Excitation functions for ${}^{18}\mathrm{O}+\alpha$ elastic scattering were measured by a method using inverse kinematics and a thick gas target. An analysis of the data corresponding to the excitation energy regions of 11.8–13.7 MeV and 19.0–22.0 MeV in ${}^{22}\mathrm{Ne}$ was carried out. A surprising splitting of $1^{-},$ $3^{-},$ $7^{-},$ and $9^{-}$ $\alpha$-cluster levels into doublets was found in ${}^{22}\mathrm{Ne}.$

• Received 12 February 2001

DOI:https://doi.org/10.1103/PhysRevC.64.051302