Primary (pre-evaporation) fragment mass distributions and fragment charge distributions have been measured for deep inelastic collisions of ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ with ${}_{}{}^{166}{}_{}{}^{}\mathrm{Er}$ at $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}\sim 400$ MeV. It is shown that the relations between the lower moments of the above fragment distributions are consistent with the formation of a statistically equilibrated intermediate dinuclear complex over a wide range of kinetic-energy damping.

A possible explanation of the intriguing problem of the so-called Coriolis attenuation factors, in the framework of the particle-plus-rotor model, is suggested. The explicit inclusion of the recoil term renders unnecessary the assumption of an attenuation factor for the Coriolis interaction and leads to a hitherto unsuspected parallelism with the cranking model.

Angular distributions and forward-backward intensities of photons emitted during electron capture have been measured in collisions between fast projectile ions (93-MeV oxygen, 110-123-MeV sulfur) and target atoms. In contrast to previous expectations, the radiation pattern in the laboratory system is not strongly shifted in forward direction but turned out to exhibit forward-backward symmetry independent of the projectile velocity. We attribute these findings to a cancellation between the Doppler-shift and retardation effects.

Blackbody radiation affects low-frequency ($h_{\nu }\ll \mathrm{kT}$) atomic transitions both by inducing transitions and producing ac frequency shifts, important effects that have previously been ignored. Here we report the calculation and experimental observation of a manifestation of the former, the threefold reduction of the Na $\mathrm{np}$ radiative lifetimes by 300-K blackbody-radiation-induced stimulated emission and absorption. Estimates of ac frequency shifts for Rydberg and ground-state atoms are given.

The two-dimensional distribution of self-generated magnetic fields near the laser-plasma interaction region is observed for the first time by the very simple method of laser irradiation of audio magnetic tape. The lobe structure is a maximum at the incident angle of 10° to 15° for $p$-polarized laser light. The direction of the fields is perpendicular to the density gradient and to the incident $p$-polarization plane. These observations support resonance absorption as the field-generation mechanism.

Multicritical phase diagrams for krypton and nitrogen submonolayers adsorbed on graphite are calculated from a position-space renormalization, with flows in a 22-parameter space. Quantitative agreement with experiment is excellent, with no adjustable parameter. Temperature variation and finite-size effects are taken into account, causing a cusped coexistence boundary at the multicritical point. Incipient liquid-gas criticality is derived.

A simple expression for the heat of formation $\Delta H$ of transition-metal alloys is derived with-in the tight-binding approximation that has the form $\Delta H=f\left(\overline{N}\right)\Delta N^2$, where $\overline{N}$ and $\Delta N$ are the average and difference in number of valence $d$ electrons, respectively. The prefactor $f\left(\overline{N}\right)$ is most negative for $\overline{N}$ lying near the middle of the series and it becomes positive towards the edges. The theory gives good agreement with Miedema's semiempirical values of $\Delta H$.

Departures from thermal equilibrium which are likely to occur in an expanding universe allow the production of an appreciable net baryon density by processes which violate baryon-number conservation. It is shown that the resulting baryon to entropy ratio can be calculated in terms of purely microscopic quantities.

An experimental study of the distribution of arrival time of energetic hadrons relative to associated air-shower particles has been made at a mountain altitude, under 730 g ${\mathrm{cm}}^{-2\mathrm{}}$. Monte Carlo simulations have shown that these observations are sensitive to the composition of primary cosmic rays of energies ${10}^4$-${10}^6$ GeV. The energy spectra $\frac{\mathrm{dN}}{\mathrm{dE}}$ of primary protons and iron-group nuclei required to understand these observations are $1.5\times {10}^4{E}^{-2.71\mathrm{}\pm 0.06}$ and $1.27E^{-2.36\mathrm{}\pm 0.06}$ ${\mathrm{m}}^{-2\mathrm{}}$ ${\mathrm{sr}}^{-1\mathrm{}}$ ${\sec }^{-1\mathrm{}}$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{N})}^{-1\mathrm{}}$, respectively, where $E$ is the energy per nucleon.

