Assigning an Energy Source to a Complex-Shaped Cell

User Support
1

I have encountered a problem assigning an energy source to a cell of complex shape. I have a cell in the form of a hexagonal prism filled with a mixture of materials, and it is necessary for the energy source to exactly match this prism in volume and spatial position.

In this regard, I have the following questions:

Is it possible to directly assign an energy source to a specific cell or material?

What methods or approaches do you use to assign an energy source to complex geometric shapes?

I would be very grateful for your help.

This is the method I use::::

# Source and geometry parameters
radius_hexagon = 234 / 2  # Half the distance between opposite flat sides of the hexagon (in millimeters)
height = tail_height      # Height of the tail section (in millimeters)

# Number of point sources to create
num_sources = 10000  

# Define a function to check if a point is inside the hexagon
def is_point_in_hexagon(x, y, radius):
    # This function checks if the given point (x, y) is inside a regular hexagon centered at (0, 0) with the given radius
    qx = abs(x)
    qy = abs(y)
    if qy > np.sqrt(3) * radius / 2 or qx > radius:
        return False
    if np.sqrt(3) * qx + qy <= np.sqrt(3) * radius:
        return True
    return False

# Generate points inside the hexagonal prism using rejection sampling
x_points = []
y_points = []
z_points = []

while len(x_points) < num_sources:
    x_try = np.random.uniform(-radius_hexagon, radius_hexagon)
    y_try = np.random.uniform(-radius_hexagon, radius_hexagon)
    if is_point_in_hexagon(x_try, y_try, radius_hexagon):
        x_points.append(x_try)
        y_points.append(y_try)
        z_points.append(np.random.uniform(0, height))

# Create a list of IndependentSource objects for point sources
source_particles = []

for i in range(num_sources):
    my_source = openmc.IndependentSource()
    my_source.space = openmc.stats.Point((x_points[i], y_points[i], z_points[i]))  # Create a point source at the specified location
    my_source.angle = openmc.stats.Isotropic()  # Set isotropic distribution
    my_source.particle = 'photon'  # Set particle type to 'photon'
    my_source.energy = openmc.stats.Discrete([1.1732e6, 1.3325e6], [0.5, 0.5])  # Energy in keV, two energies with equal probabilities
    my_source.strength = 2.55e+13 / num_sources  # Set the strength of each point source
    source_particles.append(my_source)

# Set the generated sources directly in the settings
settings.source = source_particles

# Export simulation settings to an XML file
settings.export_to_xml()

Is this the right approach? How do you do it? Are there any simpler methods?