Interchange and Infernal Fishbone Modes in Plasmas with Tangentially Injected Beams

New energetic particle mode instabilities of fishbone type are predicted. The considered instabilities are driven by the circulating energetic ions. They can arise in plasmas of tokamaks and spherical tori with weak magnetic shear in the wide core region and strong shear at the periphery, provided that the central safety factor is close to the ratio m/n, where m and n are the poloidal mode number and toroidal mode number, respectively. The instability with m = n = 1 has interchange-like spatial structure, whereas the structure of instabilities with m/n > 1 is similar to that of the infernal MHD mode (except for the region in vicinity of the local Alfvén resonance)

Stochastic loss of alpha particles in a helias reactor

Abstract. It is shown that collisionless orbit transformation of the locally trapped particles to the locally passing ones and vice versa in the Wendelstein-line optimized stellarators results in stochastic diffusion of energetic ions. This diffusion can lead to the loss of an essential fraction of energetic ion population from the region where the characteristic diffusion time is small compared to the slowing down time. The loss region and the magnitude of the loss can be minimized by shaping the plasma temperature and density profiles so that they satisfy certain requirements. The predictions of the developed theory are in agreement with the results of numerical modelling of confinementof a-particles in a Helias reactor, which was carried out in this work with the use of the orbit following code. The considered diffusion seems to represent the dominant mechanism of classical losses of a-particles in a Helias reactor

Structure of self-organized Fe clusters grown on Au(111) analyzed by Grazing Incidence X-Ray Diffraction

We report a detailed investigation of the first stages of the growth of self-organized Fe clusters on the reconstructed Au(111) surface by grazing incidence X-ray diffraction. Below one monolayer coverage, the Fe clusters are in "local epitaxy" whereas the subsequent layers adopt first a strained fcc lattice and then a partly relaxed bcc(110) phase in a Kurdjumov-Sachs epitaxial relationship. The structural evolution is discussed in relation with the magnetic properties of the Fe clusters.Comment: 7 pages, 6 figures, submitted to Physical Review B September 200

Stabilization of Sawtooth Oscillations by the Circulating Energetic Ions

The influence of the well-circulating energetic ions on the ideal kink instability and semi-collisional tearing mode are studied. It is found that the precession of these ions can be a key factor that affects the instability: it can lead to the stabilization of the mentioned instabilities, the effect being weakly dependent on the direction of the injection. The developed theory is consistent with the experimental observations of the stabilization of sawtooth oscillations during the negative-ion-based neutral beam injection in JT-60U

Current state and prospects of road infrastructure development in Ukraine

Робота присвячена аналізу сучасного стану транспортної галузі України, визначенню її основних особливостей та перспектив подальшого розвитку на прикладі дорожньої інфраструктури країни.The work is devoted to the analysis of the current state of the transport industry of Ukraine, the identification of its key features and prospects for future development, on the example of the road infrastructure of the country

Reconstruction and dynamics of food structure of the Odino people in the Baraba forest-steppe area during the 3rd millennium BC: according to archaeological and isotopic data

The paper aims at reconstructing the paleodiet of the Early Bronze Age population in the Baraba forest-steppe area of Western Siberia (the Odino culture). The study is based on materials of three large necropoleis of Sopka 2/4A, Tartas 1 and Preobrazhenka 6. Two chronological groups of the Odino culture burials have been defined by radiocarbon dating which gives us an opportunity to research the structure and changes in the paleodiet during the 3rd millennium BC. Reconstructions of the paleodiet are based on paleozoological determinations (including bone artifacts) and analyses of carbon (δ13С) and nitrogen (δ15N) isotopes in human and faunal bones (including some modern faunal samples). Results of isotopic measurements indicate that fish had formed a basic food component in the subsistence of the Odino population throughout the 3rd millennium BC. High values of δ15N in mushrooms (Boletaceae) do not exclude their important role along with fish in the human diet. A secondary food source for the Odino people was meat of herbivores and possibly also omnivores. The main game animal for the Odino population was an elk. Higher δ13С values in human bones in the last third of the 3rd millennium BC indicate changes in food sources. Preliminary, we associate this signal with an increased consumption of animal products of more southern origins (steppe?) by Odino people, which might be a result of the emergence of domesticated animals in economy