The differential cross section of the 10B(p,α)7Be reaction has been measured for bombarding proton energies between 2.1MeV and 6.0MeV, in 100keV steps, at seven laboratory angles from 30° to 150°. This reaction is of importance because it can be a source of radioactive waste in reactors which will use boron as a nuclear fuel. The total cross section was extracted at each proton energy. On average, the results of this experiment are ∼16% higher than previously reported measurements. The astrophysical S-factors were also extracted from the total cross sections.

Measurements of the absolute cross section and angular distributions for the \(^{11} \hbox{B}(p,\alpha)^{8}{\text{Be}}\rightarrow\alpha+\alpha\) and the 11B(α,α)11B reactions have been performed from 0.15 to 3.8 MeV for the 11B(p,α) study and from 2 to 5.4 MeV for the 11B(α,α) reaction. The absolute cross sections are presented in terms of the total number of α-particles detected in order to avoid uncertainties due to ambiguities in the number of alpha particles emitted in the reaction at a particular energy. The angular distributions of the 11B(p,α)8Be(2+) reaction were fit to a Legendre polynomial expansion and the coefficients are presented. Finally, the 11B(α,α)11B data were fit in terms of phase shifts (ignoring the spin of the target), providing a convenient representation of the elastic cross section data between 2 and 5.4 MeV.

Resumen en: Angular distributions of cross sections and analyzing powers were measured for 14C(p, p)14C for proton energies between 3.7 and 11.0 MeV in very small en...

Measurements of the absolute cross section and angular distributions for the ^11B(p,α)^8Be→α+α and the 11 B(α,α) 11 B reactions have been performed from 0.15 to 3.8 MeV for the 11 B( p ,α) study and from 2 to 5.4 MeV for the 11 B(α,α) reaction. The absolute cross sections are presented in terms of the total number of α-particles detected in order to avoid uncertainties due to ambiguities in the number of alpha particles emitted in the reaction at a particular energy. The angular distributions of the 11 B( p ,α) 8 Be(2 + ) reaction were fit to a Legendre polynomial expansion and the coefficients are presented. Finally, the 11 B(α,α) 11 B data were fit in terms of phase shifts (ignoring the spin of the target), providing a convenient representation of the elastic cross section data between 2 and 5.4 MeV.

Angular distributions of cross sections and analyzing powers were measured for C-14(p, p)C-14 for proton energies between 3.7 and 11.0 MeV in very small energy steps. A number of strong resonances are seen. Phase-shift analysis of the elastic scattering data yielded level parameters of eleven states in N-15 in the excitation energy region 13.7-21.0 MeV. Previous assignments of spin, parity and energy of levels are discussed.

The B11(p,α)αα reaction at energies between 200 keV and a few MeV has a very long history, dating back to studies by Lord Rutherford and Dee and Gilbert in the 1930s. It is shown that the modern view of this reaction, established in 1987, is incorrect. This model viewed the reaction as a two-step process with a primary high energy α-particle having ℓ=1 going to the first excited state of Be8, with the subsequent emission of two low energy secondary α-particles. We have found that an earlier result (1969) which showed that the primary α-particle must have ℓ=3 does, as originally noted, account for the data. Our simulations show that this view leads to the prediction of two high energy α-particles (of almost equal energy), as originally proposed in 1936, one being the primary α-particle and the other a secondary α-particle. Coincidence data verify the existence of these two high energy α-particles. The implications of this result on astrophysics and fusion energy production are noted.