Abstract
The reaction was used to measure the positions and widths of levels from 4- to 6-Mev excitation. Proton spectra were obtained at high resolution with a broad-range spectrograph. This instrument accurately measured the widths and shapes of the energy distributions of the proton groups arising from the wider levels. Disagreements among other experiments concerning the levels are explained in terms of the large difference in level widths. A comparison of these directly measured widths is made with those obtained from neutron scattering experiments. The observed shape of the energy distribution is that predicted by resonance theory. The 0.87-Mev level is found to be single rather than double as recently suggested. Excitation energies obtained (in Mev) are 0.871±0.004, 3.055±0.004, 3.846±0.005, 4.553±0.006, 5.083±0.010, 5.215±0.005, 5.378±0.007, 5.695±0.005, 5.731±0.005, 5.866±0.005, 5.94±0.015. Widths of levels 4, 5, 7, and 11 are (in kev) 40±5, 95±5, 28±7, and 23±10, respectively. The other levels have widths less than 8 kev.
- Received 5 August 1957
DOI:https://doi.org/10.1103/PhysRev.108.1007
©1957 American Physical Society