J. Vaclavik

Publication List Details

Period

1974 - 2008

Number

281

Co-Authors

A drift-kinetic Semi-Lagrangian 4D code for ion turbulence simulation (2006)

Grandgirard, V., Brunetti, M., Bertrand, P., Besse, N., Garbet, X., Ghendrih, P., ...

A new code is presented here, named Gyrokinetic SEmi-LAgragian (GYSELA) code, which solves 4D drift-kinetic equations for ion temperature gradient driven turbulence in a cylinder (r, theta, z). The...

Global gyrokinetic stability of pressure-gradient-driven electromagnetic modes in tokamaks with regions of low shear (2005)

Ganesh, R., Vaclavik, J.

Tokamaks with large pressure gradients (alpha(max)) formed in regions of weak magnetic shear are shown to be susceptible to novel, low-n, global, kinetic, electromagnetic modes with a toroidal mode...

Fine-scale structures and negative-density regions: Comparison of numerical methods for solving the advection equation (2005)

Brunetti, M., Grandgirard, V., Bertrand, P., Sauter, O., Vaclavik, J., Villard, L.

A common feature of the Vlasov equation is that it develops fine-scale filamentation as time evolves, as observed, for example, in global nonlinear simulations of the ion-temperature-gradient...

A spectral global gyrokinetic approach to plasma linear microinstability analysis (2005)

Angelino, P., Bottino, A., Falchetto, G. L., Ganesh, R., Vaclavik, J., Villard, L.

With the term microinstabilities, we indicate a class of plasma drift waves such as the ion temperature gradient (ITG) mode, the trapped electron mode (TEM), and the electromagnetic Alfvenic ion...

Full radius linear and nonlinear gyrokinetic simulations for tokamaks and stellarators: zonal flows, applied E x B flows, trapped electrons and finite beta (2004)

Villard, L., Allfrey, S. J., Bottino, A., Brunetti, M., Falchetto, G. L., Grandgirard, V., ...

The aim of this paper is to report on recent advances made in global gyrokinetic simulations of ion temperature gradient (ITG) modes and other microinstabilities. The nonlinear development and...

A full radius gyrokinetic stability analysis for large aspect ratio finite-beta tokamaks (2004)

Ganesh, R., Angelino, P., Vaclavik, J., Villard, L.

Linear, fully gyrokinetic, full radius (global), large aspect ratio studies of Alfven-ion temperature gradient mode (AITG) or kinetic ballooning modes or beta-induced Alfven eigenmodes considering...

A semi-Lagrangian code for nonlinear global simulations of electrostatic drift-kinetic ITG modes (2004)

Brunetti, M., Grandgirard, V., Sauter, O., Vaclavik, J., Villard, L.

A semi-Lagrangian code for the solution of the electrostatic drift-kinetic equations in straight cylinder configuration is presented. The code, CYGNE, is part of a project with the long term aim of...

Simulations of global electrostatic microinstabilities in ASDEX Upgrade discharges (2004)

Bottino, A., Peeters, A. G., Sauter, O., Vaclavik, J., Villard, L.

Electrostatic microinstabilities in ion internal barrier (ITB) and H-mode discharges of the ASDEX Upgrade tokamak [O. Gruber, R. Arslanbekov, C. Atanasiu , Nucl. Fusion 41, 1369 (2001)] have been...

Global-gyrokinetic study of finite beta effects on linear microinstabilities (2003)

Falchetto, G. L., Vaclavik, J., Villard, L.

Electromagnetic microinstabilities in tokamak plasmas are studied by means of a linear global eigenvalue numerical code. Ion dynamics is described by the gyrokinetic equation, so that finite ion...

Radial electric fields and global electrostatic microinstabilities in tokamaks and stellarators (2002)

Villard, L., Bottino, A., Sauter, O., Vaclavik, J.

The effects of applied radial electric fields on the stability of ion temperature gradient (ITG) modes and trapped particle modes are investigated with a full radius gyrokinetic formulation in both...

Effect of E x B flows on global linear ion temperature gradient modes (2001)

Maccio, M., Vaclavik, J., Villard, L.

Strong electric fields generate an ExB rotation of the equilibrium plasma. Experiments have shown that this effect could lower the anomalous transport in tokamaks. The study of the effect of these...

Gyrokinetic modelling of macro-instabilities in high performance tokamak plasmas (2001)

Jaun, A., Fasoli, A., Testa, D., Vaclavik, J., Villard, L.

The modelling of Alfvenic instabilities is discussed from the point of view of mode-conversion, showing how the development of the theory affects the predictions as the limitations of the models are...

Stability of Alfven eigenmodes in optimized tokamaks (2000)

Jaun, A., Fasoli, A., Vaclavik, J., Villard, L.

Alfven eigenmodes (AEs) with intermediate toroidal mode numbers are modelled using the global gyrokinetic PENN code to determine the stability of high performance tokamak discharges in the presence...

Applicability of the ballooning transform to trapped ion modes (2000)

Falchetto, G. L., Vaclavik, J., Maccio, M., Brunner, S., Villard, L.

In the scope of the study of low-frequency electrostatic microinstabilities in tokamak plasmas, attention has been focused on the effect of trapped ions. The ballooning transform has been applied to...

Global Alfven eigenmode stability in thermonuclear tokamak plasmas (1999)

Jaun, A., Fasoli, A., Vaclavik, J., Villard, L.

Relying on the good agreement observed between the gyrokinetic PENN model and the low toroidal mode number n damping measurements from JET, the stability of Alfven eigenmodes (AEs) is predicted for...

