The yrast states of ${}_{}{}^{134}{}_{}{}^{}\mathrm{Ce}$ were populated via the reaction ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sn}({}_{}{}^{16}{}_{}{}^{}\mathrm{O}, 4n\gamma )$ at a bombarding energy of 76 MeV and the time distributions of the $\gamma$ decay were measured by means of the plunger method. The deduced lifetimes and feeding times indicate a drastic retardation of the electromagnetic transition rates in the backbending region.

Experimental and theoretical ratios of pairs of heavy-ion direct reactions of the form $A(a, b)B$ and $A(a, b)b$ where $b$ and $B$ are isobaric nuclei could be used to highlight the Coulomb effects on the neutron and proton form factors in a unique manner. These results quantitatively provide evidence for the need for including the Coulomb potentials in the interaction that causes transfer previously studied in terms of the theoretical post-prior equality of the transition amplitude.

Strong ionization signals have been observed in Ca following two-photon absorption to the bound, even-parity $J=0\mathrm{}$ and $J=2\mathrm{}$ states. Using known Ca absorption lines for calibration, 72 new states have been classified, and their energies have been determined to ± 0.1 ${\mathrm{cm}}^{-1\mathrm{}}$. The new $J=0\mathrm{}$ states have a constant quantum defect, whereas the $J=2\mathrm{}$ states do not.

The real and imaginary parts of the interaction potential of metastable $\mathrm{He}\left(2^{1}S\right)$ with argon have been accurately determined from high-resolution differential scattering experiments. The real part of the potential shows an unexpected structure with two minima, while the imaginary part is monotonic, but cannot be expressed by a single exponential.

The pinch dynamics of relativistic electron beams in large aspect ratio diodes are calculated numerically, including both ion and electron currents. The effect of the ions on the pinch phenomenon is demonstrated. The roles of the time scales for ion emission and flow are discussed. Fair agreement with experiment is obtained.

Space- and time-resolved profiles of impurity ions in TFR tokamak plasmas have been used in order to deduce diffusion velocities. ${\mathrm{O}}^{4+}$ ions, present in a peripheral plasma shell, have inward diffusion velocities of ∼2×${10}^3$ cm/sec, in agreement with theoretical values. ${\mathrm{Mo}}^{30+}$ ions, characteristic of the central hot plasma, have inward diffusion velocities of ∼ 10 cm/sec.

The effects of a finite-bandwidth driver pump on the parametric-decay instability are investigated experimentally. The results include the dependence of threshold power, growth rate, and saturation level on the bandwidth of several coherently and randomly modulated pumps.

We have measured the drift velocity $\overline{v}$ of negative ions through superfluid ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ for temperatures $T<\mathrm{}0.45\mathrm{}$ K, under a pressure of 25 bar, for electric fields $20<E<\mathrm{}2.6\mathrm{}\times {10}^4$ V ${\mathrm{cm}}^{-1\mathrm{}}$. From the observed form of $\overline{v}\mathrm{}\left(E\right)\mathrm{}$, we deduce that roton emission from an ion traveling faster than the Landau critical velocity is governed by hitherto unrecognized selection rules whereby the rotons can be created only in pairs.

Analysis of low-energy-electron-diffraction beam intensities for a 2×2 chemisorbed layer of acetylene on the Pt(111) surface shows that the molecules are adsorbed in either a threefold position or a twofold bridge position at a distance of 1.95±0.10 Å above the topmost plane of platinum atoms.

The translational diffusion coefficient of Brownian particles in the ternary liquid mixture water-ethanol-chloroform near a plait point has been studied by the autocorrelation spectroscopy method. It is found that the effective viscosity ${\eta }_{\mathrm{eff}}$ exhibits a strong anomaly close to the plait point. This anomaly can be explained in terms of the existence of a "correlated layer" of liquid mixture of thickness equal to the correlation length $\xi$ on the surfaces of the Brownian particles.

