On the relevance of adhesion: applications to Saturn's rings [Elektronische Ressource] / von Nicole Albers

AusdemInstitutfu¨rPhysikderUniversita¨tPotsdamON THE RELEVANCE OF PARTICLE ADHESION:APPLICATIONS TO SATURN’S RINGSDissertationzurErlangungdesakademischenGradesdoctorrerumnaturalium“”(Dr. rer. nat.)inderWissenschaftsdisziplinTheoretischePhysikeingereichtanderMathematisch-NaturwissenschaftlichenFakulta¨tderUniversita¨tPotsdamvonNicoleAlbersPotsdam,imMai2006AbstractSince their discovery in 1610 by Galileo Galilei, Saturn’s rings continue to fascinate bothexperts and amateurs. Countless numbers of icy grains in almost Keplerian orbits reveala wealth of structures such as ringlets, voids and gaps, wakes and waves, and many more.Grains are found to increase in size with increasing radial distance to Saturn. Recentlydiscovered “propeller” structures in the Cassini spacecraft data, provide evidence for theexistence of embedded moonlets. In the wake of these findings, the discussion resumesaboutoriginandevolutionofplanetaryrings,andgrowthprocessesintidalenvironments.In this thesis, a contact model for binary adhesive, viscoelastic collisions is developed thataccounts for agglomeration as well as restitution. Collisional outcomes are crucially deter-minedbytheimpactspeedandmassesofthecollisionpartnersandyieldamaximalimpactvelocity at which agglomeration still occurs. Based on the latter, a self-consistent kineticconceptisproposed. Themodelconsidersallpossiblecollisionaloutcomesasthereareco-agulation, restitution, and fragmentation.