diff --git a/docs/source/io_formats/nuclear_data.rst b/docs/source/io_formats/nuclear_data.rst index 68019a875..9bc9d295b 100644 --- a/docs/source/io_formats/nuclear_data.rst +++ b/docs/source/io_formats/nuclear_data.rst @@ -179,7 +179,7 @@ Incident Photon Data **//stopping_powers/** -:Datasets: - **density_effect** (*double[]*) -- Density effect parameter +:Datasets: - **I** (*double*) -- Mean excitation energy in [eV] - **energy** (*double[]*) -- Energies in [eV] - **s_collision** (*double[]*) -- Collisiong stopping power in [eV-cm\ :sup:`2`\ /g] - **s_radiative** (*double[]*) -- Radiative stopping power in [eV-cm\ :sup:`2`\ /g] diff --git a/docs/source/methods/photon_physics.rst b/docs/source/methods/photon_physics.rst index 43696f0a1..836c854b0 100644 --- a/docs/source/methods/photon_physics.rst +++ b/docs/source/methods/photon_physics.rst @@ -16,7 +16,10 @@ de-excitation of these atoms can result in the emission of electrons and photons. Electrons themselves also can produce photons by means of bremsstrahlung radiation. ------------------------------- +------------------- +Photon Interactions +------------------- + Coherent (Rayleigh) Scattering ------------------------------ @@ -56,7 +59,7 @@ accounts for `anomalous scattering`_ which can occur near absorption edges. In a Monte Carlo simulation, when coherent scattering occurs, we only need to sample the scattering angle using the differential cross section in :eq:`coherent-xs` since the energy of the photon does not change. In OpenMC, anomalous scattering -is ignored such that differential cross section comes +is ignored such that differential cross section becomes .. math:: :label: coherent-xs-openmc @@ -147,7 +150,6 @@ section. The complete algorithm is as follows: 6. If :math:`\xi_2 < (1 + \mu^2)/2`, accept :math:`\mu`. Otherwise, repeat the sampling at step 3. -------------------------------- Incoherent (Compton) Scattering ------------------------------- @@ -207,24 +209,49 @@ the form factor. As in other codes, `Kahn's rejection method`_ is used for from step 1. Doppler Energy Broadening -------------------------- ++++++++++++++++++++++++++ LA-UR-04-0487_ and LA-UR-04-0488_ --------------------- Photoelectric Effect -------------------- + +Pair Production +--------------- + + +------------------- +Secondary Processes +------------------- + +New photons may be produced in secondary processes related to the main photon +interactions discussed above. A Compton-scattered photon transfers a portion of +its energy to the kinetic energy of the recoil electron, which in turn may lose +the energy as bremsstrahlung radiation. The vacancy left in the shell by the +ejected electron is filled through atomic relaxation, creating a shower of +electrons and fluorescence photons. Similarly, the vacancy left by the electron +emitted in the photoelectric effect is filled through atomic relaxation. Pair +production generates an electron and a positron, both of which can emit +bremsstrahlung radiation before the positron eventually collides with an +electron, resulting in annihilation of the pair and the creation of two +additional photons. + Atomic Relaxation ----------------- ---------------- -Pair Production ---------------- ---------------------------- -Thick-target Bremsstrahlung ---------------------------- +Electron-Positron Annihilation +------------------------------ + + +Bremsstrahlung +-------------- + + +Thick-Target Bremsstrahlung Approximation ++++++++++++++++++++++++++++++++++++++++++ + .. _Koblinger: http://www.tandfonline.com/doi/abs/10.13182/NSE75-A26646 diff --git a/docs/source/pythonapi/base.rst b/docs/source/pythonapi/base.rst index ef692755d..b9eb7033f 100644 --- a/docs/source/pythonapi/base.rst +++ b/docs/source/pythonapi/base.rst @@ -122,6 +122,7 @@ Constructing Tallies openmc.SpatialLegendreFilter openmc.SphericalHarmonicsFilter openmc.ZernikeFilter + openmc.ParticleFilter openmc.Mesh openmc.Trigger openmc.TallyDerivative diff --git a/docs/source/usersguide/scripts.rst b/docs/source/usersguide/scripts.rst index f007c67fd..29072622a 100644 --- a/docs/source/usersguide/scripts.rst +++ b/docs/source/usersguide/scripts.rst @@ -166,12 +166,31 @@ ENDF/B-VII.1. It has the following optional arguments: ``openmc-get-nndc-data`` ------------------------ -This script downloads `ENDF/B-VII.1 ACE data -`_ from NNDC and converts it to -an HDF5 library for use with OpenMC. This script has the following optional -arguments: +This script downloads `ENDF/B-VII.1 +`_ incident neutron ACE data +and incident photon ENDF data from NNDC and converts it to an HDF5 library for +use with OpenMC. This script has the following optional arguments: --b, --batch Suppress standard in +-b, --batch + Suppress standard in + +-n, --neutron_only + Whether to exclude photon interaction/atomic data + +-------------------------- +``openmc-get-photon-data`` +-------------------------- + +This script downloads `ENDF/B-VII.1 `_ +ENDF data from NNDC for photo-atomic and atomic relaxation sublibraries and +converts it to an HDF5 library for use with photon transport in OpenMC. This +script has the following optional arguments: + +-b, --batch + Suppress standard in + +-c, --cross-sections + cross_sections.xml file to append libraries to ----------------------- ``openmc-make-compton`` @@ -182,6 +201,17 @@ Compton profile data using an existing data library from `Geant4 `_. Note that OpenMC includes this data file by default so it should not be necessary in practice to generate it yourself. +------------------------------- +``openmc-make-stopping-powers`` +------------------------------- + +This script generates an HDF5 file called ``stopping_power.h5`` that contains +radiative and collision stopping powers and mean excitation energy pulled from +the `NIST ESTAR database +`_. Note that OpenMC +includes this data file by default so it should not be necessary in practice to +generate it yourself. + .. _scripts_plot: --------------------------