Study of 18F by use of ( 3He, p) and (α, d) reactions

Abstract

Spectra and angular distributions were obtained for the reactions and conditions 16O( 3He, p) 18F at E( 3H He) = 19.8 MeV from θ lab = 9 ° to 170° for 18F excited states below 11.3 MeV excitation and for 16O( α, d) 18F at E( α) = 40.3 MeV from θ lab = 8° to 80° for 18F excited states below 12.7 MeV excitation. Distorted-wave (DW) calculations for the ( 3He, p) reaction were compared to experimental angular distributions and relative total cross sections. Agreement was found when spin-independent interaction potential was used. Nuclear wave functions used in the calculations are discussed. Spectroscopic and configuration assignments were made or confirmed on the basis of excitation energy, angular distributions, comparison of (α, d) and ( 3He, p) results, relative total cross sections and comparison of experimental quantities to DW calculations. Configurations and J π values of 3 + and 4 + were suggested for 18F levels at 3.358 and 5.594 MeV excitation energy, respectively. Configurations and J π T values were confirmed for some levels at T = 0 assignments were made for a large number of levels. A new 18F level at an excitation energy of 8.596 ± 0.019 MeV was identified.