We have used the ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$(t,2n${)}^{210}$Po reaction with standard in-beam γ-ray and conversion-electron spectroscopic techniques to study the two-proton states in ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}$. With the possible &, all states of the proton ${\mathit{h}}_{9/2}^2$, ${\mathit{h}}_{9/2}$${\mathit{f}}_{7/2}$, ${\mathit{f}}_{7/2}^2$, and ${\mathit{h}}_{9/2}$${\mathit{i}}_{13/2}$ configurations have been identified. The level energies agree within 100 keV, typically, with results from shell-model calculations. Relative intensities of M1 and E2 γ transitions from the $h_{9/2}$$f_{7/2}$ and $f_{7/2}^2$ configurations are compared with calculated intensities. Published experimental single-proton transition matrix elements were used for the calculations, which were performed both for pure and for mixed states. The results indicate admixture amplitudes of only a few percent or less into the main components of the wave functions.

Existing photonuclear data for ${}_{}{}^{166}{}_{}{}^{}\mathrm{Er}$ are analyzed in the framework of both the dynamic collective model and the interacting boson approximation. In particular, the cross section for the inelastic scattering of photons populating the γ-vibrational band is reanalyzed in order to infer information about the coupling of the giant dipole resonance to γ vibrations in deformed nuclei. These data are found to be in agreement with the predictions of both models and therefore do not discriminate between them.

The giant electric dipole resonance built upon the $0^{+}$ ground state of ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ was studied via the ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$(p→,${\gamma }_0$${)}^{20}$Ne reaction. Polarized and unpolarized angular distributions were measured between $E_x$=16.1 and 23.0 MeV ($E_{\mathrm{p}=3\mathrm{}–}$10 MeV) and the E1 T-matrix elements extracted. The ${}_{}{}^1{}_{}{}^{}\mathrm{P}$, E1 partial wave dominates, but the weaker ${}_{}{}^3{}_{}{}^{}\mathrm{P}$ (spin flip) term is also resonant. A heuristic doorway state model has been used to fit the pronounced structure in the giant E1 resonance. Data for the giant resonance built on the first excited state as seen in the ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$(p→,${\gamma }_1$${)}^{20}$Ne reaction are presented and discussed. The microscopic, doorway state calculation in a deformed potential of Schmid and Do Dang is in very good agreement with the main features of the results.

Angular distributions of the relative cross sections and analyzing powers have been measured for the ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$(p→,${\gamma }_0$${)}^{16}$O reaction in ≊500 keV steps for excitation energies in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ between 17.8 and 24.9 MeV. All E1 and E2 transition matrix elements were determined using a partial-wave analysis. Below 22 MeV, little quadrupole strength was found in excess of that predicted in direct capture calculations. A clear enhancement of the E2 cross section was observed at energies above 22 MeV. Our data indicate that about 10% of the isoscalar E2 sum rule for ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ is exhausted in the ${\mathrm{p}}_0$ decay channel between 18 and 25 MeV, with approximately (3/4 of this integrated strength concentrated between 22 and 25 MeV. The E2 strength seen in (γ,${\mathrm{p}}_0$) is strikingly different from that observed in (α,α’) or (α,α’p). The effect of the M1 state at $E_x$=18.8 MeV previously found in (p,γ) studies is clearly observed.

The cross sections and analyzing powers of the ${}_{}{}^{19}{}_{}{}^{}$F(p→,${\gamma }_0$${\gamma }_1$${)}^{20}$Ne reactions have been measured with high precision at nine angles for 24 incident proton bombarding energies in the range 3.5–13.3 MeV, corresponding to excitation energies in ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ of 16.0 to 25.5 MeV. At each energy, the E1 and E2 transition matrix elements were determined from a partial wave analysis of the angular distributions of ${\gamma }_0$. For excitation energies above 23.5 MeV, the calculated direct capture E2 strength can account for most of the measured strength. However, a sizable E2 strength in excess of direct capture was measured for $E_{\gamma }$≤23.5 MeV. Our results indicate that ≊9% of the isoscalar E2 sum rule is exhausted in the (${\gamma }_0$,${\mathrm{p}}_0$) reaction for excitation energies from 16.0 to 25.5 MeV. A comparison with (α,α’) results shows for the first time essential agreement between E2 strengths observed with the two modes of excitation. The analysis of the (p,${\gamma }_0$) data reveals strong evidence for an M1 resonance near an excitation energy of 17.7 MeV. The analysis of angular distribution measurements for the ${\gamma }_1$ decay channel is also reported.

