[en] A key assumption in the usual computations of Doppler broadening is to ignore the dependence of Γ(j) on the state of the compound nucleus. This is an excellent approximation for the γ-emission contribution to Γ(j). It is not so clear that it is as good for the neutron contribution. In this paper, we derive an expression for Γ_n(j) and show that the effect of the dependence of Γ_n(j) on the intermediate energy of the target ε_j is not significant for an ideal gas, so that the absorption line shape is identical to the absorption line shape in which Γ_n is constant. Therefore, the effects of j dependence Γ_n(j) on the absorption cross section is not significant. (author). 7 refs., 1 tab., 2 figs

[en] The current status of knowledge of the sonoluminescence mechanism is reviewed. It is shown that the origin of sonoluminescence in multibubble cavitation fields is best described by the local charging theory of cavitation bubbles. For certain acoustic field configurations, a single stably pulsating cavitation bubble develops, which differs from its 'ordinary' counterparts in a number of respects, and whose sonoluminescence is a thermal effect in contrast to the luminescent glow of the ensemble of 'cold' cavitation bubbles. A model of single-bubble sonoluminescence is proposed, which includes the additional resonance absorption of energy by a solitary cavitation bubble in a symmetric acoustic field. The mechanisms of some single-bubble effects are as yet not clear. (reviews of topical problems)

No abstract available

[en] A further analysis of diagonalization approximation is made in the multichannel resonant photoionization of two-electron systems near the n=3 threshold of reduced hydrogenic ion. We have obtained excitation energies partial and total eigenwidths of a few ¹p^(-) and ³p^(-) low-lying resonances in He and some He-like ions. A comparison of our calculations with experimental data and with the results obtained using other approximations-like close-coupling calculations, enables one to assess the applicability of the diagonalization approximation for solving the multichannel resonant photo-ionization problem. (author)

[en] Short communication

No abstract available

[en] Mechanical resonances in superconducting accelerator structures and cryo-module components can lead to coupling between mechanical noise and electron beam parameters. The authors have studied the mechanical resonance spectrum of a 500 MHz-2-cell structure and cryo-module that was designed and built by Siemens for TRW, Inc., and have measured the effect of these vibrational modes on the RF eigenfrequency of the structure. They identify the most dangerous resonances of this system and discuss related design issues

[en] The basis for the phenomenon of nuclear magnetic resonance (NMR) is the ability of certain nuclei possessing both intrinsic angular momentum or ''spin'' I and magnetic moment to absorb electromagnetic energy in the radio frequency range. In principle, there are approximately 200 nuclei which may be investigated using the NMR technique. The NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum provides a variety of qualitative and quantitative analytical applications. The most obvious applications consist of the measurements of nuclear properties, such as spin number and nuclear magnetic moment. In liquids, the fine structure of resonance spectra provides a tool for chemical identification and molecular structure analysis. Other applications include the measurements of self-diffusion coefficients, magnetic fields and field homogeneity, inter-nuclear distances, and, in some cases, the water content of biological materials. (author)

[en] The physics of Alfven-wave heating is particularly sensitive to the character of the linear mode conversion which occurs at the Alfven resonance layer. Parameter changes can profoundly affect both the location within the plasma and the mechanism for the power absorption. Under optimal conditions the heating power may be absorbed by electron Landau damping and by electron transit-time magnetic pumping in the plasma interior, or by the same processes acting near the resonance layer on the mode-converted kinetic Alfven wave. The method is outlined for computing the coefficients for reflection, transmission and absorption at the resonance layer and some representative results are offered

[en] The effects of self-gravity of a dusty plasma on the Alfven and compressive resonance absorption processes are investigated. It is found that self-gravity can lead to considerable modification of the resonance processes, with removal of the resonances in some circumstances. These results are applicable to interstellar clouds and star-formation regions