We have studied the $\beta$-delayed particle decay of ${}^{17}$Ne to test the feasibility of determining both the $E1\mathrm{}$ and $E2\mathrm{}$ components of the ${}^{12}$C$(\alpha ,\gamma {)}^{16}$O cross section at energies relevant to helium burning in stars. In this context we have observed the breakup of the isobaric analog state in ${}^{17}$F at 11.193 MeV into three particles via three channels: proton decay to the 9.59 MeV state in ${}^{16}$O; and $\alpha$ decay to the 2.365 and 3.502/3.547 MeV states in ${}^{13}$N. This is the first reported observation of the decay of the IAS to the $1^{-}$ state in ${}^{16}$O at 9.59 MeV and the first reported $\beta$-delayed proton-$\alpha$ decay. With straightforward improvements to our detection apparatus to improve angular resolution, $\beta$ suppression, and solid angle coverage, we should be able to proceed to the measurement of the effect of the tail of the subthreshold state at 7.117 MeV in ${}^{16}$O on the $\alpha$ spectrum from the breakup of the 9.59 MeV state.

• Received 29 July 1997

DOI:https://doi.org/10.1103/PhysRevC.57.R475