On resonance absorption and continuum damping (1998)

Jaun, A., Appert, K., Hellsten, T., Vaclavik, J., Villard, L.

The absorption of power is studied with fluid and gyrokinetic plasma models, when Alfven resonances provide for a weak damping in a partially standing wave field. Examples chosen in slab and toroidal...

Finite element approach to global gyrokinetic Particle-In-Cell simulations using magnetic coordinates (1998)

Fivaz, M., Brunner, S., De Ridder, G., Sauter, O., Tran, T. M., Vaclavik, J., ...

We present a fully-global linear gyrokinetic simulation code (GYGLES) aimed at describing the unstable spectrum of the ion-temperature-gradient modes in toroidal geometry. We formulate the...

Global approach to the spectral problem of microinstabilities in a cylindrical plasma using a gyrokinetic model (1998)

Brunner, S., Vaclavik, J.

Considering the spectral problem of microinstabilities in a curved system, methods for solving the global gyrokinetic equation are presented for the simple case of a cylindrical plasma. They prove to...

Global approach to the spectral problem of microinstabilities in tokamak plasmas using a gyrokinetic model (1998)

Brunner, S., Fivaz, M., Tran, T. M., Vaclavik, J.

A solution to the full two-dimensional eigenvalue problem of electrostatic microinstabilities in a tokamak plasma is presented in the framework of gyrokinetic theory. The approach is the...

Alfven frequency modes and global Alfven eigenmodes (1997)

Villard, L., Vaclavik, J.

The spectrum of n = 0 Alfven modes is calculated analytically and numerically in cylindrical and toroidal geometries. It includes global Alfven eigenmodes (GAEs) and surface modes (SMs) of the fast...

Stability of global drift-kinetic Alfven eigenmodes in DIII-D (1997)

Jaun, A., Vaclavik, J., Villard, L.

Global Alfven eigenmodes are studied using two different models for the plasma and the results compared with the instability threshold measured experimentally. Fluid-resistive models predict that...

Kinetic Alfven eigenmodes in a hot tokamak plasma (1997)

Jaun, A., Appert, K., Fasoli, A., Hellsten, T., Lister, J., Vaclavik, J., ...

Kinetic effects such as finite ion Larmor excursions and resonant Landau interactions are studied in the toroidicity Alfven eigenmode (TAE) range of frequencies. A new Alfven mode conversion...

Stabilization of ion-temperature-gradient-driven tokamak modes by magnetic-field gradient reversal (1997)

Fivaz, M., Tran, T. M., Appert, K., Vaclavik, J., Parker, S. E.

Global gyrokinetic particle simulations have been used to search tokamak configurations which are stable again st the ion-temperature-gradient - driven (ITG) modes commonly held responsible for the...

Interferometric study of a machine tool (1996)

Höfling, R., Vaclavik, J., Neugebauer, R.

Higher demands on precise machining require advanced measuring techniques. Point sensors are well established in this field, but thermal analyses necessitate expensive reference structures made from...

Global Marginal Stability of Taes in the Presence of Fast Ions (1995)

Villard, L., Brunner, S., Vaclavik, J.

The global stability of toroidicity induced Alfven eigenmodes (TAEs) in the presence of fast ions in realistic tokamak fusion-grade plasmas is analysed with a global, perturbative approach. Volume...

Alfven wave heating and stability (1995)

Villard, L., Brunner, S., Jaun, A., Vaclavik, J.

Alfven waves in fusion plasmas play an important role in a number of situations. First, in Alfven Wave Heating (AWH) schemes. Second, both theory and experiment have demonstrated the existence of...

Global Waves in Resistive and Hot Tokamak Plasmas (1995)

Jaun, A., Appert, K., Vaclavik, J., Villard, L.

Maxwell's equations are solved in a toroidal axisymmetric plasma. The numerical method implemented in the PENN code is based on a formulation in terms of the electromagnetic potentials and a...

Gyrokinetic Approach to the Propagation of Electromagnetic-Waves in Nonuniform Bounded Plasma Slabs (1994)

Sauter, O., Vaclavik, J.

A new code, SEMAL, has been developed which solves the linearized Vlasov-Maxwell wave equations to all orders in Larmor radii. Arbitrary density and temperature profiles as well as non-uniform...

Dielectric Tensor Operator of Hot Plasmas in Toroidal Axisymmetrical Systems (1993)

Brunner, S., Vaclavik, J.

Kinetic theory is used to develop equations describing dynamics of small-amplitude electromagnetic perturbations in toroidal axisymmetric plasmas. The closed Vlasov-Maxwell equations are first solved...

Nonlocal Effects of Alpha-Particles on Icrf Heating (1992)

Sauter, O., Vaclavik, J.

A model based on the linearized Vlasov-Maxwell equations, taking into account the non-local interactions of particles due to their finite Larmor radii, has been developed. Assuming an inhomogeneous...

Theory of Plasma-Heating by Low-Frequency Waves - Magnetic Pumping and Alfven Resonance Heating (1991)

Vaclavik, J., Appert, K.

The present status of the theory of plasma heating by low frequency waves is reviewed from a unified point of view based on the concept of the dielectric tensor operator.

Equilibrium Gradient Effects in the Theory of Alfven-Wave Heating (1991)

Jaun, A., Vaclavik, J., Appert, K.

An explicit expression for the local power absorption density in a uniformly-magnetized slab plasma is derived from the Vlasov-Maxwell equations, taking into account density and temperature...