S>A phase-ehift analysis of the elastic p-t cross section in the energy range 0.1 to 0.76 Mev was made. It is shown that the low peak observed at 0.3 Mev is consistent with a 0/sup plus or minus / resonance at 0.5 plus or minus 0.1 Mev. The shape of the observed cusp in the p-t elastic cross section at the threshold energy of the n-He/sup 3/ channel is used to demonstrate that the energy behavior of the singlet and triplet s-wave phase obtained must be qualitatively unique. A direct comparison is made of the Breit-Wigner single- level approximation and the alternative two-channel scattering length description of the state. (auth)