The velocity distribution of fusionlike products formed in the reaction 701 MeV ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$${+}^{100}$Mo is decomposed into 26 incomplete fusion channels. If Coulomb corrections are neglected the yields of the incomplete fusion channels correlate much better with the Q value for projectile fragmentation than with the Q value for incomplete fusion. However, the correlation is much improved for incomplete fusion if a Coulomb correction is included. The partition of linear momentum between various sources is deduced using the measured residue velocity, multicomponent fits to light charged particle spectra, and mean neutron multiplicities. This reconstruction indicates that a substantial fraction of the momentum is not detected by our apparatus when slow residues are produced. With reasonable assumptions about this missing momentum component, the initial excitation of the compoundlike system is calculated as a function of the residue velocity.

Evaporation simulations are presented to illustrate the problems associated with the determination of the nuclear level density constant at high excitation energy from evaporation spectra. The methods of using either the total (whole chain) spectra or the difference (from two different initial excitation energies) spectra are discussed. Data from the study of the reaction 701 MeV ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$${+}^{100}$Mo are presented and both methods are used to extract the level density constant. We find that in order to reproduce the slopes of the light particle spectra the level density constant must have a value near 1/10A– 1) / 11 A for excited nuclei with statistical temperatures in the range of 3.5 to 5.5 MeV. This presumes that the only parameter adjustment required to treat the decay of highly exited nuclei is the level density constant. If this is so, the shapes of the evaporation spectra imply a reduction in the level density constant from the value required to explain the decay of less highly excited nuclei, a conclusion reached by others. However, the reduced level density constant leads to an overproduction of deuterons and tritons. This suggests that a more complicated set of parameter adjustments may be required to treat the decay of highly excited nuclei.

Continuum spectra for the inclusive reaction ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$(p,p’) have been measured for scattering angles between 24° and 145° at incident energies of 80 and 120 MeV. The spectra and angular distributions at various ejectile energies above 20 MeV are compared with published experimental data for ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$(p,n) at the same incident energies. Results of statistical multistep direct emission calculations are in excellent agreement with the experimental angular distributions. The extracted strength of the effective nucleon-nucleon interaction is shown to be reasonable with respect to absolute magnitude and energy dependence. A phenomenological parametrization of the angular distributions also describes the experimental quantities well.

Fusion cross sections have been measured for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$${+}^{128}$Te from ${\mathit{E}}_{\mathrm{c}.\mathrm{m}.\mathrm{}}$=40.4 to 56.6 MeV by direct detection and identification of evaporation residues using a time-of-flight technique. Average angular momenta for fusion are deduced from a sharp cutoff approximation at energies above the Coulomb barrier. These values of 〈l〉 and those already obtained from isomer ratio measurements are in very good agreement in the energy region where both methods should be valid.

The inclusive reaction ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$(p,p’) was studied at incident energies of 100, 120, 150, 175, and 200 MeV for scattering angles between 15° and 120°. Angular distributions at various emission energies are analyzed in terms of a quasifree knockout reaction mechanism, combined with parametrized systematics which should represent multistep contributions. Reasonable agreement between the experimental data and calculated distributions is obtained, with a consistent incident-energy dependence. The proportion of the quasifree component amounts to ∼30% of the preequilibrium yield. The quasifree contribution appears to be in agreement with the first-step yield of the statistical multistep-direct emission theory.

Gamma-ray multiplicities for the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${+}^{154}$Sm system have been determined using two different coincidence techniques. Fusion events are tagged either by observation of low-lying gamma transitions in the evaporation residues or by direct detection of the residues exploiting an electrostatic deflector and time-of-flight identification. The gamma-ray tagging measurements have been made with higher sensitivity than previously, allowing us to include the contribution of the 3n channel. The contribution of this channel modifies the conclusions made before in regard to the spin distribution of the compound nucleus produced at near-barrier energies. The procedure for conversion of gamma-ray multiplicities to mean spin values has been calibrated by measuring gamma-ray multiplicities and fusion cross sections for the ${}_{}{}^4{}_{}{}^{}\mathrm{He}$${+}^{166}$Er and ${}_{}{}^3{}_{}{}^{}\mathrm{He}$${+}^{167}$Er reactions that lead to the same compound nucleus as ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${+}^{154}$Sm, at bombarding energies that span the same region of excitation energies and spin. The use of an electrostatic deflector enables an inclusive tag on all evaporation residues, and has sufficient sensitivity to enable measurements at a lower energy than is possible with gamma-ray tagging techniques. The energy dependence of the mean spin deduced from gamma-ray multiplicity measurements is in qualitative agreement with model calculations which include the effects of the static and dynamical deformations of the target nucleus. There is, however, a tendency for the calculations to underestimate somewhat the mean spin near and below the barrier.

