Bulk Micromegas Detector Characterized for Nuclear Astrophysics Time Projection Chamber
Scientists at Saha Institute of Nuclear Physics have experimentally characterized a bulk Micromegas detector as part of developing an Active Target Time Projection Chamber (SAT-TPC) for nuclear astrophysics research. The detector is intended to measure the branching ratio of direct and sequential decay modes of the Hoyle state of carbon-12, a key process in stellar nucleosynthesis. The work validates both the detector's suitability and a hydrodynamic simulation model, advancing the path toward a functional SAT-TPC prototype.
Researchers at the Saha Institute of Nuclear Physics are developing the Saha Active Target TPC (SAT-TPC), a Micromegas-based detector designed to study nuclear reactions relevant to astrophysics, specifically the decay branching ratio of the Hoyle state of carbon-12 (¹²C). To optimize operating parameters, a bulk Micromegas detector was characterized using two gas mixtures — Ar + CO₂ (90:10) and Ar + isobutane (95:5) at atmospheric pressure — and tested with both 5.9 keV X-rays and 5.48 MeV alpha particles from radioactive sources. The team also developed a hydrodynamic transport model to simulate the charge-deposit profile of alpha-particle tracks on the detector readout, finding good agreement between simulation and experimental data. This agreement confirms that the bulk Micromegas technology is appropriate for the SAT-TPC prototype and that the numerical model reliably captures detector dynamics. The Hoyle state of ¹²C is astrophysically significant because it governs the triple-alpha process responsible for carbon production in stars, making precise decay branching ratio measurements important for stellar evolution models. The study, submitted to arXiv in February 2026 and revised through June 2026, represents an instrumentation milestone ahead of full physics measurements.
What's missing
The paper does not specify the timeline for completing the full SAT-TPC prototype or when physics measurements of the Hoyle state branching ratio are expected to begin.
What different sources said
- arXiv physicsCenter
Experimental Characterization of Bulk Micromegas for Development of Active Target Time Projection Chamber for Nuclear Astrophysics Studies
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