Observationer av solvindens växelverkan med regolit

This thesis aims to deepen our understanding of regolith – the layer of unconsolidated solid material that covers the bedrock of planetary bodies. For airless bodies, regolith forms the primary interface between the body and the energy and matter that permeate the solar system. One way to investigate regolith is by studying the products of its interactions with incident atomic particles. We develop a physical model of these interactions, derive observational predictions, and test them against measurements in order to evaluate and refine the model. As new data become available, this iterative, model-driven approach progressively constrains our knowledge of the physical properties of regolith. To validate or refute such models, measurements of particles emitted from regolith are required. We addressed this need by developing a dedicated particle instrument, calibrating it, and deploying it on the lunar surface, where it directly measured particles emitted from lunar regolith. When exposed to precipitating ions and photons, lunar regolith responds by anisotropically emitting a zoo of particles spanning multiple charge states, species,and energies. The instrument was specifically designed to detect negatively charged ions emitted from the surface. It successfully performed this measurement and produced valuable observational data which, when interpreted through predictive modelling, indicate that lunar regolith is a surprisinglyefficient emitter of negative ions.