Angular distributions for the elastic and inelastic scattering of 29.6 and 35.1 MeV protons from the $0_1^{+}$ (g.s.), $2_1^{+}$ (1.461 MeV), $0_2^{+}$ (2.121 MeV), $2_2^{+}$ (2.524 MeV), $4_1^{+}$ (2.893 MeV), $2_3^{+}$ (3.208 MeV), $3_1^{\mathrm{-}}$ (3.681 MeV), and $2_4^{+}$ (3.919 MeV) states in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$ have been measured. Coupled channel calculations for the $0_1^{+}$, $2_1^{+}$, and $4_1^{+}$ levels have been performed in the framework of the rigid-rotor and harmonic vibrator models. Both analyses give satisfactory descriptions of the data with slight differences in the values of the deformation parameters. Two different analyses have been performed for the $0_2^{+}$ and $2_2^{+}$ levels. In the first, they have been considered as belonging to the β band and analyzed using the rotor-vibrator model. In the second, the coupling strengths between the various states have been treated as free parameters not linked to rigid ratios from models. The intrinsic quadrupole moment of the β band extracted from the two analyses is in agreement with that deduced from γ-decay studies. The distorted wave Born approximation has been used for the analysis of the $3_1^{\mathrm{-}}$ level. The $3_1^{\mathrm{-}}$, $2_3^{+}$, and $2_4^{+}$ levels have also been analyzed with different coupled channel calculations in which their coupling amplitudes to the ground state and $2_1^{+}$ state have been adjusted as free parameters.

A microscopic analysis of the complete forward angle spectra of the ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$(p,n) reaction is presented for an incident energy of 200 MeV. It is shown that the whole spectra up to an excitation energy of $E_x$=70 MeV are the result of correlated one-particle–one-hole (1p1h) spin-isospin transitions only. The spectra reflect, therefore, the linear spin-isospin response of the target nucleus to the probing (p,n) field. Two different cross section calculations are performed: one with usual random phase approximation wave functions and one with generalized random phase approximation wave functions which include Δ isobar degrees of freedom explicitly. We find that the theoretical cross sections calculated with random phase approximation wave functions, which provide the lower limit of spin-isospin strength, describe the data rather well at all scattering angles, while the random phase approximation +Δ cross sections underestimate the data at forward angles. In this connection we discuss the quenching of the spin-isospin strength in detail.

A previously published s-wave scattering function for 1–450 keV neutrons on ${}_{}{}^{60}{}_{}{}^{}\mathrm{Ni}$ is averaged for comparison to the scattering from an optical model potential. The scattering length R’ is found to be 5.5±0.03 fm at 225 keV. Averaging of the scattering function (both by integration with a normalized weight function and by use of an analytical approximation) produces shape elastic and compound nucleus cross sections which are then fitted by adjustment of the real and imaginary well depths in both spherical and vibrational optical models with a Woods-Saxon real well ($r_0$=1.21 fm, $a_0$=0.66 fm) and a surface derivative imaginary well ($r_D$=1.21 fm, $a_D$=0.48 fm). The fitted depths are $V_0$=48 MeV and $W_D$=29 MeV for the spherical potentials, and $V_0$=50 MeV and $W_D$=24 MeV for the vibrational potentials. Uncertainties are ±5 MeV. From an upper limit on the p-wave strength function the $W_D$ for p waves is found to be 1.5 MeV for the vibrational model. Thus, the imaginary potential is l dependent for the assumed geometry. For s waves the vibrational model gives a good fit also with $W_D$=1.5 MeV and $V_0$=54.4 MeV; however, with that $V_0$ the 2p states are bound too deeply in ${}_{}{}^{61}{}_{}{}^{}\mathrm{Ni}$ and the 3s size resonance is predicted at too low a mass.

The reaction ${}_{}{}^{59}{}_{}{}^{}\mathrm{Co}$(t,p${)}^{61}$Co has been investigated with a 15-MeV triton beam. Fifty-eight energy levels of ${}_{}{}^{61}{}_{}{}^{}\mathrm{Co}$ were identified ranging in energy up to about 5.4 MeV excitation. Angular distributions were measured and compared with distorted-wave Born approximation calculations.

Anomalously strong absorption of neutron partial waves by the nuclear optical potential is investigated in detail. More than 100 cases of anomalously strong absorption are found over the entire Periodic Table of stable nuclei in the range of energy 0–80 MeV and orbital angular momentum 0–13. A study of the S matrix in the complex-k plane reveals two different types of anomalous absorption. Discussions are given on systematics of the anomaly, its wave function, its relation to the strong absorption in the heavy-ion scattering and to the so-called unstable bound states, and on the experimental observation of the anomaly, which could be a new test of the optical potential.

