Electromagnetic and particle energy fluxes are equipartitioned in a superrelativistic plasma wave. The consequences for cosmic-ray acceleration by pulsars are investigated.

From measurements of proton-proton elastic scattering at very small momentum transfers where the nuclear and Coulomb amplitudes interfere, we have deduced values of $\rho$, the ratio of the real to the imaginary forward nuclear amplitude, for energies from 50 to 400 GeV. We find that $\rho$ increases from -0.157 ± 0.012 at 51.5 GeV to +0.039 ± 0.012 at 393 GeV, crossing zero at 280 ± 60 GeV.

We have measured the mean charged multiplicity ${\overline{n}}_{\mathrm{CH}}$ as a function of transverse momentum $p_{\perp }$ of the forward proton in the reaction $p+p\to p+\mathrm{MM}$ for five intervals of missing mass (MM) using our Multiparticle Argo Spectrometer System. We observe an increase of ${\overline{n}}_{\mathrm{CH}}$ for $p_{\perp }>1\mathrm{}$ GeV/c.

A single electron has been isolated in a ∼ 6-V-deep Penning trap. Using synchronous detection its forced axial oscillation at 55.7 MHz has been observed continuously. Excitation was either sideband at 54.7 MHz or parametric at 111.4 MHz, the latter making collision-induced 180° phase jumps visible. The monoelectron oscillator is profitably looked upon as a fixed-in-space pseudoatom, free of first- and second-order Doppler shifts.

Ions field evaporating from tungsten in the presence of helium are identified by a time-of-flight atom probe of improved resolution. Helium is found to be adsorbed at all imaged surface sites. From the brightly imaged crystal regions the adsorbate comes off as ${\mathrm{He}}^{+}$, approximately in a one-to-one ratio with ${\mathrm{W}}^{+++}$ and ${\mathrm{W}}^{++++}$. The dim, high work-function regions around (011) predominantly yield ${\mathrm{WHe}}^{+++}$ molecular ions with the temperature-dependent relative abundance peaking at liquid nitrogen temperature.

The amplitude and velocity of second sound near $T_{\lambda }$ and the onset temperature $T_o\mathrm{}\left(X\right)\mathrm{}$ for superfluidity have been measured for ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ mixtures in resonators equipped with superleak transducers. The reduced temperature ${\epsilon }_o=1-\frac{T_o\mathrm{}\left(X\right)\mathrm{}}{T_{\lambda }\mathrm{}\left(X\right)\mathrm{}}$ and the quantity $\frac{l{\rho }_s}{T}$ at ${\epsilon }_o$ vary by factors of about 6 for $X=0\mathrm{} \mathrm{to} 0.4$. The exponents ${\lambda }^{\prime }$ for ${\epsilon }_o=(\frac{d}{d^{*-{\lambda }^{\prime }}}$ and ${\nu }^{\prime }$ for the onset length $l=l^{*}{\epsilon }^{-{\nu }^{\prime }}$ are independent of $X$ to within ± 3%. Contrasting with this behavior is a 20% change of the effective exponent $\zeta$ of $\frac{{\rho }_s}{\rho }=k{\epsilon }^{\zeta }$.

A computer study of the magnetic line cusp with an internal field shows that a large fraction of the particles in the field-plasma boundary move in definite guiding-center orbits. In the absence of microinstabilities such particles will remain trapped between Coulomb collisions. Since only boundary particles can escape from a "stuffed" line cusp, this result gives an optimistic assessment of line cusps for fusion.

Measurements of the longitudinal sound velocity of single crystals of hcp ${\mathrm{He}}^4$ are reported from 0.7 K to the melting temperature at melting pressures of 86 and 119 bar. The temperature dependence changes from a power law to approximate temperature independence below about 1.1 K at $p_m=86\mathrm{}$ bar and below about 2 K at $p_m=119\mathrm{}$ bar. It is believed that this marks the transition from adiabatic sound propagation to a region where coupling to the temperature field is important.

The Ising model on a triangular lattice with three-spin interactions is solved exactly. The solution, which is obtained by solving an equivalent coloring problem using the Bethe Ansatz method, is given in terms of a simple algebraic relation. The specific heat is found to diverge with indices $\alpha ={\alpha }^{\prime }=\frac{2}{3}$.

