An Overview of ND-GAr, a Gaseous Argon-Based Near Detector for the DUNE Experiment

The Deep Underground Neutrino Experiment (DUNE) is an international particle physics experiment looking to probe the relevant properties of the neutrino. DUNE uses a high power neutrino beam produced at Fermi National Accelerator Laboratory (Fermilab), and consists of a near detector also located at Fermilab and a far detector at the Sanford Underground Research Facility (SURF) in South Dakota, 1300 km away from Fermilab. DUNE is planned to be built in two phases and ND-GAr is central to Phase II of DUNE. ND-GAr is a a proposed gaseous argon time projection chamber (TPC) detector at the near detector complex. The detector is envisioned to include a magnetized one ton high pressure gaseous argon TPC surrounded by an electromagnetic calorimeter (ECAL). Because of the lower energy threshold of high pressure gas TPCs compared to liquid-argon TPCs, it will be able to better resolve low-energy hadrons. This will help to discriminate between different neutrino interaction models. In this talk, the physics motivations and requirements of ND-GAr are discussed. I will also present current conceptual design studies, as well as ongoing neutrino interaction model studies and research and development with gaseous argon test stands.