High spin states in ${}_{}{}^{99}{}_{}{}^{}\mathrm{Tc}$ have been populated via the ${}_{}{}^{96}{}_{}{}^{}\mathrm{Zr}$${(}^6$Li,3nγ) reaction. In-beam γ-γ coincidence techniques have been used to determine the level scheme while excitation function and angular distribution measurements have been used to assign spin values. The results are compared to previous work and the level systematics are discussed.

The cross sections for breakup of ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ in targets ranging from H to Pb are presented. Fragmentation modes measured include: total charge changing, fission, and central collision. The charge changing cross sections are compared with black disk geometrical and Glauber models. The central collision cross section rises as the mass of the target and reaches 20% of the measured cross section for uranium on a lead target. The limiting fragmentation hypothesis is satisfied for targets heavier than hydrogen. For uranium-uranium central collisions these data predict a cross section of 2.5 b.

High-spin states in ${}_{}{}^{157}{}_{}{}^{}$,158Er and ${}_{}{}^{158}{}_{}{}^{}$,159Tm have been studied via the ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sn}$${(}^{40}$Ar,5,4n) and ${}_{}{}^{141}{}_{}{}^{}\mathrm{Pr}$${(}^{22}$Ne,5,4n) reactions, respectively, using in-beam gamma-ray spectroscopy techniques which included γ-γ coincidence, angular correlation, angular distribution, excitation function, and multiplicity measurements. The favored (π=+, α=+(1/2)) $i_{13/2}$ neutron band in ${}_{}{}^{157}{}_{}{}^{}\mathrm{Er}$ has been established up to the ${\mathrm{}(53/2)\mathrm{}}^{+}$ level (ħω=0.417 MeV), and the favored (π=-, α=-(1/2)) and unfavored (π=-, α=+(1/2)) $h_{11/2}$ proton bands in ${}_{}{}^{159}{}_{}{}^{}\mathrm{Tm}$, up to the ${\mathrm{}(59/2)\mathrm{}}^{\mathrm{-}}$ (ħω=0.454 MeV) and ${\mathrm{}(61/2)\mathrm{}}^{\mathrm{-}}$ (ħω=0.480 MeV) levels, respectively, i.e., well above the range of rotational frequency ħω where a second backbending has been observed in the neighboring even-even nuclei. In ${}_{}{}^{158}{}_{}{}^{}\mathrm{Er}$, the yrast levels have been observed up to ${38}^{+}$, and in ${}_{}{}^{158}{}_{}{}^{}\mathrm{Tm}$, up to ${25}^{\mathrm{-}}$. The favored $i_{13/2}$ band of the odd-N nucleus ${}_{}{}^{157}{}_{}{}^{}\mathrm{Er}$ displays a strong upbending at ħω=0.40 MeV, whereas, in the two branches of the $h_{11/2}$ yrast band of the odd-Z nucleus ${}_{}{}^{159}{}_{}{}^{}\mathrm{Tm}$, no alignment effect has been observed between ħω=0.27 and 0.48 MeV. The experimental results have been analyzed in the framework of the cranked shell model. On the basis of blocking arguments and cranked shell model calculations, the obtained results show that the second backbending in the yrast band of even-even nuclei near A=158 is due to an $h_{11/2}$ proton alignment. The signature splitting of the intrinsic excitation energies (Routhians) and aligned angular momenta in ${}_{}{}^{159}{}_{}{}^{}\mathrm{Tm}$ has been reproduced in cranked shell model calculations by introducing a triaxial deformation. The observed steep rise of the B(M1)/$Q_0^2$ values in the favored and unfavored bands of ${}_{}{}^{159}{}_{}{}^{}\mathrm{Tm}$ are consistent with an increase of ‖$g_K$-$g_R$‖ at the first backbending due to the alignment of a neutron pair around ħω=0.27 MeV. The evolution of the kinematical and dynamical moments of inertia at very high rotational frequencies (ħω>0.50 MeV) yields information on the nuclear pairing correlations in this frequency range.

Energy spectra from nuclear reactions of ${}_{}{}^{20}{}_{}{}^{}$Ne${+\mathrm{}}^{197}$Au at 20 MeV/nucleon were measured for charged particles with 1≤Z≤3 and 1≤A≤9. The detection angles covered a range from 5° to 110°. The data are analyzed in terms of moving source emission and a combined preequilibrium plus projectile breakup analysis. The preequilibrium calculations reproduce angle integrated cross sections and angular distributions of protons. They fail to reproduce angular distributions of complex particles. These distributions can be explained by the coalescence model employing the calculated pre- equilibrium cross sections for nucleons.

