Plasma Physics

FAFNER2

This code is being developed jointly with the staff from the National Fusion Laboratory (CIEMAT, Spain) in the framework of the EGEE-III Project. It is an official EGI application and was present in the EELA-2 portfolio of applications.

FAFNER2 is a 3D code adapted to the TJ-II helical axis stellarator from the original one developed by Lister at Max Planck IPP [1]; it simulates by Monte Carlo methods the Neutral Beam Injection (NBI) technology (a key heating method for most of the fusion experiments worldwide).

To the date, FAFNER2 has been usually run at CIEMAT by means of a batch mode on a shared memory of a Cray architecture, but it has been also translated to MPI. From this point of view, FAFNER2 would not only mean a new code ported to the Grid, but it opens a new strategy for the fusion community. Since it deals with the heating method for the fusion devices, it is able to be coupled to ion kinetic transport codes, i.e. ISDEP [2], in a way that the outputs from FAFNER2 will be the input for the latter.

Such a complex workflow, the development of which could be done by means of Kepler Project tools [3], is of interest for both fusion and grid communities. Into this framework, the FAFNER2 porting process to the grid is the first step of a more ambitious work.

The steps of the transformation from a SHMEM over MIPS to a Grid over a X86 technology has already been achieved as well as some performance and portability gains obtained on each step of the process.

[1] G.G. Lister. "A fully 3-D Neutral Beam Injection Code Using Monte Carlo Methods". Technical Report 4/222, Max Planck IPP, Garching, Germany (1985)
[2] F. Castejón et al. "Ion kinetic transport in the presence of collisions and electric field in the TJ-II ECRH plasmas". Plasma Phys. Control. Fusion 49, 753-776 (2007)
[3] The Kepler Project, available from http://kepler-project.org/

This work has already been presented at:
HPCS2010 (Caen, June 2010)
PDP2010 (Pisa, February 2010)
EELA-2 Conference (Choroní, November 2009)
ICNSP09 (Lisbon, October 2009)
EGEE09 Conference (Barcelona, September 2009)
RSEF Biennial Conference (Ciudad Real, September 2009)
EGEE User Forum 2009 (Catania, March 2009)
EELA-2 Conference (Bogota, February 2009)
EUFORIA JRA1 Meeting (Madrid, January 2009)
EGEE08 Conference (Istanbul, September 2008)

PROCTR

This code is being developed jointly with the staff from the National Fusion Laboratory (CIEMAT, Spain).

Proctr [1] is a 1.5-D predictive transport code that solves particle and energy transport equations [2]. The power balance equation is solved by automatically considering the particle transport as ambipolar, so the electric field calculated in the code is only due to the diamagnetic effect.

To the date, Proctr has been usually run at CIEMAT by means of a batch mode on a series of old machines and several x86 architectures. Sci-Track has ported and optimized the code to the current clusters.

[1] Castejón F. et al 1999 Transport evaluation in TJ-II plasmas 12th IAEA Conf. on Stellarators, Madison, WI, 1999
[2] Howe H.C. 1990 Physics models in the toroidal transport code Proctr Report ORNL/TM-11521 Oak Ridge National Laboratory, TN

 

 

DKEsG

This code is being developed jointly with the staff from the National Fusion Laboratory (CIEMAT, Spain) in the framework of the EELA-2 Project

Neoclassical transport for the TJ-II stellarator can be calculated by means of two approaches: Monte Carlo (MC) methods and Drift Kinetic Equation solvers (DKEs). In last years, MC methods have been successfully deployed on Grid especially to solve physics challenges, but for this case only can offer an estimation of the perpendicular diffusive part of the transport matrix. On the other hand, DKES [1] provide correct quantitative results of the complete transport matrix, with the drawback of high computation time and memory consumption.

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.

Because of DKES base software calculates all the monoenergetic diffusion coefficients per each parameter provided (radius of the magnetic surface, temperature, density, ions or electrons...), and these parameters can get a wide range of values in TJ-II, when a scientist performs a bit more precise analysis he is growing dramatically his need of computational resources. Then, to achieve valuable results, final DKEsG software implementation must be able to use the maximum of available resources even if they are heterogeneous (local systems and remote resources in several Grid infrastructures). So, after complete gridification of DKES, the software has to guarantee the following aims:

  • Compatible with diverse hardware architectures and UNIX operating systems.
  • Compatible with generic submission systems as local resource managers and Grid middleware through standard compliant services such as DRMAA or SAGA.
  • Post-processing and caching of intermediate results and showing them graphically to user.

