2. Depletion Chain – chain.xml

A depletion chain file has a <depletion_chain> root element with one or more <nuclide> child elements. The decay, reaction, and fission product data for each nuclide appears as child elements of <nuclide>.

2.1. <nuclide> Element

The <nuclide> element contains information on the decay modes, reactions, and fission product yields for a given nuclide in the depletion chain. This element may have the following attributes:

name:Name of the nuclide
half_life:Half-life of the nuclide in [s]
decay_modes:Number of decay modes present
decay_energy:Decay energy released in [eV]
reactions:Number of reactions present

For each decay mode, a <decay> Element appears as a child of <nuclide>. For each reaction present, a <reaction> Element appears as a child of <nuclide>. If the nuclide is fissionable, a <neutron_fission_yields> Element appears as well.

2.2. <decay> Element

The <decay> element represents a single decay mode and has the following attributes:

type:The type of the decay, e.g. ‘ec/beta+’
target:The daughter nuclide produced from the decay
 The branching ratio for this decay mode

2.3. <reaction> Element

The <reaction> element represents a single transmutation reaction. This element has the following attributes:

type:The type of the reaction, e.g., ‘(n,gamma)’
Q:The Q value of the reaction in [eV]
target:The nuclide produced in the reaction (absent if the type is ‘fission’)
 The branching ratio for the reaction

2.4. <neutron_fission_yields> Element

The <neutron_fission_yields> element provides yields of fission products for fissionable nuclides. Normally, it has the follow sub-elements:


Energies in [eV] at which yields for products are tabulated


Fission product yields for a single energy point. This element itself has a number of attributes/sub-elements:

energy:Energy in [eV] at which yields are tabulated
products:Names of fission products
data:Independent yields for each fission product

In the event that a nuclide doesn’t have any known fission product yields, it is possible to have that nuclide borrow yields from another nuclide by indicating the other nuclide in a single parent attribute. For example:

<neutron_fission_yields parent="U235"/>