The density of the $4f$ states in all metallic rare earths has been studied with bremsstrahlung isochromat spectroscopy (BIS) and x-ray photoemission spectroscopy (XPS). The final-state multiplet structures of the $4f^{14-n}$ and $4f^n$ configurations observed by BIS and XPS, respectively, are closely related. The elements showing interconfiguration fluctuations are found to have one $4f$ level in the immediate vicinity of the Fermi level. Correlation energies are extracted directly from the spectra and compared with recent theoretical calculations.

We have obtained high-statistics, virtually systematics-free $K_L$-nucleus total-cross-section data for C, Al, Cu, Sn, and Pb from 30 to 150 GeV. These cross sections have an $A^{0.84\pm 0.01}$ dependence over most of the momentum range, in agreement with the Glauber-Franco model. Their magnitudes are, however, not compatible with that model alone: The discrepancies are clearly resolved once one allows for inelastic screening within the nucleus. The data strongly support the theory of this latter effect as given by Karmanov and Kondratyuk.

At the CERN intersecting storage ring the inclusive differential cross section ${\left[\frac{d\sigma }{d\sigma }\right]}_{y=1\mathrm{}}$ has been measured for $f^0$, $g^0$, ${K^{*}}^0\mathrm{}\left(1420\right)\mathrm{}$, and ${{\overline{K}}^{*}}^0\mathrm{}\left(1420\right)\mathrm{}$ production: We obtain 0.58±0.05 mb, 0.09±0.05 mb, 38±15 μb, and 26±13 μb, respectively. The corresponding total inclusive cross sections are estimated to be 2.62±0.26 mb, 0.40±0.22 mb, 154±60 μb, and 107±52 μb, respectively. The magnitude of the $K^{*}$ cross section implies a cross section of approximately 5 μb for production of a charmed $D\overline{D}$ pair.

The density-dependent, finite-range nuclear force of Gogny is treated via Hartree-Fock-Bogoliubov methods to calculate the $\beta -\gamma$-dependent potential energy. The cranking model is employed to calculate the moments of inertia and the mass parameters. The zero-point-motion correction of Giraud and Grammaticos is included. Rotational-vibrational bands of ${}_{}{}^{150}{}_{}{}^{}\mathrm{Sm}$ are calculated. Comparison is made with experiment and with calculations based on the Strutinsky method, and on the pairing-plus-quadrupole model.

By the cranked Hartee-Fock-Bogoliubov method in the pairing $+Q·Q$ model we find that a small second backbending occurs around $J=26\mathrm{}$ in ${}_{}{}^{158}{}_{}{}^{}\mathrm{Er}$. This is due to the antipairing effect among protons. It is further argued that it is unlikely that further backbends will be seen in any rare-earth rotors after the disappearance of both neutron and proton pairing.

The polarization of ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ produced in the reaction ${}_{}{}^{100}{}_{}{}^{}\mathrm{Mo}$(${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$)${}_{}{}^{102}{}_{}{}^{}\mathrm{Ru}$ is explained in a fully quantum mechanical way. It is found that recoil plays a decisive role.

The circular polarization of the energy-integrated $\gamma$-ray spectra and the angular correlation of discrete $\gamma$ transitions in coincidence with the light fragments detected at 35° were measured for the reaction 100-MeV ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ + Ni. A large nuclear spin polarization and at least 80% negative-angle scattering are deduced for deep-inelastic events. The decrease of the circular polarization observed at $Q>-30\mathrm{}$ MeV is ascribed to increasing positiveangle contributions to the cross section.

Resonancelike structures are observed at backward angles for elastic scattering of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$ and for the reaction ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$(${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$)${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$ which are uncorrelated with the ones seen in the system ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ + ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$. Analysis of angular distributions indicates that forward $\alpha$ transfer is dominated by partial waves different from those of backward-angle $\alpha$ transfer and elastic scattering in the entrance and exit channels.

The ${\pi }^{\pm }$-${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$ elastic scattering data are shown to be reproduced with a wide range of rms neutron radii if the optical-model parameters are suitably adjusted. The corresponding total cross sections vary significantly.

