The lifetimes of both positive and negative ions trapped on quantized vortex lines in rotating ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ mixtures have been measured at temperatures down to 0.1 K. Evidence is found that the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ condenses at the vortex core, and possibly at the surface of the electron bubble.

We have measured the drift velocity of ions trapped on vortex lines at temperatures down to 0.35 K. We observe several effects which cannot easily be explained in terms of existing theories, including the broadening of an ion pulse, a limiting velocity in high electric fields, and a zero-field mobility which increases, at lower temperatures, much more rapidly than expected. An attempt is made to explain qualitatively some of these effects.

We have observed large increases of the critical current in Josephson junctions under 10-GHz phonon excitation. Eliashberg has predicted that absorption of microwaves in a superconducting film will increase the energy gap by creating a nonthermal quasiparticle distribution. By modifying this theory to account for phonon absorption we obtain a good agreement with our results on the phonon-induced enhancement of the critical current. We conclude that absorption of phonons of frequency $\omega <\frac{2\Delta \mathrm{}\left(T\right)\mathrm{}}{\hslash }$ increases the superconducting energy gap.

The growth of W grains in sputtered W-${\mathrm{Al}}_2$${\mathrm{O}}_3$ films as a consequence of annealing results in a narrowing of the transition region from metallic to nonmetallic conductivity. The conductivity, $\sigma$, as a function of the volume fraction of the metal, $x$, exhibits a critical behavior given by $\sigma \sim {(x-x_c)}^p$, where the critical volume fraction of the metal $x_c=0.47\mathrm{}\pm 0.05$ and the critical exponent $p=1.9\mathrm{}\pm 0.2$. For $x<\mathrm{}0.47\mathrm{}$ the temperature dependence of $\sigma$ has the form $\ln \sigma \sim -\frac{1}{\sqrt{T}}$ which is characteristic of tunneling between isolated grains.

The very old and widely accepted theory for the electronic dielectric constants of ionic crystals assumes that intra-ionic excitations dominate in the crystal whereby polarizabilities of individual ions may be identified and tabulated. It is shown here that this assumption is unfounded and leads to inconsistencies and unphysical results. In turn I present theoretical and experimental evidence that the mechanism determining the dielectric constants is in fact the extreme opposite, namely strictly interionic excitations, whereby the concept of polarizability of ions in solids is physically meaningless.

$K\alpha$ x-ray satellite spectra produced by bombardment with 2.0-MeV/nucleon oxygen and neon ions have been measured for several sulfur compounds. Comparison of the satellite-peak relative-intensity distributions has revealed a dependence on chemical environment. We interpret this effect to be caused by variations in the lifetimes of $L$-shell vacancies and find evidence that transitions from ligand valence levels play an important role.

In a sample of 1.5×${10}^4$ helium and 4.0×${10}^4$ higher-charged nuclei, obtained with balloon-borne superconducting magnetic spectrometers, we find the ratio of antinuclei to nuclei in the cosmic rays to be less than 8×${10}^{-5\mathrm{}}$ for rigidities (momentum/charge) between 4 and 33 GV/c and less than ${10}^{-2\mathrm{}}$ between 33 and 100 GV/c, at the 95% confidence level.

The behavior of the fixed-point Hamiltonian, $H^{*}$, and of the eigenoperators is derived for large values of the spatially uniform order parameter. When hyperscaling is valid the limit of $H^{*}$ is characterized by the exponent, $\delta$, but if hyperscaling is invalid this limit is Gaussian-like. Possible implications of these results, including the significance of marginal operators in approximate calculations, are discussed.

The Westerbork synthesis radio telescope was used to measure the solar gravitational deflection of radio waves over a period of 10 days, in October 1973, centered on the occultation of the quasar 3C279 by the sun. Simultaneous measurements at two frequencies (5.0 and 1.4 GHz) allowed the removal of the effects of refraction in the solar corona. The gravitational bending measured was 1.038±0.033 times that predicted by general relativity. As a by-product of these observations, values for the parameters at a model of the coronal electron density were also obtained.