This paper investigates the mass, shell, and even-odd effects in the nonstatistical and statistical contributions to the radiative nucleon capture reactions. The (n,γ) cross sections for 32 even-neutron target nuclei were studied at ${\mathit{E}}_{\mathit{n}}$ of 0.1 to 3 MeV. The results indicate that the nonstatistical capture cross sections do not present any remarkably varying pattern with mass number. The statistical capture cross sections, which depend strongly on the level density, display marked mass, shell, and even-odd effects. The nonstatistical fractions show prominent downward tendency with mass number, as well as the shell effect.

Fission of ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$${,}^{232}$Th+838-MeV ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$ projectiles was studied by measuring fragment coincident neutrons. Neutron energy spectra were decomposed into preequilibrium, prescission, and postscission contributions with a constrained moving source analysis. Excitation energies deduced from the transferred linear momentum are consistent with calculations applying the Boltzmann master equation, and with an energy balance based upon the experimental neutron multiplicities and charged particles from evaporation calculations. The time scale of fission derived from the prescission neutron multiplicities extends from 5×${10}^{\mathrm{-}21}$ to 3×${10}^{\mathrm{-}20}$ s; it does not depend on the initial excitation energy, is about a factor of 2 longer for symmetric than for asymmetric fragmentations, and increases with the fissility of the primary reaction system. For all mass splits, the excitation energy left at scission is 50–60 MeV.

Cross sections for the multiple breakup of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$, and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ projectiles scattered by an Au target were measured with an array of 34 phoswich detectors. The dissociation of the projectiles into as many as five charged particles has been observed. The yields of different exit channels correlate approximately with the threshold energy for separation of the projectile into the observed fragments. The excitation spectrum of the primary projectile-like nucleus was reconstructed from the measured positions and kinetic energies of the individual fragments. The energy sharing between projectile and target is consistent with a fast excitation mechanism in which differential increases in projectile excitation energy appear to be accompanied by comparable increases in target excitation. Calculations of the yields based on a sequence of binary decays are presented.

The vector analyzing power ${\mathit{iT}}_{11}$ was measured for ${\mathrm{\pi }}^{+}$${\mathrm{-}}^6$L→i elastic and inelastic scattering ($3^{+}$, 2.19 MeV) at 100, 134, 164, and 219 MeV, in an angular range between 40° and 125° using a vector polarized ${}_{}{}^6{}_{}{}^{}\mathrm{LiD}$ target. Sizable spin effects were observed over most of the angular range. The data were compared with a number of theoretical predictions based on different scattering models and nuclear structure input. None of the calculations is able to reproduce the data set; however, it appears that the vector analyzing power ${\mathit{iT}}_{11}$ is mostly sensitive to the nuclear wave function chosen. The angular distribution of ${\mathit{iT}}_{11}$ in ${\mathrm{\pi }}^{+}$${\mathrm{-}}^6$Li elastic and inelastic scattering is discussed in terms of nuclear form factors and elementary πN amplitudes.

Beams of ${}_{}{}^6{}_{}{}^{}\mathrm{He}$ ions having E=8.8–9.3 MeV and intensity up to 2×${10}^4$ ${\mathrm{s}}^{\mathrm{-}1}$ have been produced via the ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$${(}^7$Li${,}^6$He${)}^{10}$B reaction. The beams had an energy resolution of 0.8 MeV full width at half maximum, 1-cm-diam spot size, and ±3° angular divergence. The first elastic-scattering data for ${}_{}{}^6{}_{}{}^{}\mathrm{He}$ from several targets are presented as examples of the use of this radioactive beam in secondary scattering experiments and their potential use for transfer or breakup reactions. Optical model parameters for ${}_{}{}^6{}_{}{}^{}\mathrm{He}$ are deduced by comparison with calculations using ${}_{}{}^{6,7}{}_{}{}^{}\mathrm{Li}$ and ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ parameters. The data are well reproduced with ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ or ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ optical model parameters but not with those from ${}_{}{}^4{}_{}{}^{}\mathrm{He}$.

Measurements of cross sections for pion-induced double-charge-exchange reactions to the double-isobaric-analog state for ${}_{}{}^{42,44,48}{}_{}{}^{}\mathrm{Ca}$ at incident pion energies of 300–550 MeV at ${\mathrm{\theta }}_{\mathrm{lab}}$=5° are reported, together with upper limits for cross sections for transitions to the residual ground states for ${}_{}{}^{44,48}{}_{}{}^{}\mathrm{Ca}$. The data are fitted with a two-amplitude model which gives expressions for cross sections for both transitions. The fit overpredicts the ground-state cross sections, indicating a failure of the model in this energy range.

