PHASE COEXISTENCE IN MULTIFRAGMENTATION

The charge (Z) distributions from intermediate energy heavy-ion reacti ons depend upon the multiplicity n of intermediate mass fragments thro ugh a factor of the form e(-cnZ). Experimentally c starts from zero at low values of the transverse energy E(t) and reaches a saturation val ue at high E(t). In a liquid-gas phase diagram c = 0 for the saturated vapor, while c > 0 for the unsaturated vapor. It is suggested that in the c approximate to 0 regime the source evaporates down to a sizable remnant. while for c > 0 the source vaporizes completely. Percolation of finite systems and nuclear evaporation portray a behavior similar to that observed experimentally.