We have calculated the ultrasonic attenuation by acceptor holes in Si. It was found that (1) the splitting of the quartet of acceptor ground states by random local strains is important for explaining the experiments; (2) the Raman (two-phonon) process in the relaxation attenuation predominates over the one-phonon process at higher temperatures; and (3) the "resonant" attenuation becomes important at higher temperatures.

The integrated Rayleigh intensity of N${\mathrm{H}}_4$Cl in the region of the order-disorder transition line has been studied as a function of pressure and temperature. Increased scattering is observed near the tricritical point recently detected by Garland. Although the presence of domain scattering makes unambiguous interpretation of the data difficult, these data are consistent with the Landau-Ginzburg theory of critical opalescence.

Resonance scattering on excited helium atoms is observed by focusing a tunable dye laser at 4471 Å into a cold plasma of a low degree of ionization. Scattering signals due to collisional excitation transfer and radiative decay are observed on many other lines. The magnitude and the pulse shape of the scattered signals are discussed in terms of collisional and radiative transfer rates; a few collisional rates could be deduced.

Two intense relativistic electron beams have been combined while propagating within the collapsing current sheet of a Z pinch. Appropriate choice of the time of injection of the beams into the pinch gave high transport efficiency as well as beam mixing.

Laboratory measurements indicate that a collisionless shock wave formed in a plasma-wind-tunnel device is nonstationary on the time scale of the ion gyroperiod. This behavior suggests a possible interpretation of recent data on magnetic field structure in the vicinity of Earth's bow shock. Comparison is made between the laboratory measurements and earlier computer simulations in which ion gyromotion was included.

We observe the onset of the ballistic flow of phonons using temperature pulse techniques below 0.2 K in solid ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ crystals grown from the superfluid. First-sound velocities obtained from these measurements compare satisfactorily with ultrasonic measurements recently reported.

We point out an analogy between the plasma transport across a magnetic field due to ion-ion collisions and a model for transport of momentum in velocity space in the presence of plasma fluctuations of small amplitudes. A model of this kind, relying on the trapping of particles in plasma waves, may be proposed as an explanation of the observed lack of runaway electrons in confined plasmas on which relatively strong electric fields are applied.

A new method is presented to study the coexistence curve near the critical point. We applied it to the Ga-Hg system and found $\beta =0.373\mathrm{}\pm 0.005$.

Previous experimental measurements of the paraconductivity for various materials show varying degrees of agreement with the Aslamazov-Larkin theory. Our measurements indicate that this behavior can be understood if one includes the Maki-Thompson fluctuation term with a thermal pair-breaking interaction plus an additional pair-breaking parameter proportional to the resistance per unit area of the film.

We report thermal-conductivity measurements on two samples of pure Nb in magnetic fields near ${\mathrm{H}}_{c2\mathrm{}}$. The measurements are in excellent agreement with the dependence on field, electron mean free path, and field orientation predicted by the recent theory of Houghton and Maki. The magnitude of the depression of the thermal conductivity in the mixed state is, however, about a factor of 2 less than predicted.

The Hall coefficient of liquid mercury in the density region 10.0-8.5 gm ${\mathrm{cm}}^{-3\mathrm{}}$ exhibits marked density-dependent positive deviations from the free-electron value, providing information on the formation of a pseudogap in a divalent liquid metal.

We have observed a new conduction mechanism in granular metals at low temperatures and high electric fields $\mathcal{E}$ characterized by a field-dependent conductivity ${\sigma }_0\exp \left(\frac{-{\mathcal{E}}_0}{\mathcal{E}}\right)$. A theory based on a simple model of field-induced electron-hole generation in the bulk of the granular metal predicts the observed field dependence and gives expressions for ${\sigma }_0$ and ${\mathcal{E}}_0$ which are functions of the granular-metal parameters: metal grain size, and thickness and height of the tunneling barriers separating the metal grains. Agreement between theory and experiment is satisfactory.

Magnetotransmission experiments have been carried out on InSb samples ($4\times {10}^{14}<N<\mathrm{}6\mathrm{}\times {10}^{16}$ ${\mathrm{cm}}^{-3\mathrm{}}$). These experiments reveal new absorption lines which are interpreted in terms of electron-plasmon interaction. Results are compared with a theoretical calculation.

