Multichannel R-matrix analysis of elastic and inelastic resonances in the 20,21Na+p compound systems

Resonant scattering studies were performed using radioactive 20,21Na beams at ISAC between energies of 0.5 keV/u and 1.5 keV/u. Intensities of up to 1 × 108 /sec were used with thick CH2 targets, and elastic and inelastic proton resonances were observed corresponding to states in 21,22Mg by detecting recoil protons using the LEDA silicon array. A multichannel R-Matrix formalism was used to fit the excitation functions leading to the deduction of partial widths and spin-parity assignments. In certain cases definite spin-parity assignments could be made without fitting angular distributions due to the constraining nature of Coulomb-interfering resonances. Where possible, analogue assignments are made in the A=22, T=1, system based on the 21Na+p analysis.