We have measured differential cross sections for $K^{-}p\to {\Sigma }^{+}{\pi }^{-}$ and ${\pi }^{-}p\to p{\pi }^{-}$ at 3.0 and 5.1 GeV/c near the backward direction. At 3.0 GeV/c both have a dip near $-u\sim 0.1$ (GeV/${\mathit{c})}^2$. At 5.1 GeV/c, $\frac{d\sigma }{\mathrm{du}}$ for ${\pi }^{-}p\to p{\pi }^{-}$ falls exponentially with slope 3.8±0.1 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{-2\mathrm{}}$ whereas $\frac{\mathrm{du}}{d\sigma }$ for $K^{-}p\to {\Sigma }^{+}{\pi }^{-}$ exhibits a decreasing slope for larger $\mathrm{}\left|u\right|\mathrm{}$. These data are discussed in terms of SU(3), and the relative importance of the helicity-flip and -non-flip amplitudes is investigated.

We have measured the inclusive cross sections for $\gamma$, ${K_s}^0$, $\Lambda$, and $\overline{\Lambda }$ production in ${\pi }^{+}p$ and $\mathrm{pp}$ interactions at 100 GeV/c and compared various inclusive distributions of the produced $\gamma$ and ${K_s}^0$.

We present ${\pi }^{-}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ differential cross sections at 110, 150, 180, 220, and 260 MeV, as well as total cross sections at eleven energies between 67 and 285 MeV.

Isoscalar and isovector components of $M2\mathrm{}$ and $M4\mathrm{}$ transition matrix elements are obtained by comparing stretched single-(quasi)proton transitions with stretched single-(quasi)neutron transitions. Both the isoscalar and the isovector components are found to be smaller by factors $\frac{g^{\mathrm{eff}}}{g}\simeq 0.2-0.3$ than the single-quasiparticle values. The reductions are accounted for, respectively, in terms of destructive effects of the isoscalar magnetic (spin) and the isovector magnetic (isospin-spin) core polarizations.

The fragment momentum distributions in the projectile rest frame are, typically, Gaussian shaped, narrow, consistent with isotropy, depend on fragment and projectile, and have no significant correlation with target mass or beam energy. The nuclear temperature is inferred from the momentum distributions of the fragments and is approximately equal to the projectile nuclear binding energy, indicative of small energy transfer between target and fragment.

We have measured the production cross sections of ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ in C and O targets, and ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$ and ${}_{}{}^{10}{}_{}{}^{}\mathrm{Be}$ in C targets irradiated by 2.8-GeV $\alpha$ particles. The results are discussed in terms of the applicability of a factorization relationship proposed for high-energy nuclear cross sections.

Two flashlamp-pumped, tunable, dye lasers have been utilized to study three-photon ionization in atomic sodium. The resulting ion yield shows large peaks at laser frequencies which correspond to electric quadrupole transitions. This is the first direct observation of electric quadrupole effects in multiphoton ionization. The $3p{}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}\to 4f$ matrix element is determined, and the fine-structure splitting of the $5p$ state is measured.

A sufficient condition is obtained for stability of low-frequency kink perturbations of an astron-type particle ring embedded in a dense low-temperature plasma.

The pulsed-field-gradient spin-echo method has been applied to measure the self-diffusion coefficient, $D$, for hydrogen in $\beta$-Pd${\mathrm{H}}_{0.70}$. For $296 \mathrm{K}<T<\mathrm{}413\mathrm{} \mathrm{K}$, $D=9.0\mathrm{}\times {10}^{-4\mathrm{}}\times \exp [-\frac{(0.228\mathrm{}\pm 0.006 \mathrm{eV})}{k_{\mathrm{B}}T}]$ ${\mathrm{cm}}^2$/sec with an uncertainty in $D$ of ±8% at 413 K. These results, together with proton spin-lattice relaxation-time measurements in the same specimen, are consistent with diffusion by a random walk on octahedral interstitial sites.

Using a laser-beam deflection technique and a 1-mm-high sample, we have determined, for the first time, the magnitude of the steady-state concentration gradient due to the gravitational field in a binary mixture near a consolute critical point. The data have been taken, as a function of $T-T_c$, along the critical isochore. A strong $\gamma$-type divergence is observed. A comparison with the values calculated by use of our own set of osmotic compressibility data is also presented.

Superfluid onset has been measured at several frequencies by a quartz microbalance method. We find that onset occurs earlier (i.e., at smaller thickness and/or higher temperature) when measured at higher frequencies. The results are in agreement with a prediction based upon surface heterogeneity and superfluid connectivity.