Nuclear astrophysics with RIBs at Oak Ridge National Laboratory

The Daresbury Recoil Separator (DRS) and Silicon Detector Array (SIDAR) have been installed at Oak Ridge National Laboratory (ORNL) to perform measurements of reaction cross sections of astrophysical interest using radioactive ion beams (RIBs). For example radioactive 17F beams will be used to determine the 14O(α,p)17F and 17F(p,γ)18Ne stellar reaction rates-both of which are important reactions in the Hot-CNO cycle. The first reactions studied will be 1H(17F,p)17F and 1H(17F,α)14O. These experiments will require 17F beams with intensities of 104 - 106 ions per second in conjunction with the SIDAR. The 1H(17F,p)17F reaction will be used to probe resonances in 18Ne which contribute to the 17F(p,γ)18Ne stellar reaction rate, while 1H(17F,α)14O will be used to determine the stellar reaction rate of the inverse reaction 14O(α,p)17F. In preparation for these experiments, measurements have been made of the 1H(17O,p)17O and 1H(17O,α)14N reaction cross sections. When higher beam currents of 17F become available, a direct measurement of the 1H(17F,18Ne) resonance strength will be made using the DRS. To test the performance of the DRS for measuring capture reaction cross sections, the well-known 1H(12C,13N) cross section has been measured at an energy similar to those proposed for radioactive beam experiments. Results from these stable beam experiments are discussed. copyright 1999 American Institute of Physics