Analysis of a three-body model shows that Coulomb polarization of the deuteron has very little influence on the branching ratio A(d,p)/A(d,n) for transfer reactions on target nucleus A at very low deuteron energies (the Oppenheimer-Phillips effect). We see that polarization effects in transfer reactions are not related to the long range of the Coulomb field, but are caused by the more intense fields near the target nucleus. However, even in that region the induced dipole moment is limited by the deuteron binding, and it is small for low Z targets. We see in addition that the transfer amplitudes tend to be insensitive to any polarization admixtures in the entrance channel. On the other hand, the branching ratio can be affected by the Coulomb barrier for the bound final-state wave function of the proton, especially for very weakly bound final states. Brief remarks about the relation of stripping theory to special properties of the d+d system are included.

The formation of polarized hypernuclei through kaon photoproduction is investigated in a distorted-wave impulse approximation approach. The polarization depends strongly on the model used to describe the elementary process. For one particular model and certain well populated states the amount of polarization may reach up to 50%. We present cross sections and polarizations for kaon photoproducton on ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$, and ${}_{}{}^{89}{}_{}{}^{}\mathrm{Y}$ and demonstrate the sensitivity of polarization to distortion and nonlocal effects. More information on the elementary process is needed before the feasibility of such measurements can be established.

An approximate relation is derived which allows the calculation of the two-proton correlation function for any reaction model capable of predicting the classical single-particle phase-space distribution or Wigner function in the exit channel. The sensitivity of the calculated two-proton correlation functions to source radii and lifetimes is illustrated with simple parametrizations. More realistic calculations are presented for two different regimes of emission time scales: slow particle evaporation from equilibrated compound nuclei, as predicted from the Weisskopf formula, and fast nonequilibrium particle emission in intermediate-energy nucleus-nucleus collisions, as predicted from the Boltzmann-Uehling-Uhlenbeck transport equation.

Various relativistic treatments are applied to deuteron-nucleus elastic scattering at intermediate energies. There are various possibilities for spin-one wave equations. Here we have considered three of them, the Kemmer-Duffin-Petiau, Proca, and Weinberg equations. Second-order equations are obtained from each using a similar set of approximations. Elastic-scattering observables including the differential cross section, and the vector and tensor analyzing powers are calculated using all three equations. The different predictions are compared with each other and with experimental data for 400 MeV ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$(d,d${)}^{58}$Ni and 700 MeV ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$(d,d${)}^{40}$Ca. We find that within the approximations made and for the assumed interactions there are no significant differences between the three sets of predicted observables.

Presently there exists a lack of systematic analysis on the differences in perturbation methods for studying direct rearrangement collisions. Emphasis is placed upon elucidating the formal differences in the structures of the T matrix in various perturbation theories by paying attention to differences in perturbation potentials and T operators. Extensive comparison between different perturbation theories and the relationship between them is explicitly shown to further highlight the formal differences among them.

The elastic α-α scattering is treated within the framework of a generalized phase-function method (GPFM). This generalization consists in absorbing the effect of Coulomb interaction in the comparison functions for developing the phase equation. Based on values of scattering phase shifts computed by the present method, it is concluded that the GPFM provides an uncomplicated approach to rigorous Coulomb correction in the α-α scattering.

An efficient method for construction of an analytic S matrix from experimental data based on the use of the statistical Padé approximation is proposed. The method is applied to the energy-dependent phase-shift analysis of the elastic scattering of deuterons by alpha particles in the energy range 0.87<${\mathit{E}}_{\mathit{d}}$<5.24 MeV, and partial-wave phase shifts for l=0,1,2 are obtained. In addition, the energies and widths of the three known ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ resonances are obtained, together with the energy of the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ bound state and the vertex constant of the virtual decay ${}_{}{}^6{}_{}{}^{}\to _{}^2{}_{}{}^{}$H${+}^4$He.

Using CR-39 nuclear track detectors and an automated scanning system, we have studied the behavior of projectile fragments with charges 8≤${\mathit{Z}}_{\mathit{F}}$≤13 produced in interactions of 14.5A GeV ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ nuclei with Pb and Cu targets. Both nuclear and electromagnetic spallation contribute to fragmentation of beam nuclei in Pb and Cu. The total charge-changing cross sections of nuclear projectile fragments with 9≤${\mathit{Z}}_{\mathit{F}}$≤13 interacting in Pb are found to be enhanced by 10 to 30 % relative to charge-changing cross sections of stable nuclides. The enhancement occurs primarily in interactions with large loss of charge. In Cu the charge-changing cross sections of secondaries show no significant excess. The mean free path of secondary fragments shows no dependence on the distance from the point of origin. This result rules out at 95% confidence level the production of nuclear fragments with interaction cross sections enhanced by a large factor as conjectured by some workers, but the result is consistent with a two-component model in which ∼30% of secondary beams are off-stability isotopes with total cross sections enhanced by ∼25%. Our measurements of angular distributions of projectile fragments showed that the transverse momentum distributions are similar to those measured at (1–2)A GeV. The charge pickup cross section of 14.5A GeV Si is measured to be 0.07–1.3 mb in Pb and ≤0.9 mb in Cu, which is of the same order of magnitude as that measured at ∼1A GeV.