Our data on spin resonances in $\mathrm{Ag}$-Er are inconsistent with the $J\overrightarrow{\mathrm{S}}·\overrightarrow{\mathrm{s}}$ model, and barely consistent with $J(\hat{k}, {\hat{k}}^{\prime })$. Alternatively, a suggestive temperature dependence of the $J\overrightarrow{\mathrm{S}}·\overrightarrow{\mathrm{s}}$ conduction-electron $g$ value is compatible with the data. We present general kinetic equations for a local-moment-conduction-electron system. We clarify questions of detailed balance, relaxation to exchange fields, positive energy absorption, and reduction of the kinetic equations for any possible model to either of two standard forms.

The dynamics of the 151-K Jahn-Teller phase transition in PrAl${\mathrm{O}}_3$ have been studied by means of inelastic neutron scattering; the transition is found to involve a soft $T\left[101\right]\mathrm{}$ acoustic phonon which in turn is driven soft by a quadrupole exciton mode, an electronic mode involving a wavelike modulation of the ${\mathrm{Pr}}^{3+}$ electric quadrupole moment. We report measurements both of the soft phonon behavior and of the coupled excitations in the crossing region.

We present a new interpretation of the anisotropy of the conductivity in thin films of amorphous Ge and Si. The interpretation is based on a transition from percolation conduction to Miller and Abrahams's conduction at small film thickness. A simple theory, together with experimental data, is presented. The comparison between them is found to be good.

Adsorbate ionization energies (energy levels) have been calculated for a number of metal-adsorbate systems that have been studied recently by ultraviolet photoelectron spectroscopy. The method, which is only applicable to highly "ionic" metal-adsorbate systems, is based on a point-charge-cluster approximation to the metal-adsorbate system. Values of the adsorbate ionization energies calculated by this method agree with experiment within at least 10% for the metal-adsorbate systems investigated.

We report the near-normal-incidence reflectivity spectrum of single-crystal TTF-TCNQ in the range 0.2-2.0 μm. A Drude-like edge, persisting through the metal-insulator transition at 60°K, is observed near 1.3 μm for light polarized parallel to the conducting axis. The temperature dependence of the optical parameters ${\epsilon }_0$, $\tau$, and ${\omega }_p$ are discussed in conjunction with Hopfield's relation for the electron-phonon coupling constant.

Recent accurate measurements of the electrical resistivity of Ag above 2°K have permitted a reinterpretation of the published low-temperature thermal-conductivity data for silver. We report the discovery of an additional scattering process which may correspond to the phonon-assisted defect scattering proposed by Klemens.

A fully relativistic treatment is given to analyze the electromagnetic radiation induced by gravitational perturbations in extreme relativistic regions. For the sake of clarity, results are presented here for the simplest possible example: an uncharged mass $m$ falling radially into a field of a Reissner-Nordstrøm solution. Explicit results governing the energetics of the process are found. The amount of electromagnetic radiation radiated can be of the order of magnitude of the gravitational one.

Semi-inclusive invariant cross sections for ${\pi }^{-}$ produced in $\mathrm{pp}$ interactions at 205 GeV/c are compared, at fixed $\frac{n_{-}}{〈n_{-}〉}$, with data at lower energies ranging from 13 to 28.4 GeV/c. Except in the central region ($x\simeq 0$), the data are found to be in good agreement with the predictions of Koba, Nielsen, and Olesen for semi-inclusive scaling.

It is shown that the rise in multiplicity with increasing perpendicular momentum transferred to the leading proton seen in recent experiments can be simply explained as due to double quark-quark scattering in the Glauber quark multiple-scattering model. The quark-quark inelastic-scattering amplitude is entirely consistent with the quark-quark elastic amplitudes obtained previously for elastic proton-proton scattering.

Ions scattered inelastically off neutral target atoms at low collision energies (≲ 10 keV) are measured in delayed coincidence with electrons formed in the collision. Both ions and electrons are analyzed differentially with respect to angle and energy. In the case of the ${\mathrm{He}}^{+}$/Ne system at 1-keV collision energy, it is shown that the coincidence measurements allow an unambiguous identification of the main ionization processes occurring.

We present a new ion accelerator idea which combines the basic concepts of traveling wave and collective acceleration. The lower cyclotron mode of a relativistic electron beam along a spatially decreasing magnetic field $B$ constitutes the traveling wave, the wave phase velocity varying inversely with $B$. The negative energy character of the wave allows automatic extraction of energy from the electron beam for the acceleration process. Typical ion energy versus current outputs are estimated.