A reanalysis of (p,p’) data taken on $2_1^{+}$ and $3_1^{\mathrm{-}}$ states of 37 even-even A≥40 nuclei at energies of E<50 MeV has been performed with a consistent procedure involving coupled-channels calculations and Becchetti-Greenlees optical model parameters. The matrix elements extracted from this analysis have been compared to matrix elements deduced from electromagnetic measurements of the same excitations. It is concluded that the differences between (p,p’) and electromagnetic results which are often observed do not result from variations in the method of analysis of the (p,p’) data. Instead, the differences are caused by experimental errors and nuclear structure effects. The nuclear structure effects are examined by extracting the ratios ${\mathit{M}}_{\mathit{n}}$/${\mathit{M}}_{\mathit{p}}$ of the neutron and proton multipole matrix elements for both the $2_1^{+}$ and $3_1^{\mathrm{-}}$ states from the proton and electromagnetic data.

Rotating deformed nuclei are neither rigid rotors nor irrotational droplets. The Kelvin circulation vector is the kinematical observable that measures the true character of nuclear rotation. For the anisotropic oscillator potential, mean field solutions with fixed angular momentum L and Kelvin circulation C are derived in analytic form. The cranking Lagrange multipliers corresponding to the L and C constraints are the angular ω and vortex λ velocities. Self-consistent solutions are reported with a constraint to constant volume.

We have analyzed pion scattering data to determine the proton and neutron radii of the calcium isotopes ${}_{}{}^{40,42,44,48}{}_{}{}^{}\mathrm{Ca}$ using model densities in which the neutron matter distributions are considered to have components corresponding to core and valence neutrons. The proton radii determined agree with those obtained by electromagnetic means. The radii of the valence distributions show a monotonic decrease throughout the shell from ∼4.9 fm in ${}_{}{}^{42}{}_{}{}^{}\mathrm{Ca}$ to ∼4.4 fm in ${}_{}{}^{44}{}_{}{}^{}\mathrm{Ca}$ and ∼4.2 fm in ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$, although this last case is only indicative. The large valence neutron radius of ${}_{}{}^{42}{}_{}{}^{}\mathrm{Ca}$ suggests that the ground state of this nucleus may have some characteristics of a bound dineutron orbiting a closed core.

Element distributions and fragment multiplicity distributions have been measured for E/A=50 MeV ${}_{}{}^{129}{}_{}{}^{}\mathrm{Xe}$${+}^{12}$C, ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$, ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}$, ${}_{}{}^{\mathrm{nat}}{}_{}{}^{}\mathrm{Cu}$, ${}_{}{}^{89}{}_{}{}^{}\mathrm{Y}$, and ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$ reactions using a low threshold 4π detector. Both distributions show a strong correlation with the detected charged particle multiplicity and a large degree of target independence. The measured distributions are compared with hybrid model calculations which incorporate important dynamical aspects in both the preequilibrium and statistical emission phases. Results of these calculations are in reasonable agreement with the data. However, uncertainties with regard to the compressibility of nuclear matter remain due to uncertainties in the coupling of the two models.

A revised γ-decay scheme has been deduced for the low-spin decay of ${}_{}{}^{152}{}_{}{}^{}\to _{}^{152}{}_{}{}^{}$Sm and a half-life of 15(6) ps has been measured for the $0_3^{+}$ state in ${}_{}{}^{152}{}_{}{}^{}\mathrm{Sm}$. The B(E2) and ${\mathrm{\rho }}^2$(E0) rates for the $0_3^{+}$ band (previously interpreted as the shape-coexisting ‘‘spherical’’ band) are well reproduced by the pairing-plus-quadrupole calculations which show no shape-coexisting minima. The $0^{+}$ systematics for heavy Sm and Gd is reexamined. Contrary to the shape-coexistence interpretation, all $0^{+}$ band sequences evolve rapidly towards deformation: e.g., the ‘‘spherical’’ band still spherical for N≤90 becomes deformed for N≥92. Properties of the low-lying bands could be understood from the ‘‘correspondence’’ interpretation as evolving from quadrupole phonon multiplets. It is suggested that the β’ band ($0_3^{+}$) represents a new mode of excitation in par with β and γ modes.

