Genesis capturing the sun: Solar wind irradiation at Lagrange 1

Genesis, a member of NASAs Discovery Mission program, is the world’s first sample return mission since the Apollo program to bring home solar matter in ultra-pure materials. Outside the protection of Earth’s magnetosphere at the Earth–Sun Lagrange 1 point, the deployed sample collectors were directly exposed to solar wind irradiation. The natural process of solar wind ion implantation into a highly pure silicon (Si) bulk composition array collector has been measured by spectroscopic ellipsometry and scanning transmission electron microscopy (STEM). Ellipsometry results show that bulk solar wind ions composed of approximately 95% H +, 4% He + and