The Angular Distribution of α-particles from the Reaction 19F(pα)16O*(π)16O

Abstract

The angular distribution of α-particles from the reaction ¹⁹ F ( p α) ¹⁶ O ^* (π) ¹⁶ O has been measured at fourteen energies between 800 kev and 1400 kev. The α -particles were detected and identified by coincidence with nuclear pair-electrons. The data were analyzed to give coefficients in the expansion formula σ(θ)= a ₀ + a ₁ cos θ+ a ₂ cos ² θ+ a ₃ cos ³ θ+ a ₄ cos ⁴ θ. The spins of the levels of the compound nucleus ²⁰ Ne were assigned from the evidence of anomalies in the coefficients. For the resonances at 843-, 1126-, 1355-kev J =2 and for that at 1250 kev J =1.