Strong Resonances at High Excitation Energy in $${}^{\mathbf{17}}$$ O $$+$$ Alpha Resonance Scattering

The thick target inverse kinematics (TTIK) approach was used to measure excitation functions for the elastic $${}^{17}$$ O ( $$\alpha,\alpha$$ ) scattering at the initial $${}^{17}$$ O beam energy of 54.4 MeV. We observed strong peaks corresponding to highly excited $$\alpha$$ -cluster states in the $${}^{21}$$ Ne excitation energy region of 8–16 MeV, which have never been investigated before. Additional tests were done at a $${}^{17}$$ O beam energy of 56.4 MeV to estimate a possible contribution of resonance inelastic scattering.