Volume 38, Issue 9

Fusion for Fission fuel breeding and other incentives for unconventional magnetic fusion research are introductorily mentioned. The design, operation and peculiar characteristics of dense plasma foci are briefly described with attention to their remarkable ion acceleration and plasma heating capabilities. Attempts for interpretations are reviewed, and a brief account is given for an explanation based on the concept of magnetically induced plasma rotation, recently derived in detail in this journal. Basically an ion acceleration mechanism of betraton character it describes in combination with a dynamic, generalized Bennett relation focus plasma characteristics like the polarity dependence, the current channel disruption, the axial ion beam formation and the prerequisites for the ensuing turbulent plasma dissipative stage. Fundamental differences with respect to mainline fusion research are emphasized, and some conjectures and proposals are presented as to the further development of plasma focus nuclear fusion or fission energy production.

A system of polyvalent impurity centers in a semiconductor (i.e. Au-centers in Si) is con-sidered. The ground state of the impurity pair Au - (a) + Au° (b), where an extra electron is localized on the site a, may be turned into an excited state due to a change of the charge state of a third nearby impurity site. This happens because of different shifts of the Au - -level at sites a and b due to their different distances from the third center. As a result, the original pair is able to reach a new ground state Au° (a) + Au - (b) through a slow spontaneous tunnel transition. The probability of this transition, when it is accompanied by an emission of a low energy photon, is calculated explicitly.

A transient analysis of the 1D and 2D reaction-diffusion equations associated with the model reaction of Prigogine and Lefever (Brusselator model), including diffusion of the initial (sub-strate) component, has been performed. For low system lengths and for fixed boundary conditions, the steady state low amplitude solutions are unstable. For zero flux boundary conditions a multiplicity of symmetric solutions with the same wave number may exist, the majority of them being unstable. The diffuion of initial components induce relaxation oscillations in space both for fixed as well as zero flux boundary conditions. The amplitude of the oscillation increases as the diffusion coefficient of the initial component decreases. For conditions of relaxation oscillations the spatial profiles result in single or multiple propagating fronts. High system lengths (or low diffusion coefficient of intermediate components), for both zero flux and periodic boundary conditions, may give rise to a multipeak incoherent wave pattern. For periodic boundary conditions a multiplicity of waves has been observed. Numerical simulation of the 2D-spatial structures reveal certain similarities between the 1D and 2D cases.

Potentiometrie measurements with platinum and silver electrodes of Ag + induced oscillations in the oxygen-inhibited excitable Belousov-Zhabotinsky system are reported. Calculations based on the Oregonator model lead to the conclusion that the platinum electrode's potential is composed of two contributions, the Ce(III)/Ce(IV) redox couple which dominates at low Ag + flow rates and the contribution of HBrO 2 , HOBr and BrO 2 which dominates at higher Ag + addition rates.

Brillouin spectra have been measured in liquid Benzene at high pressures up to 1300 bar and at the temperatures 298.15 K, 313.15 K, 323.15 K. and 343.15 K. From the experimental spectra the hypersound velocities and the energy relaxation times were determined. The total velocity dispersion ν 2 ∞ /ν 2 0 due to the relaxation of the vibrational specific heat c, is found to be nearly density independent in the pressure interval under study. It follows further that the experimentally determined specific heat corresponds to the theoretical value calculated with the vibrational modes of the Benzene molecule. The energy relaxation time t, connected with all vibrational modes but the lowest decreases with increasing density at constant temperature, at constant density τ 1 decreases with growing temperature. The relative relaxation rates were used to test the cell model (CM) with movable walls and the collision theory (HS) of Einwohner and Alder. Using a hard sphere diameter derived from ex-perimental transport coefficients the experimental results were predicted better by HS than by CM.

The cage-like molecules β-P 4 S 5 , As 4 S 5 , P 4 S 7 and As 2 P 2 S 7 are all supposed to have C 2v -symmetry. A normal coordinate analysis was performed for those molecules, based on a very simple initial force field with three numerical parameters and valence coordinates including redundancies. A complete set of symmetry coordinates is given. The force field was refined by adjusting the symmetry force constants to fit exactly a set of observed frequencies. This was used to calculate the mean amplitudes of vibration and perpendicular amplitude correction coefficients. The standard thermodynamical values derived from spectroscopic data are also given. A set of frequencies was calculated for the so far unknown compound P 4 S 6 .

