ON THE PLANE FRAGMENTATION BARRIERS

The symmetric emission of fragments in the same plane has been studied within the generalized liquid-drop model taking into account the nucl ear proximity energy and the temperature. For all usual masses, the pl ane fragmentation barrier heights increase rapidly with the multiplici ty of the fragmentation but they are always lower than the three-dimen sional fragmentation barrier heights. For very heavy and evanscent nuc lear systems, all the plane fragmentation barriers have almost the sam e height. The kinetic energies of the fragments are lower for the plan e fragmentation than for the three-dimensional fragmentation.