A microscopic study of the ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(d,γ${)}^4$He reaction with deuteron and ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ bound state wave functions which include the D-state components is presented. Cross section and tensor analyzing powers are calculated for deuteron energies between 1 and 15 MeV. Deuteron D-state effects are found to be particularly important in the transition amplitude arising from the ${}_{}{}^5{}_{}{}^{}\mathrm{S}_2^{}{}_{}{}^{}$ scattering state. A detailed comparison between cluster and microscopic calculations is presented. Using an effective two-body model the analysis of $A_{\mathrm{yy}}$ data, in the energy range 1≤$E_{\mathrm{d}\mathrm{\le }15}$ MeV, gives for the asymptotic D/S state ratio in ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ the value ρ=-0.18.

The isospin dependence of the weak neutral current differs from that of the electromagnetic current. A combined analysis of unpolarized and parity-violating polarized electron scattering from nuclei can exploit this difference to extract information about both members of an isospin doublet from measurements involving only one target. Estimates for scattering from the proton suggest that this should constitute an excellent way to determine the electric form factor of the neutron.

Instrumental asymmetries recently observed by Haeberli and co-workers, limit the accuracy of neutron-proton analyzing power $A_y$(θ) data. These instrumental effects are discussed and calculated for previously published n-p $A_y$(θ) data at 16.9 MeV. To enable these calculations, the analyzing power for the ${}_{}{}^2{}_{}{}^{}\mathrm{H}$(d→,n${)}^3$He reaction was measured at small angles. Additional n-p $A_y$(θ) data at extreme backward angles, obtained via proton recoil detection, are also reported for this energy in this paper. The composite data set is compared to calculations based on the new Bonn NN potential, the Paris NN potential, and to the recent NN phase-shift solution of Arndt. In addition, a detailed comparison between $A_y$(θ) calculated from the new Bonn and the Paris potentials between 10 and 50 MeV is shown to reveal unexpectedly large relative differences. The experimental data in this energy range are better described by the Paris potential than by the new Bonn potential.

Corrections to the well-known statistical sum rule that relates the summed transmission coefficients on the one hand, and 2π${\Gamma }_{\mathrm{CN}{\rho }_{\mathrm{CN}}}$ on the other, in the context of the statistical decay properties of nuclear giant resonances, are discussed. These corrections arise both from preequilibrium processes as well as from the giant resonance itself. It is shown that the compound nucleus average width is reduced as a result of these corrections.

The reaction ${}_{}{}^{112}{}_{}{}^{}\mathrm{Cd}$(t,p) has been used to investigate levels of ${}_{}{}^{114}{}_{}{}^{}\mathrm{Cd}$ up to an excitation energy of 3.7 MeV. Twenty-seven angular distributions were measured and compared with distorted-wave calculations to extract L and $J^{\pi }$ information.

