[en] The structure of ⁶⁷Ge was studied by in-beam gamma-ray spectroscopy. Thirty-one excited states up to 2.6 MeV in ⁶⁷Ge were identified, and more than sixty gamma rays were placed in the level scheme. The results of gamma-ray angular-distribution measurments uniquely determined the spins of the lowest-lying states, and provided rough values for the E2/M1 mixing ratios of prominent gamma transitions of these states. 1 figure, 1 table

[en] Operational experiences with and university use of the ANL dynamitron are recounted

[en] Proton spectra at 45⁰ from 220-MeV π⁺ on ⁴He, ¹²C, ⁶²Ni, and ¹⁸¹Ta are shown. For ⁴He clear evidence is seen for a two-body absorption mechanism in which the pion deposits its rest mass and kinetic energy on to two nucleons. This mode is weaker for the heavier nuclei, which have spectra of a distinctly different shape. 1 figure

[en] In the lower-energy region, the fusion cross sections seem to be dominated by the interaction barrier. While the barrier radii deduced have a smooth dependence on A, this A dependence is different from that of heavier systems. Barrier radii, R/sub B/, and heights, V/sub B/, are plotted versus A₁/sup 1/3/ + A₂/sup 1/3/. At higher energies, the fusion cross sections are found to saturate at magnitudes which differ significantly for systems which differ by only a nucleon or two. These results constitute evidence for nuclear structure effects in the fusion process. 1 figure

[en] Excitation functions were measured at laboratory angles of 10.5, 12.0, and 13.5 degrees. Preliminary analysis reveals that the excitation functions for at least the three strongest states, 3^-(6.88 MeV), 5^-(9.70 MeV), and the 3^- (10.18 MeV), show evidence of structure at the approx. 50% level, somewhat lower than that observed for the ground state and 2⁺ (1.78 MeV) state; the structure seems to show some correlation in energy with that for the lower states. These observations suggest that the resonance strength may be shared between several channels. 1 figure

[en] Angular distributions were measured for elastic and inelastic scattering of 45- and 75-MeV ¹⁶O by ⁴⁰Ca. DWBA and coupled-channels calculations were performed. The two calculations produced similar results for elastic scattering. For inelastic scattering, the latter agreed well with the data at the higher energy, but significant discrepancies existed at the lower

[en] The detailed energy dependences of the total fusion cross sections, sigma/sub fus/(E), for ¹²C + ²⁴Mg and ¹²C + ²⁶Mg were measured. Data were obtained for 20 less than or equal to E/sub lab/ less than or equal to 60 MeV by measuring the evaporation residues in the ΔE-E gas ionization chamber silicon detector system. Single-angle measurements (theta/sub lab = 8⁰) were made in 500-keV steps, and full angular distributions were measured at several energies over the region studied. The results indicate the presence of structure of less than or equal to 5 to 10% in sigma/sub fus/ (E) for ¹²C + ²⁴Mg, while that for ¹²C + ²⁶Mg shows a smoother behavior; moreover, sigma/sub fus/(E) for the two systems differ significantly. The fusion cross sections for the ¹²C + ²⁴Mg system are plotted. It is found that for targets in the sd shell, the specific structure of the nuclei interacting significantly affects the fusion cross-section behavior. 1 figure

[en] The configurations of the 3/2⁺ resonances at 7.7 and 8.2 MeV in ¹³C have been the subject of numerous theoretical calculations. Unfortunately, the E1 ground-state radiative widths for these resonances have not been previously measured. To extract accurate ground-state transition rates for these resonances, an observed high-resolution photoneutron cross section was interpreted in terms of a multilevel R-matrix analysis. The well-known neutron scattering channel is fully considered. The results of this analysis are compared with the data. it appears that the channel capture widths of the 7.7- and 8.2-MeV resonances are large and their influence must be included in any comparison of the radiative widths with theory. 1 figure

[en] Angular distributions were measured at 6⁰ less than or equal to theta/sub c.m./ less than or equal to 50⁰ for the ²⁴Mg(¹⁶O,¹²C)²⁸Si reaction at E/sub c.m./ = 26.3, 26.9, 27.8, 29.4, 30.1, 31.6, 32.4, and 33.8 MeV. The data were analyzed in terms of a DWBA amplitude plus a resonant term at each energy. The results confirm the hypothesis that two overlapping resonants are required to fit the data around E/sub c.m./ = 31 MeV; at 28 MeV one resonant amplitude seems to be sufficient. This analysis demonstrates that the structures observed at forward and backward angles can be explained in terms of interfering direct and resonant amplitudes. 1 figure

[en] The blisyter diameter, D/sub mp/ and blister skin thickness, t, values were evaluated for only annealed polycrystalline niobium for irradiation with ⁴He⁺ ions in the energy range 20 keV to 500 keV at 300⁰C and at 700⁰C. For the temperature range studied, the blister skin thickness values did not change within the experimental error limits for a given projectile energy. A log-log plot of D/sub mp/ against mean blister skin thickness values is shown for irradiation at room temperature, at 300⁰C, and 700⁰C. For irradiation at 300⁰C a power curve fit through the data points gives the relationship D/sup mp/ = 9.6 t¹¹⁹. The results reported here show that, as the irradiation temperature is increased, the values for both the exponent and the pre-exponential factor in the D-t relationship decrease. 1 figure