The mean lifetimes of the levels of ${}_{}{}^{34}{}_{}{}^{}\mathrm{S}$ below 5.0-MeV excitation energy have been measured by the Doppler-shift attentuation method. The ${}_{}{}^{31}{}_{}{}^{}\mathrm{P}(\alpha , p){}_{}{}^{34}{}_{}{}^{}\mathrm{S}$ reaction was used to populate these states. GaP targets evaporated onto 1-μ Ni foils were bombarded with $\alpha$ particles ranging in energy from 5.0 to 7.3 MeV. $\gamma$ rays were detected with a 30-cc Ge(Li) detector at 0, 90, and 143° to the beam axis. The following mean lifetimes were found: $\tau (2.13-\mathrm{MeV}\mathrm{level})=400\mathrm{}\pm 32$ fsec, $\tau \mathrm{}\left(3.30\right)=175\mathrm{}\pm 25$ fsec, $\tau \mathrm{}\left(3.92\right)>1.39\mathrm{}$ psec, $\tau \mathrm{}\left(4.07\right)<24\mathrm{}$ fsec, $\tau \mathrm{}\left(4.11\right)=110\mathrm{}\pm 10$ fsec, $\tau \mathrm{}\left(4.62\right)=135\mathrm{}\pm 17$ fsec, $\tau \mathrm{}\left(4.69\right)=131\mathrm{}\pm 13$ fsec, $\tau \mathrm{}\left(4.88\right)=(57\mathrm{}\pm 22 \mathrm{fsec})$,, $\tau \mathrm{}\left(4.89\right)=(52\mathrm{}\pm 14 \mathrm{fsec})$.

The yields of all rare-gas products, including stable species, with half-lives >10 h, produced in 3- and 29-GeV proton bombardment of Cu, Ag, Au, and U were measured. Mass-spectrometric measurements of ${\mathrm{Ne}}^{20}$, ${\mathrm{Ne}}^{21}$, ${\mathrm{Ar}}^{38}$, ${\mathrm{Kr}}^{83}$, and ${\mathrm{Xe}}^{131}$ represent total chain yields for these mass numbers. Spallation processes can account for Ne yields from Cu; Ar and Kr from Ag; and Xe from Au. Fission and spallation mechanisms satisfactorily describe the Kr from Au and the Kr and Xe from U. Ne and Ar yields from Au and U do not seem to be formed by spallation and fission processes, but appear to result from the same processes which lead to high yields of even lighter fragments previously observed in high-energy reactions.

Thirty-two levels in ${\mathrm{Lu}}^{174}$ have been observed up to an excitation energy of 1628 keV utilizing 12-MeV deuterons and the reaction ${\mathrm{Lu}}^{175}(d, t){\mathrm{Lu}}^{174}$. The ground-state $Q$ value was determined to be -1400±15 keV. The spectrum has been interpreted in terms of the coupling of the [404↓] Nilsson proton orbital with the neutron orbitals prominent in the ($d, t$) spectrum of ${\mathrm{Yb}}^{173}$. This interpretation has resulted in the determination of relative energies due to the residual neutron-proton interaction for seven different configurations. The observed singlet-triplet splitting energies for the [512↑], [521↓], and [521↑] neutron orbitals coupled to the [404↓] proton orbital were measured to be -110, +80, and -90 keV, respectively. Theoretical calculations of these energies made for a zero-range spin-dependent central potential gave values of -106, +71, and -77 keV, respectively. The remarkable agreement indicates that the spin-spin interaction can account for most, if not all, of the singlet-triplet splitting energy.

An analysis of semiconductor detector measurements of ternary-fission events indicates that scattering has probably not been effectively eliminated. An alternative interpretation of the observed results is given, which is consistent with the presence of scattered fission fragments. A mass or nuclear-charge identification for the third fragment in such experiments is suggested to establish unequivocal results.

Early measurements of pionic x-ray energies and widths in ${\mathrm{Th}}^{232}$ and ${\mathrm{U}}^{238}$ have suggested the possibility of an anomalous effect for the interaction between high-$Z$ nuclei and a pion in the $4f$ atomic state. We have remeasured the $5g\to 4f$ x-ray energies and widths in these isotopes, and we compare them with a calculation which considers the distortion of the nucleus. A small disagreement between theory and experiment persists, but it is probably due to uncertainties in the calculation of the strong-interaction effects.

