The magnetic susceptibility $\chi$ of liquid Pd, Si, and Pd-Si alloys was measured. For crystalline semiconducting Si, $\chi$ changes at the melting point $T_M$ from diamagnetic to paramagnetic values in good agreement with existing theoretical calculations for the liquid state. For liquid Pd, $\chi$ is discussed within the Stoner-Wohlfarth and Edwards models. The data obtained for liquid Pd-Si alloys provide an understanding of the diamagnetism of the metallic glass ${\mathrm{Pd}}_{81}$${\mathrm{Si}}_{19}$ and will be discussed in the light of recent density-of-states data obtained by photoemission.

Far-infrared absorption experiments on Pr${\mathrm{Cl}}_3$ at low temperatures show a broad temperature-dependent absorption peaked at 3.0 ${\mathrm{cm}}^{-1\mathrm{}}$ which we attribute to cooperative spin excitations. Pr${\mathrm{Cl}}_3$ is a one-dimensional $\mathrm{XY}$ system and a calculation of the mean energy of zero-wave-vector excitations for this model has been carried out. Both the calculated mean energy and the peak of the absorption occur at $1.5J$, where $J$ is the nearest-neighbor interaction parameter.

Several theories have attempted to explain the anomalous temperature dependence of the resistivity in metallic glasses including a generalized Ziman theory, a model based on Mott $s-d$ scattering, and a model based on a Kondo or tunneling mechanism. The thermoelectric power as well as the resistivity of a glass has been measured up to the crystallization temperature and was linear over the entire region. This behavior is only consistent with the Ziman theory.

Electrical conductivities of hydrogen and neon were measured during isentropic compression in a magnetic-flux compression device. Hydrogen becomes conducting at a density of about 1.06 g/${\mathrm{cm}}^3$ and a calculated pressure of about 200 GPa (2 Mbar). Neon remained an insulator to an estimated pressure of more than 500 GPa.

Self-focusing of high-frequency electromagnetic radiation is observed to produce large-scale plasma striations in the ionosphere. Development of a new observational technique has allowed the first detailed study of the instability scale sizes and associated plasma movement. Experimental results are shown to support the theory of wave self-focusing through differential electron heating.

The reaction ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$(${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$)${}_{}{}^{206}{}_{}{}^{}\mathrm{Pb}$ has been measured at incident energies of 69, 71, and 73 MeV. Calculations free of optical-potential ambiguities and utilizing spectroscopic information derived from extensive sub-Coulomb single-neutron-transfer experiments show that, even at these low energies, the sequential transfer of two neutrons is the dominant process.

$\gamma$-ray excitation functions have been measured for several residual nuclei in the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ system, from $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=12.2\mathrm{} \mathrm{to} 15.0$ MeV in steps of ∼ 27 keV. In addition to three known resonances, a fine correlated structure is found superimposed over a broad resonance, as suggested by the mechanism of a fragmented shape resonance. The data may also be interpreted to indicate that the system decays via two different paths.

I calculate the asymmetries in the integrated cross sections for ${}_{}{}^2{}_{}{}^{}\mathrm{H}({\gamma }_{\mathrm{pol}}, n)p$ and ${}_{}{}^2{}_{}{}^{}\mathrm{H}(e_{\mathrm{pol}}, n)e^{\prime }p$, with left- and right-polarized incident particles. Up to 1 MeV above threshold, the rising $p$-wave amplitude in the final $\mathrm{np}$ system is shown to have not destroyed the close relation between the asymmetries and the circular polarization of the photon in $p(n_0, {\gamma }_{\mathrm{pol}}){}_{}{}^2{}_{}{}^{}\mathrm{H}$.

${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ + ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ elastic scattering has been studied at ten angles from 28.0° to 150.8° in the energy range $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=9.8-17.8\mathrm{}$ MeV. These data, together with supporting data from the ${}_{}{}^8{}_{}{}^{}\mathrm{Be}$ exit channels, show that two strong resonances appear in the elastic scattering at energies of 12.5 and 13.2 MeV. Both resonances are approximately 300 keV wide.

