Electromagnetic dissociation of Au and Co targets by relativistic heavy ions

This investigation is a part of ongoing series of experiments designed to extend the systematics of ED for various targets and projectiles. The goal of these experiments is to determine σED for various combinations of projectile, projectile energy, and target. These cross sections are than compared to the theoretical predictions of a model based on the Weizsacker-Williams (WW) method. Determination of σED entails first finding the total crossing section (σtot) for the reaction T(RHI,X)T', where T is the target RHI is the projectile, X is the remnant of the RHI after the reaction (the details of which are not studied in this series of experiments), and T' is the new state of the target (the target minus one neutron for the one-neutron removal reaction). Since σtot consists of contributions due to both ED and nuclear processes, σnuc must also be found for this reaction. Once σtot and σnuc are determined, σED is given by σED = σtot - σnuc. In this investigation, 197Au and 59Co targets were irradiated by a beam of 238U ions with an energy of 0.96 GeV per nucleon (0.96 GeV/A). The particular reactions of interest are 197Au(238U,X)196Au and 59Co(238U,X)58Co. The cross sections for these reactions were found by studying the γ-ray activity of 196Au and 58Co in the targets. The experimental value of σED was compared to the value calculated using the WW method. Results of previous experiments are shown along with the results of the present study so that the systematics of ED can be studied. 25 refs., 26 figs