Dynamics of the Tri-Nuclear System at Spontaneous Fission of ^252Cf

To describe of dynamics of ternary fission of ^252Cf an equation of motion of the tri-nuclear system is calculated. The fission of the ^70Ni+^50Ca+^132Sn channel was chosen as one of the more probable channels of true ternary fission of ^252Cf. The collinearity of ternary fission has been checked by analyzing results of the equation of motion. The results show that if initially all nuclei are placed collinearly (potential energy of this position is the smallest) and the component of the middle fragment's initial velocity which is perpendicular to this line, is zero then ternary fission is collinear, otherwise the non collinear ternary fission takes place.