Kinetics of impurity charge-state distributions in tokamak plasmas

Shurygin, V. A.

doi:10.1134/1.1768581

Cited by 12 publications

(25 citation statements)

References 28 publications

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“…The temperature profiles of non-excited atoms of plasma (1) The urgency of the study of USP interaction with atoms in divertor plasma is connected with the diagnostic problem to determine the concentration of neutrals [10] that strongly impacts the interpretation of the charge state distribution as well as the particle transport. [11][12][13][14][15][16][17][18] The advantage of USP application is based on two facts:…”

Section: F I G U R Ementioning

confidence: 99%

Absorption of ultrashort electromagnetic pulses in plasma with inhomogeneous distribution of density and temperature

Astapenko

Sakhno

Lisitsa

2019

Contributions to Plasma Physics

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The analysis of influence of the inhomogeneous distribution of temperature and density of atoms on the probability of absorption of ultrashort electromagnetic pulses in plasma is carried out. A specific example of divertor plasma of tokamaks and absorption in the Lyman series (at the Ly-line) is considered. It is shown that the absorption probability may exceed relative populations of excited levels in divertor plasma by several orders of magnitude. The influence of the pulse duration on the probability of excitation of an atomic level is considered. The results suggest a possibility of a sharp increase in a fluorescence signal under the action of an ultrashort pulse. K E Y W O R D Sabsorption, dense plasma, ultrashort electromagnetic pulse

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Section: F I G U R Ementioning

confidence: 99%

Absorption of ultrashort electromagnetic pulses in plasma with inhomogeneous distribution of density and temperature

Astapenko

Sakhno

Lisitsa

2019

Contributions to Plasma Physics

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“…Also, one has to add matching conditions at the points z c as the continuity of the "flow in z-space" and equality of the "flow" to zero at the points z = 0 and z = A. Sometimes, the distribution over of heavy impurities over ionization states may be described by a Gaussian function whose parameters are described by simple dynamic equations [14][15][16].…”

Section: T (S)mentioning

confidence: 99%

Reduced Models of Impurity Seeded Edge Plasmas

Morozov¹

2008

Contrib. Plasma Phys.

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The reduced descriptions of the distribution of impurities over ionization states, radiation losses and plasma dynamics are reviewed. Two and three most important ion approximation for light impurities and continuous descriptions of heavy impurities are discussed. Reduced descriptions of atomic processes like ionization, photo-and dielectronic recombination rates as well as of radiation abilities are proposed. As it shown, thermal forces, final relaxation times of impurity distributions over ionization states, charge-exchange and opacity effects must be taken into account in reduced models, especially for ITER problems. Linear and nonlinear stages of the radiation-condensation mode as well as some aspects of disruptions and noble gas injection into tokamak plasmas are analyzed with the reduced models.

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“…͑1͒. 37,38 Then, R k and S k are essentially the conditional probabilities of kinetics and define, in turn, the conditional probabilities of charge state distributions. 36 This "random walk" of ions over the entire spectrum of ͑Z+1͒ charge states due to atomic processes has been identified as a charge state kinetics, presenting a typical Markovian process of "birth" ͑ionization͒ and "death" ͑recombina-tion͒ with continuous time and discrete states.…”

Section: ͑1͒mentioning

confidence: 99%

“…[34][35][36] It has allowed us to find that the ionization and recombination processes govern an impurity motion of a special type, in particular, a diffusion of ions in a space of charge states, 34 which can be represented by a single equation of the Fokker-Plank type. 38 Thus, these studies have shown that the motion of impurity charge state distributions across the magnetic field in tokamaks can consistently be interpreted in terms of the transport of charge states providing an interesting alternative to a conventional understanding. 37,38 Then, R k and S k are essentially the conditional probabilities of kinetics and define, in turn, the conditional probabilities of charge state distributions.…”

Section: ͑1͒mentioning

confidence: 99%

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Analytical approach to impurity transport studies: Charge state dynamics in tokamak plasmas

Shurygin

2006

Physics of Plasmas

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Ionization and recombination of plasma impurities govern their charge state kinetics, which is imposed upon the dynamics of ions that implies a superposition of the appropriate probabilities and causes an impurity charge state dynamics. The latter is considered in terms of a vector field of conditional probabilities and presented by a vector charge state distribution function with coupled equations of the Kolmogorov type. Analytical solutions of a diffusion problem are derived with the basic spatial and temporal dimensionless parameters. Analysis shows that the empirical scaling DA∝ne−1 [K. Krieger, G. Fussmann, and the ASDEX Upgrade Team, Nucl. Fusion 30, 2392 (1990)] can be explained by the ratio of the diffusive and kinetic terms, DA∕(nea2), being used instead of diffusivity, DA. The derived time scales of charge state dynamics are given by a sum of the diffusive and kinetic times. Detailed simulations of charge state dynamics are performed for argon impurity and compared with the reference modeling.

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Kinetics of impurity charge-state distributions in tokamak plasmas

Cited by 12 publications

References 28 publications

Absorption of ultrashort electromagnetic pulses in plasma with inhomogeneous distribution of density and temperature

Absorption of ultrashort electromagnetic pulses in plasma with inhomogeneous distribution of density and temperature

Reduced Models of Impurity Seeded Edge Plasmas

Analytical approach to impurity transport studies: Charge state dynamics in tokamak plasmas

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