Energy dependence of 209Bi fragmentation in relativistic nuclear collisions

The results of cross-section measurements for the reactions ²⁰⁹Bi(¹²C,X)Au, E=4.8 and 25.2 GeV and ²⁰⁹Bi(²⁰Ne,X)Au, E=8.0 GeV are reported. The observed yields of the gold isotopes show a similar dependence on mass number for each reaction, differing slightly in the position of the centroid of the distribution. As the projectile energy increases, the inferred excitation energy of the primary residues remains the same or decreases slightly. This observation is in agreement with the predictions of the intranuclear cascade model of relativistic heavy ion collisions. NUCLEAR REACTIONS ²⁰⁹Bi(¹²C,X)Au, E=4.8, 25.2 GeV; ²⁰⁹Bi(²⁰Ne,X)Au, E=8.0 GeV; measured Au isotopic distributions, relativistic heavy ions, target fragmentation, Ge(Li) spectroscopy.