Photoelectron spectra excited by x radiation are reported for the band-structure part on clean films of the rare-earth metals Nd, Sm, Dy, and Er. The dominant part of the spectra is due to excitation of $4f$ electrons. The spectra exhibit a complex and extended structure which is interpreted in terms of multiplet splitting of the final state in the photoemission process.

We give exact calculation, using the linked-cluster theorem, of the overlap between the ground-state wave functions of a system of $N$ fermions in the absence and in the presence of a localized potential. It is found that the overlap vanishes as $N^{-\alpha }$, where $\alpha \left(\delta \right)$ contains both a nonperiodic and a $\pi$-periodic term in the phase shift $\delta \left({\epsilon }_{\mathrm{F}}\right)$ due to the potential. The present result reduces to that of Anderson and of Nozières and de Dominicis for small phase shifts.

Anomalous features observed in the tunneling spectra of Schottky barrier junctions on Si:B are related to Hubbard's model of the metallic (Mott) transition.

We report the first observations of nonlinear phonon-induced nuclear spin-wave instabilities in an antiferromagnet possessing a nuclear magnetic moment. The observed instabilities are associated with the transverse nuclear mode of cubic RbMn${\mathrm{F}}_3$. The nuclear relaxation rates are obtained as a function of the magnon frequency and wave number. This observation verifies a recently published prediction by Platzker and Morgenthaler that a sufficiently intense elastic wave of the proper frequency and polarization can indeed drive antiferromagnetic spin waves unstable.

The cross sections for quasielastic electron scattering from nine target nuclei from lithium to lead have been measured for an electron incident energy of 500 MeV and a scattering angle of 60°. The data are interpreted in terms of a Fermi gas model, yielding the nuclear Fermi momentum as a function of atomic number. The Fermi momentum increases from lithium to calcium and remains roughly constant at about 260 $\frac{\mathrm{MeV}}{c}$ from nickel to lead.

The Ericson fluctuations of the mirror decays ${}_{}{}^{15}{}_{}{}^{}\mathrm{O}$+${}_{}{}^7{}_{}{}^{}\mathrm{Li}$ and ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$+${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ of a ${}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$ compound state near 53-MeV excitation energy are found to be correlated, providing evidence that isospin is a good quantum number at this high excitation energy.

Photons corresponding to 3040.6-keV $E6\mathrm{}$ and 1712.6-keV $M5\mathrm{}$ transitions have been observed from the decay of 2.6-min ${\mathrm{Fe}}^{53m}$. They have intensities of 2 × ${10}^{-4\mathrm{}}$ and 7 × ${10}^{-3\mathrm{}}$, respectively, compared with the 701.1-keV $E4\mathrm{}$ isomeric transition that is primarily responsible for depopulating ${\mathrm{Fe}}^{53m}$. These correspond to retardations of 650 and 43 over simple single-particle estimates.

The formal relationship between tensor-force distorted-wave Born approximation theory and $\beta$ decay is stated. Data on the reaction ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}({}_{}{}^3{}_{}{}^{}\mathrm{He},t)$ are given and compared with the cross section calculated with model wave functions adjusted to account for the known retardation in the ${}_{}{}^{58}{}_{}{}^{}\mathrm{Cu}$ positron decay. The calculated (${}_{}{}^3{}_{}{}^{}\mathrm{He},t$) cross section is also retarded but to an extent sensitively dependent on the tensor strength and the configurations present.

Magnetic electron spectrometers on satellites OGO-V and OV1-19 were used to make simultaneous measurements in interplanetary space and over the polar caps during the intense solar-particle event of April 1969. The absolute intensities and energy spectra measured on the two satellites tracked within experimental error for the entire history of the event. The results are examined in terms of the "open" and "closed" models of Earth's magnetosphere.

