Onset of multifragment emission in heavy-ion collisions

A multidetector setup with large solid angle coverage has been used to measure the particle and fragment emission associated with the production of intermediate mass fragments in reactions of ¹²C, ¹⁸O, ²⁰Ne, and ⁴⁰Ar on ⁿᵃᵗAg and ¹⁹⁷Au at bombarding energies 30 MeV≤E/A≤84 MeV. It is found that the cross sections, the element distributions, and the multiplicites of intermediate mass fragments are strongly correlated with the excitation energy Eₓ deposited in the composite system and that multifragment emission sets in at Eₓ300 MeV.