Identification of Dark Matter 2026

Simulation of the primary background of InDEx operated at 1.95 keV at JUSL

Not scheduled

20m

Josefa Amar y Borbón

Poster Direct Detection Poster session / Wine and Cheese

Speaker

Susmita Das (Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata – 700064, India and Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India)

Description

Dark matter direct detection experiments require ultra-low background conditions to observe rare interaction events. This work presents a Monte Carlo study of neutron background reduction for the Indian Dark matter search Experiment (InDEx) at the Jaduguda Underground Science Laboratory (JUSL). Neutron background, the dominant limitation at JUSL (555 m depth; 1406 mwe), arises from radiogenic and cosmogenic sources. InDEx employs superheated liquid droplet detectors of C₂H₂F₄ operated below the gamma-sensitive threshold (38.5 °C), providing intrinsic suppression of gamma and electron backgrounds. The detector geometry and setup were modelled using FLUKA and validated against published and experimental results. A passive shielding design using 20 cm high-density polyethylene (HDPE) was optimized through simulation. Results show a reduction in detector event rates by approximately two orders of magnitude compared to the unshielded configuration. The combined effect of optimized shielding and threshold-based operation significantly enhances the projected sensitivity of the InDEx dark matter search.