The 2x2 Demonstrator - A demonstrator for the DUNE ND-LAr Near Detector based on the ArgonCube Design

The Deep Underground Neutrino Experiment (DUNE) is a next generation long-baseline neutrino oscillation experiment designed to observe neutrino and antineutrino oscillation patterns to precisely measure neutrino mixing parameters. DUNE near detectors will measure and constrain the neutrino flux and constrain the response for a near-far detector oscillation measurement. The 2x2 Demonstrator is a demonstrator for the DUNE ND-LAr near detector based on the ArgonCube design. The 2x2 Demonstrator will characterize neutrino-Argon interactions in the few-GeV regime. Composed of a 2-by-2 grid of four optically segmented LArTPC modules sandwiched between upstream and downstream repurposed MINERA tracking planes, each TPC module has a footprint of 0. 7 m by 0. 7 m and is 1. 4 m tall. The 2. 4 metric ton LAr active mass is instrumented by 337k charge-sensitive pixels at 4 mm pitch and thin-profile scintillation traps for 25% optical coverage. The detector will acquire antineutrino data in 2024 in the NuMI beamline at Fermilab, marking the first neutrino physics data for the ArgonCube detector concept from which the DUNE near detector modular LArTPC (ND-LAr) design is predicated. Roughly 300k charged-current active volume fiducialized antineutrino vertex interactions are expected per year in NuMI medium energy RHC operation. In addition to the copious GeV-scale neutrino interactions, physics analysis worthy data at the MeV-scale is possible, leveraging the near 100% uptime free-streaming, few hundred keV charge readout pixel trigger thresholds. Key technical demonstrations including 3D reconstruction of neutrino signals, track-matching with external trackers, and charge-light signal correlations in a high intensity neutrino beam will be exercised to assess ND-LAr design efficacy. A system design overview and status are reported.