Examples 0: Cross-Section Computation

The purpose of this example is to provide a tool computing cross-sections

$ python cross_sections.py [-h] [-d DEVICE] [-m MATERIAL] -p [PROCESS]-e [ENERGY] [-v VERBOSE]
-h/--help           Printing help into the screen
-d/--device         Setting OpenCL id
-m/--material       Setting one of material defined in GGEMS (Water, Air, ...)
-p/--process        Setting photon physical process (Compton, Rayleigh, Photoelectric)
-e/--energy         Setting photon energy in MeV
-v/--verbose        Setting level of verbosity

Verbosity level is defined in the range [0;3]. For a silent GGEMS execution, the level is set to 0, otherwise 3 for lot of informations.


# Select a OpenCL device

Create a GGEMSMaterial instance then add a material. The initialization step is mandatory and compute all physical tables, and store them on an OpenCL device:

materials = GGEMSMaterials()

Create a GGEMSCrossSection instance and activate a process:

cross_sections = GGEMSCrossSections(materials)
cross_sections.add_process(process_name, 'gamma')

For attenuation informations, create a GGEMSAttenuations:

attenuations = GGEMSAttenuations(materials, cross_sections)

Computing cross section value (in cm2.g-1) for a specific energy (in MeV):

cross_sections.get_cs(process_name, material_name, energy_MeV, 'MeV')

# Get attenuation value in cm-1
attenuations.get_mu(material_name, energy_MeV, 'MeV')
# Get energy attenuation value
attenuations.get_mu_en(material_name, energy_MeV, 'MeV')