The in-plane and out-of-plane anisotropy has been measured for $\gamma$ rays in coincidence with deep-inelastic products from the 1064-MeV ${}_{}{}^{136}{}_{}{}^{}\mathrm{Xe}$+${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$ reaction. The $\gamma$-ray energy spectra exhibit a bump corresponding to a dominantly stretched-$E2\mathrm{}$ cascade, but only a small out-of-plane anisotropy, indicating a misalignment of the fragment spins. A simple model is used to extract a rms misalignment angle of 34°±7°.

An experimental study of the ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ + ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ systems reveals a large cross section for inelastic scattering with large negative $Q$ values at backward angles. The differential cross section is proportional to $\frac{1}{{sin\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}}>100\mathrm{}°$ and has characteristics consistent with the decay of an orbiting ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ + ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ dinuclear system.

Polarization-analyzing-power differences in ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$($p$,$n$)${}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ are predicted to be observable at selected energies below $E_p\sim 10$ MeV at the level of $\mathrm{}|P-A|\mathrm{}\gtrsim 0.1$. This result is derived from recoil-corrected continuum shell-model calculations in the one-particle, one-hole approximation, using a realistic $g$-matrix interaction.

High-energy charged pions produced at 180° in 0.8-4.89-GeV proton-nucleus collisions have been studied. Both the slopes of the energy spectra and the $\frac{{\pi }^{-}}{{\pi }^{+}}$ ratios increase rapidly with primary energy up to ∼ 3-4 GeV, where limiting values appear to be reached. The dependence on target mass also changes over this energy range. Unlike forward pion-production results, backward pions at these energies do not obey the scaling law suggested by Schmidt and Blankenbecler.

Wideband selective $n$-quantum excitation in the NMR of coupled spins is demonstrated for the first time. By a combination of multiple pulse averaging and phase shifts $\varphi$ a pure $n$-quantum excitation operator can be produced ($n=\frac{2\pi }{\varphi }$). This allows enhancement of normally weak $n$-quantum transitions. Selective excitation of the zero- and four-quantum transitions in benzene illustrates this approach. Extensions to selective absorption of only groups of $n$ photons in other regimes of spectroscopy are straight-forward, in principle.

A one-dimensional hybrid model for electron transport in laser targets is introduced, in which the suprathermal electrons are collisional particle-in-cell particles, the thermal electrons are a donor-cell fluid, and the electric field is calculated by artificially dilating the plasma period. The scheme shows that resistive electric fields are too transient and that a calculated ion-acoustic level is too low to explain experimentally observed reduced transport, that can, however, arise as convective inhibition enhanced by troughs in the target density profile.

Moderate-power (∼1 kW) excitation of lower-hybrid waves in a linear plasma column is found to increase the reflectivity of the phased waveguide exciter and to change the vertical position of the resonance cone. Probing of the plasma near the mouth of the waveguide reveals that the increased reflection results from an undulation in the plasma surface. This Letter presents evidence that this surface distortion is driven by thermal eddies associated with asymmetrical electron heating.

Strong minority proton heating is produced in the Princeton Large Torus through ioncyclotron resonance damping of fast waves at moderate rf power levels. In addition to demonstrating good proton confinement, the proton energy distribution is consistent with Fokker-Planck theory which provides the prescription for extrapolation of this heating regime to higher rf power levels and other minority species.

The local atomic environment around the iron site was measured in reduced and in oxidized dilute alloys of Fe in Cu. For these measuremements a new detector was employed that extends applicability of the technique of extended x-ray-absorption fine structure to systems a hundredfold more highly dilute than those heretofore accessible. Details of the alloy study and implications for other research of the high sensitivity of this detector system are discussed.

In ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-$A$, there is a coupling between ${\overrightarrow{\mathrm{V}}}_s$ and $\hat{l}$ which favors the spontaneous formation of supercurrent rolls and an accompanying nonuniform texture. Applying a weak (strong) magnetic field to a thick (thin) slab of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-$A$ can precipitate such a transition. Phase diagrams in these two limits are obtained, which also include the partial effects of a driving superflow.

A simple model is given for the spontaneous magnetic field generation by a detonation wave in condensed matter. The field is shown to arise from the noncollinearity of the thermal and electron density gradients near a medium boundary at the detonation shock front. The model allows calculation of approximate values for the field strength at the front and penetration ahead of the detonation wave. For typical explosive media interfaced by air the magnetic field is predicted to lie in the range 0.1 to 15 G.

