The 12C(alpha,gamma) 16O radiative capture reaction is one of the most important reactions in nuclear astrophysics as its reaction rate determines the C/O ratio in the Universe. A better understanding of this reaction is what motivates the experiments presented in this thesis.
In experiments performed at Ohio University angular distributions and branching ratios of the 7.12- and 6.92-MeV transitions in 16O were measured. An upper limit was set on the 7.12 to 6.13-MeV transition in 16O. These results will better constrain the alpha-reduced width of the 6.92-MeV state in 16O which is important for the extrapolation to helium-burning energies of both the E2 transition and cascade through the 6.92-MeV state.
At the DRAGON recoil separator at TRIUMF, Canada, the E to 6.05 MeV transition in 12C(alpha,gamma) 16O was measured over a wide range of energies. The result shows that the cascade through the 6.05-MeV state is the most important cascade in 12C(alpha,gamma) 16O with an extrapolated S-factor at 300 keV, S 6.05(300)=25±16 keV b. A new value for the total S-factor at 300 keV is proposed.