First we need to look at the reacti

First we need to look at the reactions that neutrons induce on various isotopes. This will determine the design of our spectroscopy tools and the elements that they can measure.Inelastic reactions involve the internal structure of a target nucleus getting excited via transfer of some of the incident neutron’s original kinetic energy. The neutron can scatter off with reduced energy, or it can be absorbed and cause the ejection of other particles. The excited nucleus immediately de-excites by emitting one or more gamma-rays (energetic photons), of characteristic energies. This process of exciting the nuclear structure of the target is only possible with high-energy (“fast”) neutrons.NNo direct neutron detection (not including CNM – Compact Neutron Monitor)Detecting secondary gamma rays:Inelastic reactions Fast neutrons in (En > 1 MeV)Neutron capture Slow neutrons in (En < 0.025 eV, “thermal”)Detecting gamma rays as function of both time and energy.