The inelastic scattering of 20-MeV tritons from ${}_{}{}^{92}{}_{}{}^{}\mathrm{Zr}$, ${}_{}{}^{94}{}_{}{}^{}\mathrm{Zr}$, and ${}_{}{}^{96}{}_{}{}^{}\mathrm{Zr}$ has been studied. The principal objective was to obtain an effective interaction strength to be used in a microscopic description of the excitation of neutron states. Only the lower levels of ${}_{}{}^{92}{}_{}{}^{}\mathrm{Zr}$ and ${}_{}{}^{94}{}_{}{}^{}\mathrm{Zr}$ were studied, but because of the paucity of available data on ${}_{}{}^{96}{}_{}{}^{}\mathrm{Zr}$, this isotope is studied in a more complete way, with 28 levels and 17 spins assigned. The shell-model results indicate a much smaller effective interaction strength for the excitation of neutron states than noted earlier for proton states in triton inelastic scattering.

The differential cross sections for the elastic scattering of 1.33-MeV photons from lead and uranium have been remeasured at angles ranging from 60° to 135°, using a lithium-drifted germanium detector. Dispersion relations are used to fix the relative phases among nuclear Thomson, Rayleigh, and Delbrück scattering. These relative phases and the calculations of the amplitudes for the individual scattering processes permit the theoretical cross sections to be determined. A discrepancy exists between the theoretical calculations and the experimental results. Previous suggestions for removing this discrepancy include incoherence between scattering from the nucleus and from the electrons, and a 180° phase shift between the parallel-polarization components of the nuclear Thomson and Rayleigh amplitudes. These suggestions are discussed and another possibility, destructive interference at large angles between Rayleigh scattering from the $K$ shell and from the $L$ shell, is presented.

The $\alpha$ decay of ${}_{}{}^{212g}{}_{}{}^{}\mathrm{At}$ and ${}_{}{}^{212m}{}_{}{}^{}\mathrm{At}$ to excited states of ${}_{}{}^{208}{}_{}{}^{}\mathrm{Bi}$ has been measured. Half-lives of 0.315±0.003 and 0.122±0.001 sec were determined in agreement with previous work. Out of a possible 28 transitions, 20 $\alpha$ transitions were observed to states in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Bi}$ below 1.11-MeV excitation.

A polarized-neutron transmission method is used to determine the shift of the neutron resonance energies due to the hyperfine interaction of the compound states. Resonances in ${\mathrm{Er}}^{167}$+$n$ at 0.460 and 0.584 eV are investigated. The resonance at 0.584 eV ($J=I-\frac{1}{2}$) shows a strong effect, leading to a very large value of the $g_J$ factor, while $g_J$ for the 0.460-eV resonance ($J=I+\frac{1}{2}$) is in the order of $g_I$ for the ${\mathrm{Er}}^{167}$ ground state. The results are compared to some recent predictions based on a statistical model of the compound nucleus. The role of nuclear magnetic interference terms which lead to a strong background transmission effect is discussed.

Coulomb excitation of the first $2^{+}$ state in ${}_{}{}^{142}{}_{}{}^{}\mathrm{Ce}$ was produced by 42-MeV ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ ions. The static quadrupole moment of the first $2^{+}$ excited state and the $B(E2, 0^{+}\to 2^{+})$ were determined. The values were $-0.12\mathrm{}\pm 0.09 e$ b and $0.459\pm 0.006 e^2$ ${\mathrm{b}}^2$, respectively.

An accurate absolute measurement of the longitudinal polarization of conversion electrons is reported. The investigation was stimulated by a suggestion of Mendels and Wouthuysen on a possible electron polarization in electromagnetic processes. The measurements confirm the general belief that conversion electrons from unoriented sources are not polarized. We found for the $K$- and $L$-conversion lines of ${}_{}{}^{114m}{}_{}{}^{}\mathrm{In}:P_c\mathrm{}\left(K\right)=-0.001\mathrm{}\pm 0.008$ and more accurately: $P_c\mathrm{}\left(L\right)=+0.001\mathrm{}\pm 0.004$.

The ${}_{}{}^{241}{}_{}{}^{}\mathrm{Am}$ spontaneous-fission decay constant has been determined with solid-state track recorders of preetched mica. Measurements have been carried out with electroplated ${}_{}{}^{241}{}_{}{}^{}\mathrm{Am}$ sources. Consistent spontaneousfission-rate measurements have been obtained for a large range of fission track densities over more than a 3-yr period. Systematic error due to source impurities has been established as insignificant relative to statistical error. The present experimental result for the ${}_{}{}^{241}{}_{}{}^{}\mathrm{Am}$ spontaneous-fission decay constant is ${\lambda }_f=(6.04\mathrm{}\pm 0.13)\times {10}^{-15\mathrm{}}$ ${\mathrm{yr}}^{-1\mathrm{}}$.

Contrary to the conclusions reached in a recent paper, we find that for the usual combination of long-range and pairing force that is used for calculations in heavy nuclei, the Belyaev-Inglis formula for moment of inertia is adequate and gives values close to those obtained from projection methods.

It is shown that the work of Varma et al., entitled "Comments on a Recent Paper on Moments of Inertia in Heavy Nuclei," is based on a misconception about our previous work and contains a basic error.

