Relativistic electron beams with $0.4<\mathrm{}\frac{\nu }{\gamma }<2.2\mathrm{}$ have been used in this experiment to heat a high-density [$n\sim \mathrm{}(5-8)\mathrm{}\times {10}^{13}$ ${\mathrm{cm}}^{-3\mathrm{}}$] fully ionized hydrogen plasma immersed in a magnetic field. The resulting heating levels are strongly dependent on the effective diode impedance $Z=\frac{V}{I}$ and, correspondingly, the $\frac{\nu }{\gamma }$ of the beam. Measurement of the total plasma energy from the plasma diamagnetism and the ion energy distribution from analyses of charge-exchange neutral atoms are used to determine scaling laws for the beam-plasma interaction.

The kinematic shear viscosity and the ultrasonic absorption coefficient have been measured in the ternary system water-benzene—ethyl alcohol near a critical point ("plait point") ($P_c=1\mathrm{}$ atm; $T_c=25\mathrm{}°$C; critical composition in wt%: water, 10.25; benzene, 52.10; and ethyl alcohol, 37.25), to provide a qualitative test of recent theoretical predictions. The experimental results indicate a rapid increase of the shear viscosity as a function of concentration near the plait point and a less pronounced sensibility of the absorption coefficient.

We study the propagation of surface electromagnetic waves parallel to an applied magnetic field in an electron-hole plasma. Several new modes are found. One low-frequency mode may offer an explanation to recently observed surface-wave resonances in InSb at room temperature.

Heteropolymer melting corresponds to a low-temperature phase transition in a one-dimensional two-component Ising model. A leading-order approximation for an additive physical quantity in the melting region is introduced; it is intimately connected with the microscopic statistical herteropolymer structure. This allows one to derive the heteropolymer distribution function (over the length and composition of the sections) directly from experimental data.

We have demonstrated for the first time that the condensed phase of electrons and holes in germanium can be produced by carrier injection. Germanium devices at liquid-helium temperatures emit intense 708.5-meV recombination radiation characteristic of the condensed phase.

The dynamical method of low-energy electron-diffraction intensity analysis has been applied to the system of $C(2\mathrm{}\times 2)$ oxygen on nickel(100). This system differs considerably both geometrically and chemically from the sodium-on-nickel system previously reported. The diffraction data are consistent with a model where oxygen sits in a layer displaced normal to the surface by $d=1.5\mathrm{}\pm 0.1$ Å from the center of the top layer of nickel atoms. Oxygen atoms sit above pyramidal hollows in the nickel layer below.

A model for the Ti, ${\mathrm{V}}_2$${\mathrm{O}}_3$ electronic $d$ levels is proposed and shown to account satisfactorily for observed anomalous low-temperature specific heats in the system. In the ${\mathrm{}(\mathrm{T}\mathrm{i},\mathrm{V})\mathrm{}}_2$${\mathrm{O}}_3$ systems, in particular, empty V $d$ levels lie so far below the conduction band as to penetrate the host valence band a short way.

Measurements of the thermopower of the organic conductor tetrathiofulvalinium tetracyanoquinodimethane have been made in the region 10-300°K. At high temperatures ($T>\mathrm{}140\mathrm{}°$K) the samples are metallic showing increased electron correlations as the temperature is lowered to about 56°K. At this point the thermopower is zero and a discontinuity marks the transition to the insulating state.

The analog ($p$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$) and ($p, t$) reactions on ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ have been compared at 27.0 MeV incident proton energy. In contrast to previous results at higher energies (≥43.7 MeV), the intensity ratio predicted by isospin conservation was satisfied only at small angles.

Using a new ${}_{}{}^8{}_{}{}^{}\mathrm{Be}$ identifier of high detection efficiency, we observed the ($\alpha$, ${}_{}{}^8{}_{}{}^{}\mathrm{Be}$) reaction on targets of ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ at 65 MeV. Differential cross sections (∼1-60 μb/sr) were measured from ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=20\mathrm{}°-80\mathrm{}°$. The only states strongly populated were those predicted to have large $\alpha$-structure amplitudes, implying that direct processes dominate at $E_{\alpha }=65\mathrm{}$ MeV.

A theory of the $\pi$-nucleus optical potential is developed from the exact propagator of a pion in the presence of a nucleus. The crossed $\pi$-nucleus diagrams, absent in previous work, are shown to have significant effect on the cross sections and the elastic-scattering wave functions of low-energy pions.

