The angular distribution patterns of vector analyzing powers for ($d, \alpha$) reactions on $s-d$ shell nuclei at energies near 16.5 MeV depend distinctly on the orbital angular momentum $L$ and total angular momentum $J$ transferred. Examples of $L=0\mathrm{}$, $L=2\mathrm{}$, and $L=4\mathrm{}$ transfers have been obtained for ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$, and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ targets, and these compare well with distorted-wave calculations. These measurements provide information useful in establishing the spins and parities of the levels populated in ($d, \alpha$) reactions.

Backward-angle excitation functions (${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=180\mathrm{}°\pm 5°$) have been measured for the systems ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ + ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ for elastic and inelastic scattering to the first excited state in ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$. Over the investigated energy range, $17\lesssim E_{\mathrm{c}.\mathrm{m}.\mathrm{}}\lesssim 37$ MeV, the elastic and inelastic data exhibit gross structure resonances of widths between 1 and 2 MeV modulated by a finer structure for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$ ($\Delta E_{\mathrm{c}.\mathrm{m}.\mathrm{}}\lesssim 250$ keV). Shape resonances with different principal quantum numbers are suggested as an explanation of the resonances.

Experimental results are reported which show that the backward-directed (and unusable) ion current in a reflex triode can be almost completely suppressed by adding a second anode, made of aluminized Mylar, 0.5 cm from the existing polyethylene anode. Proton-generation efficiencies in excess of 50% have been obtained.

Studies at Cornell University show experimental evidence for an anomalous electron-ion energy transfer in a relativistic-electron-beam-heated plasma that is ${10}^3$ times faster than can be predicted by classical processes. Electron cooling, ion heating, and a constant total plasma perpendicular energy on a time scale of ∼1 μsec after electron-beam injection are consistent with an empirically derived electron-ion energy equipartion time in the presence of current-driven instabilities.

Neutron inelastic scattering line shapes for [100] TA phonons in KCN have been measured for temperatures between 169 and 300 K. The results are compared to the predictions of a model incorporating a strong indirect ${\mathrm{}\left(\mathrm{CN}\right)\mathrm{}}^{-}$-${\mathrm{}\left(\mathrm{CN}\right)\mathrm{}}^{-}$ ion interaction mediated by elastic strains. The present experiments confirm the essential features of the model and elucidate the nature of the mode softening which leads to the phase transition at 168 K. In particular, the softening is shown to exist even for wave vectors one-half the distance to the Brillouin zone boundary.

Measurements have been made of the stress-strain relations and the changes in ultrasonic attenuation during plastic deformation of free-standing and constrained crystals of bcc ${}_{}{}^4{}_{}{}^{}\mathrm{He}$. Comparison is made with measurements for hcp ${}_{}{}^4{}_{}{}^{}\mathrm{He}$. During plastic deformation, bcc crystals are found to behave much like a viscous liquid. The results suggest a large concentration of highly mobile vacancies in the bcc phase.

Raman scattering and infrared reflectivity measurements have been performed on samples of porous Vycor glass. Three features in the spectra are due to intrinsic surface phonons. This identification is supported by a simple new theory for the surface.

We have measured the phonon dispersion of the superconducting transition-metal chalcogenide YS by inelastic neutron scattering. The longitudinal branches exhibit well-defined soft-mode regions that closely resemble those found in the structural and electronic analogs NbC and TiN. In contrast, no softening is observed in the transverseacoustic branches. The experimental dispersion curves are well reproduced by calculations based on a double-shell model.

We have measured the energy distribution curves of photoelectrons ($h\nu =21.2\mathrm{}$ eV) from a Zn single-crystal (0001) face covered by an ordered Cu monolayer and from bulk Cu. We have found a narrow (2.3-eV total width) Cu $d$-state peak 1.20 eV below the position of the peak of bulk Cu $3d$ structure. We have also calculated the density of states for both a Cu monolayer on Zn and an unsupported Cu monolayer. Theory is in good agreement with experiments. The overlayer density of states is shown to be very similar to that of the unsupported atomic layer.

The superlattice phenomenon observed by Cole, Lakhani, and Stiles in the electron inversion layer on (119)Si is explained by projecting the bulk band structure onto the surface. On high-index surfaces, the valley degeneracy only occurs at the surface-band-structure zone boundary. Lifting this degeneracy gives rise to minigaps which we observe in the optical conductivity as interband absorption.