Collective properties of odd-Z ${}_{}{}^{115}{}_{}{}^{}$,117I and ${}_{}{}^{121}{}_{}{}^{}$,123Sb nuclei have been investigated via ${}_{}{}^{106}{}_{}{}^{}\mathrm{Cd}$${(}^{12}$C,p2n${)}^{115}$I, ${}_{}{}^{106}{}_{}{}^{}\mathrm{Cd}$${(}^{14}$N,2pn${)}^{117}$I, ${}_{}{}^{112}{}_{}{}^{}\mathrm{Sn}$${(}^{12}$C,αp2n${)}^{117}$I, and ${}_{}{}^{120}{}_{}{}^{}$,122Sn${(}^7$Li,α2n) ${}_{}{}^{121}{}_{}{}^{}$,123Sb reactions, using in-beam γ excitation, γ-γ coincidence, γ-W(θ) and pulsed-beam-γ measurements. The two collective features common to the Z>50 transition region were observed; the first, the occurrence of ΔJ=1 bands built on low-lying ${\mathrm{}(9/2)\mathrm{}}^{+}$ states, was found in all four nuclei, and the second, ΔJ=2 bands built on ${\mathrm{}(11/2)\mathrm{}}^{\mathrm{-}}$ states, was seen in ${}_{}{}^{115}{}_{}{}^{}$,117I. The ${\mathrm{}(9/2)\mathrm{}}^{+}$ and ${\mathrm{}(11/2)\mathrm{}}^{\mathrm{-}}$ band heads involve a 1$g_{9/2}$ proton hole and a 1$h_{11/2}$ quasiproton, respectively. The systematics of these band structures in the Z>50 transition region, which have been extended in this study, are presented and discussed in terms of collective interpretations.

The number of neutrons emitted in heavy-ion reactions is counted eventwise with high efficiency in a 4π neutron counting device. This number is taken as a measure of the energy converted into internal excitation of the heavy reaction residues produced in ${}_{}{}^{20}{}_{}{}^{}\mathrm{Au}$ collisions at 220, 290, and 400 MeV. Forward emitted α particles are found preferentially with either a low number of coincident neutrons or a high neutron number. The former component is identified with α particles produced by projectile breakup, the latter with nonequilibrium emission of α particles. The inclusive cross section can be decomposed into the contributions of these two processes, and separate energy distributions and excitation functions are given. The nonequilibrium component is compatible with a massive-transfer picture of the responsible process.

Small angle cross sections for ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${(}^{16}$O,${\alpha }_0$) and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${(}^{16}$O,${\alpha }_1$) reactions have been measured from $E_{\mathrm{c}.\mathrm{m}.\mathrm{}\mathrm{\sim }12}$ to 20 MeV in 50 keV steps and angular distributions are measured at selected energies. A well-isolated resonance with $J^{\pi }$${=10\mathrm{}}^{+}$ and Γ≃100 keV is found at $E_{\mathrm{c}.\mathrm{m}.\mathrm{}\mathrm{\simeq }15.2}$ MeV. The high density of narrow structure over the entire energy range studied indicates no significant influence of dinucleus resonant states of ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$ in these reactions.

The recoil properties of thirty-five nuclides produced in reactions of 100 and 142 MeV ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ and ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$ with ${}_{}{}^{93}{}_{}{}^{}\mathrm{Nb}$ have been measured. A thick-target/thick-catcher technique was used, with the foils mounted at 45° to the beam axis so as to provide information on the transverse as well as the longitudinal momentum transfer. Relationships have been derived to extract values, from the resulting data, for the average longitudinal component of recoil velocity and the average recoil angle. The experimental results show, in almost all cases, mean recoil velocities less than the compound nuclear velocity. For products with near-target mass, transverse momentum transfers greater than those along the axis were observed. For heavier products, the momentum transfer increases with the product mass. The results from the ${}_{}{}^{22}{}_{}{}^{}\mathrm{induced}$ reactions are significantly different from those of ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$. The results are interpreted mainly in terms of two competing mechanisms: complete fusion/evaporation and a class of process involving varying degrees of mass transfer between projectile and target.

A local nucleon-nucleon effective interaction based on current phenomenological nucleon-nucleon scattering amplitudes has been constructed at several bombarding energies between 50 and 1000 MeV/nucleon within a dynamically nonrelativistic framework. The form of the interaction has been chosen for convenience in performing nucleon-nucleus scattering calculations in this energy range and for ease of comparison with one-boson-exchange potential models. Some properties of this interaction are compared with those of an earlier version based on an older set of nucleon-nucleon amplitudes.

