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The first excited state above the p + 19Ne threshold in 20Na has been identified at 2.637 MeV (+ 15 keV) with jx = 0 + or 1 + from the 20Ne(3He, t)20Na reaction, suggesting this state to be the s-wave resonance in the p + 19Ne scattering at stellar energies.In hydrogen-rich stellar sites with very high temperature, rapid proton process (rp-process) will take place, producing energy and heavier nuclides.Wallace and Woosley 1) have suggested that the rp-process will give a chance of breakout from the hot CNO (HCNO) cycle to the next cycle of heavier elements with higher rate.Specifically, 20Na is crucial for this breakoutl,2).However, the nuclear structure information on 20Na was insufficient3), especially about the spin-parities of the states above the p + 19Ne threshold.Several new states were reported 4) very recently, but no spin assignment was made for the states.We have performed an experiment of the 20Ne(3He,t)20Na reaction to determine the energies, spin parities of the states near and above the threshold in 20Na. A gas target of enriched 20Ne (99.95 %) of about 100 mmHg was bombarded by a 55.33-MeV 3He beam of about 0.5 -1.0 gA from the cyclotron of the Institute for Nuclear Study of the University of Tokyo.The reaction products tritons were measured by using a magnetic spectrograph and a position-sensitive gas counter placed on the focal plane.This system provides complete particle identification for tritons by using the energy loss, total energy and the time-offlight signals.The overall energy resolution (FWHM) is about 75 keV. The focal plane was carefully calibrated by using the known reactions 160(3He,t)16F and 14N(3He,t)140. The experimental uncertainties in excitation energies are mostly due to those of the reference peaks of 16F and 140 used, which are ranging from I0 to 60 keV, and partly due to the possible errors in fitting multiplet peaks. Figure 1 shows a typical momentum spectrum of tritons from the 20Ne(3He,t)20Na reaction.There are several states excited above the threshold of p + 19Ne, 2.199 MeV. Figure 2 shows the angular distributions for the ground state and the state at 2.637 MeV (+ 15 keV), which is the first excited state above the threshold. This excitation energy is consistent with 2.63 MeV derived by a recent precision 2~ (h, t) 2~

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