We have identified cosmic rays with $Z=40,44,52,71,77,78, \mathrm{and} 92$ slowing in a balloon-borne stack. The values of $Z$ assigned by both Lexan plastic detectors and nuclear emulsions were the same to within two units. Both low- and high-energy heavy cosmic rays are synthesized in the rapid neutron-capture process.

We present an investigation of the reaction $K^{-}p\to K^{{*}^0}\mathrm{}\left(890\right)n$ at 3.9 and 4.6 $\frac{\mathrm{GeV}}{c}$ incident momenta. The order-of-magnitude increase in statistics with respect to previous analysis allows an investigation of the $K^{{*}^0}\mathrm{}\left(890\right)\mathrm{}$-production properties in the very forward region of momentum transfer and also provides a quantitative test of the absorption-modified one-pion exchange model. This model gives an excellent description of the differential cross sections and decay correlations at the two energies.

The Amati-Bertocchi-Fubini-Stanghellini-Tonin multiperipheral model is modified to study deep inelastic electron-nucleon scattering. In particular, the scaling property of the structure functions is derived. The multiperipheral derivation is compared with derivations that use other models.

An estimate, valid for inelastic processes, of the probabilities of the high-momentum components in nuclei resulting from many-body correlations, together with data from Serpukhov, is used to derive upper limits for the quark-production cross section near threshold.

We report the results of a calculation of the total cross section for double Compton scattering ($\gamma +e\to \gamma +\gamma +e$). At very high incident photon energies the total cross section for double Compton scattering becomes larger than that for the usual Compton effect ($\gamma +e\to \gamma +e$) even though the latter is a lower order process.

All of the fine-structure intervals in the hydrogen $n=3,4\mathrm{}$ manifolds and all but the $F-G$ transitions in $n=5\mathrm{}$ have been measured using radiofrequency spectroscopy on a fast hydrogen beam. The experimental results are in agreement with theoretical predictions.

The collisionless damping of small-amplitude plasma waves is independent of the exciting voltage $V_{\mathrm{ex}}$. For large-amplitude waves, the damping rate increases linearly with $V_{\mathrm{ex}}$ and amplitude oscillations are observed. A phase transition appears at amplitude minima.

The low-temperature variation of the pressure at constant volume of a 24-${\mathrm{cm}}^3$/mole ${\mathrm{s}\mathrm{o}\mathrm{l}\mathrm{i}\mathrm{d}-}^3$He sample has been measured at 40.3 and 57.2 kG. No difference was observed from the zero-field curve. This result is thermodynamically inconsistent with previous measurements on solid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ if the system is in equilibrium. Implications of this anomalous result are discussed.

To eliminate the anomalous loss due to convective cells produced by the existence of the supports in the plasma volume, a levitated superconducting ring was installed in the Princeton spherator. The plasma decay time is increased from 10-15 msec in the supported version to a maximum of 150-220 msec for a helium discharge plasma. At $n_e=2\mathrm{}\times {10}^{11}$ ${\mathrm{cm}}^{-3\mathrm{}}$ and $T_e=1-2\mathrm{}$ eV, this decay time is ½ to ¼ of the calculated density decay time due to the classical diffusion process.

Stable excess electrons have been recently observed in liquid hydrocarbons after suitable purification, but the mobilities indicated the existence of short-lived electron traps in the liquids. We have measured electron mobilities in mixtures of $n$-hexane and neopentane and find that the mobility is given accurately by an expression of the form $\mu ={\mu }_n\exp \left(\frac{-x_{h}E}{\mathrm{kT}}\right)$, where $x_h$ is the mole fraction of hexane. It is concluded that the trap cannot be a negative-ion state of a single molecule, but is instead a collective trap involving several fluid molecules.

We applied pulses of heat to liquid He and found that below the $\lambda$ transition pulses of lower-than-ambient temperature propagate in the He II. This "cool" pulse is attributed to the temperature change that accompanies a compressive first-sound pulse. The temperature pulse is negative because the thermal expansion of He II is negative near the $\lambda$ transition.