We report the results of a calculation which point out the existence of localized electronic states in the vicinity of stacking faults in a face-centered-cubic transition metal (nickel). The results are fairly insensitive to the parameters of the calculation. The reported states appear between the two $d$ sub-bands of the bulk states, are well received, are fairly well localized, and could be observable by electron emission spectroscopy.

The measured third harmonic power output from a paramagnetically doped superconductor in a stron microwave field has been found to vary with temperature as ${\mathrm{}(1-t)\mathrm{}}^{-1\mathrm{}}$, as predicted by Gor'kov and Eliashberg's theory for concentrations close to critical and Eliashberg's theory for the dilute alloy. The magnitude of the order-parameter relaxation time deduced from the measured power is consistent with a model constructed from these two theories.

Results of electric field modulation of internal reflections in cleaved Ge(111) 2 × 1 surfaces are presented. They can be interpreted on the basis of a buckled model of the reconstructed surface with raised (lowered) atoms negatively (positively) charged. The value of the force constant for normal displacement of surface ions (1.1 × ${10}^5$ dyn ${\mathrm{cm}}^{-1\mathrm{}}$) is estimated.

We report high-precision measurements of electron energy-loss scattering intensity, giving the bulk plasmon dispersion $\omega \mathrm{}\left(q\right)\mathrm{}$ for wave vectors extending to $q>\mathrm{}{q}_F$. Some subtleties are identifiable in these data that clarify the effects of multiple scattering. These results are in qualitative agreement with random-phase-approximation concepts, showing smooth dispersion to $2{\omega }_p$ and $1.4q_F$, where $\omega \mathrm{}\left(q\right)\mathrm{}$ joins the center of the quasiparticle continuum, rather than the dispersionless result obtained previously.

Neutron scattering measurements in the dilute antiferromagnets ${\mathrm{Rb}}_2{\mathrm{Mn}}_c{\mathrm{Mg}}_{1-c}{\mathrm{F}}_4$ with $c=0.54\mathrm{} \mathrm{and} 0.57$ are presented; for this system the percolation limit is $c_p=0.59\mathrm{}$. Two-dimensional critical scattering is observed with inverse width $\xi$ and amplitude $\chi T$ which diverge as a function of $\frac{1}{T}$; the divergences cut off when $\xi$ exceeds the size of the larger clusters. A simple self-avoiding walk model accounts well for the observed $\xi$ vs $T$ behavior.

We report the measurements of the inclusive $\mu$-pair production by 150-GeV protons and ${\pi }^{+}$ mesons on beryllium. Absolute cross sections as well as the Feynman-$x$ and $P_T$ dependence are presented in the mass region between 0.211 and 3.5 ${\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c}}^2$. Upper limits are also given for the inclusive production of $\eta$ and ${\rho }^{\prime }\mathrm{}\left(1600\right)\mathrm{}$ mesons.

Using data from our recent experiment on inclusive $\mu$-pair production by 150-GeV/c protons on beryllium, we have calculated the contribution of muon pairs to the yield of single prompt muons. We find, both at 90° in the center-of-mass system and in the forward direction, that the resulting single-muon cross sections are in reasonable agreement with the existing measurements for which only one muon is detected.

Total cross sections of $K^{-}p$ and $K^{-}d$ have been measured between 410 and 1070 MeV/c with high statistical precision. In addition to the well known $\Lambda \mathrm{}\left(1520\right)\mathrm{}$, $\Lambda \mathrm{}\left(1820\right)\mathrm{}$, and $\Sigma \mathrm{}\left(1769\right)\mathrm{}$, we confirmed the presence of the $\Lambda \mathrm{}\left(1692\right)\mathrm{}$ and the $\Sigma \mathrm{}\left(1670\right)\mathrm{}$. We have also observed several structures which could be $Y^{*}$ resonances: $\Lambda \mathrm{}\left(1646\right)\mathrm{}$, $\Lambda \mathrm{}\left(1735\right)\mathrm{}$, $\Sigma \mathrm{}\left(1583\right)\mathrm{}$, $\Sigma \mathrm{}\left(1608\right)\mathrm{}$, $\Sigma \mathrm{}\left(1633\right)\mathrm{}$, and $\Sigma \mathrm{}\left(1715\right)\mathrm{}$.

Results are reported for the zero-degree analyzing power and longitudinal vector polarization transfer coefficient values of the reaction ${}_{}{}^3{}_{}{}^{}\mathrm{H}\mathrm{}(d,n)\mathrm{}{}_{}{}^4{}_{}{}^{}\mathrm{He}$. These data allowed a calibration of the neutron polarization to an absolute accuracy of ± 2%. The analyzing power of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ was measured using the calibrated neutron beam for $E_n$ in the range 20 to 30 MeV. The results of the ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ analyzing power measurements are compared to phase-shift predictions as well as other data for ${}_{}{}^4{}_{}{}^{}\mathrm{He}\mathrm{}(n,n)\mathrm{}{}_{}{}^4{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^4{}_{}{}^{}\mathrm{He}\mathrm{}(p,p)\mathrm{}{}_{}{}^4{}_{}{}^{}\mathrm{He}$ in the same energy region.