We show that recent measurements of ${\pi }^{-}$ multiplicity distributions produced in relativistic heavy-ion collisions are in remarkable agreement with the predictions of the collective tube model.

The Lyman intensities of muonic x rays from 35 oxides have been measured with Ge detectors. The dependence of the various quantities on each other and on target data is investigated with correlation theory. Many correlations are established.

We have measured the thermally averaged rate constants for rotationally inelastic collisions of ${\mathrm{Na}}_2$* and Xe for six values of initial angular momentum $j_0$ and for changes in $j$ up to 30. We propose a new scaling law which fits all these rates within 20%. This scaling law implies that $m_j$ is conserved in the collision, and shows that the square of the $T$ matrix has a power-law dependence on the energy transferred. These results suggest the importance of dynamical effects in rotationally inelastic collisions.

We have observed for the first time a pronounced increase of the molecular—$K$—x-ray production as a function of projectile charge state in 32-MeV S + Ar (gas target) collisions. The results are interpreted as evidence for strong excitation of $1s\sigma$ electrons into empty high-lying bound states. A comparison of this gas-target system and the solid-target systems Cl+Cl establishes unambiguously the predominance of one-collision processes for molecular—$K$—x-ray production.

It is suggested that the optical ray-retracing effects observed in laser-produced plasmas originate from the same mechanism believed to cause phase conjugation from backward stimulated processes in liquids. This mechanism is elucidated with the aid of a simple model, and generalized to include plasma inhomogeneity. A comparison is made with a recent experiment.

The growth of current filamentation instability is calculated for intense multi-GeV heavy-ion beams focused across a target chamber onto a fusion pellet. Conditions for which this instability growth can be kept small are given.

Using the $\sigma$-stability technique, we study the stability of the internal kink mode in toroidal geometry. We show that there are two unstable regions separated by a stable one in a $\beta -q_c$ stability diagram. In one of these regions toroidal effects are stabilizing and in the other they are destabilizing. Discrepant results of previous analytical theories and experimental results are explained.

Continuous toroidal electron currents, which sustain the poloidal magnetic field in tokamaks, may be generated by injecting waves with net parallel momentum into the plasma via phased waveguide arrays. Waves with high phase velocity can produce a current capable of confining a reactor plasma so that steady-state tokamak operation with acceptable power dissipation becomes possible.

I discuss simple Landau theory of the free surface of a nematic, including possible polar ordering effects near the surface. It is found that polar surface order favors a perpendicular alignment of molecules at the surface and this may compete with the usual quadrupolar order which favors parallel alignment. At a critical point, the surface symmetry changes from uniaxial to biaxial and there are large pretransitional fluctuations of the tilt angle of the molecules. The possibility of a soft mode associated with the transition is pointed out.

I have found with EPR that some Al impurity atoms in type-I and -II vitreous silica are bonded to only three oxygen atoms. Under ionizing radiation at 4 K, diamagnetic Al${\mathrm{O}}_3$ traps an electron and becomes paramagnetic Al${\mathrm{O}}_3^{-}$; this charge configuration is observed with EPR for $T\lesssim 330$ K. With an alkali compensator Al${\mathrm{O}}_3^{-}$ exists for $T\lesssim 550$ K, but if the compensator involves hydrogen, the extra electron can remain trapped for $T\lesssim 650$ K.

Nuclear magnetic resonance was performed on oriented ${}_{}{}^{131}{}_{}{}^{}\mathrm{I}$ nuclei implated in singlecrystal iron. Apart from the substitutional resonance, satellite resonances were found whose number and position depended on the angle between the magnetic field and the crystal axes. These lines are found to originate from impurity sites that have a neighbor vacancy, creating an electric field gradient of 1.05×${10}^{22}$ ${\mathrm{V}/\mathrm{m}}^2$ along one of the $〈111〉$ axes.