We have used $\Delta E-E$ and time-of-flight techniques to observe the products of the interaction of 4.8-GeV protons with a uranium target. Two new isotopes, ${}_{}{}^{14}{}_{}{}^{}\mathrm{Be}$ and ${}_{}{}^{17}{}_{}{}^{}\mathrm{B}$, were observed to be particle stable, and two others, ${}_{}{}^{12}{}_{}{}^{}\mathrm{Li}$ and ${}_{}{}^{16}{}_{}{}^{}\mathrm{B}$, were shown to be particle unstable. The new isotope ${}_{}{}^{17}{}_{}{}^{}\mathrm{B}$ recently had been predicted to be particle stable, but the observation of ${}_{}{}^{14}{}_{}{}^{}\mathrm{Be}$ was surprising because it was thought to be unstable on the basis of both theoretical predictions and previous experimental results.

The distorted-wave impulse approximation for knockout reactions, when written following a Faddeev prescription, contains a fully off-shell $T$ matrix whose arguments are coupled to those of the distorted waves. We show how the off-shell $T$ matrix may be expanded around its half-shell point and an approximate factorized distorted-wave impulse approximation obtained with the major off-shell effect included. The off-shell ambiguity present in the standard treatments is thereby eliminated.

A new method for precision measurements of atomic lifetimes by laser excitation of fast beams is described which is expected to allow accuracies of $\frac{\Delta \tau }{\tau }={10}^{-3\mathrm{}}$. A first application to ${\mathrm{Ba}}^{+}-6\mathrm{}{}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}$ yields as a preliminary result $\tau =6.21\mathrm{}\pm 0.06$ nsec.

The $2{}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{}\to 1{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}$ magnetic-dipole transition in the heliumlike atoms ${\mathrm{Ar}}^{+16\mathrm{}}$ and ${\mathrm{Ti}}^{+20\mathrm{}}$ has been studied by a time-of-flight technique. The lifetime of the $2{}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{}$ state is found to be 172(12)×${10}^{-9\mathrm{}}$ sec in ${\mathrm{Ar}}^{+16\mathrm{}}$ and 25.8(1.3)×${10}^{-9\mathrm{}}$ sec in ${\mathrm{Ti}}^{+20\mathrm{}}$, where the stated errors included statistical and systematic effects. These values can be compared with theoretical values of 212.4×${10}^{-9\mathrm{}}$ sec for ${\mathrm{Ar}}^{+16\mathrm{}}$ and 27.4×${10}^{-9\mathrm{}}$ sec for ${\mathrm{Ti}}^{+20\mathrm{}}$.

The lifetime of a long-lived $K$ x-ray emitter produced in foil excitation of chlorine beams between 40.3 and 57.5 MeV has been measured to be 280±25 nsec. The measured photon energy of the transition indicates that it arises from the $1{}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}\leftarrow 2{}_{}{}^3{}_{}{}^{}S_1^{}{}_{}{}^{}$ decay in heliumlike chlorine. The observed lifetime is shorter than the theoretical $M1\mathrm{}$ lifetime of 381 nsec predicted for this transition.

We report inelastic-neutron-scattering measurements on liquid ${}_{}{}^3{}_{}{}^{}\mathrm{He}_{0.05}^{}{}_{}{}^{}$ ${}_{}{}^4{}_{}{}^{}\mathrm{He}_{0.95}^{}{}_{}{}^{}$ in the $Q$ region from 0.8 to 2.3 ${\mathrm{\AA }}^{-1\mathrm{}}$ at 1.6 K. The shifts and increases in natural linewidth of the single excitation peaks relative to pure ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ at the same temperature were determined by a least-squares fitting procedure. The shifts vary from a small, possibly negative, value at the roton minimum to positive values around 0.5 K at both ends of the $Q$ range. The full widths at half-maximum of the extra broadening vary from 0.5 to 1.5 K over the same range.

The viscosity of liquid ${\mathrm{He}}^3$ is shown to saturate at high temperatures like $A+\frac{B}{T}$, in good agreement with experiment; the spin-diffusion coefficient should saturate, too, like $A^{\prime }-\frac{B^{\prime }}{T}$, while the thermal conductivity varies linearly with $T$. The same formulas reduce at very low temperature to the results of the paramagnon model.

We have produced and observed quantized vortex rings emitted from orifices when superfluid helium is forced through channels at critical velocity. The vortices are identified by measuring their velocity and size, and are found to be in the $n=1\mathrm{}$ quantum state.

An electromagnetic wave obliquely incident on an inhomogeneous plasma has a resonance near ${\omega }_0={\omega }_{\mathrm{pe}}\mathrm{}\left(x\right)\mathrm{}$. It is shown that temporally growing modes exist for parametric decay into ion-acoustic and electron-plasma waves in the vicinity of this resonance in spite of the density gradient. For typical laser fusion parameters the maximum growth rate is comparable to the ion-acoustic frequency. The mechanism can contribute to significant power absorption.