Nanostructured NaBiTe2 thin films and their properties

Multicomponent chalcogenide-contained films are appeared as an interesting nonequilibrium thermodynamic system. Structural and electric field-induced characteristics of these materials are not investigated. The paper reports for the first time experimental data on growth, morphology and electrophysical properties of NaBiTe2 thin films. The investigated samples were condensed on glass substrates under deposition rate 0.1-0.5 nm/s at T = 300 K and vacuum level P = 10-3 Pa. Metal-semiconductor (MS) Cr/NaBiTe2 structures were prepared for electrical studies. Room-temperature time dependence of the current flowing through the investigated structure under applied electric field is also discussed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2054

Experimental testing bench for the diagnostics of plasma generated by pulsed guns with the dielectric surface breakdown

The experimental testing bench “ETB-PG” was designed to study the operation of plasma guns. The constructional design of plasma guns with replaceable dielectric operating on the surface sparkover basis has been proposed. Discharge currents and voltages under atmospheric and vacuum conditions have been determined. The two types of discharges were detected in the pressure range varying from the atmospheric value to 10⁻⁵ Torr. An experimental Paschen curve has been plotted. A statistical dependence of the types of discharges on the number of pulses, the pressure in the chamber, and the breakdown voltage has been established. The results of optical studies of the plasma flow generated by plasma guns in the vacuum of 2∙10⁻⁴ to 2∙10⁻⁵ Torr have been presented. The propagation velocity of the plasma flow in axial and radial directions has been measured. The glow time of the injected plasma was determined for different types of the discharges. The spectrograms of the composition and degree of the plasma ionization have been obtained.Створено експериментальний науково-дослідний стенд «ЕНДС-ПГ» для дослідження роботи плазмових гармат. Запропонована конструкція плазмових гармат зі змінним діелектриком, що працюють за принципом електричного пробою по поверхні. Визначені струм та напруга розряду в атмосферних та вакуумних умовах. Виявлено два типи розряду в діапазоні тиску від атмосферного до 10⁻⁵ Торp. Побудована експериментальна крива Пашена. Встановлена статистична залежність типів розряду від кількості імпульсів, тиску в камері та напруги пробою. Представлено результати оптичних досліджень плазмового потоку, що створюється плазмовими гарматами у вакуумі від 2∙10⁻⁴ дo 2∙10⁻⁵ Торp. Оцінено швидкість розповсюдження плазмового потоку в аксіальному та радіальному напрямках. Визначено час свічення плазми, що інжектується при різних типах розряду. Отримано спектрограми складу та ступеню іонізації плазми.Создан экспериментальный научно-исследовательский стенд «ЭНИС-ПП» для исследования работы плазменных пушек. Предложена конструкция плазменных пушек со сменным диэлектриком, работающих с перекрытием по поверхности. Определены токи и напряжения разряда в атмосферных и вакуумных условиях. Обнаружено два типа разряда в диапазоне давлений от атмосферного до 10⁻⁵ Торр. Построена экспериментальная кривая Пашена. Установлена статистическая зависимость типов разрядов от количества импульсов, давления в камере и напряжения пробоя. Представлены результаты оптических исследований плазменного потока, создаваемого плазменными пушками в вакууме от 2∙10⁻⁴ дo 2∙10⁻⁵ Торр. Оценена скорость распространения плазменного потока в аксиальном и радиальном направлениях. Определено время свечения инжектируемой плазмы при разных типах разряда. Получены спектрограммы состава и степени ионизации плазмы

Experimental study of injector based on the spark source with titanium cathode saturated with hydrogen

The results of experimental study of short-pulse proton injector for various variants of construction of pulse spark ion source are considered. The experimental results of study of regimes of both ignition and discharge support within the source with stabilized pulse feeding (~10 μs, 5 Hz). Of special concern the increasing of the cathode electrode lifetime. The results ofmeasurements ofboth absolute and partial (in spices) density ofion beam are presented.Представлені результати іспитів короткоімпульсного інжектора протонів для різних варіантів виконання конструкції імпульсного іскрового джерела. Приводяться експериментальні результати відпрацьовування оптимальних режимів порушення і підтримки розряду в джерелі зі стабілізованим імпульсним живлення (~ 10 мкс, 5 Гц).Представлены результаты испытаний короткоимпульсного инжектора протонов для различных вариантов выполне- ния конструкции импульсного искрового источника. Приводятся экспериментальные результаты отработки оптимальных режимов возбуждения и поддержания разряда в источнике со стабилизированным импульсным питанием (~ 10 мкс, 5 Гц)

