Speaker
Description
The SABRE South experiment, located at the Stawell Underground Physics Laboratory (SUPL) in Victoria, Australia, is an ultra-low-background dark matter experiment designed to test the long-standing annual modulation signal reported by DAMA/LIBRA. The detector employs ultra-pure NaI(Tl) crystals surrounded by an active liquid scintillator veto instrumented with 32 photomultiplier tubes (PMTs), providing efficient background rejection and additional information on background-producing particles. Reliable optical calibration of the veto system is essential for monitoring PMT performance, understanding detector response, and ensuring long-term detector stability.
This contribution presents the integrated development of the hardware and software framework for the SABRE South optical calibration system. A dedicated prototype veto vessel at Adelaide University is being used to develop and validate the complete calibration chain prior to deployment in the underground detector. On the hardware side, the work includes the implementation of a diffuse optical calibration source, the optical distribution system, and the associated data acquisition (DAQ) electronics. In parallel, Geant4 simulations together with Python/ROOT analysis tools are being developed to model optical photon transport, PMT response, trigger effects, and the expected calibration data, enabling direct comparison between simulated and measured detector performance.
The combined hardware and software framework will provide a robust approach for in situ calibration and continuous monitoring of the active veto system, supporting detector commissioning and long-term operation. By validating the detector response, assessing optical uniformity, monitoring PMT stability, and reducing instrumental uncertainties, this work will contribute to the low-background performance required for the SABRE South search for an annual modulation signal from dark matter.
| Primary Abstract Topic | Experiment: WIMPs |
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