  The dynamics of an electron bunch irradiated by two focused colliding
super-intense laser pulses and the resulting gamma and electron-positron
production are studied. Due to attractors of electron dynamics in a standing
wave created by colliding pulses the photon emission and pair production, in
general, are more efficient with linearly polarized pulses than with circularly
polarized ones. The dependence of the key parameters on the laser intensity and
wavelength allows to identify the conditions for the cascade development and
gamma-electron-positron plasma creation.
