Low Energy Measurement of the 18F(p,α)15O Cross Section at TRIUMF

An experiment to measure the 18F(p,α)15O cross section at low centre of mass energies has been performed with the TRIUMF-UK Detector Array (TUDA) facility at TRIUMF. Measurements of the 18F(p,α)15O reaction rate at four separate centre of mass energies; 665 keV, 430 keV, 330 keV and 250 keV, were carried out. The main goal of the experiment was the measurement of the 18F(p,α)15O cross section between 250 keV and 300 keV to help constrain the contribution to the reaction rate from nearby states and determine the effect of interference on the overall 18F(p,α)15O reaction rate from the proposed low lying 3/2+ states with the higher 664.7 keV 3/2+ state. A high intensity 18F beam (∼5x106 pps) was used to bombard a 31.6±1.9 μg.cm−2 polyethylene target within the TUDA scattering chamber at the four centre of mass energies. Four highly segmented silicon strip detector arrays were used for coincident detection of the reaction products. Preliminary results will be presented.