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We have studied the breakup of 140 MeV 16 O into 12 C + α by targets of 12 C, 13 C and 28 Si. At least two mechanisms contribute. One can be identified as the coherent excitation of the 16 O projectile to components of the giant resonance states. Another dominant mechanism may be the quasi-free scattering of the α or 12 C constituents of the projectile by the target.

An exact calculation has been made of the kinematics for the transfer of one or more nucleons from projectile to target at bombarding energies above the Coulomb barrier. The calculation presumes that the transfer occurs in an overlapping region of the projectile and target. A comparison of calculated results with measurements of angular momentum transfer shows much better agreement than obtained from purely peripheral transfer calculations. The calculation also reproduces in detail the dependence of ejectile velocities on the ejectile mass and charge.

The collision of two nuclei is treated as a collection of collisions between the nucleons of the projectile and those of the target nucleus. The primary projectile fragments contain only those nucleons that did not undergo a collision. The inclusive and coincidence cross sections result from the decay of the excited primary fragments. 15 refs., 5 figs.

The excited levels of Cu63 have been studied by inelastic alpha scattering. Three quadrupole vibration levels at 0.668, 0.961 and 1.327 MeV are observed and are found to have enhanced B(E2)lrarr; values. These are discussed in light of a core excitation model. Of the five enhanced octupole states observed at 2.51, 3.32, 3.51, 3.74 and 3.84 MeV, four probably arise from the excitation of the 3−, Ni62 core state. The fifth level might possibly be due to the promotion of the p 3 2 proton to the g 9 2 state.

A new beam analysis system has been installed at the Berkeley 88″ cyclotron. The system consists of two 110° flat field, edge focusing bending magnets. The first magnet is used to energy analyze the cyclotron beam, and the second or “clean up” magnet is used to remove slit scattered particles produced by the analyzing magnet. The system has achieved its design performance of 0.02% energy resolution, with a long term stability of two parts in 105. Up to 0.6 μA of a beam with a radial emittance of 4.5 mm·mrad has been obtained with the above energy resolution. This paper describes the design, construction, installation shimming and testing of the magnets, as well as the construction of the regulated power supply.

The reactions $^{91,92,94}\mathrm{Zr}(\ensuremath{\alpha},t)^{92,93,95}\mathrm{Nb}$, $^{90,91,92,94}\mathrm{Zr}(\ensuremath{\alpha},d)^{92,93,94,96}\mathrm{Nb}$, and $^{92}\mathrm{Mo}(\ensuremath{\alpha},d)^{94}\mathrm{Tc}$ have been investigated with a 50-MeV $\ensuremath{\alpha}$-particle beam from the Berkeley 88-in. cyclotron. High-spin proton excited states observed in the ($\ensuremath{\alpha},t$) reaction, based on comparisons with ($^{3}\mathrm{He},d$) experiments on the same targets, include: $^{92}\mathrm{Nb}$(\ensuremath{\cong}5 MeV multiplet); $^{93}\mathrm{Nb}$(1.08, 1.29, \ensuremath{\cong}4.5 MeV); and $^{95}\mathrm{Nb}$(1.27, 1.65, 2.10 MeV). Two groups of strongly excited states appear in the ($\ensuremath{\alpha},d$) data. Members of the lower group [$^{92}\mathrm{Nb}$(g.s.), $^{94}\mathrm{Nb}$(0.08 MeV), and $^{96}\mathrm{Nb}$(0.23 MeV)] have been previously identified as being ${(\ensuremath{\pi}{g}_{\frac{9}{2}},\ensuremath{\nu}{d}_{\frac{5}{2}})}_{{7}^{+}}$ states. Based on the $^{92}\mathrm{Mo}(\ensuremath{\alpha},d)^{94}\mathrm{Tc}$ results, the $^{94}\mathrm{Tc}$ ground state can also be assigned ${7}^{+}$. The higher levels [$^{92}\mathrm{Nb}$(2.58 MeV), $^{94}\mathrm{Nb}$-(2.42 MeV), $^{96}\mathrm{Nb}$(2.38 MeV), and $^{94}\mathrm{Tc}$(2.68 MeV)] are believed to be either ${(\ensuremath{\pi}{g}_{\frac{9}{2}},\ensuremath{\nu}{g}_{\frac{7}{2}})}_{{8}^{+}}$ or ${(\ensuremath{\pi}{g}_{\frac{9}{2}},\ensuremath{\nu}{h}_{\frac{11}{2}})}_{{10}^{\ensuremath{-}}}$ states based on the results of shell-model matrix-element calculations and the ($\ensuremath{\alpha},d$) structure factors of Glendenning.

The study of transfer reactions with heavy-ion projectiles is complicated by the frequent presence of three or more nuclei in the final state. One prolific source of three-body reactions is the production of a primary ejectile in an excited state above a particle threshold. A subset of transfer reactions, viz., those producing ejectiles in bound states, can be identified experimentally. This has been accomplished with a 4..pi.. detector constructed of one-millimeter-thick scintillator paddles of dimension 20 cm x 20 cm. The paddles are arranged in the form of a cube centered around the target with small entrance and exit apertures for the beam and the projectile-like fragments, (PLF). The detection of a light particle (e.g., a proton or an alpha particle) in coincidence with a PLF indicates a breakup reaction. The absence of any such coincidence indicates a reaction in which all the charge lost by the projectile was transferred to the target. With this technique we have studied the transfer and breakup reactions induced by 220 and 341 MeV /sup 20/Ne ions on a gold target. Ejectiles from Li to Ne have been measured at several scattering angles. The absolute cross sections, angular distributions and energy spectra for the transfer and breakup reactions are presented. Relatively large cross sections are observed for the complete transfer of up to seven units of charge (i.e., a nitrogen nucleus). The relatively large probabilities for ejectiles to be produced in particle-bound states suggest that on the average, most of the excitation energy in a collision resides in the heavy fragment when mass is transferred from the lighter to the heavier fragment. The gross features and trends in the energy spectra for transfer and breakup reactions are similar. 20 references.

Reactions induced in fissionable elements by deuterons and helium ions were studied. Results from excitation-function measurements, the dependence of ( GAMMA /sub n// GAMMA /sub f/) on Z and A, and tritium production by chargedparticle bomhardment of Au, Th, and U are plotted. It was found that although most of the reactions involve formation of a compound nucleus, the reactions that survive fission best are those going by a direct interaction without the formation of a highiy excited compound nucleus. (M.H.R.)