The condensation produced in supersonic expansions of CO2 is studied quantitatively combining Rayleigh and Raman scattering. The cluster number density nc and the mean cluster size <N> are obtained for five expansions with stagnation pressures P0=1-5 bars, and temperature T0=294 K, along axial and radial directions; nc and <N> are determined from the condensation onset up to a terminal size, verifying the empirical law <N>prop.P0^(2.23). A maximum growth rate d<N>/dt approx.8x10(8) s^(-1) is estimated for the 5-bar expansion. The Raman spectra show a coexistence of solid and liquidlike phases in the jet, with a progressive transition from the liquid to the solid fraction as the clusters increase their size.Ministerio de Educación y Ciencia, Proyectos BFM2001-2276 y FIS2004-02576Peer reviewed