Measurement of the Ds lifetime

We report precise measurement of the Ds meson lifetime. The data were taken by the SELEX experiment (E781) spectrometer using 600 GeV/c Sigma-, pi- and p beams. The measurement has been done using 918 reconstructed Ds. The lifetime of the Ds is measured to be 472.5 +- 17.2 +- 6.6 fs, using K*(892)0K+- and phi pi+- decay modes. The lifetime ratio of Ds to D0 is 1.145+-0.049.Comment: 5 pages, 2 figures submitted to Phys. Lett.

Confirmation of the Double Charm Baryon Xi_cc+ via its Decay to p D+ K-

We observes a signal for the double charm baryon Xi_cc+ in the charged decay mode Xi_cc+ -> p D+ K- to complement the previously reported decay Xi_cc+ -> Lambda_c K- pi+ in data from SELEX, the charm hadro-production experiment (E781) at Fermilab. In this new decay mode we observe an excess of 5.62 events over an expected background estimated by event mixing to be 1.38+/-0.13 events. The Poisson probability that a background fluctuation can produce the apparent signal is less than 6.4E-4. The observed mass of this state is (3518+/-3)MeV/c^2, consistent with the published result. Averaging the two results gives a mass of (3518.7+/-1.7)MeV/c^2. The observation of this new weak decay mode confirms the previous SELEX suggestion that this state is a double charm baryon. The relative branching ratio Gamma(Xi_cc+ -> pD+K-)/Gamma(Xi_cc+ -> Lambda_c K- pi+) = 0.36+/-0.21.Comment: 11 pages, 6 included eps figures. v2 includes improved statistical method to determine significance of observation. Submitted to PL

Hadronic Production of Lambda_c from 600 GeV/c pion, sigma and proton beams

We present data from Fermilab experiment E781 (SELEX) on the hadroproduction asymmetry for anti-Lambda_c compared to Lambda_c+ as a function of xF and pt2 distributions for Lambda_c+. These data were measured in the same apparatus using incident pi-, sigma- beams at 600 GeV/c and proton beam at 540 GeV/c. The asymmetry is studied as a function of xF. In the forward hemisphere with xF >= 0.2 both baryon beams exhibit very strong preference for producing charm baryons rather than charm antibaryons, while the pion beam asymmetry is much smaller. In this energy regime the results show that beam fragments play a major role in the kinematics of Lambda_c formation, as suggested by the leading quark picture.Comment: 6 pages, 5 figures (postscript), RevTeX, submitted to Phy. Rev. Let

First Observation of the Cabibbo-suppressed Decays Xi_c+ -> Sigma+ pi- pi+ and Xi_c+ -> Sigma- pi+ pi+ and Measurement of their Branching Ratios

We report the first observation of two Cabibbo-suppressed decay modes, Xi_c+ -> Sigma+ pi- pi+ and Xi_c+ -> Sigma- pi+ pi+. We observe 59+/-14 over a background of 87, and 22+/-8 over a background of 13 events, respectively, for the signals. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600GeV/c Sigma- beam. The branching ratios of the decays relative to the Cabibbo--favored Xi_c+ -> Xi- pi+ pi+ are measured to be B(Xi_c+ -> Sigma+ pi- pi+)/B(Xi_c+ -> Xi- pi+ pi+) = 0.48+/-0.20, and B(Xi_c+ -> Sigma- pi+ pi+)/B(Xi_c+ -> Xi- pi+ pi+) = 0.18+/-0.09, respectively. We also report branching ratios for the same decay modes of the Lambda_c+ relative to Lambda_c+ -> p K- pi+.Comment: 15 pages, 5 figures, version 2 as accepted in PL

Total Cross Section Measurements With π- , Σ- And Protons On Nuclei And Nucleons Around 600 Gev/c

