Nearly sixty years after BBFH [1], it is very important to re-investigate neutron capture processes. Since 1957 everybody has spoken about s-process and r-process, but how are these processes realized in fact? Do s-path and r-path exist, or these are only two useful approximations?
It is the best to investigate the beginnings. How does the formation of nuclei occur starting from seed nucleus ? It is possible that other nuclei can capture a neutron as well, but because of the high abundance of iron, this process is the most important.
The possibility of experimental investigation is very limited, so it is very useful to investigate it through a model. The computational model is almost the only way to look into the details.
There is a simple full network computer model for neutron capture nucleosynthesis [2,3] which was made strictly following Käppeler [4]. In the early 2000s it was possible to run such a simple network model on a computer. In case of this model it was not necessary to exclude any nuclei from the neutron capture process arbitrarily. It is possible to get the order of formation of nuclei by the model step by step. Surprisingly the is formed before the and before any other nuclei above along the s-path.