The package janus.decaypath contains the classes that represent, store, and display decay paths for ENDF materials.
Decay data is displayed on a grid similar to the one used in the nuclide chart. The arrows in the display represent different decay modes for a material. The display of decay data is in the form of a directed graph. In Figure 3-1, the source material or node is Co58 and the product material or destination node is Fe. The set of edges or arrows represent the decay modes for a material.
Figure 3-1. Graphical display of decay path data for Cobalt 58
Numerical data from the database is displayed along each edge of the graph. The color of the arrows is dependent upon the type of decay. For example, in Figure 3-1, the arrow represents the decay mode, Beta+. Each decay mode (i.e. Alpha, Beta, Beta+, Neutron, Proton, and Isomeric) is displayed with a different color. These color assignments may be changed by the user. The user may also modify the branching threshold that controls which arrows are to be displayed. If the branching coefficient is higher than the threshold, the arrows are displayed. In Figure 3-1, the threshold is 0 and the branching coefficient is 1, so the arrow appears.
When the user checks the decay data box at the bottom of the Renderer, the decay display is placed in one tab, as shown in Figure 3-1, and the corresponding table is placed in another tab, as given in Figure 3-2. Both of these tabs are added to the list of currently available tabs in the Renderer.
The table lists the transitions from the source material to its product materials. Physical properties such as half-life, branching coefficient, and decay mode are also listed. To produce the table order, the directed graph of the decay data is traversed in breadth-first order. The length of the path between the source node and the destination node determines where the entry appears in the table. For example, all paths with a length of 1 will appear first in the table. A path length of 2 between the source and destination nodes will appear next.
Figure 3-2. Textual display of decay path data for Cobalt 58