1. Executions of the DKES code on the EELA-2 e-Infrastructure
A J. Rubio-Montero1, L. A. Flores1, E. Montes1,
F. Castejón1,2, M. Rodríguez-Pascual1, and R. Mayo1.
1CIEMAT(Spain)
2Lab. Nacional de Fusión (Spain)
Second EELA-2 Conference
Choroní, Venezuela. Nov 25th, 2009

2. Plasma behaviour simulation
High cost of a experimental discharge in a reactor
Complexity of simulating plasmas
Plasma Physics are related to Statistical Physics, Thermodynamics, Fluid, Kinetic and Chaos Theories.
1ms of complete simulation = several days in a TFlops machine like Mare Nostrum
Mathematical methods suitable to run on distributed environments as Langevin and Fokker-Plank equations, Monte Carlo, are used to solve:
Plasma-wall interaction
Neutral particle orbits
Transport
Massive Ray Tracing
Coil optimization
They could take advantage from the large amount of resources being already in Grid
Second EELA-2 Conference. Choroní, Venezuela. Nov 26th, 2009

3. Fusion Plasmas T D n
He4
17.6 MeV
How do D and T get plasma state and overcome Coulomb barrier that prevents the collisions and, hence, avoids the fusion?
Increasing its energy
Rising temperature (T)
Increasing velocity (kinetic energy, K)
Rising pressure
Injecting particles (density, n)
Plasma magnetically confined
Coil configuration (magnetic champ, |B|)
When they exceeds Lawson’s criterion reactor reaches ignition
Second EELA-2 Conference. Choroní, Venezuela. Nov 26th, 2009

4. NC transport Neoclassical (NC) transport is
a fundamental step of the complete simulation cycle of the behaviour of plasmas inside Fusion reactors.
caused by magnetic field inhomogeneities and by collisions
always present in all Fusion devices (stellarators and 3D tokamaks).
usually used to study the efficiency of a certain coil configuration before it is implemented.
DKES code (W.I. van Rij & S.P. Hirshman)
Obtain upper and lower bounds for the NC diffusion coefficients of a prescribed toroidal plasma equilibrium.
Widely accepted by the Fusion Community.
Applied to stellarators such as TJ-II, HSX, CHS, LHD, ATF, W7-AS; and to projected ones: V7-X, NCSX, QPS.
Developed in Fortran77 in 1989 for CRAY-1/X-MP
Second EELA-2 Conference. Choroní, Venezuela. Nov 26th, 2009

5. Main objectives Previous work This work Next work Final work
Achieved a Grid-enabled DKES version
This work
Calculate NC transport coefficients
Next work
DKEsG (DKE solver for Grid)  intra-application workflow
Filling a broad database with the complete [configuration - transport matrix – state] for several Fusion reactors  Grid simulation challenge
Final work
Complex application level workflows as
VMEC – DKEsG
FAFNER-2 / MaRaTra – DKEsG
ASTRA – DKEsG
Offer database as virtual observatory
Second EELA-2 Conference. Choroní, Venezuela. Nov 26th, 2009 5

6. Calculus of specific NC coefficients
Diffusion coefficients
Normalized coefficients returned by DKES depends of energy K:
Diffusion of n and T
Bootstrap current
Resistivity enhancement
Transport coefficients
Need >106 Dij to fit correctly the integral and solve only 1 Lij
Depends of n and T
Second EELA-2 Conference. Choroní, Venezuela. Nov 26th, 2009

7. Calculus performed for TJ-II
Applied to TJ-II Flexible Heliac
Sited at CIEMAT Madrid (Spain)
Began fully operational in 1997
1.5 m major plasma radius
DKEsG variable input, energy (K) dependant:
500 Normalized collisionallities (v)
9 electrostatic potentials (Erho)
DKEsG fixed inputs:
Fixed: 4cm plasma radius, 100 Legendre, 343 Fourier polynomials
Temperature and atomic mass set to 1.
Total :
4500 pairs processed distributed in jobs of 4 to 5 tasks  900 jobs
Distributed among 8 EELA-2 Grid sites  processed more than 50 jobs each.
1 job ~ mins. in a core Xeon 5160(3.0Ghz)  900 jobs > 45 hours
Real accumulated time: 90 h 30 m 21 s (middleware overhead included).
Total time spent: 2 h 30 m 21 s
Integral fitting was performed locally and spent <10 minutes.
Second EELA-2 Conference. Choroní, Venezuela. Nov 26th, 2009

8. Some results for TJ-II Diffusion of density and temperature
eF/T
L33
0.01
234816,6454
0.02
234880,8356
0.05
235398,8182
0.1
235978,7605
0.2
240174,4198
0.5
236702,9449 1
236769,6134 2
236797,3714 5
236925,5039
Normalized diffusion coefficient D^33 by normalized electrical field
NC transport coefficients L33 for T=1 KeV and M=1u
Second EELA-2 Conference. Choroní, Venezuela. Nov 26th, 2009

9. Next work?
DKEsG framework is preliminary implemented for GridWay (but not in DRMAA)
A first data challenge has been prepared to
get a broad range of NC diffusion/transport coefficients for TJ-II
be started the next December
Second EELA-2 Conference. Choroní, Venezuela. Nov 26th, 2009 9

10. Thanks for you attention?