Stripping (ionization and transfer) and excitation cross sections for the muonic helium ion (αμ) in deuterium-tritium mixtures are calculated by the classical-trajectory Monte Carlo method. It is shown by direct (three- and four-body) calculations that the effects of the target electronic structure and finite mass are not important.

K-shell ionization induced by relativistic electron impact has been studied for eleven elements of 22≤Z≤52 in the incident-electron energy region of 300–380 MeV. The I(Kβ)/I(Kα) intensity ratios and the ionization cross sections have been measured. The values of the intensity ratio are in agreement with those of previous experiments and the theoretical calculations of Scofield. Our results, along with those of previous experiments, prove the assumption that the intensity ratio is independent of the incident energy. The values of the cross section decrease with increasing Z. The decreasing tendency can be explained by Scofield’s theory, but the experimental values lie systematically lower than the calculated values. The cross sections follow a power-law dependence, σ∼$Z^{\mathrm{-}\alpha }$, and the exponent α is evaluated to be 2.51±0.13 for 300-MeV electron impact. As for the incident-energy dependence of the cross section, our results suggest a density effect in the inner-shell ionization process.

The 3d transition metals Ni, Co, and Fe are vaporized using an inductive heating method and their electron-beam-excited $L_2$,3${\mathrm{M}}_4$,5${\mathrm{M}}_4$,5 Auger spectra are measured for the first time with a double-pass simulated spherical Jost-type analyzer. The experimental spectra show a complicated manifold spectral structure, which has been analyzed by comparing it with the multiconfiguration calculations.

Total photon cross sections in Cu, Pt, and Au are measured employing the doublet 79.623- and 80.999-keV γ’s of ${}_{}{}^{133}{}_{}{}^{}\mathrm{Ba}$. A dilution of the cross section by about 12% is observed at the average energy of the doublet in Au due to K-edge falling in between these two energies. Scofield’s theoretical value in this case is seen to be underestimated by about 75% due to the use of different K-edge energies in Au. However, an alternative but customarily followed procedure is to ignore the lower K-edge data of Scofield and extrapolate using upper-edge data which yield a value agreeing satisfactorily with the experimental value at 80.905 keV.

The quasistatic plasma slow response to coherent ion acoustic waves in a magnetized plasma is considered. A multidimensional cubic nonlinear Schrödinger equation is derived. It is found that the ion acoustic waves remain modulationally stable against oblique perturbations.

A very simple yet novel derivation is presented of the dynamics of the dissipative two-state system in the ‘‘noninteracting-blip approximation.’’

We investigate statistically the scaling properties of the macroscopic-order formation process for the regime f>$f_c$, where the oscillatory instability of the director takes place above the threshold voltage $V_c$ in the electrohydrodynamics of a nematic liquid crystal. Here f is an applied field frequency and $f_c$ the threshold frequency separating two different instabilities, the convective (f<$f_c$) and oscillatory (f>$f_c$) ones. The characteristic deviation of the variance from the scaling function obtained from the noisy Landau equation is observed. This deviation increases approaching ε=0 where ε=($V^2$-$V_c^2$)/$V_c^2$. In particular, such a deviation becomes extremely large for the whole evolution stage in the case very close to the onset point $V_c$ and the universality of the scaling curve breaks down. This behavior is possibly due to the nucleation of sufficiently large oscillatory domains and the generation of defects on the borders of those domains. Thus these facts suggest that the spatial degrees of freedom play an important role in the transient kinetics. Furthermore, the scaling behavior is observed in the distribution function of the oscillation amplitude (the macroscopic order) for the early stage of the evolution.

High-resolution heat-capacity measurements have been carried out near the smectic-A to smectic-C transition of azoxy-4,4’-di-undecyl-α-methylcinnamate (AMC-11). Both extended mean-field and three-dimensional XY-like critical analyses have been performed on the results. It is shown that the heat-capacity data can be well described by the extended mean-field model. In addition, a direct comparison between the reported tilt-angle data and our heat-capacity data is made within the prediction of the extended mean-field model.

Triple-differential cross sections (TDCS) for the ionization of H(2s) by fast electrons are calculated in second Born approximation for the case of an asymmetric coplanar geometry. Results are presented at an incident electron energy of 250 eV and are compared with the corresponding ones obtained for ionization of the ground state. The cross sections for the ionization of H(2s) exhibit interesting structures, and are very large in the vicinity of the region where the process is recoilless. Our results are compared with those obtained from a post-collision interaction model. Second Born TDCS for incident positrons are also presented.

A general method is introduced for determining whether the number of zeros of a transition-matrix element (Cooper minima), considered as a function of energy, is even or odd. This method provides a general viewpoint for understanding the numerical observations and the well-known empirical rules about the existence of Cooper minima.

Critical dynamics of the laser field near the threshold of oscillation is investigated and observation of the Brownian motion of the electric field amplitude driven by quantum noise is reported. Experimental results agree well with the nonlinear oscillator model of the laser.

The stabilization of a nonlinear system against period-doubling bifurcations by means of a periodic perturbation has been investigated. With the Josephson junction as a model system, both numerical simulations (including noise) and measurements on Josephson tunnel junctions have been performed. The effect of the noise is found to be of fundamental importance.

High-resolution heat-capacity, tilt-angle, and spontaneous polarization measurements have been carried out near the smectic-A–chiral-smectic-C (SmA-Sm$C^{\mathrm{*}}$) transition of p-decyloxybenzylidene-p’-amino-1-methylpropylcinnamate (DOBA-1-MPG). The heat-capacity and tilt-angle data are well described by a mean-field model with three expansion terms. Again the ratio of the polarization (P) to the tilt angle (theta) shows a dramatic increase just below the SmA-Sm$C^{\mathrm{*}}$ transition and then remains fairly constant for $T_c$-T≳1 K. Here $T_c$ is the SmA-Sm$C^{\mathrm{*}}$ transition temperature. A mean-field model with eleven expansion terms accounts very well for this anomaly in the ratio (P/theta).

We study the transition from regularity to irregularity for a physically real Hamiltonian system, viz., the hydrogen atom in a uniform magnetic field. We obtain quantitative correspondence between the transition in classical phase space and the change in the level statistics of the quantum energy spectra. Beyond the completely regular regime, the distributions of level spacings show a pronounced minimum at small spacings and cannot be accurately fitted by the semiclassical formula of Berry and Robnik [J. Phys. A 17, 2413 (1984)].

By means of the approximate renormalization approach of Niu and Nori [Phys. Rev. Lett. 57, 2057 (1986)] the widths of subband segments in the spectrum and the occupation probabilities on subbands are obtained to the lowest order for the two-value Fibonacci chains. The global scaling properties of the spectrum are then analytically calculated.