Investigation of plasma confinement in the Princeton spherator by use of a supported superconducting ring shows that about 90% of the total particles are lost to the supports, and thus the particle loss across the magnetic field is reduced to about 10% of the total loss under the best operating conditions. An hypothesis-in terms of convective cells, which are established by the presence of supports-is proposed to explain the observed plasma loss.

Results are presented which show the classical anharmonic resonance effects (including hysteresis) on a marginal ion sound instability, when forcing at the fundamental and the subharmonic frequencies. Also, when the instability is well defined it appears to be-have as a classical Van der Pol oscillator for drive frequencies near the fundamental and the subharmonics.

Recent experiments described in the literature show that surface abrasion results in the persistence of superconductivity at enhanced magnetic fields. The suggestion has been made that the abrasion alters the boundary conditions at the superconductor surface, thus raising the surface nucleation field. Our results on In-0.7% Bi alloy foils show that this behavior is not related to conditions at the specimen boundary, but rather to the presence of a layer of severely deformed material.

The lattice constant of isotopically impure solid neon is calculated from the self-consistent harmonic approximation of Koehler. The theory predicts a large change in lattice constant with concentration, which is consistent with existing experiments. It also predicts a large strain-field scattering of phonons (an increase of 40% over the mass-defect scattering alone); so the effect should be observable in a thermal-conductivity experiment.

A method of determining wave-function amplitudes on different sheets of the Fermi surface of pure metals through de Haas-van Alphen type oscillations in the Knight shift is given. Experimental results and an analysis for Cd are presented.

Measured energy distributions of photoemitted electrons from K, Rb, and Cs show a high-energy peak identified as unscattered (primary) electrons, and an intermediate peak at somewhat lower energies which is believed to be due to a plasmon energy loss. This intermediate structure becomes more pronounced and closer to the primary peak on proceeding from K to Rb to Cs. This systematic trend, together with the absence of any clearly discernible intermediate structure in Na, is consistent with the variation of the corresponding plasmon energies. In Rb and Cs the intermediate peak is sufficiently pronounced to permit its identification as a surface rather than a volume-plasmon excitation.

The concentration-dependent static dielectric constant is calculated for degenerate $n$-type $\alpha$-Sn. The anomalous enhancement of the low-temperature and low-concentration electron mobility is explained.

The transition from the crystalline to the amorphous state has been studied in germanium thin films by observing the electroreflectance spectra related to critical points at $\Gamma (E_0, E_0+{\Delta }_0)$, along the $\Lambda$ direction ($E_1, E_1+{\Delta }_1$), and at areas with $\Delta$ and $\Sigma$ symmetry ($E_2$). A small shift of $E_0$ to lower energy with increasing disorder in the crystalline state, and weak structure in the amorphous state, have been observed. The spectral positions of $E_1$, $E_1+{\Delta }_1$ and $E_2$ do not change with disorder in the crystalline state but these responses are completely absent in the amorphous state.

We generalize the existing theory of isotope defects by a variational method to be applicable to quantum crystals, where renormalization effects are crucial, and compare the results thus obtained with experiments.

The temperature variation of pure nuclear quadrupole resonance frequencies provides a new tool for the detection of soft librational modes in spectrographically inaccessible regions. Data taken on ${\mathrm{K}}_2$Re${\mathrm{Cl}}_6$ above its 110.9°K phase transition are presented and are shown to imply a marked temperature dependence of the frequency of the $k=0\mathrm{}$ rotary mode.

The ${}_{}{}^{31}{}_{}{}^{}\mathrm{P}$ nuclear magnetic resonance in the antiferromagnetic state of metallic uranium monophosphide ($T_{\mathrm{N}}\simeq 123°$K) has been observed in zero external field over the temperature range 1.3 to 111°K. The frequency of the line changes from 46.82 MHz below 22.9±0.1°K to 42.01 MHz above, in agreement with the jump in moment found by neutron diffraction.

The electric-field-gradient tensor fluctuations at the ${\mathrm{As}}^{75}$ site in ferroelectric Rb${\mathrm{H}}_2$As${\mathrm{O}}_4$, Rb${\mathrm{D}}_2$As${\mathrm{O}}_4$, and K${\mathrm{H}}_2$As${\mathrm{O}}_4$ have been studied as a function of temperature and applied electric field. The measurements allow a direct determination of the Slater short-range energy parameter $\epsilon$ and provide a test of the nature of the ferroelectric-mode-type elementary excitations.

An approach is presented for calculating the charge form factor of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$, based on a variational method with a "healing condition" for the determination of the correlated relative two-nucleon wave function. The fit to the experimental charge form factor is very good.

A nonresonant neutron-capture cross section was found in ${\mathrm{Pb}}^{207}$ by measuring the asymmetry of a resonance in the threshold photoneutron cross section for ${\mathrm{Pb}}^{208}$. The magnitude of the nonresonant component is too large to be accounted for solely by the direct-capture mechanism of Lane and Lynn, but it might be accounted for by Brown's semidirect reaction mechanism.

We have measured the photoproton cross sections of ${}_{}{}^{88}{}_{}{}^{}\mathrm{Sr}$ and ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ for production of ground and low-energy residual states. The results are in agreement with predictions of the particle-hole model for isobaric analog states. Strong and broad resonances are found around 21 MeV in ${}_{}{}^{88}{}_{}{}^{}\mathrm{Sr}$ and around 20 and 22 MeV in ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$ which agree with coherent states expected by the theory.

Diffuse cosmic x rays arise from Compton collisions between galactic leakage electrons and the 2.7°K thermal background photons in extragalactic space. Assuming that the break seen in the electron spectra within normal galaxies is intrinsic to the cosmic-ray sources, we obtain detailed agreement with the observed x-ray spectral shape and intensity using only parameters obtained from radio observations. This serves to verify most of the properties of the microwave blackbody radiation.

An enhancement in the $\Lambda {\pi }^{+}$ mass spectrum has been observed at 1480 MeV in the reaction ${\pi }^{+}p\to K^{+}{\pi }^{+}\Lambda$ at 1.7 GeV/c. In addition, the $\Lambda$ polarization undergoes a sharp oscillation in the same $\Lambda \pi$ mass region. The best fit values for this resonance are $M=1480\mathrm{}\pm 15$ MeV and $\Gamma =35\mathrm{}\pm 20$ MeV.

We have recently reported the observation of a resonance in the $\Lambda {\pi }^{+}$ system at 1480 MeV. We have observed this same resonance decaying into the ${\left(\Sigma \pi \right)}^{+}$ and ($p{\overline{K}}^0$) channels. The mass, width, and branching ratios for this resonance are presented. We comment on the spin of the ${Y_1}^{*}\mathrm{}\left(1480\right)\mathrm{}$ and its possible SU(3) multiplet assignment.

The differential cross sections for the total scattering and the inelastic scattering of negative pions by deuterium for 5.53-GeV/c incident pion momentum have been measured over the squared four-momentum transfer interval from ∼0.3 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$ to ∼1.0 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. The results are compared with calculations based upon the impulse approximation and the Glauber approximation.

We show how the Veneziano five-point function may be used as a model for Regge residues in quasi-two-body processes. An artificial reaction with many of the properties of $\pi N\to \pi \pi N$ is studied in this model; density matrices for spin-1 and spin-2 resonances produced by pion exchange are calculated. The results are encouraging enough to warrant construction of a more detailed model along these lines.