  The characteristics of the electron-photon showers initiated by 2 to 10 GeV
electrons aligned along the <111>-axis of tungsten crystals are compared with
those for the amorphous tungsten . In this energy range, as known, the positron
yield at the optimal target thicknesses is larger in a crystal case only by
several percent. However, the amount of the energy deposition in a crystal
turns out to be considerably (by 20 - 50 %) lower than in an amorphous target
providing the same positron yield, while the peak energy-deposition density is
approximately of the same magnitude in the both cases.
