The (?,p) reaction in 16O and 18O at E?=50 - 70 MeV

Abstract: A measurement of the reactions 16O(?,p)15N and 18O(?,p)17N have been made with tagged photons in the energy range E? ? 50 – 70 MeV. The protons have been detected in ?E-E telescopes with silicon strip detectors as ?E detectors and HPGe crystals as E detectors. Two telescopes have been used with an average angle towards the photon beam of 70 and 110 degrees. The silicon strip detectors have been used to track the protons resulting in good angular resolution. Energy and angular distributions of differential cross sections for transitions to the ground and low lying excited states have been obtained. The present 16O(?,p)15N cross sections are in good agreement with previous measurements. In the experiment the reaction 18O(?,p)17N has been studied for the first time in this energy range and cross sections to a few low lying states in 17N measured. Since there are no 18O(e,e´p) data available to help identify the states populated in the residual nucleus the excited states have been partly identified using the weak coupling model.