The permanent dipole moment of a class of merocyanine dyes in their ground and first excited singlet state has been determined studying the influence of an external electric field on the absorption of the compounds in various solvents. Evaluation of the experimental results on the basis of the Onsager reaction field model also gives values for the polarizability in the ground and excited state, the latter approaches the value of a respective conducting ellipsoid with the longer chainlength molecules.

A four-level double resonance method has been developed allowing the determination of the relative collision induced change in signal intensity rj without application of the Stark modula-tion technique. The method is based on certain properties of the bridge type superheterodyne spectrometer and may be applied to molecular transitions showing strong microwave absorption, η-values have been determined for various four-level systems consisting of |M| -resolved rotational levels of the linear molecule HCCC 15 N. In addition to the measurements on the pure substance the influence of foreign gas admixtures with H 2 , He, Ne and Ar on the results has been investigated.

We present an analysis of the rotational spectrum of ethylchloride- 35 Cl in the ground state. The 35 Cl-hfs analysis was extended and the barrier to internal rotation determined from narrow splittings of high J-transitions.

The microwave spectra of CF 3 CN, CH 2 FCN, CHDFCN, CD 2 FCN and CHF 2 CN have been measured and analysed. The nuclear quadrupole hyperfine splittings due to 14 N have been measured by Microwave Fourier Transform spectroscopy. The nuclear quadrupole coupling constants, transformed to the bonding axis systems of the C-C ≡ N groups, are shown to be in accord with structural predictions of the p-electron populations at the nitrogen atom.

PA-spectroscopic Investigation on Solutions of Dyes in Polymermatrixes Dyes solved in polymer matrixes are ideal systems to examine the RG theory. PVA and PVP were used as matrixes. In these polymer matrixes the thermal properties are given by the matrix molecules being present in excess. The dye molecule serves as an indicator. Thus the thermal properties, specific heat, temperature and heat conductivity of the matrix can be measured for thermally thick layers. Further investigations to examine the RG theory show, that this theory can be used for the quantitative evaluation of PA measurements of thermally thick, non scattering samples.

An ab initio SCF calculation of better than double zeta qualitv (192 basic functions) acted as a starting point for a configuration interaction (CI) study. The final CI with 3408 configurations showed that the 3d orbital density was reduced further than the initial value of 0.1 e; the SCF configuration was dominant, but an element of in -out correlation occurred, with incorporation of the orbital 1a 2 in replacement for 1b 1 being notable in many configurations.

Exact solutions are given for May's simple difference equation and the broken linear model, both for extreme values of the parameters, and the relation between these two systems for the solvable cases is clarified. The invariant measure and the correlation function for each case are calculated using the exact solutions. The initial-value dependence of the behavior of the solutions, choatic or periodic, is completely determined. By using the exact solution, encounters of any two nonperiodic orbits can be precisely analyzed.

The possibility to determine simultaneously the effective volume and the molecular moment of inertia on the basis of the generalized equation of the rotational motion of prolate luminescent molecules in solutions is discussed.

Analysis of the dipole moment of 2-chloropyridine-5-sulphonyl chloride in benzene at 30 °C (2.00 D) supports a model in which the C(5)-SCl group is rotated by 40° from the 2-chloro-1-pyridyl group (see Figure 1). Such a model, with the S-Cl chlorine atom close to the 1-azani-trogen atom, may be explained by interplay of two con-flicting factors, namely sulphonylchloride-arene conjuga-tion and lesser repulsion between one of the oxygen atoms and the aza-nitrogen atom.

With the help of Microwave Fourier transform Spectroscopy we were able to resolve the nitrogen hyperfine structure of allylcyanide synperiplanar (cis). As the rotational relaxation is relatively rapid this molecule is even for this technique at the limit of the present possibilities.

In order to study the polar group effect upon conformations about CH 2 -CH 2 single bonds, the Raman spectra of simple sodium alkylsulfates and sodium alkyisulfonates were measured. The ethylsulfate ion (CH 3 -CH 2 -O-SO 3 - ) in aqueous solution was found to take the trans form about the CH 2 - O bond in 0.67-5.41 mol/1. For the n-propylsulfonate ion the Raman line due to the gauche form about the CH 2 -CH 2 bond was also observed, the trans form becoming predominant at higher concentrations. For the sulfate and sulfonate ions having butyl and hexyl chains, the concentration dependence of their molecular conformations was also investigated.