A combination of theoretical estimates, based on a ΛN potential model and phenomenological analysis of hypernuclear data, is used to determine a set of four $p_{\mathrm{N}{s}_{\Lambda }}$ two-body matrix elements which characterize the spin dependence of the ΛN interaction in the p shell. The central spin-spin and the Λ spin-orbit matrix elements are most strongly constrained by existing data. The spin dependence is weak in the sense that (core)×$s_{\Lambda }$ doublet splittings are predicted to be of order 100 keV, except for the special case of ${}_{\mathrm{\Lambda }}{}^7{}_{}{}^{}\mathrm{Li}$ where the central spin-spin interaction dominates and the ground state doublet splitting is likely to be of order 600 keV. Detailed consideration is given to those γ ray transitions the observation of which would best serve to further constrain the spin dependence of the ΛN interaction, particularly the tensor interaction.

Excitation functions for the formation of ${}_{}{}^{47}{}_{}{}^{}\mathrm{Ca}$ and ${}_{}{}^{47}{}_{}{}^{}\mathrm{K}$ from ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$ with 100-, 180-, and 300-MeV ${\pi }^{\pm }$ have been determined by activation methods. The contributions of both quasifree and nonquasifree processes are observed in the excitation functions. Unlike (π,πN) reactions on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, final-state nucleon charge exchange is found to play only a minor role in ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$. This decreasing importance of nucleon charge exchange with increasing nuclear mass is explained by a newly-developed (π,πN) theory. In order to establish the magnitude of nucleon charge exchange in medium-mass nuclei, we have measured the cross section for the reaction ${}_{}{}^{45}{}_{}{}^{}\mathrm{Sc}$(${\pi }^{\mathrm{-}}$,πN${)}^{44}$K at 180 MeV. An upper limit of 0.25 mb has been determined.

The spin-rotation parameters $D_{\mathrm{NN}}$, $D_{\mathrm{SS}}$, $D_{\mathrm{LS}}$, $D_{\mathrm{SL}}$, and $D_{\mathrm{LL}}$; induced polarization P; and vector analyzing power A at 496 and 647 MeV and $D_{\mathrm{SL}}$ and $D_{\mathrm{LL}}$ at 800 MeV for p-d elastic scattering have been measured using a polarized proton beam. This work represents the first measurement of the final state L component parameters $D_{\mathrm{SL}}$ and $D_{\mathrm{LL}}$ for p-d elastic scattering. Comparison with the noneikonal multiple scattering theory reveals large discrepancies between the data and current theory at 800 and 650 MeV but fairly good agreement is seen at 500 MeV. The data also provide for a test of time-reversal invariance.

The ${}_{}{}^{16}{}_{}{}^{}({\pi }^{+}$,2p${)}^{14}$N reaction has been studied at $T_{\pi }$=59.6 MeV. Good energy resolution of 1 to 2 MeV allows several states in ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ to be resolved. Triple-differential cross sections are presented for the transitions to the ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ $1^{+}$ ground state and $1^{+}$ 4 MeV state. The quasideuteron model is used to construct a T matrix for each transition. A fit to the data requires an additional term in the T matrix giving a large anisotropy in the angular distribution of the ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ recoil momentum vector. The ground state T matrix has an unexpected enhancement near zero recoil momentum of the ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ nucleus. The ‘‘measured’’ T matrices are then used to extrapolate to unmeasured regions of phase space giving double differential, single-differential, and total cross sections for each transition.

Intermediate energy (300–1000 MeV) proton-nucleus elastic observables, obtained using the relativistic and nonrelativistic impulse approximations, are compared to each other and with p${+\mathrm{}}^{40}$Ca, ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ data. Systematic, energy dependent differences between the model predictions and the data are observed and discussed. The underlying target densities are then adjusted in each model to obtain best fits to the differential cross section and analyzing power data at each energy. The variations in the resulting effective target density parameters show the deficiencies, with respect to the energy dependence, of the relativistic and nonrelativistic impulse approximations. Improvements which may eliminate some of the energy dependence are discussed.

An analytic approximation to the conventional distorted wave approximation for analyses of the elastic and inelastic scattering of pions of intermediate energy from nuclei is developed. Analyses of the elastic scattering data for ${\pi }^{\mathrm{-}}$ on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ using the ‘‘best fit’’ Kisslinger optical model potentials in the integral form of the scattering amplitude ascertain the relevant analytic function forms for use in analyses of inelastic scattering data. Using these functions, a separable pion-nucleon t matrix (in momentum space), and large basis (microscopic) structure models, good fits to data from the excitations of the $2_1^{+}$ (4.44 MeV) and $3_1^{\mathrm{-}}$ (9.64 MeV) states in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ have been obtained.