DUNE Near-Detector

DUNE: Deep Underground Neutrino Experiment

The Deep Underground Neutrino Experiment (DUNE) is an international experiment for neutrino science and proton decay studies. DUNE will consist of two neutrino detector complexes placed in the world’s most intense neutrino beam. The Near-Detector complex will track particle interactions near the source of the beam, at Fermilab in Batavia, Illinois. A second and much larger Far-Detector will be installed more than a kilometer underground at the Sanford Underground Research Laboratory in Lead, South Dakota — 1300 kilometers downstream of the source. These detectors will enable scientists to search for new subatomic phenomena and potentially improve our understanding of neutrinos and their role in the universe. More informations about DUNE is available on www.dunescience.org .

DUNE Liquid Argon Near-Detector

The core component of the DUNE Near-Detector complex will be the ArgonCube Liquid Argon detector. The current design is based on an array of 5x7 ArgonCube modules sharing a common cryostat, similar as the 4x5 modules shown in the figure below.

Compared to a monolithic design, a modular detector has several advantages: It allows for scaling the detector up to very large active volumes with a minimal amount of inactive material. Furthermore, single modules can be maintained and upgraded in steps while the rest of the detector can be kept in operation. Each module consists of two independent Time Projection Chambers (TPCs) . Due to the modularity the TPC drift distances are drastically reduced to about 0.5 meters. Therefore, the TPCs can be operated with safe cathode bias voltages of about 50 kV. Finally, the track smearing due to the electron diffusion is neglectable and there are less stringent requirements on the Liquid Argon purity.

Small scale prototype

A small scale prototype for the DUNE Liquid Argon Near-Detector is currently under construction at the University of Bern. The detector contains of four (2x2) modules sharing a common Liquid Argon bath. The pictures below show the cryostat being installed in the laboratory of the University of Bern (left) and a PhD student standing next to a prototype module (right). Red colours denote approximatively the shape of one module planned for the DUNE Near-Detector, with a footprint of 1 square metre and a height of about 3.5 metres.

The ArgonCube Collaboration has an ongoing Research and Development program to instrument the modules with new technologies . Three major developments are the pixelated charge readout, a large area photon detector and a new approach for electric field shaping.