The Angular Distribution of Long-Range Alpha-Particles from the Bombardment of Boron-11 by Protons

Abstract

The angular distribution of alpha-particles of long range from the reaction 11B(p, α)8Be has been studied over the range 130 to 280 keV proton energy. A strong anisotropy varying with energy is observed and can be explained in terms of an interference between states of opposite parity in 12C. The theoretical analysis gives the result that the well-known 16.11 MeV level in 12C formed by resonant capture of 162 keV protons in 11B has spin 2 and even parity.