The "missing" 3(+) state of 18Ne and explosive 17F(p, gamma ) burning.

Wiescher, Gorres, and Thieleman suggested that a missing J π = 3 + level in 18 Ne should occur at E x 4.33 MeV, only 410 keV above the 17 F + p threshold. They noted that this level would provide an s-wave resonance in the 17 F(p,γ) reaction, greatly increasing its thermonuclear reaction rate. This, in turn, would have a pronounced effect on the production of 17 O and 18 O in explosive stellar environments. We have searched for this level using the 16 O( 3 He, n) reaction. High-resolution time-of-flight spectra show that the 3 + level occurs at E x = 4.561 ± 0.009 MeV, 230 keV higher than suggested. The astrophysical consequences of this result are discussed.