The $T$ 23 states in ${}_{84}{}^{210}{}_{}{}^{}\mathrm{Po}_{126}^{}{}_{}{}^{}(T_3=21)$ which are the isobaric analogs of the $T=T_3=23\mathrm{}$ ground state and low-lying states in ${}_{82}{}^{210}{}_{}{}^{}\mathrm{Pb}_{128}^{}{}_{}{}^{}$ have been observed as enhancements in the excitation function for the reaction $p+{}_{83}{}^{209}{}_{}{}^{}\mathrm{Bi}_{126}^{}{}_{}{}^{}\to {}_{82}{}^{208}{}_{}{}^{}\mathrm{Pb}_{126}^{}{}_{}{}^{}+2p$. The experimentally observed enhancements in the two-proton coincidence excitation function correlate with the known level structure of ${}_{}{}^{210}{}_{}{}^{}\mathrm{Pb}$ and occur at the incident proton energies predicted by Coulomb energy formulas, thus establishing that these enhancements are due to the population of double analog levels in ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}$.

The width $〈{\Gamma }_d\uparrow 〉$ for the decay out of the doorway state is derived as a function of the average total level width $〈{\Gamma }_{\mu }〉$, the channel correlation coefficient $C_{c{c}^{\prime }}$, the ratio between the number $n_d$ of the correlating channels and the number $n$ of the open channels, and the level-overlapping ratio $\frac{〈{\Gamma }_{\mu }〉}{D}$. Using the function, the relation between the ratio $\frac{n_d}{n}$ and (1) the width $〈{\Gamma }_d\uparrow 〉$ and (2) the ratio $\frac{〈{\Gamma }_{\mu }〉}{D}$ are discussed. The results indicate that the latter relation is in agreement with the experiment of Shotter, Fisher, and Scott.

It is pointed out that the strength of (${}_{}{}^3{}_{}{}^{}\mathrm{He},d$) reactions to unbound states is correlated with the penetrability for proton decay of these states. The anomalously weak transitions to $s$ states fit into this pattern. Additional data from the reaction ${}_{}{}^{116}{}_{}{}^{}\mathrm{Sn}({}_{}{}^3{}_{}{}^{}\mathrm{He},d){}_{}{}^{117}{}_{}{}^{}\mathrm{Sb}_{}^{*}{}_{}{}^{}$ are presented. Some questions regarding extrapolations to other reations are raised.

We have oriented nuclei in free Cd atoms in a He buffer gas by an indirect process involving optical pumping of Rb atoms and subsequent transfer of orientation via ${\mathrm{Cd}}^{+}$ ions to Cd atoms by exchange collisions. The method may be used to orient a sizable density of any ${}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}$ atomic system. Applications include studies of parity-nonconserving nuclear $\gamma$-decay asymmetries as well as magnetic-moment measurements.

We present a noncollective description of the low-lying $0^{+}$ states strongly excited in ($p,t$) reactions in the actinides. The description is based on the possible weakness of the oblate-prolate pairing force, suggested by Griffin, Jackson, and Volkov, and the low density of oblate states near the Fermi surface in these nuclei.

The quadrupole interaction frequency ${\nu }_Q=\frac{e^2\mathrm{qQ}}{h}$ of the 660-keV ($I={\frac{3}{2}}^{+}$) level of ${}_{}{}^{117}{}_{}{}^{}\mathrm{In}$ has been measured by the method of time-differential perturbed angular correlations in an alloy of ${\mathrm{In}}_{0.99}$${\mathrm{Cd}}_{0.01}$ at 4.2°K. From the known quadrupole interaction of ${}_{}{}^{115}{}_{}{}^{}\mathrm{In}$ in the same alloy at 4.2°K and the atomic beam value of $Q\left({}_{}{}^{115}{}_{}{}^{}\mathrm{In}\right)$, the quadrupole moment of this level is deduced to be $\mathrm{}\left|Q\right|=0.64\mathrm{}\left(4\right)\mathrm{}$ b, in remarkable agreement with the theoretical value of 0.636 b derived from a description of this level as a rotational state of a $K={\frac{1}{2}}^{+}$ band.

The light-cone structure suggested by the quark model is used to propose a generalized scaling law in electroproduction with detection of one final hadron. At fixed momentum transfer between initial and final hadrons, the cross section scales in two variables: the usual Bjorken variable and the fractional longitudinal momentum of the final hadron.