openmc.Surface

class openmc.Surface(surface_id=None, boundary_type='transmission', albedo=1.0, name='')[source]

An implicit surface with an associated boundary condition.

An implicit surface is defined as the set of zeros of a function of the three Cartesian coordinates. Surfaces in OpenMC are limited to a set of algebraic surfaces, i.e., surfaces that are polynomial in x, y, and z.

Parameters:

surface_id (int, optional) – Unique identifier for the surface. If not specified, an identifier will automatically be assigned.
boundary_type ({'transmission', 'vacuum', 'reflective', 'periodic', 'white'}, optional) – Boundary condition that defines the behavior for particles hitting the surface. Defaults to transmissive boundary condition where particles freely pass through the surface. Note that only axis-aligned periodicity is supported around the x-, y-, and z-axes.
albedo (float, optional) – Albedo of the surfaces as a ratio of particle weight after interaction with the surface to the initial weight. Values must be positive. Only applicable if the boundary type is ‘reflective’, ‘periodic’, or ‘white’.
name (str, optional) – Name of the surface. If not specified, the name will be the empty string.

Variables:

boundary_type ({'transmission', 'vacuum', 'reflective', 'periodic', 'white'}) – Boundary condition that defines the behavior for particles hitting the surface.
albedo (float) – Boundary albedo as a positive multiplier of particle weight
coefficients (dict) – Dictionary of surface coefficients
id (int) – Unique identifier for the surface
name (str) – Name of the surface
type (str) – Type of the surface

bounding_box(side)[source]

Determine an axis-aligned bounding box.

An axis-aligned bounding box for surface half-spaces is represented by its lower-left and upper-right coordinates. If the half-space is unbounded in a particular direction, numpy.inf is used to represent infinity.

Parameters:

side ({'+', '-'}) – Indicates the negative or positive half-space

Returns:

numpy.ndarray – Lower-left coordinates of the axis-aligned bounding box for the desired half-space
numpy.ndarray – Upper-right coordinates of the axis-aligned bounding box for the desired half-space

clone(memo=None)[source]

Create a copy of this surface with a new unique ID.

Parameters:: memo (dict or None) – A nested dictionary of previously cloned objects. This parameter is used internally and should not be specified by the user.
Returns:: clone – The clone of this surface
Return type:: openmc.Surface

abstractmethod evaluate(point)[source]

Evaluate the surface equation at a given point.

Parameters:: point (3-tuple of float) – The Cartesian coordinates, \((x',y',z')\), at which the surface equation should be evaluated.
Returns:: Evaluation of the surface polynomial at point \((x',y',z')\)
Return type:: float

static from_hdf5(group)[source]

Create surface from HDF5 group

Parameters:: group (h5py.Group) – Group in HDF5 file
Returns:: Instance of surface subclass
Return type:: openmc.Surface

static from_xml_element(elem)[source]

Generate surface from an XML element

Parameters:: elem (lxml.etree._Element) – XML element
Returns:: Instance of a surface subclass
Return type:: openmc.Surface

is_equal(other)[source]

Determine if this Surface is equivalent to another

Parameters:: other (instance of openmc.Surface) – Instance of openmc.Surface that should be compared to the current surface

normalize(coeffs=None)[source]

Normalize coefficients by first nonzero value

Added in version 0.12.

Parameters:: coeffs (tuple, optional) – Tuple of surface coefficients to normalize. Defaults to None. If no coefficients are supplied then the coefficients will be taken from the current Surface.
Return type:: tuple of normalized coefficients

abstractmethod rotate(rotation, pivot=(0.0, 0.0, 0.0), order='xyz', inplace=False)[source]

Rotate surface by angles provided or by applying matrix directly.

Added in version 0.12.

Parameters:

rotation (3-tuple of float, or 3x3 iterable) – A 3-tuple of angles \((\phi, \theta, \psi)\) in degrees where the first element is the rotation about the x-axis in the fixed laboratory frame, the second element is the rotation about the y-axis in the fixed laboratory frame, and the third element is the rotation about the z-axis in the fixed laboratory frame. The rotations are active rotations. Additionally a 3x3 rotation matrix can be specified directly either as a nested iterable or array.
pivot (iterable of float, optional) – (x, y, z) coordinates for the point to rotate about. Defaults to (0., 0., 0.)
order (str, optional) – A string of ‘x’, ‘y’, and ‘z’ in some order specifying which rotation to perform first, second, and third. Defaults to ‘xyz’ which means, the rotation by angle \(\phi\) about x will be applied first, followed by \(\theta\) about y and then \(\psi\) about z. This corresponds to an x-y-z extrinsic rotation as well as a z-y’-x’’ intrinsic rotation using Tait-Bryan angles \((\phi, \theta, \psi)\).
inplace (bool) – Whether or not to return a new instance of Surface or to modify the coefficients of this Surface in place. Defaults to False.

Returns:

Rotated surface

Return type:

openmc.Surface

to_xml_element()[source]

Return XML representation of the surface

Returns:: element – XML element containing source data
Return type:: lxml.etree._Element

abstractmethod translate(vector, inplace=False)[source]

Translate surface in given direction

Parameters:

vector (iterable of float) – Direction in which surface should be translated
inplace (bool) – Whether or not to return a new instance of this Surface or to modify the coefficients of this Surface.

Returns:

Translated surface

Return type:

instance of openmc.Surface