The line shape of the 6.65-eV neutron absorption resonance of ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ is calculated for ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ bound in a U${\mathrm{O}}_2$ lattice. The calculation uses the formalism of Nelkin and Parks, in which the line shape for a chemically bound nucleus is given in terms of an intermediate scattering function associated with slow-neutron scattering by the crystal. In previously published work, the intermediate scattering function has been calculated from the distribution of normal-mode frequencies for the crystal. For a nonprimitive lattice like U${\mathrm{O}}_2$, however, it is necessary to use a normal-mode frequency distribution weighted by the squared moduli of polarization vectors describing the vibrations of the ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ atoms. Significant errors in the line shape are shown to result if this weighted distribution is not used. The weighted distribution in the present calculation is based on the realistic lattice-dynamical model for U${\mathrm{O}}_2$ of Dolling, Cowley, and Woods; and the time integral in the Nelkin-Parks formalism is carried out directly by numerical procedures. The results thus provide essentially exact line shapes for the case of a relatively complicated chemically bound system of interest in reactor applications. Comparisons are made at 50 and 296°K between the exact results and common approximations used in line-shape calculations based on Lamb's weak-binding limit.

Considerations based on the projection-operator method indicate the need for modifications of Alaga's asymptotic quantum-number selection rules for allowed beta transitions of deformed nuclei. Certain transitions previously classified as allowed-hindered can be expected to have beta moments only slightly smaller than those of allowed-unhindered transitions. The distribution of $log\mathrm{ft}$ values for the $150\le A\le 190$ region seems to show such an effect, and detailed calculations for several cases give results in agreement with the available data.

$\gamma -\gamma$ directional correlations have been measured for two cascades in the decay of 2.7-yr ${\mathrm{Sb}}^{125}$: 320-177 keV, $A_2=-0.15\mathrm{}\left(2\right)\mathrm{}$, $A_4=-0.04\mathrm{}\left(4\right)\mathrm{}$, $\delta \mathrm{}\left(177\right)=0.9(+0.9, -0.4)$; 203-177 keV, $A_2=-0.52\mathrm{}\left(5\right)\mathrm{}$, $A_4=0.02\mathrm{}\left(5\right)\mathrm{}$, $\delta \mathrm{}\left(203\right)=1.0(+1.1, -0.4)$ for spin $\frac{11}{2}$ assigned to the 525-keV level in ${\mathrm{Te}}^{125}$. The present results are inconsistent with spin $\frac{9}{2}$ for this level.

The ($d, p$) reactions on ${\mathrm{Ba}}^{130,132,134,136,138}$ have been investigated with 12.0-MeV deuterons from the Argonne Tandem Van de Graaff accelerator. Proton spectra were recorded in a broad-range magnetic spectrograph. Many new levels were observed. The ground-state $Q$ values (in MeV) for the ($d, p$) reactions (including the odd-$A$ targets) are found to be 5.269 for $A=130, 4.977$ for $A=132, 4.746$ for $A=134, 6.886$ for $A=135, 4.680$ for $A=136, 6.398$ for $A=137, \mathrm{and} 2.493$ for $A=138\mathrm{}$. Proton angular distributions were measured for states up to an excitation energy of about 3 MeV. The observed angular momentum transfers were $l_n=0, 1, 2, 3, \mathrm{and} 5$, which correspond to the population of states of the $3s_{\frac{1}{2}}$ and $2d_{\frac{3}{2}}$ configurations below the closed neutron shell at $N=82\mathrm{}$ and the $2f_{\frac{7}{2}}$, $3p_{\frac{3}{2}}$, $3p_{\frac{1}{2}}$, $1h_{\frac{9}{2}}$, and $2f_{\frac{5}{2}}$ configurations above it. From the observed $l$ values, it was possible to assign spins in some isotopes from a knowledge of the spin in other isotopes by taking account of systematic shifts in the $Q$ values of levels and also from shell-model expectations. Distorted-wave Born-approximation calculations were used to extract absolute spectroscopic factors. The problems and uncertainties arising in such calculations were studied in some detail. They derive, in part, from the need to use a sharp radial cutoff to fit the experimental angular distributions; calculations with nonlocal potentials and finite-range approximations did not yield satisfactory fits. Another source of uncertainty is the dependence of the spectroscopic factors upon the geometric parameters of the bound-state potential well. The results are interpreted with the help of pairing theory; centers of gravity and single-particle energies are deduced.

