An experimental survey has been made of the elastic and inelastic scattering of ${\mathrm{C}}^{12}$ by ${\mathrm{C}}^{12}$ at a laboratory energy of 127 MeV. Inelastic scattering is found to occur for (1) $Q=-4.4\mathrm{}$ MeV (exciting the 4.4-MeV level of ${\mathrm{C}}^{12}$), (2) $Q=-9.1\mathrm{}\pm 0.3$ MeV [a combination of (a) exciting the 9.65-MeV level of ${\mathrm{C}}^{12}$ and (b) exciting both ${\mathrm{C}}^{12}$ nuclei to their 4.4-MeV levels], (3) $Q=-14.0\mathrm{}\pm 0.5$ MeV (exciting the 14.05-MeV level of ${\mathrm{C}}^{12}$), and (4) possibly $Q=-19\mathrm{}\pm 1$ MeV (exciting a level, or levels near 19 MeV). Angular distributions of the elastically and inelastically scattered ${\mathrm{C}}^{12}$ nuclei have been obtained between 14° and 39° in the center-of-mass system. The elastic and $Q=-4.4\mathrm{}$ MeV inelastic distributions show large oscillations which are out of phase in agreement with Blair's phase rule. The $Q=-14\mathrm{}$ MeV distribution, on the other hand, has no oscillations larger than a maximum to minimum ratio of 1.5 to 1.

• Received 26 February 1962

DOI:https://doi.org/10.1103/PhysRev.127.187