openmc.stats.Watt

class openmc.stats.Watt(a=988000.0, b=2.249e-06)

Watt fission energy spectrum.

The Watt fission energy spectrum is characterized by two parameters \(a\) and \(b\) and has density function \(p(E) dE = c e^{-E/a} \sinh \sqrt{b \, E} dE\).

Parameters:

• a (float) – First parameter of distribution in units of eV

• b (float) – Second parameter of distribution in units of 1/eV

Variables:

• a (float) – First parameter of distribution in units of eV

• b (float) – Second parameter of distribution in units of 1/eV

classmethod from_xml_element(elem: Element)

Generate Watt distribution from an XML element

Parameters:

elem (lxml.etree._Element) – XML element

Returns:

Watt distribution generated from XML element

Return type:

openmc.stats.Watt

sample(n_samples=1, seed=None)

Sample the univariate distribution

Parameters:

• n_samples (int) – Number of sampled values to generate

• seed (int or None) – Initial random number seed.

Returns:

A 1-D array of sampled values

Return type:

numpy.ndarray

to_xml_element(element_name: str)

Return XML representation of the Watt distribution

Parameters:

element_name (str) – XML element name

Returns:

element – XML element containing Watt distribution data

Return type:

lxml.etree._Element