Effect of Density Correlations on the Coherency of Relativistic Bunch   Radiation
  The coherent radiation of the electron beam with account of particle position correlations because of strong Coulomb interaction is considered. For the first time it is shown that the coherency of the radiation of the bunch with account of correlations depend on the mean inter particle distance (mean density of the bunch). The conditions of coherency are found. The influence of deviations from mean distance on the radiation coherency is considered. 
R. V. Tumanian, L.A. Gevorgian