Coherent electric echo magnitudes and decay rates have been studied systematically in four silica glasses with differing OH concentrations at a frequency of 0.7 GHz and to temperatures as low as 19 mK. Echoes have been observed in glasses with negligible OH content and originate from intrinsic tunneling systems possessing a mean electric dipole moment of approximately 0.5 D. We show that the OH in fused silica is associated with a distinct extrinsic tunneling species with a larger dipole moment and weaker phonon coupling.

Measurements of the temperature dependence of the electrical resistivity of sodium and potassium give $\rho ={\rho }_0+A{T}^n$, with $n=2.0\mathrm{}\pm 0.1$ below 2.1 K for sodium and below 1.4 K for potassium, where ${\rho }_0$ is the residual resistivity. It was found that $A$ is sample dependent, varying linearly with ${\left(\frac{{\rho }_d}{{\rho }_0}\right)}^2$, where ${\rho }_d$ is the contribution to ${\rho }_0$ arising from electron-dislocation scattering.

NMR and magnetization measurements in ${\mathrm{Y}}_{1-x}{\mathrm{Er}}_x{\mathrm{Rh}}_4{\mathrm{B}}_4$ indicate a strong conduction-electron-local-moment interaction with only a weak depression of the superconducting transition temperature $T_c$. The appearance of large hyperfine interactions below $T_c$ indicates that a grossly uncompensated conduction-electron spin state exists in the superconducting phase of Y${\mathrm{Rh}}_4$${\mathrm{B}}_4$. These results are discussed in terms of both itinerant electron antiferromagnetism and non—$s$-wave Cooper pairing.

A sharp $3d$-electron satellite excitation has been found for Cu which exhibits a strong resonant enhancement (∼ × 5) at the Cu $3p$-core-level threshold similar to the 6-eV resonant satellite observed previously in Ni. This satellite, which has two peaks at 11.8 and 14.6 eV below $E_{\mathrm{F}}$, is identified as a quasiatomic two-electron excitation with two $3d$ holes plus one $4s$ electron ($3d^{8}4s$). Present models for the Ni resonant satellite are not able to describe our Cu results.

Resistivity and magnetoresistance data in the field range 0-180 kG at low temperatures are presented. The temperature dependence ($T^3$), suppression of residual resistance, and large magnetoresistance are understood as resulting from the unusual Fermi surface. In spite of the large number of defects and the relatively weak interchain coupling ($\frac{\Delta \epsilon }{E_{\mathrm{F}}}\sim {10}^{-2\mathrm{}}$) inferred from the magnetoresistance, the states near $E_{\mathrm{F}}$ are extended over distances greater than 100 μm.

Photoemission studies of Pd on clean Si(111) surfaces show that formation of the ${\mathrm{Pd}}_2$Si compound dominates the microscopic chemistry and properties of the Pd-Si interface. No evidence is found for interface dipoles or occupied metal-induced interface states in this system. The ${\mathrm{Pd}}_2$Si reaction product (a metal) has an electronic structure more like that of the noble metals than the transition metals, with an occupied $4d$ band located ∼2.75 eV below the Fermi energy.

The integral equation of the scattering is solved exactly for a one-dimensional exponential corrugated potential. Numerical results are presented for a sinusoidal and a triangular profile of small amplitude. As the "slope" of the exponential increases the intensities given by the hard corrugated wall are approached. The finite slope of the potential has the strong effect of forcing the particles into the specular peak and tends to reduce the effect of multiple scattering.

A resonance is observed in the diffractively photoproduced two-pion final state with a mass of ∼ 1600 MeV and a width of ∼ 300 MeV. The four-pion distribution is characterized by a width of ∼ 600 MeV and peaks around 1500 MeV.

Quantum chromodynamics predicts significant noncollinearity of two-jet processes, resulting from recoil against gluons outside the jets. Jet angular radii measured in collinear experiments should therefore be much larger than those predicted by Sterman and Weinberg. Exact calculations of this effect in first-order perturbation theory are presented and compared with numerical estimates of nonperturbative contributions. The result of resumming large logarithms to all orders is also presented.