The low-lying level structure of ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sb}$ is studied through the observation of coincident $\gamma$ rays following the ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sn}\mathrm{}(p,n)\mathrm{}$ reaction using two Ge(Li) detectors. Thirteen 1024-channel coincidence $\gamma$-ray spectra were obtained simultaneously in a PDP-7 computer by means of a two-parameter program. High-resolution singles spectra taken with a small-volume thin-window Ge(Li) detector (full width at half maximum approximately 0.6 keV at 121 keV) were also helpful in determining a level scheme for ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sb}$. A ($d,p$) experiment was also performed in order to gain additional information. The information obtained from the ($p,n$) reaction was combined with existing ${}_{}{}^{121}{}_{}{}^{}\mathrm{Sb}\mathrm{}(d,p)\mathrm{}$ and ${}_{}{}^{121}{}_{}{}^{}\mathrm{Sb}(n,\gamma )$ data in constructing a proposed level scheme for ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sb}$.

Differential range curves (at an angle of 90°) have been obtained by radiochemical methods for 17 isotopes of Cu, Sr, Pd, and Ba which recoil out of thin uranium targets irradiated with 2.2-GeV protons. Neutron-rich isotopes of Ba, Pd, and Sr all have sharply peaked spectra with mean momenta >120 ${\mathrm{}\left(\mathrm{MeV}\mathrm{amu}\right)\mathrm{}}^{1/2}$, consistent with their production by binary fission. Neutron-deficient isotopes of these elements are characterized by lower mean momenta [<106 ${\mathrm{}\left(\mathrm{MeV}\mathrm{amu}\right)\mathrm{}}^{1/2}$] and broader spectra which include significant low-momentum components [<50 ${\mathrm{}\left(\mathrm{MeV}\mathrm{amu}\right)\mathrm{}}^{1/2}$]. The absolute contribution of these low-momentum recoils decreases from the order of a few mb/amu at mass 128 or 131 to ≅0.1 mb/amu at mass 83. Fission and some contribution from a spallationlike process are suggested as the probable formation mechanisms for the neutron-deficient products. The formation mechanism for copper isotopes is not clear. Spectra of ${}_{}{}^{61}{}_{}{}^{}\mathrm{Cu}$, ${}_{}{}^{64}{}_{}{}^{}\mathrm{Cu}$, and ${}_{}{}^{67}{}_{}{}^{}\mathrm{Cu}$ have widths comparable to those observed for binary fission and contain few low-momentum recoils; however, mean momenta are lower than those observed in semiconductor measurements of fission or predicted by a liquid-drop theory.

The relative quadrupole moments of the first excited states of ${\mathrm{W}}^{180}$ and ${\mathrm{W}}^{182}$ are found to be $Q_{22}^{180}:Q_{22}^{182}=1.031\mathrm{}\pm 0.043$ from Mössbauer-effect measurements following Coulomb excitation.

The isotopic distributions of Rb and Cs from the fission of ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$, ${}_{}{}^{232}{}_{}{}^{}\mathrm{Th}$, and ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}$ induced by 40- to 60-MeV protons have been measured by means of an on-line mass spectrometer. The Rb isotopic distributions have a Gaussian shape, but those of Cs are somewhat asymmetrical. As the proton bombarding energy increases, the neutron-excess sides of the distributions remain approximately fixed while the neutron-deficient sides shift to lower mass numbers. The distributions also show significant variations with the neutron-to-proton ratio of the target. All the isotopic cross sections show a significant odd-even structure, with the formation of even neutron isotopes being favored. The effect is more pronounced for the neutron-rich isotopes. A similar structure is found to occur in Rb and Cs distributions from fission induced by thermal neutrons, 155-MeV protons, and 24-GeV protons, as well as in the Na and K cross sections from 24-GeV-proton reactions with a variety of targets. The odd-even effect in the Rb and Cs distributions can be accounted for by a 10 to 15% neutron-pairing effect in the prompt yields and a 2 to 3% pairing effect in the neutron emission. From the mean mass numbers of the Rb and Cs distributions, the average total number of emitted neutrons has been estimated for each reaction. This information, together with other results on neutron emission as a function of fragment mass, has allowed the mean mass numbers to be corrected for prompt neutron emission. These corrected values differ by about one mass unit from the values predicted by the unchanged-charge-density mechanism and are consistent with the same mechanism of charge division as that operating in thermal-neutron fission.

The elastic scattering of $\alpha$ particles is analyzed with an optical potential obtained by a simple folding of the nuclear-matter distribution with an $\alpha$-nucleon interaction. The ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ neutron-matter radius is extracted using the charge-distribution parameters. The result $r_{\mathrm{nm}}=5.75\mathrm{}\pm 0.09$ fm is compared with other determinations and some theoretical calculations.

