Fakultät für Physik Studienprogrammleitung Physik ssc-physik.univie.ac.at/ Martin Hopf Boltzmanngasse 5, 1090 Wien T +43(1) 4277 60330 [email protected] An alle Mitglieder der Fakultät für Physik Wien, am 09. Juni 2015 Einladung zur Defensio der Dissertation Development of a versatile size analyzing nuclei counter (vSANC) and application to ambient aerosol studies von Tamara Pinterich Donnerstag, 18. Juni 2015, 14:00 Uhr Lise-Meitner-Hörsaal, Boltzmanngasse 5, 1090 Wien The operation of the versatile size analyzing nuclei counter (vSANC) is based on heterogeneous nucleation of supersaturated vapor on preexisting aerosol particles and subsequent droplet growth. Well-defined uniform vapor supersaturation is achieved by adiabatic expansion. Thereby nanoparticles down to 1-2nm in diameter can be activated and grow to visible sizes. Absolute particle number concentrations ranging from 102cm-3 to 107cm-3 and droplet growth curves are obtained by means of the multi-angle constant angle Mie scattering method. During Spring 2014, the vSANC has been operated at the SMEAR II station in Finland. The main goal was to investigate the formation and growth of atmospheric clusters. Using npropanol as working fluid, atmospheric new particle formation (NPF) was observed only when operating temperatures were close to the ambient air temperature. Diurnal concentration evolution during NPF events showed that the vSANC detected the NPF signal 2-3 hours before a differential mobility particle sizer. A continously present pool of highly concentrated neutral clusters in the sub-3nm diameter range could not be confirmed during these measurements. Prüfungssenat: Peter H. McMurry, University of Minnesota, USA (Gutachter) Wladyslaw Szymanski Paul E. Wagner (Betreuer) Martin Hopf (Vorsitz)