Low-energy nuclear reactions are governed by two principal kinds of mechanisms: direct reaction mechanisms characterized by reaction times of the order of the transit time of the bombarding particle through the nucleus , and compound nucelar reaction mechanisms. The reaction times ot the latter are many orders of magnitude longer. They are determined by the decay times of the excited states formed in the compound nucleus. Reactions taht can be described by the preequilibrium decay oof the compound system have intermediate reaction times. This type of reaction forms a category in between the two just mentioned. ... Zie: Chapter
