Broad nonintegral mass bands at the 0.66- and 0.75-u mass positions appear in the hydrogen mass spectrum at high pressure (${10}^{-4\mathrm{}}$ Torr). A primary peak is also observed at the 1.5-u mass position. These Aston bands and mass peak may be interpreted as resulting from the creation and collision-induced reactions of the ${\mathrm{H}}_3^{++}$ ion, which would be formed in a surface reaction between ${\mathrm{H}}_3^{+}$ and adsorbed hydrogen.

A broad x-ray emission structure with several maxima has been found on the low-energy side of the $K{\alpha }_1{\alpha }_2$ line in Mg, Al, Si, and S. It is interpreted as a radiative $K\to L^2$ transition resulting in the simultaneous emission of a photon and an $L$-shell electron.

Optical pumping methods have been extended to high buffer-gas pressures by replacing the customary resonance lamp by a white-light source. Rb ground-state Zeeman transitions were detected by resonance fluorescence at argon buffer-gas pressures up to 23 atm. Hyperfine-transition frequencies were measured at 4170 Torr (0°C) and at 7390 Torr (0°C) and showed the first nonlinear pressure dependence so far observed.

The tunneling splitting of the torsional-oscillator ground state of a hindered methyl group is taken into account in calculating the temperature dependence of the proton spin-lattice relaxation time. Thermal vibrations cause spin-independent transitions leading to a fluctuation in the sign of the splitting parameter. It is predicted that a second maximum in $T_1^{}{}_{}{}^{-1\mathrm{}}$ may occur at low temperature due to a tunneling-assisted process. This effect is detected in some methyl-substituted benzenes in good agreement with the theory.

We suggest an alternative scaling law with which to judge toroidal confinement experiments. A phenomenological model of ($\overrightarrow{E}\times \overrightarrow{B}$)-driven convective cells of diameter comparable with the minor diameter of the plasma is used to derive a new scaling law for plasma containment time. Using new experimental results we show that this law describes a large number of toroidal experiments better than does earlier interpretation in terms of "Bohm" diffusion.

It is shown that for the quantum mechanical Heisenberg ferromagnet, the correlation is not necessarily a monotone increasing function of interactions.

This paper presents the experimental details and the results obtained when using a feedback system to suppress drift instabilities present in a magnetoplasma.

Using a light-beat laser spectrometer, we observe the relaxation of the thermally excited fluctuations of anisotropy in the nematic phase of $p-\mathrm{azoxyanisole}$. We identify the two low-frequency purely dissipative modes recently predicted. A first study of the angular dependence of the width of these modes allows a determination of three among the six viscosity coefficients introduced by Leslie.

The effects of thermal fluctuations on the dc Josephson effect in a junction of small capacitance are calculated using an analogy with the Brownian motion of a particle in a field of force. The results are presented in a form suitable for comparison with experiment.

Quantized magnetic flux trapped in hollow superconducting lead cylinders of extremely small dimensions (0.6 μ i.d., film thickness ≤0.5 μ, length 100 μ) was observed in an electron interferometer. The flux was found to be quantized in integer multiples of $\frac{h}{2e}\pm 4\%$. No influence of the size of the tube upon the fluxoid quantum has been observed.

The absorption coefficients of thin films of NaI, KI, and CsI were measured with a grazing-incidence spectrometer in the range 75-250 Å utilizing the synchrotron continuum from the University of Wisconsin 250-MeV electron storage ring. The observed structure is interpreted in terms of both atomic and solid-state effects.

A tunnel capacitor is an array of microscopic resistance-capacitance circuits with the resistive element provided by a tunnel junction. Because of their small size, such microcircuits display special properties due to charge quantization. An array of such circuits shows an oscillatory behavior in its capacitance-versus-voltage measurements. A new type of memory effect is found.

The excess tunneling current due to electron-surface-plasmon interactions in semiconductor-metal tunnel junctions is calculated. The expression for the second derivative of this excess current, which corresponds to structure in $\frac{d^{2}I}{d{V}^2}$ as an increase in conductance at bias voltages near the surface plasmon energy in the semiconductor, agrees with experiment both in magnitude and line shape.

Evidence for the presence of two-dimensional indirect excitions is presented in terms of the absorption spectra in GaSe. The phonon and exciton parameters at the $K$ point are determined.

The spin-spin correlation function for the $S=\frac{1}{2}$ Ising ferromagnet is evaluated in zero magnetic field and for $T>~T_c$ by the method of series expansions. Evidence is presented showing that the scaling of correlations is valid in the (weak) limit $r\to \infty$, $\kappa r$ fixed, but is not valid in the (strong) limit $\kappa a\to 0$, $r\gg a$, with $\kappa r$ arbitrary.

The reflectance of EuO from above the Curie point at 69°K down to 1.5°K shows splittings in the two main peaks near 1.5 and 4.7 eV. The first peak is a polarization-dependent triplet at 1.5°K and a doublet at 70°K. The data suggest that the 1.5-eV peak is associated with the absorption edge and arises from the transition $4f^7\left({}_{}{}^8{}_{}{}^{}S_{\frac{7}{2}}^{}{}_{}{}^{}\right)\to 4f^6\left({}_{}{}^7{}_{}{}^{}F_J^{}{}_{}{}^{}\right)5d\left(t_{2g}\right)$. The narrow $t_{2g}$ sub-band is exchange split by 0.25 eV at low temperatures.

Measurements of the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$ and ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ spallation production in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ are presented. These cross sections are related to theories on the origin of the elements lithium, beryllium, and boron.

We report observations of $A_1^{}{}_{}{}^{-}$, $A_2^{}{}_{}{}^{-}$, and higher mass bosons produced near 180° in ${\pi }^{-}p\to p{B}^{-}$ at 16 GeV/c, where $B^{-}$ denotes missing mass with negative charge. Differential cross sections for $pA_1^{}{}_{}{}^{-}$ and $pA_2^{}{}_{}{}^{-}$ final states are given. Data obtained in the mass range $1.40<~M_{B^{-}}<~2.66$ GeV are presented and compared with existing evidence for high mass bosons produced near 0°.

We have studied the production and decay characteristics of low-mass $K^{*0\mathrm{}}\mathrm{}\left(890\right)\mathrm{}{\pi }^{+}$ systems produced in the reaction $K^{+}p\to K^{+}p{\pi }^{+}{\pi }^{-}$ at 12.7 GeV/c. Comparisons between these data and two diffractive production models are presented

The 980-MeV enhancement in the effective-mass spectrum of the ${\pi }^{-}+ \mathrm{neutrals}$ is observed in the reaction $K^{-}n\to \Lambda {\pi }^{-}$ neutrals, when the effective mass of the neutrals lies in the $\eta \mathrm{}\left(550\right)\mathrm{}$ region. However, no corresponding enhancement is seen when the $\eta$ decays by the charged modes. An effect found in the ${\rho }^0{\pi }^{-}$ system from the final state $\Lambda {\pi }^{+}{\pi }^{-}{\pi }^{-}$, when extended to $\Lambda {\rho }^{-}{\pi }^0(\to \Lambda {\pi }^{-}{\pi }^0{\pi }^0)$, predicts the observed enhancement in the $\Lambda {\pi }^{-}$ neutrals final state and accounts for its absence when charged $\eta$ decays are considered.