Origin of pulsar pulse fine structure
  We give a new numerical model of pulsar pulse radiation through the interstellar medium (ISM) considering the propagation effects. It explains the deficit of a scattering measure at the decameter range of frequencies that leads to the possibility of detecting the pulsar pulse fine structure. The results of numerical simulation confirm that the fine structure may be detected at low frequencies and this is qualitatively agreed with the observational data. 
O. M. Ulyanov, A. A. Seredkina and A. I. Shevtsova
astro-ph.GA