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

This work has already been presented at:
GISELA KoM (San Luis Potosí, September 2010)
PDP2010 (Pisa, February 2010)
EELA-2 Conference (Choroní, November 2009)
ICNSP09 (Lisbon, October 2009)
EGEE09 Conference (Barcelona, September 2009)
EGEE User Forum (Catania, March 2009)
EELA-2 Conference (Bogota, February 2009)
EUFORIA JRA1 Meeting (Madrid, January 2009)

gGEM

This code has been jointly implemented with the Max-Planck-Institut für Plasmaphysik (Germany)

The study of core turbulence represents a key line of research in fusion plasmas. By adding collisions and electromagnetic induction to the parallel dynamics of the standard six-moment toroidal model, it is possible to study the gyrofluid electromagnetic phenomena in the context of edge turbulence with the GEM code [1]. Currently, the code describes the fluctuation free-energy conservation in a gyrofluid model by means of the polarization equation which relates the ExB flow and eddy energy to the combinations of the potential, the density, and the perpendicular temperature. To do so, supercomputers have been used only to date. gGEM demonstrates its feasibility as a cluster application on a production environment based on any kind of distributed memory, enhancing in this way its scope.

[1] Bruce D. Scott. "Free-energy conservation in local gyrofluid models". Physics of Plasmas 12, 102307 (2005)

This work has already been presented at:
PDP2010 (Pisa, February 2010)
ICNSP09 (Lisbon, October 2009)
EGEE09 Conference (Barcelona, September 2009)
EUFORIA JRA1 Meeting (Madrid, January 2009)

FastDEP

This code has been developed jointly with the National Fusion Laboratory (CIEMAT, Spain).

FAFNER2 and ISDEP are two Monte Carlo codes that solve the Neutral Beam Injection process and the plasma dynamics in a fusion device respectively. In this work, the new application FastDEP has been developed for solving NBI fast ion distribution and the steady state distribution functions by plugging both codes. In addition, from the results provided, toroidal rotation and its influence on the confinement, slowing down time of the NBI ions, escape distribution and confinement itself can also be estimated in many fusion facilities.

The performance results have been obtained by using Montera, a framework developed for achieving Grid efficient executions of Monte Carlo applications on the Grid.

Vashra-T

This code has been developed by the the Distributed Systems Architecture Group - Universidad Complutense de Madrid (Spain) and the National Fusion Laboratory (CIEMAT, Spain). The ICT Division supports its implemetation and impact.

The ASTRA code [1] solves diffusion equations subject to magnetic fusion plasmas. This code is being run on a shared memory machine at CIEMAT, which makes it difficult to scale. To begin with, after analyzing the different external modules called by ASTRA, a Ray Tracing one was chosen for Grid execution. In this way, all jobs related to Ray Tracing will run onto the Grid, increasing their number and the module's level of parallelism. Actual ASTRA executions take seconds but it is often required that different, computationally demanding modules are called from ASTRA. One such modules is Truba [2], a Ray Tracing code that calculates the trajectories and power deposition of a pre-set number of rays, in which the microwave beam shot inside the reactor is decomposed. The Vashra-T framework, which consists in a set of scripts and machine configurations, is responsible of performing the Ray Tracing onto the Grid when asked by ASTRA.

[1] G.V. Pereverzev, P.N. Yushmanov. "ASTRA-Automated System for TRansport Analysis". Max-Plack Institut für Plasmaphysik, IPP-Report, IPP 5/98 (2002)
[2] M. Tereshchenko et al., 30th EPS Conf., ECA 27 A (2003)

This work has already been presented at:
EGEE09 Conference (Barcelona, September 2009)

CAnELA

This code has been jointly developed with the Atomic Spectroscopy Group of the Faculty of Physics, Universidad Complutense de Madrid (Spain)

The Código para el Analisis Espectral de Líneas Atómicas (CAnELA, Code for the Spectral Analysis of Atomic Lines) has been implemented in MATLAB¿ and it is able to either fit spectral lines by means of a spline methodology or by simulating a Voigt profile, convolution of a Lorentzian and Gaussian profiles. It is actually an evolution of the firsty implemented code LINEFIT, which was developed at the Atomic Spectroscopy Group of the UCM, and can provide to the users in an automatic way of several physical parameters of every line such as relative intensity, widht Gaussian and Lorentzian components, etc. In addition, from these parameters, CAnELA can obtain absolute values for transition probabilities or Stark widths.

A manual of CAnELA can be found here.