Cross sections and vector and tensor analyzing powers for the main levels in ${}_{}{}^{207}{}_{}{}^{}\mathrm{Pb}$ have been measured via the ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$(d→,t${)}^{207}$Pb reaction at 200 and 360 MeV incident energies. ${\mathit{A}}_{\mathit{y}}$ and ${\mathit{A}}_{\mathit{y}\mathit{y}}$ spin observables allow a clear identification of the valence levels, especially at 200 MeV. The results are compared with finite range distorted-wave Born approximation calculations using the Paris projectile-ejectile form factor including the S and D components. The analysis shows a large effect of the D component on the tensor analyzing powers at the most forward angles. At both energies, the spin part of the deuteron optical potential is very important to describe the analyzing powers and especially ${\mathit{A}}_{\mathit{y}\mathit{y}}$. A good description of all observables at 200 MeV allows this reaction to be used as a spectroscopic tool.

We have measured the mass and kinetic-energy distributions of fragments from the spontaneous fission of ${}_{}{}^{259}{}_{}{}^{}\mathrm{Lr}$. The ${}_{}{}^{259}{}_{}{}^{}\mathrm{Lr}$ was produced via the ${}_{}{}^{248}{}_{}{}^{}\mathrm{Cm}$ ${(}^{15}$N,4n) reaction with a production cross section of 100 nb using 81-MeV projectiles. The kinetic energies and times of the alpha particles and coincident fission fragments were measured using our rotating wheel system. From these data the half-life, mass, and kinetic-energy distributions were derived. The total kinetic-energy (TKE) distribution appears to consist of a single component with a most probable pre-neutron-emission TKE of 215±3 MeV. The mass distribution is predominantly symmetric with a full width at half maximum of about 20 mass numbers. These results are consistent with trends observed for other trans-berkelium spontaneously fissioning isotopes. We determined the half-life to be 6.14±0.36 s by measuring its alpha decay and the observed spontaneous fission half-life was consistent with that value. An energy of 8.439±0.010 MeV was measured for the main alpha transition of ${}_{}{}^{259}{}_{}{}^{}\mathrm{Lr}$. We measured a spontaneous fission to alpha-decay ratio of 0.25±0.03 which results in a partial half-life for spontaneous fission of 31±4 s, if there are no other appreciable modes of decay.

The fore-aft asymmetry and the 90° differential cross section in the ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$(n,${\gamma }_0$) reaction were measured from ${\mathit{E}}_{\mathit{n}}$=8 to 44 MeV. An energy-dependent asymmetry is observed that is interpreted as the result of the isovector giant quadrupole resonance interfering with background E1 amplitudes. The present data agree with previous low-energy data. At higher incident neutron energies, the present data do not agree with the predictions of a direct-semidirect model calculation based on the low-energy data alone. Calculations using the pure resonance model are in agreement with the data.

Neutron–light-charged-particle (LCP) and LCP-LCP correlation functions were measured for the 215 MeV ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${+}^{27}$Al reaction, together with the neutron-proton correlation function for the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${+}^{12}$C reaction at ${\mathit{E}}_{\mathrm{lab}}$=60.5 MeV. The np and pp correlation data are compared with the predictions of the Koonin model and a semiclassical evaporation model. Both models provide an excellent fit to the np data, while the pp data are not reproduced as well. Production yields of singlet deuterons, ground state ${}_{}{}^5{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^5{}_{}{}^{}\mathrm{Li}$, and ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ nuclei in the 2.186 MeV state were obtained from the coincidence data, and a nuclear temperature of T=2.$0_{\mathrm{-}0.6}^{+0.8\mathrm{}}$ MeV for the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${+}^{27}$Al compound system was determined from the ratio of singlet to ground state deuteron emission, after corrections for sequential emission and noncompound deuteron production. This temperature value is well below the Fermi gas model estimate, and a similar result is observed for the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${+}^{12}$C compound system.

