139 research outputs found
Spectroscopic diagnostic complex based on the magnetron sputtering device with a digital method of the data mining
A diagnostic complex based on a magnetron sputtering device is proposed for studying a magnetron discharge plasma parameter by optical emission spectroscopy, using two spectroscopic systems: photographic and photoelectric. Software for digital processing of the obtained emission spectra is developed. The results obtained by the two spectroscopic systems are compared
Study of low-pressure discharge by optical emission spectroscopy
The axial distribution of excited argon and tungsten atoms in plasma of direct current magnetron discharge in crossed fields have been analyzed by optical emission spectroscopy. The influence of discharge parameters (discharge current I, buffer gas pressure pAr and zone of discharge glow Δl) and excited states energy E* of studied particles on the axial distribution Ar and W atoms have been observed. The assumption about the excitation processes in the magnetron plasma is given.Методом оптичної емісійної спектроскопії проаналізовано аксіальний розподіл збуджених атомів аргону і вольфраму в плазмі постійного магнетронного розряду в схрещених E×H-полях. Виявлено вплив параметрів розряду (струм розряду Id, тиск буферного газу pAr і область світіння розряду Δl) та енергії збуджених станів E* досліджуваних частинок на розподіл атомів Ar і W уздовж осі розряду. Зроблено припущення про процеси збудження в магнетронній плазмі.Методом оптической эмиссионной спектроскопии проанализировано аксиальное распределение возбуж- денных атомов аргона и вольфрама в плазме постоянного магнетронного разряда в скрещенных E×H-полях. Обнаружено влияние параметров разряда (ток разряда Id, давление буферного газа pAr и область свечения разряда Δl) и энергии возбужденных состояний E* исследуемых частиц на распределение атомов Ar и W вдоль оси разряда. Сделано предположение о процессах возбуждения в магнетронной плазме
Digital identification of the emission spectrum lines of magnetron discharge
To obtain the qualitative and quantitative characteristics of the discharge plasma spectrum in the Python programming language, a multifunctional interactive GUI-application OSA (Optical Spectrum Analyzed) was created. The application allows you to download a digital image of the optical spectrum, automatically determine the wavelength of the selected spectral line and do elements interpretation.Для отримання якісних і кількісних характеристик спектра плазми розряду на мові програмування Python створено багатофункціональний діалоговий GUI-додаток OSA (Optical Spectrum Analyzed). Додаток дозволяє завантажити цифрове зображення оптичного спектра, в автоматичному режимі визначити довжину хвилі обраної спектральної лінії і виконати елементну інтерпретацію.Для получения качественных и количественных характеристик спектра плазмы разряда на языке программирования Python создано многофункциональное диалоговое GUI-приложение OSA (Optical Spectrum Analyzed). Приложение позволяет загрузить цифровое изображение оптического спектра, в автоматическом режиме определить длину волны выбранной спектральной линии и выполнить элементную интерпретацию
Multiplicity Distributions in Canonical and Microcanonical Statistical Ensembles
The aim of this paper is to introduce a new technique for calculation of
observables, in particular multiplicity distributions, in various statistical
ensembles at finite volume. The method is based on Fourier analysis of the
grand canonical partition function. Taylor expansion of the generating function
is used to separate contributions to the partition function in their power in
volume. We employ Laplace's asymptotic expansion to show that any equilibrium
distribution of multiplicity, charge, energy, etc. tends to a multivariate
normal distribution in the thermodynamic limit. Gram-Charlier expansion allows
additionally for calculation of finite volume corrections. Analytical formulas
are presented for inclusion of resonance decay and finite acceptance effects
directly into the system partition function. This paper consolidates and
extends previously published results of current investigation into properties
of statistical ensembles.Comment: 53 pages, 7 figure
Digital processing of optical emission spectra of magnetron sputtering plasma system
