Inelastic Scattering of 6- to 19-MeV Alpha Particles from Carbon

The inelastic scattering of alpha particles from ${\mathrm{C}}^{12}$ was studied in detail. The 4.43-MeV gamma rays were observed from 6- to 17-MeV bombarding energy; the particles were observed from 10 to 19 MeV. Analysis of the gamma-ray data yielded the following specific conclusions: (1) Near 13.1-MeV excitation energy in ${\mathrm{O}}^{16}$ there is apparently a $2^{+}$ level in addition to the well known $1^{-}$ level. (2) The 13.27-MeV level is $3^{-}$, as previously reported. (3) The previously unassigned state at 13.88 MeV is $4^{+}$. (4) A previously unreported level at 14.80 MeV has a low spin value. Numerous additional levels were found. The "two-channel" coupled equations approximation predicts many of the qualitative features of the particle angular distributions. Since the coupling is very strong, calculations for ${\mathrm{C}}^{12}$ illustrate well some of the features of this approximation.