From the observed neutron scattering from ${}_{}{}^{89}{}_{}{}^{}\mathrm{Y}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ at energies from 5 to 10 MeV, there is empirical evidence that the shape of the surface imaginary part of the neutron optical model potential depends upon energy; the radius increases and the diffuseness decreases with decreasing energy. It is shown that the empirical energy dependence for the radius of the surface imaginary potential is approximately the same as that for the positions of the surface nodes for those partial waves which have the same orbital angular momentum l and total neutron angular momentum j=l±(1/2 as for the unoccupied bound single-particle states. The fact that those nodes are clustered near the center of the imaginary potential has the effect of reducing absorption for those partial waves. Therefore, the empirical variation in radius can be reinterpreted by a model for which the radius of the imaginary potential is constant but its strength depends upon the neutron orbital. This dependence can be adequately described by dividing the partial waves into two groups, one with the same quantum numbers l and j as for the bound unfilled orbitals and the other for the unbound states. In the case of n${+}^{208}$Pb, for an assumed constant imaginary radius, the quality of the optical model descriptions to the data is improved and the dispersion-relation constraint is more nearly satisfied if the partial waves associated with the quasibound single-particle states are also included with those associated with the unoccupied bound single-particle states. However, since the surface nodes for wave functions associated with the quasibound states are not clustered with those associated with the bound states, this optical model potential is not equivalent to the more conventional model which does not have a state dependence but does have an energy-dependent radius for the surface imaginary potential. Furthermore, this model cannot be replaced by one with only a parity dependence in the imaginary potential depth because the parity of the quasibound states is opposite to the parity of the dominant bound states.

The systematics of continuum angular distributions in nucleon- and alpha-particle-induced reactions at energies up to several hundred MeV have been studied and parametrized. It has been confirmed that at lower bombarding energies the shapes of the angular distribution are determined mainly by the kinetic energy in the exit channel, and by the division of the cross section into its multistep direct and multistep compound parts. For incident nucleons with energies above 130 MeV there is a change in the systematics, and the ratio of the energies in the exit and entrance channels of the reaction becomes the important energy parameter. Small second order dependences are also evident for nucleon-induced reactions. The systematics are parametrized using exponentials in cosθ and a small number of universal parameters.

The level structure of the doubly-odd ${}_{}{}^{242}{}_{}{}^{}\mathrm{Am}$ nucleus was investigated by means of thermal-neutron-capture gamma-ray and conversion electron spectroscopy. Pair, curved-crystal, and β spectrometers were used. The data from these measurements, combined with previous direct reaction results, permit us to establish a detailed level scheme including six new well-developed bands. Our experimental results are interpreted in the framework of the Nilsson model. Precise Gallagher-Moszkowski splittings and Newby odd-even shifts extracted from the data are compared with theoretical calculations.

The γ-ray spectra of the ${}_{}{}^{112}{}_{}{}^{}\mathrm{Cd}$(p,nγ${)}^{112}$In and ${}_{}{}^{109}{}_{}{}^{}\mathrm{Ag}$(α,nγ${)}^{112}$In reactions were measured with Ge(Li) spectrometers for bombarding energies of 4.8 MeV protons and 17.1 MeV α particles. The energies and relative intensities of 79 ${}_{}{}^{112}{}_{}{}^{}\mathrm{In}$ γ-ray transitions have been determined. The electron spectra were measured with combined magnet plus Si(Li) as well as superconducting magnetic lens plus Si(Li) spectrometers. Internal conversion coefficients of 40 ${}_{}{}^{112}{}_{}{}^{}\mathrm{In}$ transitions have been determined, and the level scheme of ${}_{}{}^{112}{}_{}{}^{}\mathrm{In}$, γ-ray branching ratios and transition multipolarities have been deduced. Computed Hauser-Feshbach (p,n) cross sections were compared with experimental ones, obtained from γ-ray measurements. On the basis of the internal conversion coefficients and Hauser-Feshbach analysis, level spins and parities have been determined. The energies of several ${}_{}{}^{112}{}_{}{}^{}\mathrm{In}$ proton-neutron multiplets were calculated on the basis of the parabolic rule derived from the cluster-vibration model. The level energy spectrum and electromagnetic properties were calculated on the basis of the interacting boson-fermion-fermion/odd-odd truncated quadrupole phonon model and satisfactory agreement was obtained between the experimental and theoretical results. More than 20 p-n multiplet states have been identified in ${}_{}{}^{112}{}_{}{}^{}\mathrm{In}$.

