Neutrons and Gamma Rays from the Alpha-Particle Bombardment of Be9, B10, B11, C13, and O18

Abstract

Excitation curves at 0° and 90° were studied for neutrons and γ rays produced in bombardment of thin targets of Be9, B10, B11, C13, and O18 by α particles with energies of from 1.8 to 5.3 Mev. Resonances were observed in the Be9(α, n)C12 reaction at bombarding energies of 1.9, 2.3, 2.6, 3.98, 4.4, and 5.0 Mev. The C13(α, n)O16 reaction showed resonances at 2.09, 2.25, 2.42, 2.605, 2.69, 2.775, 2.825, 3.09, 3.33, 3.42, 3.67, 3.73, 4.125, 4.42, 4.50, 4.63, 4.75, and 5.05 Mev. The B10(α, n)N13 excitation curve has resonances at 2.16, 2.25, 2.90, 4.53, 4.85, and 5.36 Mev, while the γ-ray yield from the B10(α, pγ)C13 reaction showed all these as well as resonances at 3.6 and 3.95 Mev. The B11(α, n)C13 reaction has resonances at bombarding energies of 2.06, 2.60, 2.93, 2.97, 3.23, 3.54, 3.72, 3.92, 4.25, 4.34, and 5.00 Mev. The O18(α, n)Ne21 reaction was studied with a thicker target (90-130 kev). Resonances in the neutron yield were resolved at 2.21, 2.47, 2.57, 2.72, 2.94, 3.24, 3.63, 3.91, 4.12, 4.22, 4.33, 4.52, and 4.82 Mev. Cross sections and widths of the resonances in the various reactions were determined.