A. C. Roy

12C + 7Li Reaction measurements and the 12C(7Li, t)16O reaction

Abstract A measurement of the residues from the 12 C + 7 Li reaction has been obtained for 7 Li energies from 10 to 38 MeV. From these measurements the fusion cross sections and critical angular momenta for the 12 C + 7 Li system have been deduced. Cross sections for the 7 Li( 12 C, t) 16 O reaction have been obtained for 12 C energies from 54 to 62 MeV at θ lab = 2.7°. The critical angular momenta obtained from the fusion cross sections have been used to perform Hauser-Feshbach calculations for the 12 C( 7 Li, t) 16 O reaction. These calculations have been compared to measured angular distributions over a wide energy range. By comparing the fusion cross sections required by the Hauser-Feshbach calculations to fit the 12 C( 7 Li, t) 16 O(8.87 MeV) reaction and the measured residue cross section it is estimated that at least 80 % of the measured residues are fusion products. The calculations also indicate that direct processes dominate the population of many 16 O levels at forward angles and the 10.35 MeV state at backward angles. The necessity for using a critical angular momentum in Hauser-Feshbach calculations is discussed.

Search for 8+ strength in 16O via the 12C(α, α2)12C∗(7.66 MeV) reaction

Abstract Closely spaced angular distributions have been measured for the 12 C (α, α 2 ) 12 C ∗(7.66 MeV ) reaction between Eα = 17.39 and 20.5 MeV in a search for 8+ strength in 16O. No evidence of 8+ strength is found, but evidence is found for a narrow 7− resonance at 21.52 MeV excitation.