Fast fission factor from resonance escape probability
=====================================================

The fast fission factor is the ratio of the fast neutrons produced by fissions at all
energies to the number of fast neutrons produced in thermal fission. Unfortunately
proper fast fission factor formula is too complex for actual use. Approximate formula is
not very useful since there is no actual data on :math:`P_\text{FAF}`,
:math:`P_\text{TAF}`, and :math:`u_\text{f}` values.

**Links:**

#. `Wikipedia, fourth row in table <https://en.wikipedia.org/wiki/Six_factor_formula>`__.

.. py:currentmodule:: symplyphysics.laws.nuclear.fast_fission_factor_from_resonance_escape_probability

.. py:data:: fast_fission_factor

    :attr:`~symplyphysics.symbols.nuclear.fast_fission_factor`.

Symbol:
    :code:`epsilon`

Latex:
    :math:`\varepsilon`

Dimension:
    :code:`dimensionless`


.. py:data:: resonance_escape_probability

    :attr:`~symplyphysics.symbols.nuclear.resonance_escape_probability`.

Symbol:
    :code:`p`

Latex:
    :math:`p`

Dimension:
    :code:`dimensionless`


.. py:data:: thermal_utilization_factor

    :attr:`~symplyphysics.symbols.nuclear.thermal_utilization_factor`.

Symbol:
    :code:`f`

Latex:
    :math:`f`

Dimension:
    :code:`dimensionless`


.. py:data:: fast_utilization

    :attr:`~symplyphysics.symbols.nuclear.fast_utilization`.

Symbol:
    :code:`u_f`

Latex:
    :math:`u_\text{f}`

Dimension:
    :code:`dimensionless`


.. py:data:: fast_neutrons_per_fission

    Number of fast neutrons produced per fission. See :attr:`~symplyphysics.symbols.basic.particle_count`.

Symbol:
    :code:`nu_f`

Latex:
    :math:`\nu_\text{f}`

Dimension:
    :code:`dimensionless`


.. py:data:: thermal_neutrons_per_fission

    Number of thermal neutrons produced per fission. See :attr:`~symplyphysics.symbols.basic.particle_count`.

Symbol:
    :code:`nu_t`

Latex:
    :math:`\nu_\text{t}`

Dimension:
    :code:`dimensionless`


.. py:data:: fast_absorption_fission_probability

    :attr:`~symplyphysics.symbols.nuclear.fast_absorption_fission_probability`.

Symbol:
    :code:`P_FAF`

Latex:
    :math:`P_\text{FAF}`

Dimension:
    :code:`dimensionless`


.. py:data:: thermal_absorption_fission_probability

    :attr:`~symplyphysics.symbols.nuclear.thermal_absorption_fission_probability`.

Symbol:
    :code:`P_TAF`

Latex:
    :math:`P_\text{TAF}`

Dimension:
    :code:`dimensionless`


.. py:data:: thermal_non_leakage_probability

    :attr:`~symplyphysics.symbols.nuclear.thermal_non_leakage_probability`.

Symbol:
    :code:`P_TNL`

Latex:
    :math:`P_\text{TNL}`

Dimension:
    :code:`dimensionless`


.. py:data:: law

    :code:`epsilon = 1 + (1 - p) / p * P_FAF * u_f * nu_f / (P_TNL * P_TAF * f * nu_t)`


    Latex:
        .. math::
            \varepsilon = 1 + \frac{1 - p}{p} \frac{P_\text{FAF} u_\text{f} \nu_\text{f}}{P_\text{TNL} P_\text{TAF} f \nu_\text{t}}