Abstract
Charged particles from four sets of reactions induced by , on , targets have been observed. The incident beam energy in each case corresponds to 3.05 MeV in the center-of-mass system. A , counter coupled to an on-line computer is used to obtain 115 angular distributions and absolute cross sections of , , , , and particles. , , , and are formed in several different reactions. The observed relative cross sections are often independent of the mode of formation. Cross sections for low-lying states of these nuclei, and , are closely proportional to () where is the spin of the residual state. On this basis it is suggested that the statistical compound nucleus mechanism dominates the cross sections to many low-lying states. At high-level excitations, yields typically deviate upwards from () dependence. The 9.16-MeV and 9.13-, 10.09-, and 11.06-MeV states have very large yields in the (, ), (, ) reactions. At these higher excitations direct reactions evidently supplement the statistical yields. Unambiguous evidence for the following unreported levels is found: 7.17±0.04, 7.37, 8.14, 8.55, 8.93, 9.26, and 9.74 MeV in ; 7.66±0.05, 8.10, 8.36, 8.83, and 9.47 MeV in ; and 10.79±0.03 MeV in (previously reported as 10.71±0.09 MeV).
- Received 3 January 1966
DOI:https://doi.org/10.1103/PhysRev.145.802
©1966 American Physical Society