We have measured positive-ion mobilities in liquid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ down to 3 mK. At 5 bar the low-temperature mobility is given by $\mu =(0.17-441\mathrm{}\ln T)\times {10}^{-6\mathrm{}}$ ${\mathrm{m}}^2$/V.s. At 27 bar two mobilities are seen, ${\mu }_{\mathrm{fast}}=(-12.85-6.21\mathrm{}\ln T)\times {10}^{-6\mathrm{}}$ ${\mathrm{m}}^2$/V.s and ${\mu }_{\mathrm{slow}}=(-6.26-3.64\mathrm{}\ln T)\times {10}^{-6\mathrm{}}$ ${\mathrm{m}}^2$/V.s. At temperatures near the discontinuity we see multiple mobilities and time-dependent conversion from one species of ion to another.

The hyperfine magnetic field $H_{\mathrm{hf}}$ at extremely dilute impurities of Ga, Ge, and As in a single crystal of hcp Co has been measured as a function of the temperature $T$ up to $T\cong 900°$ K. The functions $H_{\mathrm{hf}}\mathrm{}\left(T\right)\mathrm{}$ exhibit dramatic differences for these adjoining elements; while $H_{\mathrm{hf}}\mathrm{}\left(T\right)\mathrm{}$ in $\mathrm{As}\mathrm{Co}$ scales with the hcp host magnetization $\sigma \mathrm{}\left(T\right)\mathrm{}$, $H_{\mathrm{hf}}\mathrm{}\left(T\right)\mathrm{}$ in $\mathrm{Ga}\mathrm{Co}$ decreases much faster than $\sigma \mathrm{}\left(T\right)\mathrm{}$ and $H_{\mathrm{hf}}\mathrm{}\left(T\right)\mathrm{}$ in $\mathrm{Ge}\mathrm{Co}$ increases by ∼25%. This is the first observation of an increase with temperature of the magnitude of the hyperfine field at an impurity atom in any ferromagnetic metal.

Using precise lattice-parameter measurements, "cubic" ${\mathrm{Na}}_x\mathrm{W}{\mathrm{O}}_3(0.62\mathrm{}<~x<~0.94)$ has been found to transform from the ideal perovskite structure to three other related forms. The transition sequence is described in terms of a single vectorlike order parameter involving static in-phase tilts of W${\mathrm{O}}_6$ octahedra and is the zone-boundary analog of the ferroelectric series of transitions in BaTi${\mathrm{O}}_3$, the [001] tilt component arising from the condensation of the $M_3$ mode. Unexplained features of structural and Raman studies can now be interpreted.

EPR is used to probe the ion-motion spectral density in a superionic conductor. ${\mathrm{Mn}}^{2+}$ EPR in Pb${\mathrm{F}}_2$ shows a vacancy-diffusion-induced collapse of the ${\mathrm{F}}^{19}$-transferred hfs above 400 K. At higher temperatures, a linewidth dependence on $m^{\mathrm{}\left(55\right)\mathrm{}}$ of each ${\mathrm{Mn}}^{55}$ hfs component appears which we attribute to the dynamic modulation of the crystalline field resulting from the coupling between diffusive excitations of the "ionic liquid" and acoustic phonons.

Using a new quenching technique to minimize gravitationally induced density gradients, we find that the shape $\frac{({\rho }_L-{\rho }_V)}{{\rho }_c}$ of the xenon liquid-vapor coexistence curve is described over the reduced-temperature range $3\times {10}^{-6\mathrm{}}<\epsilon <3\mathrm{}\times {10}^{-5\mathrm{}}$ [where $\epsilon =\frac{(T_c-T)}{T_c}$] by the pure power law $B{\epsilon }^{\beta }$ with $\beta =0.317\mathrm{}\pm 0.011$. For $3\times {10}^{-6\mathrm{}}<\epsilon <2\mathrm{}\times {10}^{-4\mathrm{}}$ where $B{\epsilon }^{\beta }$ is a poor description of our data, adding the first correction term $B_1{\epsilon }^{{\beta }_1}$ provides an improved description with $\beta =0.305\mathrm{}\pm 0.010$ and ${\beta }_1=0.77\mathrm{}\pm 0.13$ in agreement with lattice-gas, binary-alloy, and $n=1\mathrm{}$ magnetic results.

We present results of light-scattering experiments on thermal acoustic spin waves in EuO. The Brillouin spectra show two peaks which can be shifted by an external magnetic field. One of these is identified as due to a modified bulk spin wave of the material. The other one, by its anomalous behavior on reversal of the magnetic field or change of the scattering geometry, reveals itself as a spin wave propagating along the surface of the crystal.

The evolution of the electronic structure of disordered Te and Ge films upon thermal annealing and/or laser irradiation has been traced with use of the newly developed double-beam photoemission technique. In particular, it is shown that, contrary to what occurs in Te films, the onset of short-range crystalline ordering appears abruptly and uniformily within the Ge films, but over a much too short range to avoid $\overrightarrow{\mathrm{k}}$ randomization before emission of the electrons.

X-ray photoelectron spectra from the valence bands of polycrystalline copper have been obtained for various electron emission angles. For grazing angles of emission, the dominant $d$-band peak is found to narrow in width by ∼12% and also to exhibit changes in fine structure. Calculations based upon tight-binding densities of states for various near-surface layers and including electron inelastic attenuation predict all of the observed changes in spectra with angle. No near-surface core binding-energy shift is found.

