Effects of Deuterium Concentration on Deuterium Desorption Temperature Range from Ni - In Composites

Spectra thermal desorption deuterium from the samples of system Ni-In preliminary implanted by var-ious doses of deuterium ions at Т~100 K. On the basis of these spectra are studied dependences of change are constructed. It is shown that the structure of spectrum, thermal desorption deuterium is function doses. On satura-tion of composite Ni70In30 with deuterium through ion implantation at T ~100 K the ultimate attainable concentration of deuterium makes ~2 at.D/at.Met.The increase in deuterium concentration brings about in composite Ni70In30, in addition to the solid state solution deuterium (decomposition at temperature ~530 K), the formation of the hydride, whose temperature of decomposition in vacuum is ~350 K. Change of the component content in system Ni-In leads to essential change of a kind of a spectrum thermal desorption deuterium, shown in occurrence of additional temperature areas desorption (peaks) that testifies to formation of additional structural formations. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3523

Effects of Cold Deformation and Electron Irradiations on Deuterium Desorption Temperature Range from Zr – 1 %Nb Alloy

The explored warm-up ranges of desorption ion-implanted deuterium from Zr – 1 %Nb alloy, with different structure: after crystallization from melt, plastic deformation and irradiations electron. Cool deformation under 300 K Zr – 1 %Nb alloy with degree 3.9 has allowed to reach the nanostructure conditions in alloy with average size crystallite d 61 nm, high three-dimensional concentration of the borders (~ 3,4 %) and significant level microstrain that in spectrum of thermodesorption ion-implanted deuterium was shown as additional low temperature area thermodesorption deuterium within the range of the temperature 770-1000 K. Irradiation electron to energy 10 MeV by fluence ~ 6 × 1017 cm – 2 has brought about active development of the revocable processes in nanostructure alloy: reduction of the average grain size d 58 nm, increase to concentrations of the borders (~ 8,8 %) and appearance additional peaks in spectrum of thermodesorption deuterium with the temperature 700 and 800 K and, accordingly, increase the warmup range desorption deuterium toward reduction of the temperature. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3512

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

Effects of Concentration Titanium on Threshold Character of Deuterium Desorption Temperature Range from Mg-based Composites

The plasma evaporation-sputtering method was applied to make composite materials of the Mg-Ti system. The ion-implanted deuterium desorption temperature variations as a function of the component concentration were studied. It has been established that, by introducing titanium into magnesium, the deuterium desorption temperature can be appreciably decreased (to 400-450 K) in comparison with the case of deuterium desorption from magnesium ( 800 K). A step-like shape of the curve of deuterium desorption temperature evidences on the presence of two different structure states of the Mg-Ti system depending on the ratio of components. The deuterium temperature decrease can be caused by filamentary inclusions of insoluble component (titanium) atoms formed in the process of composite making and annealing, providing the deuterium diffusion from the sample at a lower temperature (channels for deuterium diffusion through the surface barrier). The deuterium desorption data obtained on the example of Mg-Ti, Mg-V and Mg-Zr composites provide support for further research into hydrogen storage materials containing low-soluble chemical elements in the alloy component. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3550

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

On topological properties of vacuum defects in lattice Yang-Mills theories

We study correlations between low-lying modes of the overlap Dirac operator and vacuum defects, center vortices and three-dimensional volumes, in lattice SU(2) gluodynamics. The low-lying modes are apparently sensitive to topological properties of the underlying gluon field configurations while the vacuum defects are crucial for the confinement. We find distinct positive correlation in both cases. In case of vortices the correlation is stronger

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

Performance of a fine-sampling electromagnetic calorimeter prototype in the energy range from 1 to 19 GeV

The fine-sampling electromagnetic calorimeter prototype has been experimentally tested using the 1-19 GeV/c tagged beams of negatively charged particles at the U70 accelerator at IHEP, Protvino. The energy resolution measured by electrons is Delta{E}/E=2.8%/\sqrt{E} + 1.3%. The position resolution for electrons is Delta{x}=3.1 + 15.4/sqrt{E} mm in the center of the cell. The lateral non-uniformity of the prototype energy response to electrons and MIPs has turned out to be negligible. Obtained experimental results are in a good agreement with Monte-Carlo simulations.Comment: Article is prepared for pdflatex using the class elsart. 13 pages, 9 figures in 11 PDF file

Comparison of Radiation Damage in Lead Tungstate Crystals under Pion and Gamma Irradiation

Studies of the radiation hardness of lead tungstate crystals produced by the Bogoroditsk Techno-Chemical Plant in Russia and the Shanghai Institute of Ceramics in China have been carried out at IHEP, Protvino. The crystals were irradiated by a 40-GeV pion beam. After full recovery, the same crystals were irradiated using a $^{137}Cs$ $\gamma$-ray source. The dose rate profiles along the crystal length were observed to be quite similar. We compare the effects of the two types of radiation on the crystals light output.Comment: 10 pages, 8 figures, Latex 2e, 28.04.04 - minor grammatical change

Correlation of Beam Electron and LED Signal Losses under Irradiation and Long-term Recovery of Lead Tungstate Crystals

Radiation damage in lead tungstate crystals reduces their transparency. The calibration that relates the amount of light detected in such crystals to incident energy of photons or electrons is of paramount importance to maintaining the energy resolution the detection system. We report on tests of lead tungstate crystals, read out by photomultiplier tubes, exposed to irradiation by monoenergetic electron or pion beams. The beam electrons themselves were used to measure the scintillation light output, and a blue light emitting diode (LED) was used to track variations of crystals transparency. We report on the correlation of the LED measurement with radiation damage by the beams and also show that it can accurately monitor the crystals recovery from such damage.Comment: 9 pages, 6 figures, LaTeX2