RISØ

Optics and Fluid Dynamics Department

And The Graduate School in Nonlinear Science

SEMINAR

Interstellar grains, icy satellites and comets are subject to irradiation by energetic particles and ions. The resulting radiation physics and chemistry alter the surfaces and affect their optical reflectance. We perform laboratory experiments to answer questions posed by astronomical observations. Gases are condensed on cold surfaces (5-150 K) in vacuum and Irradiated by 5-100 keV ions or 10.2 eV photons (Lyman-alpha). We study reflectance changes, erosion (sputtering), and gases evolved during and after irradiation. The seminar will discuss results, current models, and unsolved questions in this area.