A ${}_{}{}^2{}_{}{}^{}\mathrm{He}$ detection system has been developed and used to investigate the ($\alpha ,{}_{}{}^2{}_{}{}^{}\mathrm{He}$) reaction at 65 MeV on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$, and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ targets. Extreme spectroscopic selectivity with preferential population of final states with ${\left(d_{\frac{5}{2}}\right)}_{4^{+}}^2$ character was observed. Applications of this experimental technique to the detection of other unbound reaction products are proposed.

A giant-resonance-like structure at $E_{\mathrm{exc}}\sim \frac{32}{A^{\frac{1}{3}}}$ MeV is observed in ($\alpha ,{\alpha }^{\prime }$) spectra in nuclei from ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ to ${}_{}{}^{154}{}_{}{}^{}\mathrm{Sm}$. Analysis of the angular distributions leads to an assignment of $J^{\pi }=3^{-}$ and an energy-weighted sum-rule fraction of 16-22% for this structure. Comparison with random-phase-approximation calculations shows that $\sim \frac{2}{3}$ of the expected $1\hslash \omega$ octupole energy-weighted sum-rule strength is found at $\sim \frac{32}{A^{\frac{1}{3}}}$ MeV; the remainder occurs in low-lying $3^{-}$ states.

The total cross section for the reaction ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(\gamma ,{\pi }^{-}){}_{}{}^{12}{}_{}{}^{}\mathrm{N}$ has been determined by observation of the residual ${}_{}{}^{12}{}_{}{}^{}\mathrm{N}$ radioactivity. The cross section was extracted from the bremsstrahlung excitation function which was measured in the region between 3.6 and 12.6 MeV above the threshold, with one point 33.5 MeV above the threshold. The variation of the measured cross section with energy is far more rapid than is predicted by calculations using the $\overrightarrow{\epsilon }·\overrightarrow{\sigma }$ interaction. Even when the full interaction Hamiltonian is used, the experimental cross section rises somewhat more rapidly than predicted.

We have identified several high-$K$ four- and six-quasiparticle states between 2.5 and 5 MeV excitation in ${}_{}{}^{176}{}_{}{}^{}\mathrm{Hf}$, which are well described by the collective model with axial symmetry. Isomers with $K^{\pi }={14}^{-},{19}^{+}, \mathrm{and} {22}^{-}$ form traps at or near the yrast line. The yrast structure changes from the ground band to a $K^{\pi }={16}^{+}$ band at $I=16\mathrm{}$ and again to a $K^{\pi }={22}^{-}$ state at $I=22\mathrm{}$, providing the first demonstration that intrinsic excitations of a heavy deformed nucleus can become yrast.

An etch parameter almost unnoticed previously, etch induction time, has been measured in Kodak Pathé cellulose nitrate track detector films using ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$, ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$, and ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ ions of known low energy per unit mass for calibration. The etch induction time appears to vary with the parameter $\frac{{\left(\frac{\mathrm{dE}}{\mathrm{dx}}\right)}_{W<\mathrm{}1000\mathrm{}}}{Z^{*}}$ where $Z^{*}$ is the effective ion charge and ${\left(\frac{\mathrm{dE}}{\mathrm{dx}}\right)}_{W<\mathrm{}1000\mathrm{}}$ is the restricted energy loss, calculated for a $\delta$-ray cutoff energy of 1000 eV.

We have found that numerical simulation and experiment both show laser-imploded spherical glass shells to expand in two successive pulses: The first corresponds to the ablated material, while the second corresponds to the compressed material. The relative speeds and intensities of the two pulses indicate the efficiency of transferring absorbed laser energy to the compressed core.

High-resolution tunable laser resonance diagnostics reveal ion density decreases within the unstable region of an ion-cyclotron wave as well as hot-ion transport out of the unstable region, showing that instability and heating are dominated by a nonlocal process combining ion transport with heating.

Neon-filled glass spherical shell targets were irradiated by a four-beam laser system of incident power 0.6-0.8 TW. By measuring $K\alpha$ x-ray lines of neon and silicon we are able to determine the number of fast (nonthermal) electrons and their preheating effect. Correlation is made with fast ion measurements.

A pressure-induced tricritical point is indicated for ${\mathrm{KH}}_2$${\mathrm{PO}}_4$ near 2 kbar pressure. This estimate is based on analysis of our static dielectric data for pressures up to 3 kbar.

The neutron inelastic scattering function of liquid helium-3 at 0.015 K has been measured for wave vectors in the range $0.8{\AA }^{-1\mathrm{}}<~q<~2.2{\AA }^{-1\mathrm{}}$. For $q<\mathrm{}1.4\mathrm{}$ ${\mathrm{\AA }}^{-1\mathrm{}}$, the scattering function contains two peaks. The peak at lower energy is due to spin-fluctuation scattering in the particle-hole region while the peak at higher energy is identified to be the zero sound mode. By comparing the measured structure factor with the x-ray structure factor, the spin-dependent scattering cross section and the corresponding structure factor are determined.

The density fluctuation spectrum of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ is calculated using a generalized polarization potential approach and shown to yield both zero sound and quasiparticle spectra in good agreement with the recent neutron scattering experiments. Landau Fermi-liquid theory is used to calculate the spin density fluctuation spectrum; and sum-rule arguments are presented which enable us to establish the qualitative nature of this spectrum at larger wave vectors with results in good qualitative agreement with the recent experiment of Sköld et al.