Differential cross section measurements have been made for 250 MeV proton inelastic scattering from ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$. Hadronic deformation lengths for the states at 1.78 ($2^{+}$), 4.62 ($4^{+}$), 6.8 ($3^{\mathrm{-}}$ and $4^{+}$), 9.70 ($5^{\mathrm{-}}$), and 10.2 MeV ($3^{\mathrm{-}}$) have been extracted using a first-order vibration model distorted-wave Born approximation description. Deformation lengths for the $2^{+}$ and $4^{+}$ states are found to be independent of proton energy from 40 to 500 MeV. Cross sections for the excitation of the giant resonance region are found to be highly fragmented between 16 to 25 MeV. This region of excitation is found to contain an energy weighted sum rule depletion of 70% for the isovector giant dipole resonance, 26% for the isoscalar giant quadrupole resonance, and 5% for the isoscalar hexadecapole resonance. No structure was observed in the inelastic continuum region of 25 to 45 MeV of excitation energy.

Resonance fluorescence has been used for measuring the widths of over 42 levels in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$ below 11 MeV by employing Ge(Li) detectors and bremsstrahlung beams with end point energies of 8.5, 10.3, and 11.8 MeV. The g${\Gamma }_0^2$/Γ of these levels were measured, and several J=1 levels were identified. A strong photon strength was found, extending between 8 and 11 MeV which complements a bump observed between 10.4 and 12.4 MeV using the (γ,n) reaction. This behavior is theoretically explained using the open-shell-linear-response method.

Resonant photon scattering from ${}_{}{}^{39}{}_{}{}^{}\mathrm{K}$ has been studied with bremsstrahlung produced by electrons with end-point energies of 6.6, 8.5, and 9.4 MeV. Values of g${\Gamma }_0^2$/Γ for 24 levels below 9 MeV were measured and the g${\Gamma }_0$ values of 17 levels were deduced. The widths of some levels above 4 MeV were found to be much larger (on the average, more than a factor of 10) than those reported from experiments using the Doppler shift attenuation method. Three of these levels are known from studies of the (d${,}^3$He) reaction to carry most of the $d_{5/2}^{\mathrm{-}1}$ proton strength in ${}_{}{}^{39}{}_{}{}^{}\mathrm{K}$. The B(M1↑) strength of J${=(5/2\mathrm{}}^{+}$ levels below 7 MeV is compared with predictions based on simple single-particle shell-model wave functions coupled with free-nucleon and empirically renormalized M1 operators and weighted by single-proton pickup spectroscopic factors.

The enhancement of compound elastic scattering is a function of the probability distribution of the resonance decay widths. It is calculated for four different forms of this distribution and then shown that—in the regime of overlapping levels—the experiment confirms Gaussian statistics.

The angular distribution of nucleons emitted in nucleon-induced precompound nuclear reactions are calculated taking into account the effect of excitation on the kinematics of nucleon-nucleon scattering inside the target-plus-projectile system. The results are compared with quantum mechanical calculations and those of reaction models based on a pure nucleon-nucleon collision picture.

We present a detailed microscopic quantum molecular dynamic analysis of fragment formation in the reaction Ne(1.05 GeV/nucleon) + Au. The theoretical predictions of the total mass yield, the multiplicity distribution of clusters, their average momentum, and their angular distribution agree well with the available data. We find a rather localized hot participant zone, which predominantly emits protons and neutrons. The multiplicity of light clusters depends strongly on the impact parameter whereas the heavier fragments A≥40 result from the decay of spectator residues. Their yield can provide a good measure for the impact parameter. The hypothesis of a compound system of $A_P$ and $A_T$ nucleons which is globally heated and equilibrated is not supported by our results. Light and massive fragments occupy different regions in phase space. Semiperipheral reactions do not lead to a stopping of the projectile. We observe a power law behavior of the inclusive mass yield distribution. Its form, however, is caused by averaging over different impact parameters. This rules out inclusive mass yield distributions as candidates for revealing a possible liquid gas phase transition. Light and intermediate mass fragments are formed during the early compressional stage of the reaction. We find that the projectile causes a high density wave to travel through the target. It causes the target to fragment and transfers transverse momentum to the intermediate mass fragments. Lighter fragments receive additional momentum transfer due to n-n collisions.