Seventeen-MeV deuteron-induced ($d, t$) reactions on ${\mathrm{Pd}}^{110}$, ${\mathrm{Pd}}^{108}$, and ${\mathrm{Ru}}^{104}$ are used to complement ($d, p$) studies exciting the same final nuclei. Many new states are reported, and in several cases previous $I-\pi$ assignments are changed. The sum of spectroscopic factors gives roughly the same degree of filling as was found from the ($d, p$) work for the $s$ and $d$ states; further anomalous behavior was found for the $g_{\frac{7}{2}}$ and $h_{\frac{11}{2}}$ states. There is a tendency for the spectroscopic strength to be shifted to higher excitation energy in ($d, t$) reactions than in ($d, p$) reactions. There are strong similarities between the Pd and Ru isotopes as regards the number of nuclear states of each $I-\pi$ and the degree of filling of $s$ and $d$ states, but the $g_{\frac{7}{2}}$ state seems to be much less full in Ru than in Pd. In both Pd isotopes, there is a low-energy state (0.671 MeV in ${\mathrm{Pd}}^{109}$ and 0.781 MeV in ${\mathrm{Pd}}^{107}$) excited by $l=1\mathrm{}$ transitions in both ($d, p$) and ($d, t$) reactions, indicating that they probably include components with $2p$ holes and $3p$ particles.

A search for spontaneous fission isomerism in uranium and neptunium isotopes has resulted in the identification of a new isomer in ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ with a half-life of 195 ± 30 nsec. A measurement of the half-life of previously reported ${}_{}{}^{236m}{}_{}{}^{}\mathrm{U}$ gives a value of 105 ± 20 nsec. Excitation functions have been determined for the production of the spontaneous fission isomers of ${}_{}{}^{236}{}_{}{}^{}\mathrm{U}$ and ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ by deuteron bombardment of ${}_{}{}^{236}{}_{}{}^{}\mathrm{U}$ and ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$ targets. Isomer ratios have also been estimated. The low values of the isomer ratios and the failure to observe delayed fission in lighter uranium isotopes and in neptunium isotopes suggest that $\gamma$ decay may be the dominant mode of decay of shape isomers in this mass region.

The energy spectra and yields of particles of $3<~Z<~8$ emitted in the spontaneous fission of ${\mathrm{Cf}}^{252}$ were measured. The experiment was carried out using a particle telescope consisting of two $\frac{\mathrm{dE}}{\mathrm{dx}}$ gas-filled proportional counters and a solid-state $E$ counter. The cutoff energies were relatively low since essentially no absorber foil was placed between source and detector. The yields per ${10}^3$ fission $\alpha$ particles are: Li, 2.9 ± 0.5; Be, 6.5 ± 0.7; B, 0.35 ± 0.10; C, 4.3 ± 0.9; N, ≥ 0.66 ± 0.15; O, ≥ 0.05 ± 0.01. Trajectory calculations were carried out for Li, Be, and C, and the initial conditions which give best agreement with the experimental results were obtained.

The Mössbauer resonance in ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$ has been observed for a source of dilute Pt in Fe at temperatures between 0.06 and 20 K, obtained by employing a ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ dilution refrigerator for cooling. At these low temperatures, the source nuclei are partially oriented because of the magnetic hyperfine interaction present in the alloy. The intensities of the observed hyperfine lines allow the determination of the polarization of the 77-keV first excited state in ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$, which is populated by $\beta$ decay from the ${}_{}{}^{197}{}_{}{}^{}\mathrm{Pt}$ source. From this polarization, one can calculate the mixing ratio of the squares of the reduced matrix elements of different tensor rank present in the $\beta$ transition. For the first-forbidden $\beta$ decay of ${}_{}{}^{197}{}_{}{}^{}\mathrm{Pt}$ ($\Delta I=0\mathrm{}$, $\Delta \pi =-1\mathrm{}$), we find the mixing ratio of rank-one elements to the rank-zero elements to be ${\beta }^2=7\mathrm{}\pm 1$.

