[en] K beta X-ray lines from partially M-shell-ionized ions of titanium through nickel which are produced in vacuum-spark plasmas have been observed systematically for the first time, using a high-resolution curved-crystal spectrometer. Each K beta line is clearly separated into its corresponding charge state. As a result, it is possible to measure the K beta-type transition energies of the M-shell-ionized ions. The transition energies accurately determined are compared with those calculated for iron ions, and the agreement is excellent except for ions having some additional 3d outer-shell electrons or 3s inner-shell vacancies. The square root of the K beta transition frequency is expressed as a linear function of the nuclear charge for isoelectronic sequences. The effective nuclear charges have been also determined for each K beta transition. The 3p electrons do not affect the effective nuclear charges. 10 references

[en] Stimulated Raman process is used to selectively pump a highly excited vibrational state in a molecular beam. Theoretical evaluation shows that continuous lasers with power of less than 1 W can efficiently pump a single rotational-vibrational level of many simple molecules. Characteristics of the selectively pumped molecular beam and operational conditions are discussed theoretically. The experiment on a Na2 beam is found to agree with theoretical predictions. A flux of 4 x 10 to the 7th/s in the v = 31, J = 5 excited level has been obtained with use of two CW dye lasers with powers of 80 and 300 mW. 33 references

[en] We clarify the assumptions involved in our analysis of the Rayleigh-Taylor instability in a spherical geometry published recently

[en] The aerothermodynamic studies of proposed space missions require atmospheric charge-transfer data. N2(+) eigenstate energies are calculated with use of the complete-active-space self-consistent-field method with an extended Gaussian basis set. The N(+)-N charge-exchange cross section, determined from these energies, agrees with merged-beam measurements. This contradicts the previous theoretical conclusion. A simple physical description of the long-range interaction is presented and should expedite future charge-transfer studies. 12 references

[en] The threshold photoionization method was used to study low-energy electron attachment phenomena in and cross sections of CCl4 and SF6 compounds, which have applications in the design of gaseous dielectrics and diffuse discharge opening switches. Measurements were made at electron energies from below threshold to 140 meV at resolutions of 6 and 8 meV. A narrow resolution-limited structure was observed in electron attachment to CCl4 and SF6 at electron energies below 10 meV, which is attributed to the divergence of the attachment cross section in the limit epsilon, l approaches zero. The results are compared with experimental collisional-ionization results, electron-swarm unfolded cross sections, and earlier threshold photoionization data. 34 refs

[en] A theory is developed for the interaction of coherent electromagnetic (EM) radiation with a free electron gas and for the influence of the plasma on the photon statistics of the radiation field. Two important possibilities for generating squeezed states are shown: squeezed states can be generated by the interaction of a one-mode laser with a plasma in a cavity; squeezed states can be generated by transmitting coherent radiation through the plasma. The maximal squeezing of the radiation obtained in the latter case is equal to the reciprocal of the dielectric constant of the plasma. Inside the plasma the EM field is represented by quasi-photons. Their dispersion relations are derived by using Bogoliubov transformations together with a self-consistency requirement for the motion of the electrons interacting with these quasi-photons. The squeezing processes are found to be strong when the frequency of the radiation is a little above the plasma frequency. By adding a constant magnetic field in the direction of propagation of the EM wave different amounts of squeezing are obtained for right- and left-circularly polarized EM waves. 28 references

[en] It is the purpose of this paper to point out that the creation of fractal basin boundaries is a characteristic feature accompanying the intermittency transition to chaos. (Here ''intermittency'' transition is used in the sense of Pomeau and Manneville [Commun. Math. Phys. 74, 189 (1980)]; viz., a chaotic attractor is created as a periodic orbit becomes unstable.) In particular, we are here concerned with type-I and type-III intermittencies. We examine the scaling of the dimension of basin boundaries near these intermittency transitions. We find, from numerical experiments, that near the transition the dimension scales with a system parameter p according to the power law dcongruent d₀-kchemical bondp-p/sub I/chemical bond/sup β/ with β=1/2, where d₀ is the dimension at the intermittency transition parameter value p=p/sub I/ and k is a scaling constant. Furthermore, for type-I intermittency d₀< D, while for type-III intermittency d₀=D, where D is the dimension of the space. Heuristic analytic arguments supporting the above are presented

[en] A very rapid, but accurate, fully relativistic method for calculating the atomic-structure data needed in determining collision strengths for highly charged ions is developed. A more rapid quasirelativistic approximation to this approach is also described. Results for oscillator strengths and energies are compared with those by mostly more elaborate programs for neonlike and nickel-like ions and generally good agreement is obtained

[en] The far-infrared pure rotational absorption spectrum of HD and HD-X mixtures was measured at 77 and 195 K. Specifically, the rotational lines R(0)--R(2) were observed for HD-HD, HD-He, HD-Ne, and HD-H₂ at 77 K and R(0)--R(3) for HD-HD, HD-He, and HD-Ar at 195 K. Refined values of the permanent dipole moment of HD are deduced. Collisional interference in the spectrum is characterized by a parameter proportional to the ratio of the average-induced dipole moment to the permanent dipole moment. Its variation with temperature, particularly a change in sign, is not explainable by current theory. The spectral line-shape parameters of width, frequency shift, and asymmetry are determined and their density and temperature behavior discussed with reference to the impact theory of line broadening

[en] In this Reply, it is shown how our experimental results lead us to the conclusion that the two-step process proposed in the recent Comment by Gillen [Phys. Rev. A 39, 2248 (1989)] cannot explain the ion signals observed for E_c.m.≤50 eV, whereas laser-assisted ionization is the only mechanism consistent with our observations in this energy range. The measured amplitude of the signals can be interpreted in terms of a transition-dipole enhancement induced by the collision. Such an enhancement has been ignored in the estimates of Gillen