Topic/Type: 2.1 MHD, EHD & other fluid methods, Oral

Development of a discrete ordinates radiation transport code in AMR

C. Garc?a-Fern?ndez, P. Velarde

Instituto de Fusi?n Nuclear, Universidad Polit?cnica de Madrid, Madrid, Spain

In a number of different problems involving high energy density plasmas, such as ICF or laboratory
astrophysics, radiation plays a relevant role. For an accurate study of the hydrodynamics
of these situations, it has been developed the ARWEN [1] code, a 2D Adaptive Mesh Refinement
(AMR) code for hydrodynamic simulations of plasmas that includes multigroup radiation
transport using diffusion synthetic acceleration (DSA).
The aim of this work is to present the new advances in the radiation transport solver. The code
solves the multigroup Bolztmann equation in 2D using a discrete ordinates approximation. The
new solver presents some important new features that have been recently added: the parallelization
of the AMR structure, the inclusion of temporal dependence in the radiation equation and
the development of TSA acceleration scheme together with the already existent DSA.
To show the performance of these features, different studies on the influence of these parameters
have been carried out. A new parallelization scheme for AMR based in Boxlib Library
([2]) has been developed and its scalability studied. The advantages and disadvantages of the
different acceleration schemes are evaluated, showing that DSA is the best option in most cases.
In order to check the reliability of the code, several benchmark problems are also presented,
such as [3], and new ones are proposed and compared with other transport approximations such
as diffusion and M1 ([4]).
Finally, a study on the influence of the radiation transport in fast ignition cone-shell is presented,
showing the need to take into account the role of the radiation in the implosion process.

[1] Ogando F., Velarde P., JQSRT 71, 541, 2001

[2] Rendleman C.A., Beckner V. E. et al., Comp. Vis. Sci., 3, 147-157, 2000

[3] Su B., Olson G.L., JQSRT 69, 279, 1999

[4] M.Gonzalez, C.Garcia-Fernandez, P. Velarde Annals of Nucl. Ener., 36, 7, 886-895, 2009