Rather than start a new topic, I have a related question to this one - but it is much simpler.
I want to compute keff for a hollow cylinder. This is to prepare a criticality safety table.
I created a hollow cylinder like so:
Instantiate Surfaces
B1 = openmc.ZPlane(surface_id=1, z0= 0, name=‘B1’)
B2 = openmc.ZPlane(surface_id=2, z0= 14, name=‘B2’)
R1 = openmc.ZCylinder(surface_id=11, x0=0, y0=0, r=5.0, name=‘R1’)
R2 = openmc.ZCylinder(surface_id=12, x0=0, y0=0, r=7.0, name=‘R2’)
B1.boundary_type = ‘vacuum’
B2.boundary_type = ‘vacuum’
R1.boundary_type = ‘vacuum’
R2.boundary_type = ‘vacuum’
Instantiate Cells
cellF1 = openmc.Cell(cell_id=101, name=‘cellF1’)
Use surface half-spaces to define regions
cellF1.region = +B1 & -B2 & +R1 & -R2
settings_file.source = openmc.Source(space=openmc.stats.Point(xyz=(6,0,7)))
And it fails with the:
ERROR: More than 95% of external source sites sampled were rejected. Please
check your external source definition.
As a first cut (and creating sources in cylindrical geometry looks complicated) I wanted to test simply placing a source at a point in the cylinder material.
But I am thinking that maybe my geometry definition does not work. Do I need to fill space in the model and create an internal empty cell in the middle of the hollow cylinder?