.. _physics-radiativeTransferPhotonPacket:

Radiative Transfer Photon Packets
=================================

Class providing photon packets for Monte Carlo radiative transfer calculations---discrete bundles of photon energy that are launched from sources and propagated through the computational domain, interacting with matter via absorption and scattering. Each packet carries a wavelength (in \AA), a wavelength range, a luminosity (in :math:`L_\odot`), a 3-D position, a direction of propagation, and a weight tracking how much of the original energy remains. The packet's trajectory through the grid determines the local radiation field and drives the ionization and heating of the matter.

**Default implementation:** ``radiativeTransferPhotonPacketSimple``

Methods
-------

``wavelengthSet`` → ``void``
   Set the wavelength (in \AA) of the photon packet.

   * ``double precision, intent(in ) :: wavelength``

``wavelength`` → ``double precision``
   Get the wavelength (in \AA) of the photon packet.

``wavelengthMinimumSet`` → ``void``
   Set the minimum wavelength (in \AA) of the photon packet.

   * ``double precision, intent(in ) :: wavelength``

``wavelengthMinimum`` → ``double precision``
   Get the minimum wavelength (in \AA) of the photon packet.

``wavelengthMaximumSet`` → ``void``
   Set the maximum wavelength (in \AA) of the photon packet.

   * ``double precision, intent(in ) :: wavelength``

``wavelengthMaximum`` → ``double precision``
   Get the maximum wavelength (in \AA) of the photon packet.

``luminositySet`` → ``void``
   Set the luminosity (in :math:`L_\odot`) of the photon packet.

   * ``double precision, intent(in ) :: luminosity``

``luminosity`` → ``double precision``
   Get the luminosity (in :math:`L_\odot`) of the photon packet.

``positionSet`` → ``void``
   Set the position of the photon packet.

   * ``double precision, intent(in ), dimension(3) :: position``

``position`` → ``double precision, dimension(3)``
   Get the position of the photon packet.

``directionSet`` → ``void``
   Set the direction of the photon packet.

   * ``double precision, intent(in ), dimension(3) :: direction``

``direction`` → ``double precision, dimension(3)``
   Get the direction of the photon packet.

``sourceType`` → ``integer``
   Get a integer type describing the source of the photon packet.

``sourceTypeSet`` → ``void``
   Set an integer type describing the source of the photon packet.

   * ``integer, intent(in ) :: sourceType``

.. _physics-radiativeTransferPhotonPacketSimple:

``radiativeTransferPhotonPacketSimple``
---------------------------------------

A simple photon packet class for Monte Carlo radiative transfer that tracks the minimum required properties: wavelength, luminosity, three-dimensional position, and propagation direction. The initial wavelength and luminosity of each packet are set by ``[wavelength]`` and ``[luminosity]``, with wavelength bounds given by ``[wavelengthMinimum]`` and ``[wavelengthMaximum]``.

**(Default implementation)**

**Methods**

* ``calculationReset`` — Reset memoized calculations.

**Parameters**

* ``[wavelength]`` (real; default ``1.0d4``) — The wavelength of the photon packet (in \AA).
* ``[wavelengthMinimum]`` (real; default ``0.5d4``) — The minimum wavelength of the photon packet (in \AA).
* ``[wavelengthMaximum]`` (real; default ``2.0d4``) — The maximum wavelength of the photon packet (in \AA).
* ``[luminosity]`` (real; default ``1.0d0``) — The luminosity of the photon packet (in :math:`L_\odot`).