New Benchmarks from Tokamak Experiments for Theoretical Calculations of the Dielectronic Satellite Spectra of Helium-like Ions

Dielectronic satellite spectra of helium-like argon, recorded with a high-resolution X-ray crystal spectrometer at the National Spherical Torus Experiment, were found to be inconsistent with existing predictions resulting in unacceptable values for the power balance and suggesting the unlikely existence of non-Maxwellian electron energy distributions. These problems were resolved with calculations from a new atomic code. It is now possible to perform reliable electron temperature measurements and to eliminate the uncertainties associated with determinations of non-Maxwellian distributions

ICRF plasmas for fusion reactor applications

The ICRF plasma production technique is considered as a promising alternative tool for the following applications in the present and next generation superconducting fusion devices: (i) Wall conditioning in the presence of permanent high magnetic field; (ii) Assistance for the tokamak start-up at low inductive electric field (E₀ ~ 0.3 V/m in ITER); (iii) Target dense plasma production (ne ≥ 10¹⁹ m⁻³) in stellarators. The paper presents a review of the ICRF plasma production technique and its applications in the present-day tokamaks and stellarators. The perspective of the alternative technique applications in ITER is analyzed in the frame of 0-D plasma modeling.ВЧ-метод утворення плазми (ICRF) розглядається як перспективний альтернативний інструмент для таких застосувань у сучасних й майбутніх надпровідних термоядерних установках: (i) ВЧ-чистка стінок в присутності постійного сильного магнітного поля; (ii) Aсистування старту токамака у режимі слабого вихрового електричного поля (E₀~ 0.3 В/м в ITERі); (iii) Створення густої вихідної плазми (ne ≥ 10¹⁹ м⁻³) в стелараторах. Зроблено огляд ВЧ-метода створення плазми та його застосування у сучасних токамаках й стелараторах. В рамках моделювання 0-D плазмовим кодом проведено аналіз перспективності використання даного метода в ITERі.ВЧ-метод создания плазмы (ICRF) рассматривается как перспективный альтернативный инструмент для следующих применений в современных и будущих сверхпроводящих термоядерных установках: (i) ВЧ-чистка стенок в присутствии постоянного сильного магнитного поля; (ii) Aссистирование старту токамака в режиме слабого вихревого электрического поля (E₀ ~ 0.3 В/м в ITERе); (iii) Создание плотной исходной плазмы (ne ≥ 10¹⁹ м⁻³) в стеллараторах. Сделан обзор ВЧ-метода создания плазмы и его применений в современных токамаках и стеллараторах. В рамках моделирования 0-D плазменным кодом проведен анализ перспективности использования данного метода в ITERе

ATOMIC PHYSICS FOR HOT PLASMAS

This report treats some aspects of how to obtain and apply main atomic characteristics responsible for the intensities and satellite structures of spectral lines in hot plasmas

Excitation cross sections for Li-like ions of beryllium and boron

We report on calculation of electron-impact excitation cross sections for Li-like ions of boron and beryllium. The data were produced with a number of modern methods in atomic collision theory, such as convergent close-coupling, K-matrix and Coulomb-Born-exchange. The results obtained are compared with other calculations and available expermental data, and the recommended cross sections for all transitions between atomic terms with principal quantum numbers n ≤ 4 are presented as tables of fitting parameters

Excitation Collision Strengths, Cross Sections and Rate Coefficients for OV, SiXI, FeXXIII, MoXXXIX by Electron Impact(1s22s2 -1s22s2p-1s22p2 Transitions)

Excitation collision strengths, cross sections and rate coefficients by electron impact are calculated for the transitions among the Is^22s^2, Is^22p^2, 1 s^22s2p levels of Be-like system of OV, SiXI, FeXXlll and MoXXXIX ions by Coulomb-Born approximation with exchange including relativistic effect and configuration interactions. The theoreticai method for calculation is described and the results are compared with the previous calculations. Numerical data and comparison are presented in Tables as well as in Figures. Two kinds of fitting formulae for cross sections and rate coefficients are discussed

Dielectronic satellite spectra of hydrogen-like titanium (Ti XXII)

High resolution spectra of the Ly ..cap alpha../sub 1/ and Ly ..cap alpha../sub 2/ lines of hydrogenlike titanium, TiXXII, and the associated dielectronic satellites which are due to transitions 1snl-2pnl with n greater than or equal to 2, have been observed from tokamak discharges with auxiliary ion cyclotron heating (ICRH) with central electron temperatures of 2 keV and central electron densities of 8 x 10/sup 13/ cm/sup -3/ on the Princeton Large Torus (PLT). The data have been used for a detailed comparison with theoretical predictions based on the Z - expansion method and Hartree - Fock calculations. The results obtained with the Z - expansion method are in excellent agreement with the observed spectral data except for minor discrepancies between the theoretical and experimental wavelengths of 0.0003 A for the n = 2 satellites and of 0.0001 A for the separation of the Ly ..cap alpha../sub 1/ and Ly ..cap alpha../sub 2/ lines. Very good agreement with the experimental data is also obtained for the results from the Hartree - Fock calculations though somewhat larger discrepancies (approx. = 0.0009 A) exist between experimental and theoretical wavelengths which are systematically too small. The observed spectra are used for diagnosis of the central ion and electron temperatures of the PLT discharges and for a measurement of the dielectronic recombination rate coefficient of TiXXII

H-LIKE AND He-LIKE SPECTRUM IN LOW AND HIGH DENSITY PLASMAS

Les raies satellites des raies de résonances du Phosphore à un et deux électrons ont été observées dans le dispositif DELPHIN (plasma créé par laser) au Lebedev Institute de Moscou. L'analyse de certains domaines du spectre est effectuée en construisant un spectre théorique qui est ajusté au spectre observé. Différents modèles du plasma (équilibre thermodynamique local ou équilibre collisionnel radiatif) doivent être considérés pour obtenir un bon ajustement.Satellite lines of the Phosphorus H-like and He-like resonance lines have been observed in the DELPHIN plasma laser device at the Lebedev Institute in Moscow. Analysis of some wavelength ranges is carried out by adjusting a theoretical spectrum to the observed one. Different plasma conditions (collisional radiative equilibrium or local thermodynamical equilibrium) are assumed to obtain a good fit of various parts of the observed spectrum. A fitting of the whole spectrum may be used to obtain a density diagnostic