  The influence of the space charge fields on the dynamics of the particles of
the bunch, which is moved in a bending magnet is calculated. It is shown, that
such influence of the Coulomb force on the energy of the particles of a
modulated beam causes in the decreasing of the bunch energy spread during the
compression due to energy deviation along the compressed bunch, i.e. bunch
cooling. The necessary conditions of the maximal cooling are found. The
attainable ordering of the bunch is investigated.
