The Study of Anisotropy and Domain Condition of Permalloy Thin Films

Hysteretic Loops, 1,5; 3,0; 4,5; 6 and 10 nm in thickness, obtained by magnetron sputtering of Ni81Fe19 alloy, were measured by means of vibration magnetometer. It has been detected that by increasing the film thickness from 3 to 10 nm coercive force (HC) increases as well. In the direction perpendicular to the axis of easy magnetization the loop form considerably differs from the right-angled one, which is caused by amplitude dispersion of anisotropy. The films, derived in scattered magnetic field of the Earth, are by magnetic parameter isotropic. The results of atomic force microscope investigation indicate to the granular structure of films and confirms the presence of non-magnetized areas among the examined films. The critical thickness at which permalloy films pass from multi-domain to single-domain state was 10 nm. Estimation of the critical thickness of the transition from single-domain state to superparamagnetic led to the values of 1.5-2 nm. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3362

Classification of voting algorithms for N-version software

A voting algorithm in N-version software is a crucial component that evaluates the execution of each of the N versions and determines the correct result. Obviously, the result of the voting algorithm determines the outcome of the N-version software in general. Thus, the choice of the voting algorithm is a vital issue. A lot of voting algorithms were already developed and they may be selected for implementation based on the specifics of the analysis of input data. However, the voting algorithms applied in N-version software are not classified. This article presents an overview of classic and recent voting algorithms used in N-version software and the authors' classification of the voting algorithms. Moreover, the steps of the voting algorithms are presented and the distinctive features of the voting algorithms in Nversion software are defined. © Published under licence by IOP Publishing Ltd

LED Monitoring System for the BTeV Lead Tungstate Crystal Calorimeter Prototype

We report on the performance of a monitoring system for a prototype calorimeter for the BTeV experiment that uses Lead Tungstate crystals coupled with photomultiplier tubes. The tests were carried out at the 70 GeV accelerator complex at Protvino, Russia.Comment: 12 pages, 8 figures, LaTeX2e, revised versio

Influence of Deuterium Ion Implantation on the Structure and Hardness of Nanocrystalline Films

Titanium nitride based coatings are very attractive for protection of materials in extreme conditions. However, their behavior under different kinds of irradiation is not entirely well understood. In this work, the influence of ion-implanted deuterium on changes of the structure and mechanical properties TiZrN, TiAlSiN, TiAlYN films were investigated. Films were deposited by filtered vacuum arc plasma technique. After deposition all films were irradiated at room temperature with 12 keV D+ ions to dose 1 1018 D/cm2. Composition, structure and nanohardness of the coatings were determined by X-ray fluorescence method, X-ray diffraction and nanoindentation. The effusion of the implanted deuterium was studied by thermal desorption spectroscopy. It is shown that irradiation by deuterium ions does not make structural changes in multicomponent films. Deuterium thermal desorption spectrum of various coatings are substantially different. Nanohardness of all investigated coatings after irradiation and thermal desorption are decreased. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3545

Development of a Momentum Determined Electron Beam in the 1 -45 GeV Range

A beam line for electrons with energies in the range of 1 to 45 GeV, low contamination of hadrons and muons and high intensity up to 10^6 per accelerator spill at 27 GeV was setup at U70 accelerator in Protvino, Russia. A beam tagging system based on drift chambers with 160 micron resolution was able to measure relative electron beam momentum precisely. The resolution sigma_p p was 0.13% at 45 GeV where multiple scattering is negligible. This test beam setup provided the possibility to study properties of lead tungstate crystals (PbWO_4) for the BTeV experiment at Fermilab.Comment: 12 pages, 8 figures; work done by the BTeV Electromagnetic Calorimeter grou

Exact 2-point function in Hermitian matrix model

J. Harer and D. Zagier have found a strikingly simple generating function for exact (all-genera) 1-point correlators in the Gaussian Hermitian matrix model. In this paper we generalize their result to 2-point correlators, using Toda integrability of the model. Remarkably, this exact 2-point correlation function turns out to be an elementary function - arctangent. Relation to the standard 2-point resolvents is pointed out. Some attempts of generalization to 3-point and higher functions are described.Comment: 31 pages, 1 figur

BGWM as Second Constituent of Complex Matrix Model

Earlier we explained that partition functions of various matrix models can be constructed from that of the cubic Kontsevich model, which, therefore, becomes a basic elementary building block in "M-theory" of matrix models. However, the less topical complex matrix model appeared to be an exception: its decomposition involved not only the Kontsevich tau-function but also another constituent, which we now identify as the Brezin-Gross-Witten (BGW) partition function. The BGW tau-function can be represented either as a generating function of all unitary-matrix integrals or as a Kontsevich-Penner model with potential 1/X (instead of X^3 in the cubic Kontsevich model).Comment: 42 page

Design and performance of LED calibration system prototype for the lead tungstate crystal calorimeter

A highly stable monitoring system based on blue and red light emitting diodes coupled to a distribution network comprised of optical fibers has been developed for an electromagnetic calorimeter that uses lead tungstate crystals readout with photomultiplier tubes. We report of the system prototype design and on the results of laboratory tests. Stability better than 0.1% (r.m.s.) has been achieved during one week of prototype operation.Comment: 10 pages, 6 figures, LaTeX2

Effects of Deuterium Implantation Dose on Hardness and Deuterium Desorption Temperature Range from High Entropy TiVZrNbHf and TiVZrNbHfN Coatings

High entropy TiVZrNbHf and TiVZrNbHfN coatings prepared by filtered vacuum arc plasma from a single equiatomic HEA cathode. Similarly were obtained titanium and titanium nitride coatings. The structure of coatings was investigated by X-ray analysis and the changes in nanohardness by nanoindentation method. The effusion of the implanted deuterium was studied by thermal desorption spectroscopy (TDS). It is shown that the structure of effusion spectrum is a function of deuterium dose. With increasing implantation dose deuterium desorption temperature range from coatings is expanding in the direction of lowering the temperature and the temperature of the peak maximum gas emission gradually shifts to lower temperatures. For nitride coatings deuterium desorption starts at about room temperature and the maximum rate of desorption at a temperature of ~500 K. When irradiation doses more than 5×1017 D/cm2 hardness of nitride coatings decreased by half. Hardness reduction of coatings is caused by occurrence hydride structural formations in coatings. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3536

Study of Radiation Damage in Lead Tungstate Crystals Using Intense High Energy Beams

We report on the effects of radiation on the light output of lead tungstate crystals. The crystals were irradiated by pure, intense high energy electron and hadron beams as well as by a mixture of hadrons, neutrons and gammas. The crystals were manufactured in Bogoroditsk, Apatity (both Russia), and Shanghai (China). These studies were carried out at the 70-GeV proton accelerator in Protvino