Proton-boron fusion in a compact scheme of plasma oscillatory confinement.

We present the results of experiments on the aneutronic fusion of proton-boron (pB) in a single miniature device with electrodynamic (oscillatory) plasma confinement. The device is based on a low energy (∼1-2 J) nanosecond vacuum discharge with a virtual cathode, the field of which accelerates protons and boron ions to the energies required for pB synthesis (∼100-300 keV) under oscillating ions' head-on collisions. The yields of α particles registered for different conditions of the experiment are presented and discussed in detail. The experiment was preceded by particle-in-cell modeling of main processes accompanying pB reaction within the framework of the full electromagnetic code karat. The summary yield of α particles of about 5×10^{4}/4π was obtained during the pulse-periodic operation of the generator within total 4µs of the high voltage applied, which is ∼10α particles/ns.

Magnetized plasma implosion in a snail target driven by a moderate-intensity laser pulse.

Optical generation of compact magnetized plasma structures is studied in the moderate intensity domain. A sub-ns laser beam irradiated snail-shaped targets with the intensity of about 1016 W/cm2. With a neat optical diagnostics, a sub-megagauss magnetized plasmoid is traced inside the target. On the observed hydrodynamic time scale, the hot plasma formation achieves a theta-pinch-like density and magnetic field distribution, which implodes into the target interior. This simple and elegant plasma magnetization scheme in the moderate-intensity domain is of particular interest for fundamental astrophysical-related studies and for development of future technologies.

Deleterious effects of nonthermal electrons in shock ignition concept.

Shock ignition concept is a promising approach to inertial confinement fusion that may allow obtaining high fusion energy gains with the existing laser technology. However, the spike driving laser intensities in the range of 1-10 PW/cm2 produces the energetic electrons that may have a significant effect on the target performance. The hybrid numerical simulations including a radiation hydrodynamic code coupled to a rapid Fokker-Planck module are used to asses the role of hot electrons in the shock generation and the target preheat in the time scale of 100 ps and spatial scale of 100 µm. It is shown that depending on the electron energy distribution and the target density profile the hot electrons can either increase the shock amplitude or preheat the imploding shell. In particular, the exponential electron energy spectrum corresponding to the temperature of 30 keV in the present HiPER target design preheats the deuterium-tritium shell and jeopardizes its compression. Ways of improving the target performance are suggested.

Ablation pressure driven by an energetic electron beam in a dense plasma.

An intense beam of high energy electrons may create extremely high pressures in solid density materials. An analytical model of ablation pressure formation and shock wave propagation driven by an energetic electron beam is developed and confirmed with numerical simulations. In application to the shock-ignition approach in inertial confinement fusion, the energy transfer by fast electrons may be a dominant mechanism of creation of the igniting shock wave. An electron beam with an energy of 30 keV and energy flux 2-5 PW/cm(2) can create a pressure amplitude more than 300 Mbar for a duration of 200-300 ps in a precompressed solid material.

[Electrophysiological and neuroradiological methods in the diagnosis and prognostication of functional outcome in young children with lesions of the visual tract]. / Elektrofiziologicheskie i neiroradiologicheskie metody v diagnostike i prognozirovanii funktsional'nykh iskhodov u detei rannego vozrasta s porazheniem zritel'nykh putei.

The authors analyze the data of computer-aided tomography, neurosonography, and visual evoked potentials to chess pattern reversal in 14 infants aged 6 to 11 months with partial atrophy of the optic nerve and/or visual cortex involvement before and in various periods after transcutaneous electric stimulation combined with neurotrophic drug therapy. The advantages of comprehensive examinations in neuroophthalmological diagnosis in infants are shown, as is the possibility of using electrophysiological and neuroradiological methods for prediction of functional outcomes in the said patient population.

[Changes in the matching of somato-autonomic rhythms in the human operator during learning]. / Izmeneniia soglasovannosti somatovegetativnykh ritmov u cheloveka-operatora v protsesse obucheniia.

In subjects during the 1st through 15th day of training of the assemble job, before and during the work, the changes of concordance between the heart rate and respiration rhythm were studied in comparison with the dynamics of the activity results and of psychophysiological characteristics. In subjects with bad results of learning higher indices of respiratory-cardiac concordance and tremor were initially observed, what may serve as a criterion for professional selection for this kind of activity. In well learning subjects during transition from rest to work the initial desynchronization of somato-vegetative rhythms ("stress" type of reaction) was changed by an increase of their concordance. The relation of the training success to the type of working capacity of the subject ("morning", "evening") was also revealed.

[Divergent effect of acetylcholine on processes of habituation and disinhibition]. / Raznonapravlennoe vliianie atsetilkholina na protsessy privykaniia i rastormazhivaniia.

The elaboration of habituation to repeated tactile stimuli was studied in snail (Helix pomatia) by means of intracellular recording of the neuronal activity and microionophoresis of acetylcholine (ACh). Light or a stronger tactile stimulation served as extrastimulus. The elaboration of habituation was accompanied by a rise in the threshold of action potentials (APs) generation, evoked by the habitual stimulus, and by a lowering of the threshold of APs elicited by the extrastimulus. Prior to the habituation neuronal responses to tactile or photic stimuli did not change against the ACh background. After habituation was elaborated the ACh administration led to disinhibition of responses to the habitual stimulus (in particular, the AP threshold became lower), and to a decrease in responses to the extrastimulus (AP threshold rose). It is assumed that hibituation changes the chemical responses caused in the neurone by the activation of both the pool of synapses, corresponding to the habitual stimulus, and the pool of synapses corresponding to the extrastimulus. These changes, however, are of a qualitatively different character.