Investigation of the 10B(p, α) 7Be reaction from 0.8 to 2.0 MeV

Background: A multitude of broad interfering resonances characterize the B-10(p, alpha) Be-7 cross section at low energies. The complexity of the reaction mechanism, as well as conflicting experimental measurements, have so far prevented a reliable prediction of the cross section over the energy ranges pertinent for a boron-proton fusion reactor environment. Purpose: To improve the evaluated cross section of the (10) B(p, alpha) Be-7 reaction, this study targets the proton energy region from 0.8 to 2.0 MeV, where kinematic overlap of the scattered protons and reaction a particles have made past measurements very challenging. Method: New detailed studies of the reaction have been performed at the Edwards Accelerator Laboratory at Ohio University and the Nuclear Science Laboratory at the University of Notre Dame using time-of-flight and degrader foil techniques, respectively. Results: Proton and alpha-particle signals were clearly resolved using both techniques, and 16 point differential cross sections were measured over an angular range of theta(lab) = 45 degrees and 157.5 degrees. A comprehensive R-matrix analysis of , the experimental data, including data from previous low-energy studies of the B-10(p , alpha)Be-7 B-10 (p, p) B-10 and B-10 (p, gamma) C-11 reactions, was achieved over the region of measurement. Using a representative set of previous data, the fit was extended to very low energies. Conclusions: On the basis of this data and R-matrix analysis, a more reliable and consistent description of the B-10 (p, alpha) Be-7 cross section has been established. The uncertainty over the energy range of this study has been reduced from approximate to 20% to approximate to 10% and the level structure over this region has been clarified considerably.

Automated summary

This study aimed to improve the evaluation of the B-10(p, alpha) Be-7 reaction by conducting detailed research. Proton and alpha-particle signals were successfully resolved using different techniques, reducing the uncertainty of the cross section and clarifying the level structure. Overall, a more reliable and consistent description of the reaction has been established.