The use of radioactive nuclear beams to study the equilibration of the N Z degree of freedom in intermediate-energy heavy-ion reactions

Abstract The effect of the neutron to proton ratio of the colliding system on the isotope ratio of the emitted fragments (1 ⩽ Z ⩽ 5) was studied for for a variety of constant mass beam-target combinations. To extend the N Z ratio as far as possible, one of the projectiles employed, 40 Cl, was a radioactive secondary beam. The isotopic ratios depend on the N Z of the target and beam in a way which is not consistent with N Z > equilibration on the timescale of the emission of intermediate-mass fragments.