The (He3, n) reactions on B11, N15, O16, and O18 targets have been studied using a pulsed-beam time-of-flight spectrometer.Special emphasis was placed upon the determination of the excitation energies and properties of states with T = 1 (in Ne18), T = 3/2 (in N13 and F17) and T = 2 (in Ne20).The identification of the T = 3/2 and T = 2 levels is based on the structure of these states as revealed by intensities and shapes of angular distributions.The reactions are interpreted in terms of double stripping theory.Angular distributions have been compared with plane and distorted wave stripping theories.Results for the four reactions are summarized below:
1)O16 (He3, n).The reaction has been studied at incident energies up to 13.5 MeV and two previously unreported levels in Ne18 were observed at Ex = 4.55 ± .015 MeV (Γ = 70 ± 30 keV) and Ex = 5.14 ± .018 MeV (Γ = 100 ± 40 keV).
2)B11 (He3, n).The reaction has been studied at incident energies up to 13.5 MeV.Three T = 3/2 levels in N13 have been identified at Ex = 15.068 ± .008 MeV (Γ ˂ 15 keV), Ex = 18.44 ± .04, and Ex 18.98 ± .02 MeV (Γ = 40 ± 20 keV).
3)N15 (He3, n).The reaction has been studied at incident energies up to 11.88 MeV.T = 3/2 levels in F17 have been identified at Ex = 11.195 ± .007 MeV (Γ ˂ 20 keV), Ex = 12.540 ± .010 MeV (Γ ˂ 25 keV), and Ex = 13.095 ± .009 MeV (Γ ˂ 25 keV).
4)O18 (He3, n).The reaction has been studied at incident energies up to 9.0 MeV.The excitation energy of the lowest T = 2 level in Ne20 has been found to be 16.730 ± .006 MeV (Γ ˂ 20 keV).
Angular distributions of the transitions leading to the above higher isospin states are well described by double stripping theory.Analog correspondences are established by comparing the present results with recent studies (t, p) and (He3, p) reactions on the same targets.