The response of the orbital degrees of freedom of superfluid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-$A$ to a magnetic field suddenly rotated through a small angle is a decaying exponential rather than an oscillatory response. Analysis of the field and temperature dependence of the time constant supports the Cross-Anderson orbital-viscosity theory as complemented by the Pethick-Smith relaxation-time theory but reveals a discrepancy in the susceptibility-anisotropy energy near $T_c$.

The equivalence of the critical behavior of the $d$-dimensional Ising model at a finite temperature to that of a $d$- 1 dimensional system at zero temperature as a function of a transverse magnetic field is used to calculate the critical exponents for the three-dimensional model by applying the Niemeijer-Van Leeuwen renormalization-group method to the two-dimensional problem.

An EPR spectrum, labeled Si-$G12\mathrm{}$, is identified as arising from an isolated interstitial carbon atom in silicon. A $〈100〉$ C-Si interstitialcy model is suggested for the defect in which a silicon and carbon atom pair partially share single substitutional site. Because carbon is isoelectronic with silicon, these results suggest a similar $〈100〉$ Si-Si interstitialcy configuration for the silicon self-interstitial, a fundamental defect which has so far eluded direct detection.

Diffuse-neutron-scattering measurements at $2<T<\mathrm{}300\mathrm{}$ K have been employed to determine the fractional occupancy $\eta$ of the localized $4f^1$ configuration. For Ce${\mathrm{Al}}_3$, $\eta =0.9-1.0\mathrm{}$ at 11 K. For ${\mathrm{Ce}}_{0.8}$ ${\mathrm{Th}}_{0.2}$, $\eta =0.4\mathrm{}\pm 0.1$ at 11 K. No evidence of a compensating conduction-electron polatization was observed.

Surface electronic states associated with defects produced by Ar-ion bombardment of Ti${\mathrm{O}}_2$ crystals have been studied by ultraviolet-photoemission, electron-energy-loss, and Auger spectroscopy and low-energy-electron diffraction. Evidence is given for three distinct phases dependent upon the extrinsic surface-defect concentration. Phase I contains isolated surface states 0.7 eV below the conduction band, phase II is associated with the creation of ${\mathrm{Ti}}^{3+}$ pairs, and phase III consists of a surface layer of ordered ${\mathrm{Ti}}_2$${\mathrm{O}}_3$.

The electronic energy levels of a hydrogen (1×1) monolayer adsorbed on the (100) tungsten single-crystal face have been investigated by angle-resolved photoemission. Three bands of adsorbate levels are found that disperse and split with angle, at energies of about 2, 6, and 12 eV below the Fermi level. The results suggest that hydrogen chemisorption takes place by interaction with localized directional surface-group orbitals of the tungsten $d$ band.

Under magnetic field in the Faraday configuration, linearly oriented excitonic polaritons are subject to a kind of "resonant Faraday effect." It is first reported here, in the case of CdSe. An energy-dependent lifetime for excitonic polaritons from the bottleneck region can be deduced and is found to be at maximum 7 × ${10}^{-12\mathrm{}}$ sec.

Phase shifts in extended x-ray-absorption fine-structure (EXAFS) measurements have been empirically determined for atom pairs. For photoelectron energies > 100 eV it is shown that these phase shifts, because they are essentially independent of chemical environment, can be used with EXAFS spectra to determine interatomic distances typically to accuracies of 0.02 Å.

An experiment was performed to search for the anomalous two-photon polarization correlation observed earlier by Holt and Pipkin using a cascade of atomic mercury. The experiment is a sensitive test of various aspects of the foundations of quantum mechanics. Although the present experimental arrangement differed only slightly from theirs, the anomalous results were not observed.

We consider the possible role of $Y\to \mathrm{Ke}\nu$ new-particle decays in the ${\mu }^{-}{e}^{+}{K}_s$ events in neutrino bubble-chamber experiments. We calculate transverse momentum distributions of $e$ and $K$, including effects of initial $Y$-particle transverse motion, and invariant $K-e$ mass distributions. We also calculate the $E_e$ spectrum in a current-fragmentation model, and estimate expected $\mu e$ event rates from dimuon event rates assuming that they have a common origin.