The interaction parameter of moving dislocations with electrons and with phonons in aluminum was determined from measurements of ultrasonic attenuation changes with stress. The results indicate that the interaction with electrons is temperature independent and that the interaction with phonons increases with increasing temperature. These results are consistent with theoretical predictions.

By modifying the characteristic-momentum formalism of Williams and Matthews, we demonstrate the existence of two characteristic lengths of quite different magnitude. The larger, analogous to the mean free path for extended states in higher dimensions, is the distance of localization within energy bands. The smaller is that of states in the band tails. Finally, a formula for the conductivity in terms of the characteristic momentum is obtained.

It is shown that resonant scattering of the conduction electrons in a metal, when combined with ordinary impurity scattering and phonon scattering, leads to significant deviations from Matthiessen's rule for the total resistivity. The implication for the analysis of the observed resistivity of metals with magnetic impurities is discussed.

By a perturbation-theoretic calculation, we find that vertex corrections make an important contribution to the renormalized spin-fluctuation temperature in dilute alloys, in the limit of strong local enhancement.

Conductivity edges inside the bands are proposed to be responsible for the thermal activation energy of the semiconductivity in glasses. Coulomb-repulsive centers provide the potential barriers, above which carrier drift becomes the predominant charge transport mechanism for narrow gap glasses, yielding a reasonable value for carrier mobility and providing quantitative explanation of the typical behavior of the conductivity. Ambipolar conductivity and highly perturbed band edges due to charged defects are suggested to be responsible for the small observed Hall mobility.

The far-infrared absorption in solid alpha oxygen at 27 ${\mathrm{cm}}^{-1\mathrm{}}$ is shown to be definitively associated with the magnetic rather than orientational ordering in the crystal. A second magnetic excitation has been found at 6.5 ${\mathrm{cm}}^{-1\mathrm{}}$. The properties of both absorptions are described using the excitation-wave formalism.

The elastic scattering of protons from deuterons has been measured at 580 MeV. The results for large-angle scattering are presented and discussed here. The backward peak observed in the experiment is consistent with a baryon-exchange mechanism including the transfer of baryon resonances.

In order to resolve inconsistencies in existing data, differential cross sections for the scattering of protons by protons have been measured at 9.690 and 9.918 MeV with accuracies near 0.4% relative and 0.6% absolute. Sources of error are given and the data are compared with previous experiments and theory.

A strong disagreement for predictions near 10 MeV is found between two previous multienergy phase-shift analyses. The data also contain contradictions, but are found to definitely favor one of the analyses over the other. Unresolved normalization discrepancies make further experimental work in the energy range 1-10 MeV mandatory.

Evidence is given for the existence of two distinct populations of cosmic-ray protons and alpha particles in the energy range of 4 to 80 MeV/nucleon: (1) a highly variable component with an inverse energy dependence and (2) a quasisteady "residual" component which shows a positive dependency on energy. The analysis is based on a series of four-day energy spectra obtained from the cosmic-ray experiments aboard IMP-IV during the time interval from 24 May 1967 to 20 August 1968. It is suggested that the highly variable component is probably entirely of solar origin. The "residual" component is most likely of galactic origin although below 10 MeV it may also contain some solar particles.

The influence of ionic excitation on heavy-ion charge-changing collisions has been studied by measuring cross sections for electron capture and loss as a function of target-gas density. The results show a decreased probability for electron capture rather than the increased probability for electron loss predicted by Bohr and Lindhard.

It is frequently stated that the $1s^2{}_{}{}^1{}_{}{}^{}S$ state is the only bound state of ${\mathrm{H}}^{-}$, although Holøien estimated that the $2p^2{}_{}{}^3{}_{}{}^{}P$ state may also be bound. We show by a variational calculation that the $2p^2{}_{}{}^3{}_{}{}^{}P$ state is definitely bound below the $n=2\mathrm{}$ threshold of hydrogen. The best eigenvalue obtained is -0.125350 a.u.

Angular correlations between $K$ and $L$ x rays in Pb were measured. The angular correlation functions for the $K-L_{\alpha }$ and $K-L_{\beta }$ cascades were found to be $W\left(\theta \right)=1+(4.13\mathrm{}\pm 0.36)\times {10}^{-2\mathrm{}}{P}_2\left(cos\theta \right)$ and $W\left(\theta \right)=1+(1.22\mathrm{}\pm 0.42)\times {10}^{-2\mathrm{}}{P}_2\left(cos\theta \right)$, respectively. These results are in relatively good agreement with theoretical predictions only when the small admixtures of magnetic quadrupole radiation in the x-ray transitions are taken into account.

Recent work has shown that an ion-sound instability in a plasma behaves in a manner similar to a classical Van der Pol oscillator. Experimental results are presented which show that the classical method of "asynchronous quenching of a Van der Pol oscillator" can be used to suppress this instability in a plasma. Further, the effects observed as the amplitude and/or frequency are changed are compared with theories due to Minorsky and to Kobsarev (or Bogolyubov).

Imposition of a powerful electrostatic bias allows a dense uniform-pressure plasma to be held in a static equilibrium in a toroidal closed-magnetic-line system. A small wall current of 3.5-MeV $d-t$ alpha particles easily maintains the 6-MV/cm electric field necessary for controlled thermonuclear reaction conditions. As ions can be confined in an enormously deep energy well, the system lends itself also to production of highly stripped heavy nuclei.

The multiple-scattering model of molecular electronic structure, in conjunction with the Korringa-Kohn-Rostoker method of band theory, is used as the basis for a cluster approach to calculating the one-electron states of complex molecules and solids. Illustrative examples include the molecular clusters C${\mathrm{H}}_4$ and N${\mathrm{H}}_4^{+}$, the pyrite crystal Cu${\mathrm{S}}_2$, a polyene chain molecule, and a substitutional impurity cluster.

An analysis of differential cross-section data for the reaction ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sn}(t, p){}_{}{}^{124}{}_{}{}^{}\mathrm{Sn}$ indicates that strongly excited levels seen at an excitation energy of 5.5 MeV may be of the particle-quasihole type. Such levels are formed in the ($t, p$) reaction by transferring one neutron into one of the usual quasihole states of tin and the other neutron into one of the levels in the next major shell above tin. The position of such levels yields information on the energy gap between the two major shells as well as information on the quasiparticle configuration of ${}_{}{}^{122}{}_{}{}^{}\mathrm{Sn}$. It is shown that the coherence which produces the strong ($t, p$) ground-state transition also would give added strength to these states.

High-energy elastic electron scattering from ${\mathrm{Ca}}^{40}$ and ${\mathrm{Ca}}^{48}$ nuclei has been fitted by means of a nuclear charge distribution obtained from single-particle wave functions with configuration mixing generated in a nonlocal, energy-independent potential well.

Fission fragments produced by the isotope ${}_{}{}^{252}{}_{}{}^{}\mathrm{Cf}$ were accelerated to energies of ∼200 MeV using a model MP Van de Graaff accelerator. The fragment-energy spectra were measured as a function of accelerator voltage. Some information was obtained on the average charges of the fragments. Estimates are given of the energies which could be attained by fragments if much higher acceleration voltages are used.

Measurements are reported of form factors for the electroexcitation of the $0^{+}$ (6.052-MeV), $3^{-}$ (6.131-MeV), $2^{+}$ (6.916-MeV), and $1^{-}$ (7.115-MeV) states of ${\mathrm{O}}^{16}$, in the momentum-transfer region 0.5 to 1.0 ${\mathrm{fm}}^{-1\mathrm{}}$. The data are compared with the predictions of various particle-hole shell models and a two-component phenomenological model.