The identification of multiple-quantum transitions and their utilization in enhancing the resolution of electron-nuclear double-resonance (ENDOR) spectra are described. It is shown that for ${}_{}{}^{53}{}_{}{}^{}\mathrm{Cr}_{}^{3+}{}_{}{}^{}$ ions substituted in hydrated crystals the linewidths of double-quantum ENDOR transitions are an order of magnitude smaller than those of the normal ENDOR transitions.

uv-induced and x-ray-induced photoelectron spectra have been taken on hydrogenated amorphous silicon prepared in situ by reactive sputtering. Hydrogen-induced features in the $a$-Si valence-band region have been identified by comparison with spectra and calculations appropriate to the adsorption of hydrogen onto Si surfaces. Films sputtered at room temperature show peaks related to Si multiply bonded to hydrogen, while deposition at 300°C or above is mainly causing the formation of singly bonded SiH groups.

Specific-heat measurements from 1.3 to 6.2 K provide new information about super-conductivity in an "amorphous" transition-metal system, ${\mathrm{La}}_{1-x}{\mathrm{Au}}_x$. These measurements indicate some qualitative differences between "amorphous" transition metals and simple amorphous metals such as Bi, Ga, Pb, and Sn.

A large differnce in widths and intensities between Stokes and anti-Stokes spin-flip Raman scattering lines of donor electrons in $n$-CdS has been observed. This asymmetry arises from the linear $k$ term, $\lambda (\overrightarrow{\mathrm{k}}\times \overrightarrow{\mathrm{c}})·\overrightarrow{\mathrm{s}}$. In a diffusional linewidth, the term $\lambda$ appears as $D{(q\pm \frac{\lambda m^{*}}{{\hslash }^2})}^2$ from which we find $\lambda =1.6\mathrm{}\times {10}^{-10\mathrm{}}$ eV cm in good agreement with our theoretical estimate. A new effect called Doppler narrowing is implied.

The problem of astrophysical sources of detectable gravitational radiation is considered from the stellar-evolution viewpoint. Calculations are presented which indicate that the final stages of evolution may well be dominated by rapidly rotating, collapsing cores which develop nonaxisymmetric configurations. Such events emit large amounts of gravitational radiation which should be detectable in the near future.

We report results from a measurement of the inclusive processes $\mathrm{pp}\to \mathrm{Xp}$ and $\mathrm{pd}\to \mathrm{Xd}$ in the range $5<\mathrm{}\frac{{M_x}^2}{s}<0.1\mathrm{}$, $0.01\lesssim \mathrm{}\left|t\right|\mathrm{}\lesssim 0.1$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$, and incident proton momenta of 65, 154, and 372 GeV/c. Both $\mathrm{pp}$ and $\mathrm{pd}$ data show an exponential $t$ dependence and a dominant $\frac{1}{{M_x}^2}$ behavior for $\frac{{M_x}^2}{s}\lesssim 0.05$. By comparing $\mathrm{pp}$ and $\mathrm{pd}$ data we test factorization and, using the Glauber model, we measure the $\mathrm{XN}$ total cross section, ${\sigma }_{\mathrm{XN}}=43\mathrm{}\pm 10$ mb.

The properties of hadronic jets in $e^{+}{e}^{-}$ annihilation are examined in quantum chromodynamics, without using the assumptions of the parton model. We find that two-jet events dominate the cross section at high energy, and have the experimentally observed angular distribution. Estimates are given for the jet angular radius and its energy dependence. We argue that the detailed results of perturbation theory for production of arbitrary numbers of quarks and gluons can be reinterpreted in quantum chromodynamics as predictions for the production of jets.

We have studied the high-mass dihadron continuum in 400-GeV $p$-Be collisions over the mass range 4-10 GeV. The experiment was performed at Fermilab using a double arm magnetic spectrometer including Čerenkov particle identification. Mass spectra for all combinations formed with an identified ${\pi }^{\pm }$, $K^{\pm }$, or $p\left(\overline{p}\right)$ in each arm have been examined. No evidence for resonance production was observed. Results on mass and $p_T$ dependence of the dihadron inclusive cross sections are presented.

Calculated spectra are presented for the target ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ for 90-MeV ($e, e^{\prime }$), 120-MeV ($\alpha , {\alpha }^{\prime }$), and 80-MeV ($d, d^{\prime }$), reactions using microscopic form factors based on random-phase-approximation eigenvectors. It is shown that the existence of a monopole excitation at about 14 MeV in addition to the well-known giant dipole resonance is consistent with ($e, e^{\prime }$), ($\alpha , {\alpha }^{\prime }$), and ($d, d^{\prime }$) data.

Differential cross sections for elastic scattering of 0.8-GeV protons from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ have been measured. Preliminary analysis of the data in terms of the Kerman-McManus-Thaler formalism with spin-dependent nucleon-nucleon amplitudes shows sensitivity to details of proton and neutron matter distributions.

A peak about 2 MeV wide is observed at $E_x\sim 8-9$ MeV in six even-even tin isotopes and at lower excitation in ${}_{}{}^{104}{}_{}{}^{}\mathrm{Cd}$ and ${}_{}{}^{102}{}_{}{}^{}\mathrm{Pd}$ in the ($p, t$) reaction at 42 and 45 MeV. The excitation energy of the peak and its width increase with increasing neutron number. The peak may arise from two-neutron pickup from the lower-lying $\mathrm{gpf}$ shell. Distorted-wave Born-approximation calculations agree well with the angular distributions and indicate that 45% of the total strength is observed experimentally.

Outgoing-nucleon charge exchange has been used to explain reduction in $\pi -N$ isospin selectivity in a large number of nucleon-removal experiments. The present work tests the validity of this model by measuring the total cross sections for nucleon removal to the 4.44-MeV, $T=0\mathrm{}$ and the 15.11-MeV, $T=1\mathrm{}$ states in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, where analog charge exchange is possible for the latter, but not the former state.