Measurements of the interaction cross sections for Ar and Cl isotopes

摘要

We have measured the interaction cross sections (sigma(I)) of Ar31-40 and Cl31-37 on carbon targets at energies of around 950 A MeV. The effective matter radii for these nuclei were deduced by a Glauber-model analysis. Combining our matter radii with measured charge radii for Ar isotopes, we could deduce the proton-skin thicknesses for the Ar32-40 isotopes, which were found to increase monotonically with decreasing neutron number. The larger radius of the proton drip-line nucleus Ar-31 suggests an anomalous structure for this nucleus. In addition, using NaI(TI) arrays surrounding the carbon target, we measured gamma-rays emitted from excited states in these isotopes. In this way we could deduce the upper limits for the inelastic cross sections (sigma(inela)) on carbon targets at energies of around 950 A MeV. [References: 19]