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Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 CONT

Ray effects. An artefact related to the method of discrete ordinates, known as the “ray effect,” is illustrated … For a two-dimensional case, which is easier to represent, we have considered the problem of a point source in a purely absorbent medium. The arrows represent the directions of the discrete ordinates, and the squares represent the meshing of the spatial discretisation. Because neutrons are obliged to travel along the discrete directions, we note that only the shaded mesh elements will “see” a certain neutron flux, since the others cannot receive any neutrons. The resulting lines are clearly visible on the diagram. In practical cases, the artefact is never so clear, since the sources are spread out and there is scattering, but it can still be identified. The only way to improve this situation is to refine the angular meshing.  1, record 1, English, - ray%20effect

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 CONT

Effets de raies. Un artefact lié à la méthode des ordonnées discrètes, connu sous le terme d'«effet de raies» est illustré […] Pour un cas à deux dimensions, plus facile à représenter, nous avons considéré le cas d’une source ponctuelle, dans un milieu purement absorbant […] Puisque les neutrons sont assujettis à voyager selon les directions discrètes […] seules les mailles grisées «verront» un certain flux neutronique, les autres ne pouvant pas recevoir de neutrons. [Des] raies […] en résultent […]  2, record 1, French, - effet%20de%20raies

Record 1,  Textual support,  Spanish