We have measured the collision-induced light-scattering spectrum of gaseous helium at $T=298\mathrm{}$ K for densities between 46 and 366 amagats to obtain the two-body spectrum in the frequency range 10 to 250 ${\mathrm{cm}}^{-1\mathrm{}}$. The comparison between the dipole-induced-dipole theoretical values of the two-body spectral moments and the experimental values show large discrepancies.

A new theory of atomic motion in a resonant standing or traveling electromagnetic wave is presented. It is shown that, when effects of spontaneous emission are negligible, the motion of a two-level atom in the resonant radiation is determined by two noninterfering wave functions, each of which satisfied a time-dependent Schrödinger equation with time-independent potential energy. An experiment is proposed to test the theory.

We report an electron-beam study of dissociative attachment from excited hydrogen in the energy range of 1-5 eV. A marked dependence of ${\mathrm{H}}^{-}$/${\mathrm{H}}_2$ and ${\mathrm{D}}^{-}$/${\mathrm{D}}_2$ cross sections on initial vibrational ($v=0-5\mathrm{}$) and rotational ($j=0-7\mathrm{}$) states is observed. These results provide a new mechanism to interpret the anomalous ${\mathrm{H}}^{-}$ density recently observed in a hydrogen plasma.

Resonant scattering theory is applied to the calculation of $e$-${\mathrm{H}}_2$ dissociative attachment cross sections near threshold for several vibrational and rotational states of the ${\mathrm{H}}_2$ molecule. Typical values just above threshold are, in ${\mathrm{cm}}^2$, 2.8×${10}^{-21\mathrm{}}$ for the ground state ($v=0\mathrm{}$, $J=0\mathrm{}$), 8.3×${10}^{-20\mathrm{}}$ for (1, 0), 1.0×${10}^{-18\mathrm{}}$ for (2, 0), and 3.5×${10}^{-20\mathrm{}}$ for (0, 10). The effect of rotational excitation is found to be significant, although it is not as large as suggested by Chen and Peacher.

The instability of plane envelope Langmuir solitons subject to transverse perturbations is reconsidered for the cubic nonlinear Schrödinger equation as well as the coupled set of high- and low-frequency equations in the case of nonadiabatic ion response. The nonlinear investigation demonstrates instability with a cutoff in all cases and predicts a drastic lowering of the instability growth rates when nonadiabatic ion motion is allowed for. Our analytical results agree with recent numerical computations.

An energy principle, involving a self-adjoint operator, and a sufficient condition for stability are derived for low-frequency kink perturbations of Astron-type particle rings in a dense plasma in the presence of an applied toroidal magnetic field.

A second-order ordinary differential equation on each flux surface is derived for the high-mode-number limit of resistive magnetohydrodynamic (MHD) ballooning modes in tokamaks with arbitrary cross section, aspect ratio, and shear. The equation is structurally similar to that used to study ideal MHD ballooning modes computationally. The model used in this paper predicts linear instability in the high-mode-number limit, with growth rate proportional to resistivity when the pressure gradient is small compared with the critical value needed for ideal MHD stability.

Computer simulations present evidence that the localized anisotropic heating from resonant absorption drives a Weibel-like instability that generates megagauss magnetic fields for typical laser-fusion parameters. The magnetic fields can inhibit heat transport and partially isotropize the hot electrons.

Remarkable density structures are observed in the plasma generated during the rise of a high-power C${\mathrm{O}}_2$ laser. Jetlike structures and density bowls are seen in interferograms. Infrared imaging shows that these bowls are linked to localized Brillouin-instability backscatter. Depolarization measurements also exhibit filamentary structures that extend far into the underdense regions of the plasma.

The yield strengths of thin-layered Al-Cu and Al-Ag laminates greatly increase as the layer thicknesses are reduced. This strength enhancement is interpreted as evidence for the retardation of dislocation generation and motion as has been theoretically proposed.

Two-loop calculations indicate that the order parameter in liquid helium at the $\lambda$ point may relax by an order of magnitude more slowly than the entropy. Consequently the critical region for entropy relaxation is expanded by an order of magnitude, both above and below the $\lambda$ point, which may help to reconcile light-scattering data, second-sound damping, and dynamic scaling theory. Characteristic double-humped spectra are calculated, providing a crucial test of the present theory.