How to set the direction of the neutron source?

User Support
1

Hi ereryone,
I’m newer to coding, I want to know how to set the direction of the base circle of the cylinder source?

The following is part of my code, I want to design a disc perpendicular to the y-axis as the source, but I don’t know how to set it.

source = openmc.IndependentSource()
r_dist   = openmc.stats.Uniform(a=0, b=5)        
phi_dist = openmc.stats.Uniform(a=0, b=2*math.pi) 
z_dist   = openmc.stats.Discrete([0], [1])      
origin   = (0.0, 15.0, 0.0)                      
direction_vector = (0.0, -1.0, 0.0)              
cylindrical_dist = openmc.stats.CylindricalIndependent(r=r_dist, phi=phi_dist, z=z_dist, origin=origin) 
...
2

The source.angle is perhaps what you are looking for as it controls the “Angular distribution of source sites” anbd accepts an openmc.stats.UnitSphere as a value

https://docs.openmc.org/en/stable/pythonapi/generated/openmc.IndependentSource.html?highlight=openmc.source%20

3

yes, i will try your suggestion, thank you very much for your reply!

4

Hi, is there a way to orient a cylindrical light source to face the Y-axis direction?

I’m referring to the positioning of the cylindrical circle of the sampling location, not the uvw angle of the created particles.