The electron momentum spectrum observed in the decay $\tau \to {\nu }_{\tau }e{\nu }_e$ is in good agreement with the $V-A$ hypothesis. The measured value of the Michel parameter, $\rho =0.72\mathrm{}\pm 0.15$, excludes a $V+A$ current and disfavors pure $V$ or $A$ currents. The spectrum allows us to set an upper limit of 250 MeV/${\mathit{c}}^2$ (95% confidence level) for the $\tau$ neutrino mass. Finally, by measuring the $\tau$-lifetime upper limit of 2.3×${10}^{-12\mathrm{}}$ sec (95% confidence level), we show that the square of the coupling constant at the $\tau -{\nu }_{\tau }-W$ vertex is at least 12% of full weak strength.

Inelastic scattering of 163- and 241-MeV positive pions by ${}_{}{}^{\mathrm{nat}}{}_{}{}^{}\mathrm{Ca}$ has been studied with special attention paid to the giant-resonance region. Pronounced giant resonance structures are observed at both incident energies. The analysis indicates a strong excitation of the giant quadrupole resonance at 18.2 MeV ($\Gamma \sim 3-3.5$ MeV).

Velocity-dependent light shifts may be used to suppress the Doppler broadening of an atomic spectral line observed along a given direction. We present emission spectra of ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$ demonstrating the existence of such an effect for an appreciable portion of the atoms. Various possible applications taking advantage of the high anisotropy of this effect are suggested.

Differential and total cross sections for ${\mathrm{He}}^{+}\mathrm{}\left(1s\right)+\mathrm{H}\mathrm{}\left(1s\right)\mathrm{}\to {\mathrm{He}}^{+}\mathrm{}\left(1s\right)+\mathrm{H}\mathrm{}(n=2\mathrm{})\mathrm{}$ are calculated using a formalism developed for ion-atom and atom-atom collisions. Results are obtained in terms of amplitudes for electron-hydrogen ($e\mathrm{H}$) and proton-hydrogen ($p\mathrm{H}$) $n=2\mathrm{}$ excitations and elastic scattering of electrons by a ($p+e$)-"atom," the ${\mathrm{He}}^{+}$($1s$) form factor, and the $n=2\mathrm{}$ form factors of hydorgen. Agreement with recent data is good. A remarkably simple approximation, $\sigma \approx {\sigma }_{p\mathrm{H}}(1s\to n=2)+3\mathrm{}{\sigma }_{p\mathrm{H}}(1s\to 2s)$, is obtained and agrees with recent data.

It is shown that the mode coupling of drift-wave-type fluctuations via thermal ions in a magnetized plasma can cause a negative diffusion of the ion perpendicular energy across the magnetic field. The resulting diffusion flux is estimated to be of the neoclassical value in the plateau regime.

The density profile in the corona of 70-μm-diam glass spheres, irradiated by 50-GW pulses from a Nd-glass laser, was measured in the density range $2\times {10}^{19}<n_e<3\mathrm{}\times {10}^{20}$ ${\mathrm{cm}}^{-3\mathrm{}}$. The profile was found to be rather flat. In a computer simulation of the experiment we have to include strong inhibition of electron heat conductivity to explain the results.

Scaling laws are derived for the energy spectrum of accelerated ions of different masses and charges. The results are compared with existing experiments.

Experiments are performed in an attempt to stabilize the magnetic-curvature-driven interchange instability (mirror flute mode) using a $Q$-machine plasma. The stabilization method consists of applying a tenuous plasma blanket, which is line tied to the end wall, around a flute-susceptible higher-density core plasma which has no electrical contact to the wall. By controlling the degree of line tying between the blanket and the wall, the stabilizing effect of surface line tying is demonstrated.

Experimental results are presented which reveal the important role played by nonlinear radiation or ponderomotive forces in laser plasma interactions. The existence of these nonlinear forces are clearly revealed by the properties of tenuous helium plasmas generated by focusing of intense laser beams.

It is shown that sheared Alfvén waves in a current-carrying plasma, such as that in a tokamak or in a pinch, may grow linearly in time at a rapid rate. These waves may attain a large amplitude before they eventually decay. The implication of this result is discussed.

The interfacial surface tension and the angle of contact between superfluid ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ and bcc and hcp ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ crystals have been measured in the same way as for a free liquid surface. Contrary to expectations, neither crystal is found to "wet" the wall of the container. At 0.4 K the surface tension between hcp ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ and the liquid is 2.5 times larger than that between liquid and vapor.