A systematic study of inclusive pion double charge exchange is reported for nuclei between A=16 and A=208. The doubly differential cross sections for the A(${\mathrm{\pi }}^{+}$,${\mathrm{\pi }}^{\mathrm{-}}$) and A(${\mathrm{\pi }}^{\mathrm{-}}$,${\mathrm{\pi }}^{+}$) reactions in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{103}{}_{}{}^{}\mathrm{Rh}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ were measured at incident energies between 120 and 270 MeV at three to five outgoing pion angles. Pion spectra were measured over the energy range from 10 MeV to the kinematic limit for double charge exchange. Integrating these spectra over outgoing pion energy generated angular distributions, and subsequently integrating these angular distributions generated total reaction cross sections. The shapes of the measured spectra are compared with those determined by the distribution of events in four-body phase space and with those predicted by a model in which the pion undergoes two sequential single charge exchanges on nucleons in a Fermi gas. The cross sections are compared with predictions of cascade calculations in which more than two interactions, including pion absorption and scattering without charge exchange, may occur.

Pre- and post-scission protons and α particles are measured in the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${+}^{197}$Au, ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$${+}^{181}$Ta, ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$, and ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$${+}^{197}$Au and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ reactions in the compound nucleus excitation energy range of 43 to 117 MeV. The angular correlation measurements between α particles and fission fragments suggest that the pre-scission α particles seem to be mainly emitted from spherical compound nuclei or nuclei in an early stage of the fission process before saddle. The pre-scission multiplicities of protons and α particles are compared to the statistical model calculations and are reproduced by assuming the ratio ${\mathit{a}}_{\mathit{f}}$/${\mathit{a}}_{\mathit{n}}$ of the saddle point deformation to the ground-state deformation within the limit of 1.00 to 1.02. The post-scission protons and α particles are consistent with the evaporations from the fission fragments whose excitation energies are considerably reduced by the pre-scission neutron emissions.

Detailed angular distributions for the reaction ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$${(}^{16}$O${,}^{16}$O($0_2^{+}$,6.05 MeV)${)}^{16}$O(g.s.) were obtained for nine center of mass energies varying from 25.5 to 35.5 MeV. From these angular distributions a dominant partial wave is assigned to three of the gross resonances in this system. The spin assignments are consistent with a rotational sequence, and are in disagreement with the results of a previous study of the same reaction.

Using a track-recording phosphate glass detector with a standard deviation ${\mathrm{\sigma }}_{\mathit{Z}}$=0.23 charge unit, we collected ∼2100 tracks of energetic clusters emitted from ${}_{}{}^{231}{}_{}{}^{}\mathrm{Pa}$. Of these, 1348 survived cuts on energy, angle of incidence to the detectors, and ${\mathrm{\chi }}^2$. All but one of them are consistent with ${}_{}{}^{24}{}_{}{}^{}\mathrm{Ne}$, and our measured branching ratio, B(Ne/α)=(13.4±1.7)×${10}^{\mathrm{-}12}$, for an alpha-decay half-life for ${}_{}{}^{231}{}_{}{}^{}\mathrm{Pa}$ of 3.28×${10}^4$ yr. This value of B is a factor of 2.2 greater than was determined by Tretyakova et al., who observed 252 Ne decays. We identify one event as ${}_{}{}^{23}{}_{}{}^{}\mathrm{F}$, the nucleus predicted by cluster emission models to have the second highest branching ratio for emission from ${}_{}{}^{231}{}_{}{}^{}\mathrm{Pa}$. This corresponds to a branching ratio B(Ne/F)=${1347}_{\mathrm{-}940}^{+6440\mathrm{}}$, the 1σ limits being governed by inverse Poisson statistics. Published models predict lower values of B(Ne/F), ranging from 3 to 400. Our event, if its 4σ deviation from Ne is regarded as sufficient evidence for F, would be the first example of emission of an odd-Z cluster in spontaneous cluster radioactivity.

