## thermal flux through a part of surface and particlar direction

Discussion on physics, models and calculation methods
Ana Jambrina
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### Re: thermal flux through a part of surface and particlar direction

I might not be clear before:
- The idea is to define a current surface detector which track particles crossing in/out the surface - regardless whether the particle interacts inside the surface, and limit the spatial domain of integration of the surface by adding a collision detector (of type cell or mesh - super-imposed). The surface detector estimates are integrated over the “reduced” surface, energy and all directions - by “reduced” I mean region define by the original surface with boundaries defined by the mesh and/or cell detector.
- Collision detectors, e.g. mesh detectors are volumetric in 3D geometries. Meaning, its definition should involved a real volume. Setting in a curvilinear detector an equal minimum and maximum radius would not define a zero volume (theoretically that corresponds with a line).
- I will try to exemplify this capability:

Code: Select all

``````       surf 100   cube   0 0 0  50
surf 200   cube   0 0 0 100
surf 300   py     50
surf 400   py     25

cell 50  0 material_1  -100
cell 60  0 material_2   100 -200
cell 70  0 outside     -200

det   1    ds 100 1
det   2    ds 300 1
det   3    ds 100 1  dx -25 25 1
det   4    ds 300 1  dx -25 25 1
det   5    ds 300 1  dx -25 25 1 dz -25 25 1
det   6    ds 400 1  dc 50
``````
where: detector (1) evaluates the outward current over surface 100 (all faces defining the cube); detector (2) evaluates the outward current over surface 300 (infinite plane at y = 50 with x/z limits of integration, INFTY, defined by the geometry boundaries); detector (3) same as detector (1) but the region of interest is limited to x in [-25, 25] (meaning the contribution of the cube faces at y = -50, 50 with x in [-25, 25]); detector (4) same as detector (2) but the region of interest is limited to x in [-25, 25] (with z limits of integration INFTY, defined by the geometry boundaries); detector (5) analogously to detector (2) and (4) but the region of interest is defined at plane y =50 with x in [-25, 25] and z in [-25,25]; finally, detector (6) evaluates the outward current over surface 400 (infinite plane at y = 25) limited by cell 50: area between x in [-50, 50] and z in [-50, 50].

Note that dx -25 25 1 Cartesian detector defines a volume: x in [-25,25] y in [-INFTY, INFTY], z in [-INFTY, INFTY] - y and z ultimately defined by the 3D (model) geometry boundaries. As well, dc 50 cell detector defines a volume: within surface 100, x in [-50 50], y in [-50 50] and z in [-50 50].

Results are integrated over space, energy and all directions (particles/s). Keep in mind that the integration domain has been re-defined when normalise by the detector area.
- Ana