  The structure of the unbound proton-rich isotope 19Na was studied in
resonance elastic scattering of a radioactive 18Ne beam on a proton target
using the thick-target inverse-kinematics method. The experiment covered
excitation energy range from 0.5 to 2.7 MeV in c.m.s. Only one state of 19Na
(the second excited state) was observed. A combined R-matrix and
potential-model analysis was performed. The spin and parity assignment of this
second excited state was confirmed to be 1/2+. We showthat the position of the
1/2+ state significantly affects the reaction rate through that state but the
total reaction rate remains unchanged since the 18Ne(2p,gamma) proceeds mostly
via the ground and first excited states in 19Na at stellar temperatures.
