Cylindrical source

[fnovais11]

Hello.
Is there an easy way to make an infinite cylindrical source in openmc? I am assuming it would be similar to your ring source, but I am having a hard time trying to modify it.

I have a geometry like this:
c1=openmc.ZCylinder(x0=0.0, y0=0.0, r=300.0, boundary_type="reflective")
c2=openmc.ZCylinder(x0=0.0, y0=0.0, r=100.0)

breeding_zone = +c2 & - c1
cell_bz=openmc.Cell(region = breeding_zone)
cell_bz.fill = mixed_mat

I want to place an axial source inside.

Thanks,
Felipe.

[shimwell]

Interesting source.

From the docs I can see that the Z arg accepts univariates which might do what you are after
https://docs.openmc.org/en/stable/pythonapi/generated/openmc.stats.CylindricalIndependent.html#openmc.stats.CylindricalIndependent

It might also be worth plotting the OpenMC source with https://github.com/fusion-energy/openmc_source_plotter

[fnovais11]

I am trying to modify the ring source example:

z_values = openmc.stats.Discrete([0], [1]) angle = openmc.stats.Uniform(a=0.0, b=2 * 3.14159265359) my_source.space = openmc.stats.CylindricalIndependent(.....

My confusion is what z_values = openmc.stats.Discrete([0], [1] actually represents.

I have also been trying to use openmc_source_plotter but it fails and kills my kernel.

[shimwell]

The openmc.stats.Discrete([0], [1]) sets the z value to 0 for 100% of the particles

Setting openmc.stats.Discrete([42], [1]) sets the z value to 42cm for 100% of the particles.

Lists are also acceptable so you could do [10,20], [0.5, 0.5] for 50% of the particles to be at z=10 and 50% at z=20

However you want a different Univariate to the Discrete Univariate. I think you want a Uniform distribution of Z, R and phi values

Perhaps something like this is what you are after

openmc.stats.CylindricalIndependent(
      r=openmc.stats.Uniform(a=0, 100),  # 0 cm to 100 cm radius of cylinder
      phi=openmc.stats.Uniform(a=0, b=2*3.141592653589793238),  # 0 radians to 2 pi radians
      z=openmc.stats.Uniform(a=-10, b=10), # -10 cm to 10cm in height
      origin=(0.0, 0.0, 0.0),
)

For the openmc_source_plotter it just got updated a few days ago but it does need the latest development version of openmc to work. If it still crashes with the new versions of both packages would you mind sending me any error messages. Thanks