It is suggested that the study of the nuclear deexcitation $\gamma$ rays emitted following $K^{-}$ capture may help clarify the nature of the capture mechanism. We consider capture in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$. Capture rates to the various proton or neutron single-hole states in ${}_{}{}^{207}{}_{}{}^{}\mathrm{Pb}$, ${}_{}{}^{207}{}_{}{}^{}\mathrm{Tl}$, ${}_{}{}^{15}{}_{}{}^{}\mathrm{O}$, and ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ are estimated, and the consequences of capture to the isomeric states in ${}_{}{}^{207}{}_{}{}^{}\mathrm{Pb}$ and ${}_{}{}^{207}{}_{}{}^{}\mathrm{Tl}$ are discussed.

A relativistic self-consistent theory is used in conjunction with meson field potentials having the form of the generalized one-boson-exchange potentials (GOBEP) to construct a relativistic self-consistent meson field theory of nuclear structure. A simple GOBEP model with qualitative features of successful $N-N$ models, e.g., approximate cancellation of static terms arising from generalized (or regularized) scalar- and vector-meson fields, is used to calculate ground-state properties of the doubly-magic spherical nuclei ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$, and one superheavy nucleus ${}_{}{}^{298}{}_{}{}^{}114$. Good agreement is obtained between theoretical and experimental total binding energies and radial charge distributions. The isotopic shift in charge distributions between the isotopes ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ and ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$ and the single-particle eigenvalues agree quite well with the experimental numbers. The absence of explicit correlation corrections, the relationship of this model to earlier meson-theoretic descriptions, and physical interpretation in terms of nucleon form factors and relativistic interactions are discussed.

The level structure of ${}_{}{}^{178}{}_{}{}^{}\mathrm{Hf}$ has been studied via $\gamma$ singles, $\gamma -\gamma$ coincidences in the 2048 × 4096 channel mode, and $\gamma -\gamma$ directional-correlation measurements with Ge(Li) detectors from the decay of ${}_{}{}^{178}{}_{}{}^{}\mathrm{Ta}$. These data yielded 7 new transitions and the addition of 13 transitions to the decay scheme, which includes 5 new levels. The following levels were observed (energies in keV followed by the spin and parity): 93.13, $2^{+}$; 306.52, $4^{+}$; 1174.64, $2^{+}$; 1199.24, $0^{+}$; 1276.54, $2^{+}$; 1309.91, $1^{\pm }$, $2^{+}$; 1362.36, $2^{\mathrm{}(-)\mathrm{}}$; 1433.97, $0^{+}$; 1443.86, $0^{+}$; 1496.02, $2^{+}$; 1513.64, $1^{\pm }$, $2^{+}$; 1561.27, $2^{+}$; 1566.45, $1^{\pm }$, $2^{\pm }$; and 1771.95, $0^{+}$. $\gamma -\gamma$ directional correlations were measured with the $2^{+}$ → $0^{+}$, 93.13-keV transition and eight transitions that feed the first excited state. From the $\gamma -\gamma \left(\theta \right)$ data, spins of 2 and 0 are established for the 1362.36-and 1771.95-keV levels and $M1\mathrm{}$ admixtures of ${85.6}_{-1.7\mathrm{}}^{+1.2\mathrm{}}$ and 65.2 ± 3.2% for the 1183.40- and 1402.87-keV transitions. With these multipole admixtures, the branching ratios for the $K^{\pi }I=0^{+}2$, 1276.54-keV level cannot be brought into agreement with theory for a single $Z_{\beta }$ band-mixing parameter; while for the $K^{\pi }I=0^{+}2$, 1496.02-keV level they can be.

Fission-produced nuclides ${}_{}{}^{94}{}_{}{}^{}\mathrm{Kr}$ and ${}_{}{}^{143}{}_{}{}^{}\mathrm{Xe}$ have been measured directly using on-line mass separation. The half-lives derived from the $\beta$-decay curve are 0.20 ± 0.01 and 0.3 ± 0.03 sec, respectively. $\gamma$-ray spectra in the mass chain 93 have been measured and various $\gamma$ peaks were assigned to the individual nuclides.

The half-life of ${}_{}{}^{14}{}_{}{}^{}\mathrm{O}$ is measured as 70.48 ± 0.15 sec, in agreement with a recently reported value. The error assigned to the present result is thought to include a realistic assessment of the systematic errors in the measurement and analysis.

The relation between the half-off-shell $T$ matrix, the on-shell $T$ matrix, and the two-particle wave function is generalized to the fully-off-shell $T$ matrix and tensor forces. The new relation is used to derive the boundary-condition-model $T$ matrix when tensor coupling is present.