Total cross sections for Σ- and π- on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600GeV/c . These measurements were performed with a transmission technique in the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron-nucleus cross sections and on results for σtot(Σ-N) and σtot(π-N) , which were deduced from nuclear cross sections. © 2000 Elsevier Science B.V.57901/02/15277312Langland, J.L., (1995) Ph.D. Thesis, , University of IowaKleinfelder, S.A., (1988) IEEE Trans. Nucl. Sci., 35 (1)Dersch, U., (1998) Ph.D. Thesis, HeidelbergBiagi, S.F., (1981) Nucl. Phys. B, 186, pp. 1-21Bellettini, G., (1966) Nucl. Phys., 79, pp. 609-624Schiz, A.M., (1980) Phys. Rev. D, 21, pp. 3010-3022Murthy, P.V.R., (1975) Nucl. Phys. B, 92, pp. 269-308Caso, C., (1998) Eur. Phys. J. C, 3. , http://pdg.lbl.gov/1998/contents_plots.html, and data on total cross sections from computer readable filesSchiz, A.M., (1979) Ph.D. Thesis, , Yale University(1973) Landolt Börnstein Tables, 7. , Springer editionEngler, J., (1970) Phys. Lett. B, 32, pp. 716-719Babaev, A., (1974) Phys. Lett. B, 51, pp. 501-504Glauber, R.J., (1959) Boulder Lectures, pp. 315-413Franco, V., (1972) Phys. Rev. C, 6, pp. 748-757Karmanov, V.A., Kondratyuk, L.A., (1973) JETP Lett., 18, pp. 266-268Burq, J.P., (1983) Nucl. Phys. B, 217, pp. 285-335Gross, D., (1978) Phys. Rev. Lett., 41, pp. 217-220Beznogikh, G.G., (1972) Phys. Lett. B, 39, pp. 411-413Vorobyov, A.A., (1972) Phys. Lett. B, 41, pp. 639-641Foley, K.J., (1967) Phys. Rev. Lett., 19, pp. 857-859Fajardo, L.A., (1981) Phys. Rev. D, 24, pp. 46-65Jenni, P., (1977) Nucl. Phys. B, 129, pp. 232-252Breedon, R.E., (1989) Phys. Rev. Lett. B, 216, pp. 459-465Amos, N., (1983) Phys. Rev. Lett. B, 128, pp. 343-348Amaldi, U., (1977) Phys. Rev. Lett. B, 66, pp. 390-394Amos, N., (1985) Nucl. Phys. B, 262, pp. 689-714Akopin, V.D., (1977) Sov. J. Nucl. Phys., 25, pp. 51-55Amirkhanov, I.V., (1973) Sov. J. Nucl. Phys., 17, pp. 636-637Foley, K.J., (1969) Phys. Rev., 181, pp. 1775-1793Apokin, V.D., (1976) Nucl. Phys. B, 106, pp. 413-429Burq, J.P., (1982) Phys. Lett. B, 109, pp. 124-127Dakhno, L.G., (1983) Sov. J. Nucl. Phys., 37, pp. 590-598Kazarinov, M., (1976) Sov. Phys. JETP, 43, pp. 598-606De Jager, C.W., (1974) At. Data Nucl. Data Tables, 14, pp. 479-508Donnachie, A., Landshoff, P.V., (1992) Phys. Lett. B, 296, pp. 227-232Lipkin, H., (1975) Phys. Rev. D, 11, pp. 1827-1831Barnett, R.M., (1996) Phys. Rev. D, 54, pp. 191-192Carroll, A.S., (1979) Phys. Lett. B, 80, pp. 423-427Badier, J., (1972) Phys. Lett. B, 41, pp. 387-39

Total Cross Section Measurements with pi-, Sigma- and Protons on Nuclei and Nucleons around 600 GeV/c

Total cross sections for Sigma- and pi- on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600GeV/c. These measurements were performed with a transmission technique adapted to the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron-nucleus cross sections and on results for sigma_tot(Sigma- N) and sigma_tot(pi- N), which were deduced from nuclear cross sections.Comment: 42 pages, submitted to Nucl.Phys.