Speaker
Description
Low-background experiments are strongly affected by the cosmic-ray muon background, which is commonly characterized in terms of meters of water equivalent (m.w.e.). However, direct measurements of the effective overburden in natural environments, in particular in water, remain limited and are often restricted in angular coverage.
We present the DSTAR, a compact modular 4π muon detector, composed of paired scintillator–SiPM modules with dedicated DAQ and slow control and arranged in reconfigurable three-dimensional geometries. In its full configuration, the detector forms a near-spherical modular geometry providing a full solid-angle (4π) coverage. The detector architecture is easily scalable. The DSTAR is portable, enabling rapid deployment and long-term autonomous field operation in different natural and experimental environments.
A 14-module prototype has been operating at the Kalinin Nuclear Power Plant since October 2025, providing a continuous muon background monitoring for background rejection in a neutrino experiment and demonstrating a stable performance. On the basis of the results obtained by the prototype, the system has been scaled up to a 64-module configuration. The full-scale detector is prepared for underwater deployment in Lake Onega for direct measurements of the effective water equivalent at the depths up to 30 m. The modular design provides a flexible platform for evaluating ambient conditions in future low-background experiments and, in the longer term, for near-surface muon radiography and tomography.