To solve the actual problem of the analysis of the sputtered particles radiation during coating deposition in a magnetron sputtering system, a digital technique was proposed for processing the emission spectra of the discharge plasma. A graphic OSA application has been created, which allows obtaining qualitative and quantitative characteristics of the magnetron discharge plasma. The obtained information about the distribution of excited particles along the direction parallel to the axis of the magnetron discharge permits one to control the mode of the discharge operation and, as a consequence, the properties of the deposited coatings.Для вирішення актуального завдання, пов'язаного з аналізом світіння розпилених частинок при нанесенні покриттів у магнетронно-розпилювальній системі, була запропонована цифрова методика обробки спектрів випромінювання плазми розряду. Створено графічний додаток OSA, що дозволяє отримати якісні та кількісні характеристики плазми магнетронного розряду. Отримана інформація про розподіл збуджених частинок вздовж напрямку, паралельного осі магнетронного розряду, дозволяє контролювати режим роботи розряду і, як наслідок, властивості нанесених покриттів.Для решения актуальной задачи, связанной c анализом свечения распыляемых частиц при нанесении покрытий в магнетронно-распылительной системе, была предложена цифровая методика обработки спектров излучения плазмы разряда. Создано графическое приложение OSA, позволяющее получить качественные и количественные характеристики плазмы магнетронного разряда. Полученная информация о распределении возбужденных частиц вдоль направления, параллельного оси магнетронного разряда, позволяет контролировать режим работы разряда и, как следствие, свойства наносимых покрытий
Anomalous Diffusion in Infinite Horizon Billiards
We consider the long time dependence for the moments of displacement < |r|^q
> of infinite horizon billiards, given a bounded initial distribution of
particles. For a variety of billiard models we find ~ t^g(q) (up to
factors of log t). The time exponent, g(q), is piecewise linear and equal to
q/2 for q2. We discuss the lack of dependence of this result
on the initial distribution of particles and resolve apparent discrepancies
between this time dependence and a prior result. The lack of dependence on
initial distribution follows from a remarkable scaling result that we obtain
for the time evolution of the distribution function of the angle of a
particle's velocity vector.Comment: 11 pages, 7 figures Submitted to Physical Review
The spectrum features of UHECRs below and surrounding GZK
The energy spectrum of UHECRs is discussed on the basis of the Yakutsk array
database analysis. In the region E=0.1 to 30 EeV the showers are detected under
trigger-500, while at energies above 30 EeV the whole acceptance area for
trigger-1000 is used in order to utilize all the data available in the region
of GZK cutoff.Comment: Invited talk at CRIS2004: GZK and surroundings, Catania, Italy,
31.05.04. To appear in Nucl. Phys. B Proc. Supp
Adiabatic description of nonspherical quantum dot models
Within the effective mass approximation an adiabatic description of
spheroidal and dumbbell quantum dot models in the regime of strong dimensional
quantization is presented using the expansion of the wave function in
appropriate sets of single-parameter basis functions. The comparison is given
and the peculiarities are considered for spectral and optical characteristics
of the models with axially symmetric confining potentials depending on their
geometric size making use of the total sets of exact and adiabatic quantum
numbers in appropriate analytic approximations
Consequences of temperature fluctuations in observables measured in high energy collisions
We review the consequences of intrinsic, nonstatistical temperature
fluctuations as seen in observables measured in high energy collisions. We do
this from the point of view of nonextensive statistics and Tsallis
distributions. Particular attention is paid to multiplicity fluctuations as a
first consequence of temperature fluctuations, to the equivalence of
temperature and volume fluctuations, to the generalized thermodynamic
fluctuations relations allowing us to compare fluctuations observed in
different parts of phase space, and to the problem of the relation between
Tsallis entropy and Tsallis distributions. We also discuss the possible
influence of conservation laws on these distributions and provide some examples
of how one can get them without considering temperature fluctuations.Comment: Revised version of the invited contribution to The European Physical
Journal A (Hadrons and Nuclei) topical issue about 'Relativistic Hydro- and
Thermodynamics in Nuclear Physics' guest eds. Tamas S. Biro, Gergely G.
Barnafoldi and Peter Va
Pion Freeze-Out Time in Pb+Pb Collisions at 158 A GeV/c Studied via pi-/pi+ and K-/K+ Ratios
The effect of the final state Coulomb interaction on particles produced in
Pb+Pb collisions at 158 A GeV/c has been investigated in the WA98 experiment
through the study of the pi-/pi+ and K-/K+ ratios measured as a function of
transverse mass. While the ratio for kaons shows no significant transverse mass
dependence, the pi-/pi+ ratio is enhanced at small transverse mass values with
an enhancement that increases with centrality. A silicon pad detector located
near the target is used to estimate the contribution of hyperon decays to the
pi-/pi+ ratio. The comparison of results with predictions of the RQMD model in
which the Coulomb interaction has been incorporated allows to place constraints
on the time of the pion freeze-out.Comment: 9 pages, 12 figure
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