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Minsk April 20131 Количественный нейтронный текстурный анализ Д.И.Николаев, Т.А. Лычагина Лаборатория нейтронной физики Объединенный институт ядерных исследований Дубна, Россия
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Minsk April 20132 Statement of the QTA problem Neutron diffraction for the QTA Applications Perspectives
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Minsk April 20133 Statement of the QTA problem (nonuniqueness)
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Minsk April 20134 Nonuniqueness(Statement of the QTA problem)
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Minsk April 20135 Applications of ODF
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Minsk April 20136 Texture applications
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Minsk April 20137 Experimental Setup
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Minsk April 20138 SKAT spectrometer sample detector Klaus goniometer collimator
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Minsk April 20139 Характеристики СКАТ
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Minsk April 201310 Суммарный спектр (19×72=1368) МА21
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Minsk April 201311 Соответствующие полные ПФ Min= 0.0 (65, 245) Max 11.48 (0, 310) Min= 0.0 (0, 0) Max 3.24 (85, 125) Min= 0.0 (0, 335) Max 1.81 (55, 115)
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Minsk April 201312 Традиционная обработка данных Intensity= Background=
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Minsk April 201313 Обработка данных Локальное фитирование
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Minsk April 201314 Результаты обработки данных Параметры и их ошибки Параметры фона Интенсивности ПФ и их ошибки
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Minsk April 201315 Кристаллографически эквивалентные ПФ. Фон
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Minsk April 201316 Conventional X-ray technique
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Minsk April 201317 РКУ прессование МА21 (маршрут А)
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Minsk April 201318 РКУ прессование МА21 (маршрут С)
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Minsk April 201319 Изменение текстуры при различных маршрутах рку прессования
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Minsk April 201320 Marble study
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Minsk April 201321
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Minsk April 201322 Texture and internal strain
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Minsk April 201323 Biological application
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Minsk April 201324
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Minsk April 201325 After modernization
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Minsk April 201326 2θ-related parameters d maxBest resolution Δd/d Secondary beam path 2θ = 65° 6.5 Å / 13.6 Å*6.2·10-31.10 m 2θ = 90° 5.0 Å / 10.3 Å*5.0·10-31.00 m 2θ = 135° 3.8 Å / 7.9 Å*3.1·10-30.95 m
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Minsk April 201327 Выводы Нейтронный текстурный анализ позволяет измерять полные полюсные фигуры Качество измеренных полюсных фигур существенно выше измеряемых традиционным рентгеновским методом. Нейтронный текстурный анализ позволяет измерять крупнозернистые образцы, что практически принципиально не достижимо для традиционного рентгеновского метода.
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Minsk April 201328 Спасибо за внимание !!!
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Minsk April 201329
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Minsk April 201330
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Minsk April 201331
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Minsk April 201332 Sum spectra of Mg(4.5%Al 1%Zn)
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Minsk April 201333 Data processing Local spectra fit
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Minsk April 201334 Data processing results Parameters and uncertainties Background parameters Pole figure value and uncertainty
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Minsk April 201335 Pole figures, errors, amplitude errors
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Minsk April 201336 Crystallographically equivalent pole figures. Background
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Minsk April 201337 Problems Adjust methods to experimental errors Self consistency of measured PFs. QTA from Laue diagrams (SANS) Statistical verification of component functions
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Minsk April 201338
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Minsk April 201339
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Minsk April 201340
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Minsk April 201341
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Minsk April 201342
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Minsk April 201343 Quantitative Texture Analysis (QTA) Micromechanics Crystallography Integral geometry Distributions and statistics on manifolds
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Minsk April 201344 Series expansion method
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Minsk April 201345 Advantages and disadvantages General Fast Easy to compute Phys. Properties Negative values Ghost peaks Sensitivity of C coefficients Large PF number for sharp textures and low symmetry materials Zero region Positivity Regularisation
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Minsk April 201346 Discrete ( WIMF, ADC, Maximum entropy )
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Minsk April 201347 Advantages and disadvantages General Number of PF is not growing Positivity Ghost peaks Convergence is not proven Hard to compute Phys. Properties Unclear number of iterations
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Minsk April 201348 Components
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Minsk April 201349 Advantages and disadvantages Parameters have clear physical meaning Number of PF is not growing and small Positivity Hard to find parameters in general Sensitive to self consistency of the PFs Choice of component number
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Minsk April 201350 Experimental pole figures
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Minsk April 201351 Choice of the component positions
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Minsk April 201352 Recalculated pole figures
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Minsk April 201353 Series expansion and components
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Minsk April 201354 ODF sections
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Minsk April 201355 Texture simulation
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Minsk April 201356 Averaging details Model functions
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Minsk April 201357 Young’s modulus of the textured polycrystalline sample
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Minsk April 201358 Error estimation
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Minsk April 201359 Motivation for error study Experimental errors - instrumental - sample - process (flux, exposure time)
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