Russian Orthodox cross is also called just Orthodox cross. At the same time the Orthodox churches use different crosses and any of them is called "Orthodox cross". Moreover, there are no such crosses like just "Orthodox" or "Catholic", each type of cross is a feature of local tradition. The cross has three horizontal crossbeams — the top one represents the plate which in the older Greek tradition is inscribed with a phrase based on John's Gospel "The King of Glory", but in later images it represents , and the bottom one, a footrest. In many depictions, the side to Christ's right is higher.
Neutron cross section of the order of "π r" or roughly 10 cm (thus justifying the definition of the barn). However, if measured experimentally ( "σ" = "R" / ("Φ N") ), the experimental cross sections vary enormously. As an example, for slow neutrons absorbed by the (n, γ) reaction the cross section in some cases (xenon-135) is as much as 2,650,000 barns, while the cross sections for transmutations by gamma-ray absorption are in the neighborhood of 0.001 barn (See here for more example of cross sections). The "nuclear cross section" is consequently a purely conceptual quantity representing how big the nucleus should