In order to search for new neutron-deficient isotopes of uranium and thorium, targets of ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ were bombarded with beams of ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$, ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$, ${}_{}{}^{19}{}_{}{}^{}\mathrm{F}$, ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$, and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ in the Berkeley HILAC. The reaction products were transported from the reaction cell by the helium-jet technique and their $\alpha$-disintegration characteristics measured by on-line techniques of $\alpha$ spectroscopy. Energy values, excitation functions, and half-lives of $\alpha$-particle groups were measured. Only fragmentary evidence for uranium nuclei was found, because of intense losses by nuclear fission, but definite proof was obtained for the previously unknown millisecond isotopes ${}_{}{}^{222}{}_{}{}^{}\mathrm{Th}$ and ${}_{}{}^{221}{}_{}{}^{}\mathrm{Th}$, and for their decay products ${}_{}{}^{218}{}_{}{}^{}\mathrm{Ra}$, ${}_{}{}^{214}{}_{}{}^{}\mathrm{Rn}$, ${}_{}{}^{217}{}_{}{}^{}\mathrm{Ra}$, and ${}_{}{}^{213}{}_{}{}^{}\mathrm{Rn}$. Improvements were made on the literature values for ${}_{}{}^{223}{}_{}{}^{}\mathrm{Th}$ and its decay products.

The new $\alpha$ data help greatly in the determination of the trends in $\alpha$-decay energies for isotopes of even-$Z$ elements, particularly in the poorly defined region just above the 126 neutron shell. This allows the preparation of a more reliable set of predictions for many unknown nuclei.

The ($d, t$) reactions on ${\mathrm{Mo}}^{94}$, ${\mathrm{Mo}}^{96}$, and ${\mathrm{Mo}}^{100}$ were studied with 17-MeV incident deuterons. The experimental angular distributions of the triton groups were compared with distorted-wave Born-approximation (DWBA) calculations to determine the $l$ values and the spectroscopic factors. The $I^{\pi }$ and excitation energy of the levels found in this study are compared with those from ($d, p$) reactions leading to the same final states. The occupation numbers and single quasiparticle energies are calculated and compared with previous results.

The shifts of single-particle energy levels caused by distortions of nuclear equipotential surfaces is examined. Application of this approach is made to neutron single-particle states in the heavy-element region. Typical single-particle energy shifts are displayed in figures.

The equipotential shapes studied in this paper are axially symmetric and were obtained by the replacement ${{\omega }_0}^2{\mathcal{r}}^2\to {{\omega }_{\rho }}^2{\rho }^2+{{\omega }_z}^2{z}^2+{{\omega }_0}^2({\rho }^2+z^2)G\left(z^2\right)$ with $G\left(z^2\right)$ of the form $G\left(z^2\right)=e^{-A{Z}^2}\Sigma \stackrel{}{n}{B}_n{\left(z^{2t}\right)}^n$

A Woods-Saxon well was used for the central field, and eigenstates of the cylindrical harmonic oscillator ($|n_{\perp }, \lambda , n_Z〉$) were used as a basis set in these calculations. ${}_{}{}^{235}{}_{}{}^{}\mathrm{U}$ is analyzed in detail.

Excitation functions for proton elastic and inelastic scattering from ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$, studied from 2.0- to 6.0-MeV bombarding energy and for various scattering angles, revealed structure which was ascribed to isobaric analog resonances of the nucleus ${}_{}{}^{57}{}_{}{}^{}\mathrm{Fe}$. The conjecture that these resonances may have a significant influence on the spin-flip probability observed in inelastic scattering was tested by varying the transmission coefficients in a Hauser-Feshbach calculation. It was found that this effect can give rise to an enhancement of the calculated spin-flip probability consistent with previous measurements.

The recently discovered second diffraction minimum in the elastic form factor of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, alternatively described by a harmonic-oscillator model containing pair correlations or by an independent-particle model with a finite Woods-Saxon well, can also be obtained by the much simpler $\alpha$-particle model.

Cross sections for complete fusion of ${}_{}{}^{64}{}_{}{}^{}\mathrm{Ni}$, ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$, and ${}_{}{}^{136}{}_{}{}^{}\mathrm{Xe}$ projectiles with various targets are calculated as a function of the mass of the compound nucleus formed. Maximum completefusion cross sections of 200-300 mb are indicated for production of excited nuclei with $A\simeq 300$.