The dependence of scattering intensities for the quenching process ${\mathrm{Na}}^{*}\left(3\mathrm{}{}_{}{}^2{}_{}{}^{}P\right)+{\mathrm{N}}_2\mathrm{}(v=0\mathrm{})\mathrm{}\to \mathrm{Na}\left(3\mathrm{}{}_{}{}^2{}_{}{}^{}S\right)+{\mathrm{N}}_2\left(v^{\prime }\right)$ on the polarization of the exiciting laser light has been studied. A distinct anisotropy is observed at small scattering angles, which is most pronounced where the scattering cross section is largest. It is found that the quenching cross section ${\sigma }_1$ for a $3p\pi$ state is smaller that ${\sigma }_0$ for the $3p\sigma$ state and thus electronic angular momentum is transferred to collisional and/or rotational angular momentum.

We have observed two-photon resonantly enhanced tripling of C${\mathrm{O}}_2$-laser radiation in liquid CO mixtures. Using a tight-focusing geometry, a power conversion efficiency of 0.3% for the C${\mathrm{O}}_2$ $R\left(6\right)\mathrm{}$ line at 1069.01 ${\mathrm{cm}}^{-1\mathrm{}}$ has been achieved for a CO-${\mathrm{O}}_2$ solution. The solvent dependence of the CO two-photon resonance has been studied. Phasematching with an additional molecular constituent has been demonstrated.

Direct measurement of the depth of thermal penetration in flat laser targets shows the electron thermal conductivity to be considerably smaller than classical. X-ray line emission was resolved axially by using layered targets and laterally by employing a slit in front of the spectrometer. The spatial pattern of x-ray emission was found to be compatible with numerical predictions which account for thermoelectrically generated magnetic field.

Scattering of pulsed C${\mathrm{O}}_2$-laser radiation by current-driven waves in a plasma is observed. A theory of the fluid-ion cyclotron instability is developed. The measured dispersion of the wave, the electron density fluctuation associated with it, and its subsequent stabilization and damping are interpreted theoretically.

The variation of the ordering temperature $T_c\mathrm{}\left(H\right)\mathrm{}$ of the (very nearly) isotropic antiferromagnet RbMn${\mathrm{F}}_3$ with magnetic field $H$ was determined from thermal expansion measurements in fields up to 180 kOe. With increasing $H$, $T_c\mathrm{}\left(H\right)\mathrm{}$ first increases, then reaches a maximum, and finally decreases. The bow-shaped phase boundary, in the $T-H$ plane, is well described by recent theories based on scaling and renormalization-group calculations.

The propagation characteristics of quasiparticles in bulk superconducting Pb single crystals is studied. A transition from quasiparticle diffusion to diffusion of the combined gas of quasiparticles and phonons is observed as the temperature is increased. The intrinsic quasiparticle recombination time, as well as the decay time of the quasiparticle density, is determined. The latter is found to be at least an order of magnitude longer than this quasiparticle recombination time.

The line shape of the first-order Raman spectra of $F$ centers in KCl is calculated for various incident light wavelengths in resonance with the $F$ and $K$ optical absorption bands. It is found that the diffuse nature of the excited state responsible for the $K$ band leads to strong electron-phonon coupling to the LO phonons in the $A_{1\mathrm{g}}$ spectra, in agreement with recent experimental observations of line-shape changes by Pan and Lüty.

We describe a high-resolution method to determine the spatial distribution of trapped charged or of a permanent dipole polarization in dielectrics. The method is capable of a resolution of 1 μm in a 25-μm-thick film.

We show that a soft mode arises when the vibrational modes of double-helical DNA are perturbed by increasing the electrostatic or Van der Waals interactions between atoms. We believe this soft mode drives the $B$ to $A$ conformation change which is observed when DNA has water of hydration removed from it.

At squared momentum transfers $0.8<~q^2<~6.0$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$, we measured nine spectra of inelastic electron-deuteron scattering cross sections in the threshold region between 0 and 2.3% in $\frac{\Delta p}{p}$ below the elastic peak and deduced the deuteron inelastic structure function $\nu W_2$. We found $\nu W_2\left({\omega }^{\prime }\right)$ approaching a universal scaling curve and a close relation between $\nu W_2$ and the deuteron elastic structure function $A\left(q^2\right)$.

