Exploring Double-Layer Water Cherenkov Detector Designs for SWGO: Bridging the Gap with CTAO

• Grant number: 25/10735-5
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2025
• End date: November 30, 2028
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Astronomical Instrumentation
• Principal Investigator: Elisabete Maria de Gouveia Dal Pino
• Grantee: Elisabete Maria de Gouveia Dal Pino
• Principal researcher abroad: James A Hinton
• Institution abroad: Max Planck Society, Heidelberg , Germany
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• City of the host institution: São Paulo
• Associated researchers: Diego Antonio Falceta Gonçalves ; Ulisses Barres de Almeida

Abstract

The Southern Wide-field Gamma-ray Observatory (SWGO) is poised to become a key facility for ground-based gamma-ray astronomy in the Southern Hemisphere. Its wide field of view and high duty cycle will complement the capabilities of the Cherenkov Telescope Array Observatory (CTAO), the next-generation gamma-ray observatory currently under construction. This synergy will enable continuous monitoring of transient phenomena and extended sky coverage, strengthening the global gamma-ray observatory network.This proposal aims to investigate innovative double-layer Water Cherenkov Detector (WCD) configurations for SWGO, focusing on practical, scalable, and cost-effective solutions. Specifically, we will explore two main design strategies for a double-layer tank solution: (i) double-layer rotomolded polyethylene tank with an integrated internal reflective wall, and (ii) a single-chamber rotomolded polyethylene tank where a flexible internal bladder is used as separator for implementation of the double-layer solution. These configurations are expected to improve light collection efficiency, enhance background discrimination, and offer advantages in manufacturing and transport, as well as deployment in remote high-altitude locations in comparison to corrugated-sheet metal tank solutions.The proposed study will include detailed simulations of optical performance, assessments of mechanical feasibility, and cost-benefit analyses. The outcomes will directly contribute to the ongoing detector R&D for SWGO and help guide design decisions for its large-scale implementation, while reinforcing technical and scientific alignment with CTAO. (AU)