It is shown that there may exist five axisymmetric vortices in ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-$B$, different in their internal symmetries. The Landau theory for phase transitions between them is constructed. Numerical calculations show that one of the observed vortices possesses a novel new structure: a superfluid core, which is ferromagnetic. This explains the measured large magnetic moment of the vortex.

A new model theory for spinodal decomposition is presented. It is based on a straight-forward generalization of the recursion relation derived previously for the quasistatic structure factor in the nonconserved case. The theory leads to a qualitative understanding of all the major features of spinodal decomposition: Equilibration of local degrees of freedom, a coarsening small-wave-number peak associated with domain formation, and scaling behavior.

Alexander and Orbach have recently made the remarkable numerical discovery that for the incipient infinite cluster in percolation the ratio of $d_f$ (the fractal dimension of the aggregate) to $d_w$ (the fractal dimension of a random walk on the aggregate) is approximately "superuniversal"—independent of $d$ for $d>\mathrm{}1\mathrm{}$. Does this discovery also hold for aggregates other than percolation? A plausibility argument (rigorous for the Cayley tree) is presented that it should hold, exactly, for "homogeneous" fractals, but need not for nonhomogeneous fractals such as the percolation backbone, the Sierpinski gasket, and the Havlin carpet.

Near-edge x-ray-absorption fine-structure (NEXAFS) spectra for oxygen adsorption on Ni(100) are found to exhibit pronounced variations with oxygen exposure and x-ray incidence angle. The measured spectra are compared to calculations of the NEXAFS with use of a multiple-scattering formalism. The theory shows considerable sensitivity to changes in the O-Ni coordination and x-ray incidence angle. By comparison of experimental and theoretical spectra NEXAFS is shown to be a new technique for determining the local structure of adsorbates on surfaces.

The valence of Tm compounds is derived from $M_{\mathrm{V}}$ x-ray absorption spectra recorded by total electron yield under ultra-high-vacuum conditions. For mixed-valent systems the spectra are superpositions of ${\mathrm{Tm}}^{3+}$ (three lines) and ${\mathrm{Tm}}^{2+}$ (one line) components, providing accurate mean valence values even in highly dilute systems, such as ${\mathrm{Tm}}_x{\mathrm{Y}}_{1-x}\mathrm{Se}$, which agree well with those from lattice-constant systematics. A surface valence change on TmS(100) is identified as an initial-state effect.

It is shown here that quantum voltage fluctuations (due to finite capacitance energy) cause the resistance of a normal-normal junction to vary with temperature and frequency. These variations are characterized by an activation energy related to the transfer of an electron, and should be observable in junctions with low capacitance, $C\sim {10}^{-13\mathrm{}}$ F. An expression for the resistance is derived with use of the recent model of Ambegaokar, Eckern, and Schön.

The current and voltage fluctuations in a normal tunnel junction are calculated from microscopic theory. The power spectrum can deviate from the familiar Johnson-Nyquist form when the self-capacitance of the junction is small, at low temperatures ($C\lesssim 0.1$ pF, $T\lesssim 10$ mK), permitting experimental verification. The deviation reflects the discrete nature of the charge transfer across the junction and should be present in a wide class of similar systems.

A quantum interference experiment is proposed which can unambiguously test for odd half-integer eigenvalues in the angular momentum spectra predicted for a spinless charged particle orbiting, but not penetrating, a solenoid with confined magnetic field or a superconducting vortex with odd integer number of flux quanta.

A phenomenological model of dendritic solidification incorporating interfacial kinetics, crystalline anisotropy, and a local approximation for the dynamics of the thermal diffusion field is proposed. The preliminary results are in qualitative agreement with natural dendritelike pattern formation.

A three-loop superconductive monopole detector has been continuously operated for over 150 days. Its sensing area is 476 ${\mathrm{cm}}^2$ (71 ${\mathrm{cm}}^2$ loop area and 405 ${\mathrm{cm}}^2$ near-miss area) for double coincidence events. The data, which contain no candidate events, set an upper limit of 3.7 × ${10}^{-11\mathrm{}}$ ${\mathrm{cm}}^{-2\mathrm{}}$ ${\sec }^{-1\mathrm{}}$ ${\mathrm{sr}}^{-1\mathrm{}}$ (90% C.L.) for monopoles of any mass and at any velocity passing through the Earth's surface.