We have studied the evolution towards mass equilibration in ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$${+}^{16}$O orbiting interactions. ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$ beams of energies between 75 and 115 MeV were used to bombard targets of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$. Targetlike particles were detected at forward angles to determine the yields from orbiting interactions. The ratio of the orbiting yields of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ exit channels rises continuously with energy from values below unity to above. The data are interpreted as demonstrating a strong entrance channel dependence at low energies, and an evolution towards mass equilibration with increasing energy.

The decay of excited ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ projectiles into the four alpha particle exit channel has been investigated. The projectiles, with bombarding energies of E/A=25 MeV, were excited through peripheral interactions with ${}_{}{}^{159}{}_{}{}^{}\mathrm{Tb}$ target nuclei. A 4π counter was used to detect both the projectile alpha particles and the light charged particles evaporated from the target nucleus. Criteria for selecting true ${}_{}{}^{16}{}_{}{}^{}\mathrm{\alpha }$ events with the minimum contamination from incorrectly identified events were examined. The distribution of relative angles between the four alpha particles in their center of mass frame was compared to simulations of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ decay by sequential decay mechanisms. The relative angles were shown to be consistent with a sequential evaporation mechanism if a nonzero angular momentum is assumed for the excited projectile. The momentum distribution of the alpha particles in the reaction plane was examined and found to be anisotropic for high projectile excitation energies. This anisotropy was shown to be consistent with Coulomb interactions between the first emitted alpha particle and the target nucleus, which would indicate that the lifetime of the projectile is very short, on the order of ${10}^{\mathrm{-}22}$ s.

Inclusive inelastic scattering spectra from C, Ca, Sn, and Pb were measured for 100-MeV pions at a number of angles. The observed ratios of the ${\mathrm{\pi }}^{\mathrm{-}}$ and ${\mathrm{\pi }}^{+}$ total inelastic cross sections for the different targets are explained in terms of a simple model which is based on the assumption that the scattered pion has interacted with only one nucleon. This model also accounts for the ratio between normal and charge-exchange scattering cross sections at 100 MeV.

The Glauber model with first- and second-order non-eikonal corrections has been applied to elastic nuclear scattering of 178- and 800-MeV protons, 180-MeV antiprotons, and 140-MeV α particles. Reasonable agreement with the corresponding partial-wave calculations is obtained for the differential cross sections, polarizations, spin rotations, and reaction cross sections. Relativistic kinematics is taken into account in such a way that the relativistic Rutherford cross section is reproduced in both the Glauber model and the optical model.

The Glauber model approach for the description of elastic scattering has been extended to the low energy range. The overlap integral of the nuclear densities derived in our previous paper has been calculated along a trajectory characterized by the distance of closest approach, to account for the deviation in the projectile trajectory due to the Coulomb field. The only ingredients in this formalism are the densities of the colliding ions and elementary nucleon-nucleon scattering amplitude. At low energies we have given a prescription for the calculation of ${\mathrm{\alpha }}_{\mathit{N}\mathit{N}}$, the ratio of real to imaginary part of the forward nucleon-nucleon scattering amplitude. Elastic scattering angular distributions at low energies for several heavy-ion systems are described reasonably well.

Problems associated with transparency schemes based on sharp cutoff models are discussed. The soft spheres model of hadron-nucleus and nucleus-nucleus collisions has been used to explore the influence of the realistic nuclear density geometry on transparency. An average nuclear transparency and an average reaction transparency are defined and their dependence on target and projectile dimensions and on the hadron-nucleon collision cross section are described. The results are expected to be valid for projectile energies above several hundred MeV/nucleon through the ultrarelativistic regime. For uniform (hard sphere) nuclear profiles, methods for obtaining effective total transparencies are suggested.

The analysis of isotopic effects in the production of intermediate mass fragments from light-ion-induced reactions on heavy nuclei reveals a high degree of equilibration in the isotopic degree of freedom. The observed effects are quantitatively reproduced by the quantum statistical model based on chemical equilibrium. The nearly identical isotopic yield ratios for reactions induced by light ions (p,d,α) of several GeV and by heavy ions ${(}^{12}$C${,}^{14}$N${,}^{18}$O) of 30–100 MeV/nucleon suggest that the statistical parameters of the hot nuclear systems produced in both types of reactions are very similar.