摘要: The statistical theory of nuclear reactions has evolved from a rough tool, used for several decades to provide global order large body data, into one the most quantitative tools we possess in physics. It is based on compound nucleus picture reactions. closely spaced narrow resonances which are characteristic processes individually interest only at low energies, say energies few million electron volts or less all but lightest systems. At higher with increasing numbers resonances, physical (and usually measurements themselves) concerns cross sections averaged over resonances. deals such average sections.