The effect of a random uniaxial anisotropy axis on the magnetic properties of an amorphous ferromagnet is considered. It is found that in a quenched system random anisotropy with an isotropic angular distribution destroys the ferromagnetic state in fewer than four dimensions. The low-temperature phase is, instead, an Edwards-Anderson spin-glass. In more than four dimensions ferromagnetism or spin-glass ordering is found depending on the degree of disorder. Some properties of the ferromagnetic state are outlined.

The resistance of ultrathin films condensed on low-temperature substrates has been measured. All of the materials studied (Au, Cu, Al, Sn, and Pb) show a transition from activated to metallic behavior as the resistance is reduced below 30 000 Ω/□. This result gives strong evidence in support of the concept of a minimum two-dimensional conductivity. In Pb films with resistance >30 000 Ω/□, the onset of superconductivity is marked by an increase in activation energy.

This paper treats the problem of solving the linear equation which arises when a nonlinear evolution equation is linearized around some particular solution. It is shown that if the original equation is of completely integrable Hamiltonian form there are an infinity of explicit solutions of the linearized equation. These are almost always linearly independent.

We observe a $K^{-}{\pi }^{+}$ state at 1786 ± 8 MeV with a width 95 ± 31 MeV in the reaction $K^{-}p\to K^{-}{\pi }^{+}n$ at 6 GeV/c, from an experiment carried out at the Brookhaven National Laboratory multiparticle spectrometer.

The reactions ${}_{}{}^{148}{}_{}{}^{}\mathrm{Sm}$(${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$ ↔ ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$) ${}_{}{}^{150}{}_{}{}^{}\mathrm{Sm}$ and ${}_{}{}^{150}{}_{}{}^{}\mathrm{Sm}$ (${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$) ${}_{}{}^{148}{}_{}{}^{}\mathrm{Sm}$ have been performed as part of a heavy-ion study of the transitional samarium region. The angular distributions for the ground-state transitions have a typical bell shape. While the $2_1^{+}$ angular distribution is bell shaped in the stripping reaction, it is flat with an interference minimum in both pickup reactions. The striking difference between the $2_1^{+}$ angular distributions is not explained satisfactorily by current theories.

The existence of static triaxial shapes is investigated in the framework of the Hartree-Bogoliubov method. Although some statically triaxial nuclei are found the main result of the calculation is the $\gamma$ softness of nuclei. This fact implies appreciable dynamic triaxiality for most nuclei.

Angular distributions for the reaction ${}_{}{}^{180}{}_{}{}^{}\mathrm{Hf}(\alpha ,{\alpha }^{\prime })$ were measured for laboratory $\alpha$-particle energies of 21 and 24 MeV. Data were obtained for $0^{+}$, $2^{+}$, $4^{+}$, and $6^{+}$ members of the ground-state rotational band. Data for the $4^{+}$ state show unambiguously that $〈0^{+}|\times |M\mathrm{}\left(E4\mathrm{}\right)\mathrm{}\mathrm{}\left|\right|\mathrm{}{4}^{+}〉$ is large and negative. Data for the $6^{+}$ state are not well-fitted by rotational-model coupled-channels calculations. These results may indicate that the interpretation of the $E4\mathrm{}$ matrix element as arising from a static ${\beta }_4$ deformation in the framework of the simple rotational model is incorrect.

Elastic and inelastic form factors for electron scattering from the ground-state rotational band of ${}_{}{}^{181}{}_{}{}^{}\mathrm{Ta}$ have been studied for momentum transfers $0.4 {\mathrm{fm}}^{-1\mathrm{}}<~q_{\mathrm{eff}}<~2.7 {\mathrm{fm}}^{-1\mathrm{}}$. The data are shown to provide an independent check of the rotational assumption, thus adding confidence that the experimental form factors are characteristic of a stable intrinsic state associated with the rotational band. The data are also compared to a Hartree-Fock calculation using density-dependent interactions.

New data on resonances in the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ system are presented. A systematic pattern is observed suggesting that theoretical models which have recently been formulated for the mechanism of resonances appearing in the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ system also apply to this system. Furthermore, energies, spins, and widths for entrance-channel resonances predicted by a recent microscopic calculation of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ + ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ scattering agree very well with the data presented here.

It is suggested that the general form of the hadronic mass spectrum can be determined by studying the decay of hot hadronic matter produced in very-high-energy nuclear collisions. In a thermodynamic model we find that at presently attainable energies the temperature and the hadron populations in the matter depend strongly on the form of the hadronic spectrum.