mc-hammer

3D Monte Carlo neutron transport

This is a 3D Monte Carlo neutron transport code developed at the University of Michigan.

called from command line as: ./a.out xml_input_filename

Example

./a.out berpinpolyinair.xml

All simulation parameters are specified in the xml input file.

Note

• XML input file must be located in the directory "inputfiles/".
• Cross section file (specified in xml input file) must be located in the directory "xsfiles/".
• Mesh (specified in xml input file) file must be located in the directory "meshfiles/".

Cross section file formatted as:

Line 1: number of materials

Block 1: each entry in this block contains cross sections for a single material. Each entry contains L*G+ 6 lines.

Entry line 1: material_id

Entry line 2: fission_spectrum_1 fission_spectrum_2 … fission_spectrum_G

Entry line 3: energy_group_boundary_1 energy_group_boundary_3 … energy_group_boundary_G

Entry line 4: fission_xs_1 fission_xs_2 fission_xs_3 … fission_xs_G

Entry line 5: nu_bar_1 nu_bar_2 … nu_bar_G

Entry line 6: total_xs_1 total_xs_2 … total_xs_G

Entry line 7: sig_scat_{0, 1->1} sig_scat_{0, 2->1} … sig_scat_{0, G->1}

Entry line 8: sig_scat_{0, 1->2} sig_scat_{0, 2->2} … sig_scat_{0, G->2}

   :

Entry line G + 6: sig_scat_{0, 1->G} sig_scat_{0, 2->G} … sig_scat_{0, G->G}

Entry line G + 7: sig_scat_{1, 1->1} sig_scat_{1, 2->1} … sig_scat_{1, G->1}

Entry line G + 8: sig_scat_{1, 1->2} sig_scat_{1, 2->2} … sig_scat_{1, G->2}

   :

Entry line 2 * G + 6: sig_scat_{1, 1->G} sig_scat_{1, 2->G} … sig_scat_{1, G->G}

   :

Explanation:

1. G = total number of groups.
2. L = scattering expansion.
3. fission_spectrum_g: fraction of neutrons born in fission that appear in energy group g.
4. energy_group_boundary_g: currently unused, can be filled with 0s. Upper bound of energy group g.
5. fission_xs_g: fission cross section (NOTE: not nu_bar * fission_xs) in group g.
6. nu_bar_g: average number of neutrons released by fission caused by a neutron in energy group g.
7. total_xs_g: total cross section in energy group g.
8. sig_scat_{l, g'->g}: l-th Legendre polynomial moment of the scattering cross section from group g' to g. The (2 * l + 1) factor may be included in the value of the cross section or not, THOR can handle both cases. It needs to be specified separately every time.

Mesh file formatted as:

Output

All output files are written to the "outfiles/" directory

• Mesh tally file (filename specified in xml input file)
• Timing results file (filename specified in xml input file)
• Mesh tally xml-style VTK file (filename specified in xml input file)
  • VTK files can be opened with ParaView. ParaView is an open-source, multi-platform data analysis and visualization application. You can download Paraview here.