Differential cross sections for $\alpha$ particles to the ground and first excited states of ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ in the reaction ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}(n,\alpha ){}_{}{}^7{}_{}{}^{}\mathrm{Li}$ have been calculated from $R$-matrix parameters that fit neutron elastic scattering, neutron polarization, and ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}(n,\alpha ){}_{}{}^7{}_{}{}^{}\mathrm{Li}$ reaction data. It is pointed out that a measurement of these $\alpha$-particle angular distributions could resolve some of the ambiguities that remain in the interpretation of the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}(n,\alpha ){}_{}{}^7{}_{}{}^{}\mathrm{Li}$ reaction for neutron energies below 1 MeV.

The reaction ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}(\alpha ,n){}_{}{}^{57}{}_{}{}^{}\mathrm{Ni}$ has been used to investigate the properties of levels at 2.443 and 3.003 MeV in ${}_{}{}^{57}{}_{}{}^{}\mathrm{Ni}$. A spin-parity assignment of ${\frac{5}{2}}^{-}$ is made for the 2.443-MeV level. The 3.003-MeV level is found to have possible spins of $\frac{3}{2}$ of $\frac{5}{2}$ and a mean lifetime of 11 ± 6 fsec.

$\gamma$-ray energy measurements utilizing a Ge(Li) detector result in excitation energies of 429.20 ± 0.10, 2127.52 ± 0.20, and 1726.44 ± 0.20 keV for the first excited states of ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{34}{}_{}{}^{}\mathrm{S}$, and ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$; and 843.76 ± 0.07 and 1014.38 ± 0.10 keV for the first two excited states of ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$.

The new method of angular projection in which one makes use of the rotation operator in evaluating the matrix of the projection operator but does not have to perform the numerical integrations over the Euler angles is applied to the Bardeen-Cooper-Schrieffer type of wave function, where one has to project both the angular momentum and the given number of particles.

A Brueckner-Hartree-Fock calculation of the deformed nuclei ${\mathrm{C}}^{12}$ and ${\mathrm{Ne}}^{20}$ becomes possible with the use of a density-dependent effective interaction to produce effective $G$ matrix elements. An average-density approximation is employed. The inclusion of the rearrangement energy in the calculation leads to an improved estimate of the binding energies. The calculation is done in the matrix representation with deformed Cartesian oscillator functions as a basis. The effects of mixing deformed major shells are compared with the mixing implicit in the Nilsson model.

A method is proposed for determining the ground state of the Hamiltonian $H=\Sigma \stackrel{}{k}{\epsilon }_k{N}_k-\Sigma \stackrel{}{\mathrm{ijkl}}{V}_{\mathrm{ijkl}}{a}_i^{†}{a}_j^{†}{a}_k{a}_l$

when the residual interaction is such that $〈a_i^{†}{a}_j^{†}{a}_k{a}_l〉={〈N_i{N}_j(1-N_k)(1-N_l)〉}^{\frac{1}{2}}{〈N_k{N}_l(1-N_i)(1-N_j)〉}^{\frac{1}{2}}$

is a good approximation. The method is applied to pairing interactions involving one type of nucleon as well as to the generalized pairing problem containing neutron-neutron, neutron-proton, and proton-proton interactions.

Realistic, generalized, and regularized velocity-dependent one-boson-exchange-potential models of the nucleon-nucleon interaction are applied to calculate the low-lying energy levels of the nucleus ${\mathrm{O}}^{18}$ in the harmonic-oscillator shell model. The singlet even states are treated by the Moszkowski-Scott separation method technique. The energy levels so obtained are comparable to those obtained from the phenomenological Hamada-Johnston hard-core potential. We do not attempt to calculate core-polarization effects explicitly, but rather we attempt to simulate them by varying the coupling constant of the light scalar meson.

The effects of allowing variations in the radial orbital wave functions, or major shell mixing, have been investigated within the framework of Brueckner-Hartree-Fock (BHF) theory for ${\mathrm{O}}^{16}$. The calculation is carried out in the matrix representation using harmonic-oscillator wave functions as a basis. Effective $G$ matrix elements are calculated through the use of a density-dependent, two-body operator following a prescription of Bethe. Two possible parametrizations, the local-density approximation and an average-density approximation, are compared. Consideration of the rearrangement energy shows that it is an important contribution to the binding energy. The problem is formulated in a way which facilitates the application of BHF theory to deformed as well as spherical nuclei.

Excitation energies of the states in ${}_{}{}^{19}{}_{}{}^{}\mathrm{Ne}$ are measured via the reaction ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}({}_{}{}^3{}_{}{}^{}\mathrm{He},\alpha ){}_{}{}^{19}{}_{}{}^{}\mathrm{Ne}$ up to an excitation of ∼10.6 MeV. Angular distributions for several states are measured and analyzed by use of the conventional distorted-wave Born approximation. Relative spectroscopic factors are extracted and compared with the predictions of the spectroscopic-factor sum rule. The analysis fails to confirm an assignment of $j=\frac{3}{2}$ for the excited states at 6.01 and 6.74 MeV.