We have investigated the decays of 58-min ${}_{}{}^{69g}{}_{}{}^{}\mathrm{Zn}$ and 14-h ${}_{}{}^{69m}{}_{}{}^{}\mathrm{Zn}$ with a 30-${\mathrm{cm}}^3$ Ge(Li) detector. In addition to the 438.6-keV isomeric transition in ${}_{}{}^{69}{}_{}{}^{}\mathrm{Zn}$, $\gamma$ rays of energies 318.6, 574.3, and 872.5 keV were observed. These $\gamma$ rays have been incorporated into the known level scheme of ${}_{}{}^{69}{}_{}{}^{}\mathrm{Ga}$. Our studies show that the ${\beta }^{-}$ feeding to the 872-keV level in ${}_{}{}^{69}{}_{}{}^{}\mathrm{Ga}$ is from the ${\mathrm{½}}^{-}$, ${}_{}{}^{69}{}_{}{}^{}\mathrm{Zn}$ ground state and not from the ${\frac{9}{2}}^{+}$, ${}_{}{}^{69}{}_{}{}^{}\mathrm{Zn}$ metastable state as has been reported. The present results are consistent with a ${\frac{3}{2}}^{-}$ assignment for the 872-keV level.

It is shown that the yield of even-$Z$ x rays is relatively greater, over all, in the $\alpha$-particle-accompanied ternary than in the binary fission of ${}_{}{}^{252}{}_{}{}^{}\mathrm{Cf}$. A possible reason for this difference is suggested.

An example is given for the use of single-particle resonant-state wave functions in describing nuclear-resonance phenomena. The resonant-state functions are generated by solving numerically the one-body Schrödinger equation with pure outgoing asymptotics. The Lane-model Hamiltonian of the target+nucleon system is diagonalized on a basis consisting of bound-neutron and resonant-proton wave functions. The agreement with the result obtained by the exact integration of the coupled Lane equations is good.

Both a static and a momentum-dependent potential are derived from one-meson-exchange Born amplitudes, and are adjusted to fit (i) the deuteron binding energy and quadrupole moment, (ii) $S$, $P$, and $D$ partial waves from 25 to 310 MeV, and (iii) the binding energy and saturation property of nuclear matter. This is possible through a different form of the central and tensor potentials which has not been used previously to calculate problems (i), (ii), and (iii) above. We find the $\sigma$ meson unsuitable to describe the two-pion-exchange region in that a potential with meson parameters common to all partial waves is not achieved.

The variational bounds on scattering parameters are reformulated without the explicit use of multichannel projection operators, thus avoiding completely the difficulty of nonorthogonality in rearrangement and exchange collisions. Resonance-energy calculations can be carried out using the operator which is effectively projected on the closed channels.

The differential cross section for the ${}_{}{}^{10}{}_{}{}^{}\mathrm{Be}(p, {\gamma }_0){}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ reaction has been measured at 90° for $0.6\le E_p\le 6.3$ MeV. Compound resonances in ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ have been located at (12.17±0.04)-, 12.55±0.03-, 12.91±0.02-, 14.33±0.02-, and 15.3±0.1-MeV excitation energy. The last four are probably analogs to the lowest four levels in ${}_{}{}^{11}{}_{}{}^{}\mathrm{Be}$. Total widths and ground-state $\gamma$-ray widths of these levels are presented. The spins of the 12.55- and 14.33-MeV levels are shown to be ${\frac{1}{2}}^{+}\left({\frac{3}{2}}^{+}\right)$ and ${\frac{5}{2}}^{\mathrm{}(+)\mathrm{}}\left({\frac{3}{2}}^{-}\right)$, respectively.

The left-unitary operators that introduce the correlations of the hard core in an uncorrelated bound-state wave function of a finite number $A$ of particles are explicitly determined up to a unitary transformation. Left unitarity is required in order to keep orthonormality. Using a shell-model basis, transformed according to the correlation operator, it is possible to diagonalize the Hamiltonian in a subspace of the full Hilbert space with the technique of Bloch and Horowitz. Ground as well as excited states are treated on the same footing. In practice, the diagonalization is accomplished using the original single-particle basis and transforming back the Hamiltonian. This results in an $A$-body operator for which a cluster expansion is possible. In this cluster expansion, there are three- and four-body terms easy to evaluate, because they factorize. A particularly interesting application can be made to few-body systems, evaluating the integrals numerically. The unique approximation is then connected with the cut of the basis. The method developed seems comparatively simple and is free of the mathematical problems of the hard core.

Using a complex square-well distorting potential, the quasifree inelastic scattering of protons has been calculated in the impulse approximation. Calculations were performed for the nucleus ${\mathrm{C}}^{12}$ at both 160 and 1014 MeV to compare with experiment. The calculation was done with parameters determined from other data and was therefore essentially parameter-free. The agreement with experiment is quite satisfactory and relatively independent of the parameters. While the magnitude of the cross section is well determined, the location of the quasifree peak is in disagreement with experiment and only slightly shifted from the no-distortion case.

Using a theory previously developed for the ${\mathrm{O}}^{16}$ nucleus, the energy levels of ${\mathrm{He}}^4$ were calculated using the nuclear shell model and the random-phase approximation (RPA). Though no attempt was made to optimize the parameters of the calculation, the predicted energies of the excited states compare favorably with those determined from experimental analyses. Qualitative agreement with experiment is obtained for the calculated electron inelastic-scattering form factor to the first $0^{+}$ excited state and for the integrated photoabsorption cross section. However, the prediction of the majority of the $E1\mathrm{}$ strength in the higher of the 1—, $T=1\mathrm{}$ levels does not conform to most experiments which indicate the lower level to have the stronger ${}_{}{}^1{}_{}{}^{}P_1^{}{}_{}{}^{}$ component. The RPA produces some improvement over an ordinary shell-model calculation by decreasing the energies of the lower excited states by several hundred keV and by increasing the relative $E1\mathrm{}$ strength of the lower 1—, $T=1\mathrm{}$ level.