Topic/Type: 2.2 Kinetic methods, Particle-In-Cell and Vlasov, Oral

Drift Kinetic Equation solver for Grid (DKEsG)

A.J. Rubio-Montero1, L.A. Flores1, F. Castej?n1, 2, E. Montes1, R. mayo1

2 Spanish Laboratory of Fusion

Neoclassical transport for stellarators devices can be calculated by means of two approaches: Monte Carlo (MC) methods [1] and Drift Kinetic Equation (DKE) solvers [2]. In last years, MC methods have been successfully deployed on Grid to solve a wide range of scientific challenges in many disciplines, among them Physics, but for this specific case only can offer an estimation of the perpendicular diffusive part of the transport matrix. On the other hand, DKE solvers provide correct quantitative results of the complete transport matrix, with the drawback of high computation time and memory consumption.

For the aforementioned reason, and as much other software for plasma fluids calculations, DKE solvers are usually executed in shared memory systems. Nevertheless, its parametric and sequential nature makes possible its division in minimal tasks that can run on cluster and Grid environments. In this way, a huge computational power can be accessed, so the physical problem can be easily overcome.

In this work, we present the porting process and further optimization to the Grid of the Drift Kinetic Equation solver code [2], a high throughput scientific application used in the TJ-II Flexible Heliac at National Fusion Laboratory, and the results obtained to the moment over the European Commission funded Project EELA-2 infrastructure [3].

To the previous, a new implemented module for calculating the transport coefficients from the outputs of the DKEs code, i.e. the diffusion coefficients, is also described. As a consequence, a wide range of both kind of coefficients will be presented, the calculation of which can be also performed for any other fusion device by changing the geometry module which rules the execution.

[1] V. Tribaldos. ?Monte Carlo estimation of neoclassical transport for the TJ-II stellarator?. Phys. Plasmas 8, 1229-1239 (2001)

[2] W.I. van Rij and S.P. Hirshman. ?Variational bounds for transport coefficients in three-dimensional toroidal plasmas?, Phys. Fluids B 1 (3), 563-569 (1989)

[3] The EELA-2 Project, available from