An algorithm for the calculation of three-dimensional ICRF fields in tokamak geometry

Smithe, D. N.; Colestock, P.; Kashuba, R.J.; Kammash, T.

doi:10.1088/0029-5515/27/8/012

Cited by 58 publications

(55 citation statements)

References 25 publications

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“…These methods are therefore applicable to all orders in k Ќ , where k Ќ ϭ2/ Ќ . Previous calculations [3][4][5][6][7][8][9][10][11][12][13][14] of rf wave propagation and heating in two dimensions ͑2-D͒ have relied on either cold plasma approximations or finite Larmor radius expansions (k Ќ Ӷ1) to treat the plasma response to the rf waves. These models are therefore limited to relatively long wavelengths and low cyclotron harmonics (lр2).…”

Section: Introductionmentioning

confidence: 99%

All-orders spectral calculation of radio-frequency heating in two-dimensional toroidal plasmas

et al. 2001

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Spectral calculations of radio-frequency (rf) heating in tokamak plasmas are extended to two dimensions (2-D) by taking advantage of new computational tools for distributed memory, parallel computers. The integral form of the wave equation is solved in 2-D without any assumption regarding the smallness of the ion Larmor radius (ρ) relative to the perpendicular wavelength (λ⊥). Results are therefore applicable to all orders in k⊥ρ, where k⊥=2π/λ⊥. Previous calculations of rf wave propagation and heating in 2-D magnetized plasmas have relied on finite Larmor radius expansions (k⊥ρ≪1) and are thus limited to relatively long wavelengths. In this paper, no such assumption is made, and we consider short wavelength processes such as the excitation and absorption of ion Bernstein waves in 2-D with k⊥ρ>1. Results show that this phenomenon is far more complex than simple one-dimensional plasma models would suggest. Other applications include fully self-consistent 2-D solutions for high-harmonic fast-wave heating in spherical tokamaks. These calculations require the storage and inversion of a very large, dense matrix, but numerical convergence can be improved by writing the plasma current in the laboratory frame of reference. To accurately represent the wave spectrum in this frame, the local plasma conductivity is corrected to first order in ρ/L, where L is the equilibrium scale length. This correction is necessary to ensure accuracy in calculating the wave spectrum and hence the fraction of power absorbed by ions and electrons.

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Section: Introductionmentioning

confidence: 99%

All-orders spectral calculation of radio-frequency heating in two-dimensional toroidal plasmas

et al. 2001

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“…(24). This approach, admittedly heuristic, is similar in spirit to the order reduction algorithm (ORA) [25], which simulates the excitation of IB waves by an equivalent power sink in the fourth order wave equations of the cold plasma approximation; and also to the model wave equations which have been used in Ref. [26] to evaluate launching of IB waves with an external antenna.…”

Section: Simulating Electron Landau Damping In Numerical Codesmentioning

confidence: 99%

“…There is, however, an important difference between the present case and the other two. In Refs [25] and [26] the model wave equations are used in domains where one expects a kind of 'singularity' of the solution. In the ORA the exact dispersion relation has a branching point at the mode conversion layer, which is suppressed in the model equations; it is, nevertheless, empirically well known that the ORA gives results in excellent agreement with those of the FLR wave equations, which describe mode conversion correctly.…”

Section: Simulating Electron Landau Damping In Numerical Codesmentioning

confidence: 99%

Dynamic small-scale self-focusing of a femtosecond laser pulse

Kandidov¹,

Kosareva²,

Shlenov³

et al. 2005

Quantum Electron.

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Absorption of ion Bernstein (IB) waves by electrons is investigated. These waves are excited by linear mode conversion in tokamak plasmas during fast wave (FW) heating and current drive experiments in the ion cyclotron range of frequencies. Near mode conversion, electromagnetic corrections to the local dispersion relation largely suppress electron Landau damping of these waves, which becomes important again, however, when their wavelength is comparable to the ion Larmor radius or shorter. The small Larmor radius wave equations solved by most numerical codes do not correctly describe the onset of electron Landau damping at very short wavelengths, and these codes, therefore, predict very little damping of IB waves, in contrast to what one would expect from the local dispersion relation. We present a heuristic, but quantitatively accurate, model which allows account to be taken of electron Landau damping of IB waves in such codes, without affecting the damping of the compressional wave or the efficiency of mode conversion. The possibilities and limitations of this approach are discussed on the basis of a few examples, obtained by implementing this model in the toroidal axisymmetric full wave code TORIC.

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“…Therefore, a considerable amount of work on antenna-plasma coupling in the ICRF has been performed [1][2][3][4][5][6][7][8][9][10]. Coupling of fast waves is considered in .…”

Section: Introductionmentioning

confidence: 99%

“…Both DIII-D and TFTR will use this type of antenna, and it is the preferred choice for most of the current and planned machines. The fields in a recessed cavity are quite different from those of the conventional loop modelled in Refs [1][2][3][4][5][6][7]. The main difference is that the side walls of the cavity squeeze the magnetic field lines of the wave field, affecting the spectrum and causing significant differences in the loading characteristics.…”

Section: Introductionmentioning

confidence: 99%

The Applications of a Liquid Crystal Panel for the 15 Gbyte Optical Disk Systems

Ohtaki¹,

Murao²,

Ogasawara³

et al. 1999

Jpn. J. Appl. Phys.

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A numerical code has been developed to calculate the loading of a cavity loop antenna in threedimensional geometry. The loading of the cavity is calculated for fast wave and ion Bernstein wave coupling and compared with the loading of a conventional loop antenna. For fast waves, the cavity loading increases with increasing edge density, while the conventional loop loading is less sensitive to the edge density but shows a slight decrease of loading because of a steeper density gradient. For ion Bernstein waves, the two types of antenna behave similarly; however, in contrast to the loading for fast waves, the loading for ion Bernstein waves increases with decreased edge density and a steeper density gradient.

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An algorithm for the calculation of three-dimensional ICRF fields in tokamak geometry

Cited by 58 publications

References 25 publications

All-orders spectral calculation of radio-frequency heating in two-dimensional toroidal plasmas

All-orders spectral calculation of radio-frequency heating in two-dimensional toroidal plasmas

Dynamic small-scale self-focusing of a femtosecond laser pulse

The Applications of a Liquid Crystal Panel for the 15 Gbyte Optical Disk Systems

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