Deep Underground Neutrino Experiment (DUNE) Near Detector Conceptual Design Report

Abstract

The Deep Underground Neutrino Experiment (DUNE) is an international, world-class experiment aimed at exploring fundamental questions about the universe that are at the forefront of astrophysics and particle physics research. DUNE will study questions pertaining to the preponderance of matter over antimatter in the early universe, the dynamics of supernovae, the subtleties of neutrino interaction physics, and a number of beyond the Standard Model topics accessible in a powerful neutrino beam. A critical component of the DUNE physics program involves the study of changes in a powerful beam of neutrinos, i.e., neutrino oscillations, as the neutrinos propagate a long distance. The experiment consists of a near detector, sited close to the source of the beam, and a far detector, sited along the beam at a large distance. This document, the DUNE Near Detector Conceptual Design Report (CDR), describes the design of the DUNE near detector and the science program that drives the design and technology choices. The goals and requirements underlying the design, along with projected performance are given. It serves as a starting point for a more detailed design that will be described in future documents.

Searching for physics beyond the Standard Model in an off-axis DUNE near detector

“…The near detector physics program will be taken to the next level by the DUNE-PRISM detectors, to be installed 574 m downstream from the target [23] at the long-baseline neutrino facility (LBNF) at Fermilab, the neutrino source for the DUNE experiment. These detectors -a liquid argon time projection chamber (TPC) and a magnetized gaseous argon TPC -will be mounted on a movable platform, allowing them to be displaced up to 30.5 m (53 mrad) away from the beam axis.…”

“…The ND-LAr detector is box-shaped, with a width (perpendicular to the beam axis) of 7 m, a height of 3 m, and a depth (along the beam axis) of 5 m. The ND-GAr detector is cylindrical, with the cylinder axis oriented horizontally and perpen-JHEP01(2022)048 dicular to the beam axis. The detector's width is 5 m, and the cylinder radius is 2.6 m [23]. We compute the 3D coordinates at which each trajectory enters and exits the detectors by using some elementary geometry, courtesy of the trimesh Python package [76].…”

Neutrino interaction measurements with the MicroBooNE and ArgoNeuT liquid argon time projection chambers

“…Additionally, the ICARUS detector will make measurements of two GeV-scale neutrino beams over the next few years (the BNB on-axis and the NuMI beam off-axis), which will also include approximately 10,000 electron neutrino interactions in the NuMI dataset [5]. Further in the future, the DUNE near detector complex will include a liquid argon detector and a gaseousargon detector in a wide-band beam peaked at 4 GeV, expected to collect 30 million and 1.6 million ν μ CCinclusive events respectively per year in neutrino-mode beam running [66]. These data sets will be crucial to reach the precise understanding of neutrino-argon interactions needed for DUNE's oscillation program.…”

Dielectric strength of noble and quenched gases for high pressure time projection chambers

“…Since their introduction in 1974 [1], time projection chamber (TPC) detectors have become pervasive in neutrino physics and rare event searches [2][3][4][5][6][7][8]). The working principle of a TPC [9] is that ionization electrons or ions created by a charged particle in a liquid or gaseous medium are drifted to a detection plane preserving the three dimensional event structure.…”

“…In some situations, the increased precision available from tracking in a lower density medium favors the use of gaseous working media, however. Examples include identification of the topological two-electron signature [10] and exquisite energy resolution [11] for neutrinoless double beta decay searches in xenon gas, as employed by the NEXT program; and precise studies of neutrino interactions in the high-rate environment of the LBNF neutrino beam that will be made by an argon-gasbased detector in the DUNE near detector complex [3,12]. In both of these applications, the relevant gas operating pressures are around 10 bar.…”