Studies of intermediate-mass fragment emission in the He3+natAg, Au197 reactions between 0.48 and 3.6 GeV Academic Article uri icon

abstract

  • Intermediate-mass fragments formed in reactions of He3 ions with Agnat and Au197 targets have been studied at five energies between 0.48 and 3.6 GeV. Inclusive measurements show that as the bombarding energy increases, there is a strong enhancement in fragment cross sections and a trend toward isotropic angular distributions. Between 0.90 and 1.8 GeV, a change in the emission mechanism is suggested by (1) kinetic energy spectra with high-energy tails that become distinctly flatter, (2) a broadening of the spectral Coulomb peaks toward lower energies, and (3) charge distributions that become constant, exhibiting a power-law exponent τ2.0. Exclusive studies of the He3+natAg system at 0.90 and 3.6 GeV detected multifragment events with multiplicities up to four. The probability for high-multiplicity events increases about 40-fold between 0.90 and 3.6 GeV. At both energies, the kinetic energy spectra depend on multiplicity, especially when triggering on backward-emitted fragments. For multiplicity three events, a rapidity analysis of the data at 3.6 GeV is consistent with a single, relatively low source velocity, vS0.4 cm/ns. The data are compared with predictions of a coplanarity-sphericity calculation, the sequential statistical decay code GEMINI, and a hybrid intranuclear cascade/percolation model. © 1993 The American Physical Society.

author list (cited authors)

  • Yennello, S. J., Kwiatkowski, K., Pollacco, E. C., Volant, C., Cassagnou, Y., Dayras, R., ... Viola, V. E.

citation count

  • 20

publication date

  • September 1993