5. ChainΒΆ

Chain.xml file stored information about nuclear transition from one nuclide to others.The chain structure format is copied from OpenMC package. The script generating this file automaticaly based on nuclear data file presented in this project too. There are three ways to describe such transitions:

  1. Simple decay with pointing target nucleus, decay type and quantative characteristics like``half_life``[sec] and branching_ratio with their uncertainties

  2. Transition induced by external source with pointing type of interaction, target nucleus and energy released/absorbed.

  3. For neutron radiation fission reaction is described separately in section neutron_fission_yields because of huge amount of fission product data.

<energies>2.53000e-02</energies>
<fission_yields energy="2.53000e-02">
  <products>Gd157 Gd156 I135 Xe135 Xe136 Cs135</products>
  <data>6.142710e-5 1.483250e-04 0.0292737 0.002566345 0.0219242 4.9097e-6</data>
</fission_yields>

Data are printing for every existing energy of flying neutron in data files and stored in arrays with target names <products> and according values <data>.

Note: The size of chain generated by nuclear data is more than 3000. It means that matrix to solve general equation has a dimension 3000x3000 and calculation be slowed down. For a number of problem it is not necessery to have a lot of nucleus. To reduce chain user can install OpenMC package and call for reduce() method from Python 3.5+ (read openmc)