$T$- and $P$-nonconserving nuclear moments induced by a parity- and $\mathrm{CP}$-nonconserving interaction in the QCD Lagrangian are discussed. The mixing of nearly degenerate opposite-parity ground-state doublets in certain deformed nuclei leads to electric dipole and magnetic quadrupole moments ${10}^1$-${10}^3$ and ${10}^3$-${10}^4$ times larger, respectively, than those generated by the unpaired valence nucleon.

The differential cross sections for lepton pair production in $e^{+}{e}^{-}$ annihilation at 29 GeV have been measured and found to be in good agreement with the standard model of the electroweak interaction. With the assumption of $e-\mu -\tau$ universality, the weak neutral-current couplings are determined to be ${g_a}^2=0.23\mathrm{}\pm 0.05$ and ${g_v}^2=0.03\mathrm{}\pm 0.04$.

The quark mixing matrix (Kobayashi-Maskawa matrix) is expanded in powers of a small parameter $\lambda$ equal to $sin{\theta }_c=0.22\mathrm{}$. The term of order ${\lambda }^2$ is determined from the recently measured $B$ lifetime. Two remaining parameters, including the $\mathrm{CP}$-nonconservation effects, enter only the term of order ${\lambda }^3$ and are poorly constrained. A significant reduction in the limit on $\frac{{\epsilon }^{\prime }}{\epsilon }$ possible in an ongoing experiment would tightly constrain the $\mathrm{CP}$-nonconservation parameter and could rule out the hypothesis that the only source of $\mathrm{CP}$ nonconservation is the Kobayashi-Maskawa mechanism.

When fragments of $1.85A$-GeV ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$ projectiles are observed in a CR-39 etched track detector, anomalously short mean free paths of secondary nuclei with $11>~Z>~17$ are found within the first 2 cm after their production, at ∼ 3 standard deviations. This confirms the previous reports of this "anomalon" effect in nuclear emulsion. The data can be fitted by the hypothesis that ∼ 3.6% of the secondaries have a mean free path of ∼ 1.0 cm and infinite lifetime.

Relative cross sections for the ($p$, ${\pi }^{-}$) reaction for nuclei in the region $40<A<\mathrm{}56\mathrm{}$ are calculated with use of ${\left(1\mathrm{}{f}_{\frac{7}{2}}\right)}^n$ wave functions and a zero-range plane-wave approximation for this three-nucleon process. The results of the calculation for the low-lying discrete states are in excellent agreement with recent data and many detailed aspects of the spectra are understood for the first time.

Plasma with significant central-cell beta can be sustained in a tandem mirror composed of three axisymmetric simple mirror cells by the use of ion-cyclotron resonant heating. Radial ponderomotive force due to the rf electric field opposes the centrifugal force due to the field-line curvature to ensure interchange stability. This is indicated by the sensitive dependence of the plasma stability on the sign of the difference between the rf frequency and the ion-cyclotron frequency.

Numerical studies show that by indenting the small-major-radius side of conventional finite-aspect-ratio tokamaks, significant improvements to the stability of pressuredriven ideal magnetohydrodynamic modes can be achieved. The internal $n=1\mathrm{}$ kink mode can be stabilized completely with quite modest indentation. In the presence of a nearby conducting wall, kink-ballooning mode stability is also improved, and accessibility to a second stable region at high plasma $\beta$ is possible.

Indentation of a tokamak plasma on its inner-major-radius side is shown to be strongly beneficial for achieving high-$\beta$ stability against ballooning modes. With use of a set of reasonable equilibrium profiles, it is found that moderate indentation provides accessibility to the second region of stability. Ohmic equilibrium configurations which exhibit the second stability region have not yet been found.

Introduction of an anisctropic, highly energetic trapped-particle species into a tokamak may allow direct stable access to the high-beta regime of second stability. Under certain conditions, the mode at marginal stability acquires a real frequency close to the precessional drift frequency of the energetic particles, perhaps correlating with recent "fishbone" observations on PDX.

The behavior of a two-dimensional solid near melting is analyzed by the molecular-dynamics technique. Two size-dependent properties are determined: the mean amplitude of vibration ($\theta$) from the lattice positions and the elasticity (shear modulus $\mu$), which vary logarithmically with system size. When the size is increased to give $\theta \approx 0.18$ the particles begin to diffuse and the elasticity is close to its predicted melting value. The result demonstrates that previous computer models have been too small to simulate bulk solid near melting.