Proton groups from the ${\mathrm{B}}^{10}({\mathrm{He}}^3, p){\mathrm{C}}^{12}$ reaction leading to levels up to 16.2-Mev excitation were analyzed with a broad-range spectrograph. At a bombarding energy of 3.74-Mev spectra were taken at 11 angles from 5 to 139 degrees. Levels were found at excitation energies of 4.43(7), 7.655±0.006, 9.645±0.006, 10.849±0.025, 11.841±0.025, 12.713±0.006, 13.29±0.03, 14.083±0.015, 15.108±0.006, and 16.108±0.006 Mev. Widths of the 9.6-, 10.8-, 11.8-, 13.3-, and 14.1-Mev levels are 35±6, 320±30, 245±30, 430±100, and 252±15 kev respectively. Widths of the other levels are less than 15 kev. No levels were found at excitations of 9.0, 11.1, or 15.6 Mev. A level 2 Mev wide at 10.1-Mev excitation would not have been seen above the high background from three-particle breakup. Yields at each angle were measured relative to the yield of the ${\mathrm{B}}^{10}({\mathrm{He}}^3, d){\mathrm{C}}^{11}$ reaction. An angular distribution of this reaction was obtained. Absolute differential cross sections were found by comparing the yields with the known yield from the ${\mathrm{B}}^{10}(d, p){\mathrm{B}}^{11}$ reaction. Cross sections for the ${\mathrm{B}}^{10}({\mathrm{He}}^3, p){\mathrm{C}}^{12}$ reaction vary from 0.02 mb/sr to 0.6 mb/sr.

• Received 26 September 1961

DOI:https://doi.org/10.1103/PhysRev.125.992