HOT-SPOTS IN QUASI-ONE-DIMENSIONAL ORGANIC CONDUCTORS

The distribution of the electron scattering rate on the Fermi surface of a quasi-one-dimensional conductor is calculated for the electron-el ectron umklapp interaction. We find that in certain regions on the Fer mi surface the scattering rate is anomalously high. The reason for the existence of these ''hot spots'' is analogous to the appearance of th e van Hove singularities in the density of states. We employ a general ized tau-approximation (where the scattering integral in the Boltzmann equation is replaced by the scattering time which depends on the posi tion se the Fermi surface) to study the dependence of the electric res istance on the amplitude and the orientation of a magnetic field. We f ind that the ''hot spots'' do not produce a considerable magnetoresist ance of commensurability effects at the ''magic angles''.