2003A&A...408.1057P

Propagation of natural waves through the ultrarelativistic highly magnetized plasma in the rotating magnetosphere of a pulsar is considered. Based on the quantitative description of the polarization-limiting effect, we develop a technique of density diagnostics of pulsar plasma according to the observed polarization profiles of radio pulses. For the first time, it appears possible to obtain the profiles of the plasma density distribution across the open field line tube. The density profiles found for PSR B0355+54 and PSR B0628-28 show a perfect exponential decrease towards the tube edge. The multiplicity factors derived are compatible with those predicted by modern theories of pair cascade in pulsars. The results of the plasma density diagnostics may have numerous implications for the physics of the pulsar magnetosphere. Further application of the suggested technique to single-pulse polarization data seems to be promising.