$\frac{J}{\psi }$ photoproduction has been measured from beryllium and tantalum targets by observing the yield of single muons at a transverse momentum of 1.65 GeV/c with a bremsstrahlung beam of $E_0=20\mathrm{}$ GeV. The results have been interpreted in terms of a nuclearoptics model to yield the $\psi$-nucleon total cross section. The result is ${\sigma }_{\psi N}=3.5\mathrm{}\pm 0.8$ mb.

A search for $\mu e$ events produced in an antineutrino hydrogen-neon experiment using the Fermilab 15-ft bubble chamber is reported. Based on a single candidate, the 90%-confidence upper limit for the relative yield of ${\mu }^{+}{e}^{-}$ events is 0.5% of all charged-current events with antineutrino energy greater than 10 GeV.

A sample of 1200 $\varphi$ mesons produced in the Zweig-rule-forbidden reactions ${\pi }^{\pm }N\to \varphi N$ shows a flat $t$ distribution (slope=1.7 ± 0.2 Ge${\mathrm{V}}^{-2\mathrm{}}$) and a cross section suppressed by 0.0032±0.0004 relative to ${\pi }^{-}p\to \omega n$. Natural-parity-exchange $\omega$ and $\varphi$ production have similar $t$ dependences, while $\omega$ and $\varphi$ production by unnatural-parity exchange differ markedly. Interference between the $\varphi$ and the underlying $\overline{K}K$ $S$ wave indicates substantial nucleon-spin incoherence between the amplitudes for $\varphi$ and $S$-wave production.

Fission and evaporation-residue excitation functions for 170-340-MeV ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$+${}_{}{}^{109}{}_{}{}^{}\mathrm{Ag}$ have been analyzed with a code which treats multiple-particle emission with explicit angular-momentum dependence. It is found that the liquid-drop barriers must be reduced by 40% to reproduce experimental results, and that multiple-chance fission contributions are essential to the analysis.

The optical analog of pulse Fourier-transform NMR spectroscopy is demonstrated. Doppler-free infrared spectra are obtained for a set of closely spaced ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$H${}_3{}^{}{}_{}{}^{}\mathrm{F}$ transitions at 9.66 μm from two-pulse echo and free-induction decay transients. The effects of elastic or inelastic collisions on the decay rate are obtained for each transition, and the long-range force laws are deduced from the dependence of the scattering cross section on molecular velocity.

We have observed that circularly polarized laser beams of opposite (equal) polarizations in an alkali vapor repel (attract) each other for laser frequencies on the high-frequency wing of the $D_1$ line. Our experiments indicate that these long-range noncontact interactions are mediated by the exchange of polarized atoms between the beams. The repulsion between ${\sigma }_{+}$ and ${\sigma }_{-}$ beams leads to the breakup of a linearly polarized laser beam into two coherent beams of opposite circular polarization.

An x-ray pinhole camera is coupled to an x-ray streak camera for detailed measurements of the implosion of laser fusion targets. Simultaneous spatial and temporal resolutions of 6 μm and 15 psec are attained. Resultant $R$ and $t$ implosion diagrams show time-dependent implosion velocites in the range of (3-4) × ${10}^7$ cm/sec.

A stochastic model of the diffusion of atomic clusters on crystalline surfaces, capable of treating complex systems, has been developed. Novel methods allow the analysis of diffusion data in field-free and-biased experiments. Expressions for the complete determination of parameters characterizing the individual cluster configurations from measurable quantities are derived.

The Hubbard model is studied by employing a random-potential approximation, which incorporates the effects of magnetic ordering and dynamical processes. Comparison of our results to existing data on one-dimensional systems shows that the present approximation is very accurate over the whole range of values of the physical parameters.

dc and ac plasma-density and vector-electric-field detectors on a polar orbiting satellite have measured spatially confined regions of extremely large (∼½ V/m) electric fields in the auroral zone at altitudes below 8000 km. Such regions frequently have double structures of opposing electric fields containing characteristic and different wave spectra internal and external to themselves. These structures are identified as paired electrostatic shocks which are associated with electrostatic ion cyclotron wave turbulence.