Low background nuclear astrophysics measurements at the CASPAR underground laboratory

Nuclear reactions lie at the heart of stellar evolution, driving the processes that power stars and shape the cosmos. For decades, scientists have sought to understand these reactions at the low energies relevant to stellar interiors. However, efforts have been hindered by a formidable challenge: the overwhelming background noise caused by cosmic rays at the Earth's surface. This has forced researchers to rely heavily on theoretical extrapolations, often burdened with significant uncertainties through lack of input parameters. Deep underground accelerator laboratories are an innovative solution that shields experiments from cosmic interference, enabling the direct measurement of astrophysically important reactions at previously unreachable energy levels.

The CASPAR (Compact Accelerator System for Performing Astrophysical Research) laboratory, located at the Sanford Underground Research Facility (SURF), represents a major step forward in this pursuit. Operating the U.S.'s first and only deep underground accelerator, CASPAR houses a fully refurbished 1 MV Van de Graaff accelerator, capable of delivering intense proton and alpha beams for cutting-edge nuclear astrophysics research. After a period of hibernation, the system has been revitalized. This presentation will explore the current projects underway at CASPAR, highlight its recent work, and offer a look at the exciting research programs planned for the future