Transitions to states in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ at 7.40 and 7.91 MeV excitation are suggested to be components of a giant magnetic quadrupole resonance in ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$.

Measurements of the spectrum of resonance fluorescence induced by a monochromatic laser field in an atomic beam of sodium have been made over a wide range of laser intensities for both on- and off-resonance excitation. The spectra are consistent with theoretical calculations first made by Mollow.

The vibrational excitation in the energy ranges of the lowest resonances in benzene has been measured and it is found that only few fundamental modes become excited. This selectivity of the excitation process can be understood in terms of selection rules which are based on symmetry considerations. The angular distribution of scattered electrons in the range of the lowest shape resonance (∼1.2 eV) is consistent with an $f_{\delta }$ wave as the dominant partial wave.

Fully nonaxisymmetric magnetohydrodynamic equilibria have been calculated numerically for the Proto-Cleo stellarator utilizing a fully three-dimensional magnetohydrodynamic equilibrium code. It was found that recently observed anomalous circulating currents in stellarators may be a result of the equilibrium condition.

A cold, constant-density, cylindrical, nonneutral plasma column confined by a uniform axial magnetic field has equilibria characterized by rigid-rotation frequencies given by $\dot{\theta }=\frac{1}{2}{\omega }_c[1\mathrm{}\pm {(1-\frac{2{{\omega }_p}^2}{{{\omega }_c}^2})}^{\frac{1}{2}}]$. Measurements of these fast (+) and slow (-) equilibria are compared with a cold-fluid-theory model of nonneutral plasmas.

The bulk rotation velocity and surface envelope of a drifting unneutralized electron beam have been measured. These measurements verify various properties predicted by nonneutral-plasma theory. One unusual feature is that in some instances, the bulk rotation is opposite to that normally associated with the equilibria. Rotation at angular velocities greater than ${\omega }_c$ is also observed. In addition, the wavelength of the time-independent surface envelope is found to depend on the amount of ripple present.

We have made mean-field calculations with a Hamiltonian obtained from two-, three-, and four-atom exchange in bcc solid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$. We are able to fit the high-temperature experiments as well as the phase diagram of Kummer et al. at low temperatures. We find two kinds of antiferromagnetic phases as suggested by Kummer's experiments.

Neutron-scattering measurements have been made at 10 $K$ of phonons in a copper crystal neutron-irradiated at 4 $K$. The results, though clearly showing $q$-dependent defect-phonon perturbation effects, could not be explained entirely by simplified calculations for the $〈100〉$ split interstitial. A 300-K anneal removed the irradiation-induced line broadening and frequency shifts but only ∼ 50% of the additional peak structure, which was completely removed only after an 800-K anneal.

Inelastic light scattering is used to study the dynamics of an ordered suspension of macromolecules.

Rayleigh-Brillouin measurements of depolarized light scattering in the plastic phase of succinonitrile are reported as a function of crystal orientation. The Rayleigh wing is characterized by two distinct molecular-reorientation modes and strongly angular-dependent shear-wave peaks are seen with typical resonance line shapes. These spectra are understood as arising from coupling between acoustic phonons and reorientation modes. Excellent agreement with a hydrodynamic description of the coupled modes is obtained.

We perform a microscopic calculation of the memory function of the velocity autocorrelation function in a classical one-component plasma. Our theory yields oscillatory behavior in the velocity autocorrelation function consistent with recent molecular-dynamics computations. We also calculate the self-diffusion coefficient as a function of density.

We report measurements on the spin resonances in $a$-Tb${\mathrm{Fe}}_2$ and $a$-Gd${\mathrm{Fe}}_2$. A preliminary interpretation in terms of an oversimplified model involving clusters in a disordered material is also outlined.

By use of the photoemission-into-electrolyte technique, the photoyields of silver have been measured for $p$- and $s$-polarized light in the energy range 3 to 5 eV with a wide range of incident angles. Pronounced structure, providing striking evidence for the validity of the nonlocal theory of the surface photoeffect, is obtained.

We have conducted the first experiment on two-photon excitation of the $F$ center and obtain new and conclusive information about the structure of the relaxed excited states, the strength of electron-phonon interaction, and the amount of vibronic mixing of $|2s〉$ and $|2p〉$ states, allowing the exact solution of the dynamic problem. A new resonance arising from an additional vibronic mixing ($3s-3p$) has been found. The values of the $2s-2p$ splitting and of the fluorescence lifetime from $|2\mathrm{}{p}^{\prime }〉$ have been measured for the first time.

We have observed population of the heavy-mass sub-band in $n$-type (100) Si inversion layers at an electron density of (7.4 ± 0.3) × ${10}^{12}$/${\mathrm{cm}}^2$, corresponding to an energy splitting of 46 meV. These data are inconsistent with results from recent self-consistent-field calculations and confirm that the many-body effects are important.

We report evidence for extrinsic metal-induced surface states during the early stages of Schottky-barrier formation on Si(111), $\mathrm{GaAs}\left(\overline{1}\overline{1}\overline{1}\right)$, Ge(111), and Ge(100). Results on Ge(110) are related to those of Eastman and Freeouf for GaAs(110) and GaSb(110) and we propose a simple structural model to account for the anomalous results on (110) semiconductor surfaces.

A scaling argument is used to demonstrate the existence of a minimum metallic conductivity with a universal value for two-dimensional random lattices. We present a summary of the results of a detailed numerical experiment which supports this suggestion and indicates that the minimum metallic conductivity is $(0.12\mathrm{}\pm 0.03)\frac{e^2}{\hslash }$, in fair agreement with some experimental results for inversion layers.

We report measurements of the electroproduction reaction $\mathrm{ep}\to e{\pi }^{+}n$ for pions produced between 60 and 90° in the virtual-photon-proton center-of-mass system. The cross section is studied as a function of the center-of-mass energy, $W$, and the square of the virtual-photon mass, $-Q^2$, in the region $1.2 \mathrm{GeV}<~W<~3.0 \mathrm{GeV}$, $1.2 \mathrm{Ge}{\mathrm{V}}^2<~Q^2<~4.4 \mathrm{Ge}{\mathrm{V}}^2$. The data show a strong $W$ dependence in accord with simple quark-model predictions but exhibit a $Q^2$ dependence which is difficult to explain in the context of such a model.

Charged-current $\nu$ and $\overline{\nu }$ data are reported from the first application at Fermilab of a narrow-band neutrino beam for the measurement of normalized cross sections. Cross sections of about 20% accuracy were measured with a 120-GeV secondary hadron beam for $\nu \left(\overline{\nu }\right)$ originating from $\pi$ decay ($〈E_{\nu }〉=38\mathrm{}$ GeV) and $K$ decay ($〈E_{\nu }〉=105\mathrm{}$ GeV). The $\nu$ and $\overline{\nu }$ fluxes were determined by directly measuring the hadron flux and the $\frac{\pi }{\frac{K}{p}}$ ratios for the hadron beam.

We have observed an azimuthal asymmetry in inclusive hadron production by $e^{+}{e}^{-}$ annihilation at the center-of-mass energy $\sqrt{s}=7.4\mathrm{}$ GeV. The asymmetry is caused by the polarization of the circulating beams in the storage ring and allows separate determination of the transverse and longitudinal structure functions. We find that transverse production dominates for $x>\mathrm{}0.2\mathrm{}$ where $x$ is the scaling variable $\frac{2p}{\sqrt{s}}$.