z ( y is set at 0 mm). The position of the cathode 18 and the ground grid are highlighted. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 19 1.14 Evolution of the visibility and peak time as a function of the source-PMT distance as 20 simulated in the ProtoDUNE-DP geometry (Preliminary study). . . . . . . . . . . . . . 22 21 1.15 Averaged waveform of the S1 light signal taken with one PMT from the WA105 3 × 1 × 22 1 m 3 LAr DP TPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 23 24 iii

List of Tables 1 1.1 Summary of tentative requirements for the photon detection system of the DP LAr TPC. 4 2 1.2 Default optical properties. Below the thick line are presented some quantities used in 3 our studies although they are not linked to the optical properties of the LAr. . . . . . . 18 4 1.3 DPPD interface documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5 1.4 DPPD Consortium institutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 6 1.5 DPPD schedule of activities and milestones. . . . . . . . . . . . . . . . . . . . . . . . 33 7 8 iv

Todo list 1 v

Chapter 1: Photon Detection System 1–1 Chapter 1 1 Photon Detection System 2 ch:fddp-pd 1.1 Overview 3 sec:fddp-pd-1 1.1.1 Introduction 4 sec:fddp-pd-1.1 This chapter describes the Photon Detection System (PDS) for the DUNE Dual-Phase (DP) Far 5 Detector (FD). It is essential to ensure that the DP FD PDS is optimized for the full DUNE physics 6 program. In particular, low energy signals like supernova (SN) neutrinos and multi-messenger 7 astronomy, other low-energy signals, and proton decay, will have more stringent requirements on 8 photon detector system performance than the primarily higher energy, beam-synchronous, neutrino 9 oscillation physics. The final specifications of the system will be determined in order to achieve 10 these physics requirements. This Technical Proposal chapter will concentrate on direct projection 11 of the ProtoDUNE-DP design to the DUNE scale. The optimization and final design of the 12 protoDUNDP-tdr Dual-Phase Photon Detector (DPPD) system will be driven by the ProtoDUNE-DP [ ? ] data and 13 simulation studies. 14 sec:fddp-pd-1 sec:fddp-pd-2 The chapter begins with an overview of the system in section 1.1. Section 1.2 describes the photo- 15 sensors, namely photomultiplier tubes (PMTs) and the related high-voltage system, wavelength 16 sec:fddp-pd-3 shifters and light collectors. The mechanics associated with the PMTs is described in Section 1.3, 17 sec:fddp-pd-4 sec:fddp-pd-5 and the readout electronics in 1.4. Section 1.5 details the photon calibration system to monitor 18 sec:fddp-pd-6 the PMT gain and stability. Then, the photon detector performance is described in Section 1.6, 19 sec:fddp-pd-7 sec:fddp-pd-8 and the operations in Section 1.7. Interfaces with other subsystems are described in Section 1.8. 20 sec:fddp-pd-9 Section 1.9 includes the installation, integration and commissioning plans. Then, the quality 21 sec:fddp-pd-10 control procedures are outlined in Section 1.10. The main safety issues to consider are specified in 22 sec:fddp-pd-11 sec:fddp-pd-12 Section 1.11. To finish, the management and organization is described in Section 1.12. 23 Volume n: Sample for Overleaf Editing DUNE Technical Proposal