Add to ORKGThe even-mass samarium isotopes 148,...,152Sm have been investigated by polarized proton scattering at 20.4 MeV beam energy. The data have been analysed with an 'extended' optical model, where the intensities of the first maxima of the main inelastic channels are fitted in a coupled-channels calculation. The availability of analysing-power data turned out to be very helpful in the analysis. The well known phase transition from vibrator to rotor shows up clearly with increasing neutron number